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Intra-articular injection of two different doses of autologous bone marrow mesenchymal stem cells versus hyaluronic acid in the treatment of knee osteoarthritis: Multicenter randomized controlled clinical trial (phase I/II)

  • ITRAMED (Instituto de Traumatologia y Medicina Regenerativa Avanzada)
  • University Hospital of Salamanca

Abstract and Figures

Background Mesenchymal stromal cells are a promising option to treat knee osteoarthritis. Their safety and usefulness must be confirmed and the optimal dose established. We tested increasing doses of bone marrow mesenchymal stromal cells (BM-MSCs) in combination with hyaluronic acid in a randomized clinical trial. MaterialsA phase I/II multicenter randomized clinical trial with active control was conducted. Thirty patients diagnosed with knee OA were randomly assigned to intraarticularly administered hyaluronic acid alone (control), or together with 10 × 106 or 100 × 106 cultured autologous BM-MSCs, and followed up for 12 months. Pain and function were assessed using VAS and WOMAC and by measuring the knee motion range. X-ray and magnetic resonance imaging analyses were performed to analyze joint damage. ResultsNo adverse effects were reported after BM-MSC administration or during follow-up. BM-MSC-administered patients improved according to VAS during all follow-up evaluations and median value (IQR) for control, low-dose and high-dose groups change from 5 (3, 7), 7 (5, 8) and 6 (4, 8) to 4 (3, 5), 2 (1, 3) and 2 (0,4) respectively at 12 months (low-dose vs control group p = 0.005 and high-dose vs control group p < 0.009). BM-MSC-administered patients were also superior according to WOMAC, although improvement in control and low-dose patients could not be significantly sustained beyond 6 months. On the other hand, the BM-MSC high-dose group exhibited an improvement of 16.5 (12, 19) points at 12 months (p < 0.01). Consistent with WOMAC and VAS values, motion ranges remained unaltered in the control group but improved at 12 months with BM-MSCs. X-ray revealed a reduction of the knee joint space width in the control group that was not seen in BM-MSCs high-dose group. MRI (WORMS protocol) showed that joint damage decreased only in the BM-MSC high-dose group, albeit slightly. Conclusions The single intraarticular injection of in vitro expanded autologous BM-MSCs together with HA is a safe and feasible procedure that results in a clinical and functional improvement of knee OA, especially when 100 × 106 cells are administered. These results pave the way for a future phase III clinical trial.Clinical identifier NCT02123368. Nº EudraCT: 2009-017624-72
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Lamo‑Espinosa et al. J Transl Med (2016) 14:246
DOI 10.1186/s12967‑016‑0998‑2
Intra‑articular injection oftwo
dierent doses ofautologous bone marrow
mesenchymal stem cells versushyaluronic
acid inthe treatment ofknee osteoarthritis:
multicenter randomized controlled clinical
trial (phase I/II)
José M. Lamo‑Espinosa1†, Gonzalo Mora1†, Juan F. Blanco2,3, Froilán Granero‑Moltó1,3,4,5,
Jorge M. Nuñez‑Córdoba5,6,7, Carmen Sánchez‑Echenique1, José M. Bondía8, Jesús Dámaso Aquerreta8,
Enrique J. Andreu3,4, Enrique Ornilla9, Eva M. Villarón3,10,12, Andrés Valentí‑Azcárate1, Fermín Sánchez‑Guijo3,10,12,
María Consuelo del Cañizo3,10,12, Juan Ramón Valentí‑Nin1 and Felipe Prósper3,4,5,11*
Background: Mesenchymal stromal cells are a promising option to treat knee osteoarthritis. Their safety and useful‑
ness must be confirmed and the optimal dose established. We tested increasing doses of bone marrow mesenchymal
stromal cells (BM‑MSCs) in combination with hyaluronic acid in a randomized clinical trial.
Materials: A phase I/II multicenter randomized clinical trial with active control was conducted. Thirty patients
diagnosed with knee OA were randomly assigned to intraarticularly administered hyaluronic acid alone (control), or
together with 10 × 106 or 100 × 106 cultured autologous BM‑MSCs, and followed up for 12 months. Pain and func‑
tion were assessed using VAS and WOMAC and by measuring the knee motion range. X‑ray and magnetic resonance
imaging analyses were performed to analyze joint damage.
Results: No adverse effects were reported after BM‑MSC administration or during follow‑up. BM‑MSC‑administered
patients improved according to VAS during all follow‑up evaluations and median value (IQR) for control, low‑dose and
high‑dose groups change from 5 (3, 7), 7 (5, 8) and 6 (4, 8) to 4 (3, 5), 2 (1, 3) and 2 (0,4) respectively at 12 months (low‑
dose vs control group p = 0.005 and high‑dose vs control group p < 0.009). BM‑MSC‑administered patients were also
superior according to WOMAC, although improvement in control and low‑dose patients could not be significantly
sustained beyond 6 months. On the other hand, the BM‑MSC high‑dose group exhibited an improvement of 16.5 (12,
19) points at 12 months (p < 0.01). Consistent with WOMAC and VAS values, motion ranges remained unaltered in the
control group but improved at 12 months with BM‑MSCs. X‑ray revealed a reduction of the knee joint space width in
the control group that was not seen in BM‑MSCs high‑dose group. MRI (WORMS protocol) showed that joint damage
decreased only in the BM‑MSC high‑dose group, albeit slightly.
© 2016 The Author(s). This article is distributed under the terms of the Creative Commons Attribution 4.0 International License
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provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license,
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publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Open Access
Journal of
Translational Medicine
José M. Lamo‑Espinosa and Gonzalo Mora contributed equally to this
11 Department of Hematology, Clínica Universidad de Navarra, Avenida
Pío XII 36, 31009 Pamplona, Navarra, Spain
Full list of author information is available at the end of the article
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Lamo‑Espinosa et al. J Transl Med (2016) 14:246
Osteoarthritis (OA) is a chronic disease involving pro-
gressive degeneration of the articular cartilage and sub-
chondral bone, accompanied by synovitis [1]. Due to its
avascular nature and the limited self-renewal capacity
of chondrocytes, adult articular cartilage presents lim-
ited repair capability [2]. Current treatment options for
articular cartilage injury and osteoarthritis are aimed to
relieve inflammation and pain, but have no effect on the
natural progression of the disease [3]. To date, in severe
cases of knee OA, knee replacement is the only therapeu-
tic option [4].
During the last two decades focal cartilage defects
have been treated using cell therapy and tissue engineer-
ing approaches. In this context, autologous chondro-
cyte implantation (ACI) or matrix-induced autologous
chondrocyte (MACI) implantation techniques have
been applied with promising results, although the large
non-contained cartilage defects found in OA and its
own pathogenesis cannot be treated using ACI or MACI
[57]. e use of intraarticular injections of mesenchy-
mal stromal cells (MSCs) may represent some advantages
over chondrocytes in patients with OA. First, because
of their ability for self-renewal, the number of cells that
can be obtained is increased without cartilage donor site
morbidity and with reduced cost [68]. Second, MSCs
are responsible for the normal turnover and mainte-
nance of adult mesenchymal tissues, including cartilage,
and has been suggested that the number of MSCs pre-
sent in the subchondral bone decreases with age and OA
grade, suggesting that such MSCs deficit could prime the
degenerative process [912]. It has also been proposed
that during tissue injury MSCs migrate to participate in
the reparative process, giving MSCs a potential therapeu-
tic value when added exogenously [13, 14]. Additionally,
cultured MSCs induce in vitro chondrocyte prolifera-
tion and extracellular matrix protein synthesis, including
aggrecan and type II collagen, which support their criti-
cal role in cartilage tissue repair [15, 16].
ere is an increasing number of reports on the treat-
ment of OA using MSC, but these are methodologically
heterogeneous in dose, cell source, coadjuvants and cell
processing methods, which makes it difficult to com-
pare the different studies [17]. In many cases, treatments
consist of the administration of bone marrow concen-
trates as a source of MSCs. However, it is well known
that only 0.001% of the mononuclear cells found in the
bone marrow could be considered as MSCs as defined
by the ICRS in 2006. erefore, their number in a bone
marrow concentrate is very limited compared to that
obtained upon culturing MSCs [1820]. Only a few stud-
ies using MSCs produced by good manufacture practices
(GMP) such as advanced cell-therapy products have
been reported [2124]. In addition, there is a need to
explore the effect of different cell doses in a randomized
way to gain insight into the ideal conditions for knee OA
patients to take advantage of MSC therapy. For these rea-
sons, the purpose of this study was to randomly assess
the safety, feasibility and efficacy of the intra-articular
injection of two different doses of GMP-produced autol-
ogous bone marrow MSCs (BM-MSCs) with hyaluronic
acid (HA) in patients with knee OA.
Participants andstudy design
is is a phase I/II randomized clinical trial with active
control conducted between August 2012 and Octo-
ber 2014, involving the Clínica Universidad de Navarra
(Pamplona, Spain) and IBSAL-Hospital Universitario de
Salamanca (Salamanca, Spain). All the procedures were
approved by the Institutional Review Board of Nav-
arra and the Spanish Agency of Medicines and Medical
Devices (Nº EudraCT: 2009-017624-72, Clinical Trials.
gov identifier: NCT02123368). All participants provided
written informed consent.
Criteria foreligibility ofpatients
Inclusion criteria were as follows: males and females aged
50–80, diagnosis of knee OA according to American
College of Rheumatology criteria, visual analogue scale
(VAS) joint pain 2.5, Kellgren–Lawrence radiological
classification scale 2, body mass index between 20 and
35kg/m [2], and availability to be followed during the
study period; exclusion criteria were: previous diagnosis
of polyarticular disease, severe mechanical extra-articu-
lar deformation (>15° varus/15° valgus), systemic auto-
immune rheumatic disease, arthroscopy or intraarticular
infiltration in the last 6months, chronic treatment with
Conclusions: The single intraarticular injection of in vitro expanded autologous BM‑MSCs together with HA is a safe
and feasible procedure that results in a clinical and functional improvement of knee OA, especially when 100 × 106
cells are administered. These results pave the way for a future phase III clinical trial.
Clinical identifier NCT02123368. Nº EudraCT: 2009‑017624‑72
Keywords: Bone marrow‑mesenchymal stromal cells, Knee osteoarthritis, Non‑surgical management,
Stem cell therapy
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Lamo‑Espinosa et al. J Transl Med (2016) 14:246
immunosuppressive or anticoagulant drugs, corticoster-
oids treatment in the 3 last months, nonsteroidal anti-
inflammatory drugs therapy in the last 15days, bilateral
knee OA requiring treatment in both knees, poorly con-
trolled diabetes mellitus, blood dyscrasias, and allergy to
HA or bird proteins.
Treatment groups
Participants were assigned to comparison groups by
an unblinded computer-generated list, based on unre-
stricted randomization, which was maintained centrally
by staff with no clinical involvement in the trial so no
center knew the treatment allocation of any patient until
the patient had been recruited into the trial.
ree groups were created:
Control group, constituted by patients who received a
single intra-articular injection of 60mg HA (Hyalone®)
in a final volume of 4ml.
Low-dose BM-MSCs group, constituted by patients
who received a single intra-articular injection of 10×106
autologous cultured BM-MSC in 1.5ml Ringer’s lactate
solution, followed by an intraarticular injection of 4ml
High-dose BM-MSCs group, constituted by patients
who received a single intra-articular injection of
100×106 autologous cultured BM-MSCs in 3ml Ring-
er’s lactate solution, followed by an intraarticular injec-
tion of 4ml HA.
Sample size calculation
We estimated that a sample size of ten patients per group
was required to detect an effect size of 0.6 with a power
of 80 %, assuming a balanced allocation to treatment
groups, and a 5% type I error probability.
Cell culture
BM-MSCs were generated under good manufacturing
practice conditions (GMP) with standard operating pro-
cedures. Briefly, bone marrow (100 ml) was harvested
from the pelvic bone (iliac crest) under sterile condi-
tions. e mononuclear cell fraction was isolated by
Ficoll density gradient centrifugation (Ficoll-Paque, GE
Healthcare Bio-Sciences AB, Uppsala, Sweden). Cells,
ranging between 20 × 106 and 60 × 106, were subse-
quently seeded in 175cm2 flasks with growth medium,
which consisted of αMEM without ribonucleosides
(Gibco, Life Technologies, Carlsbad, CA, USA) supple-
mented with 5% platelet lisate, 2units/ml heparin, peni-
cillin–streptomycin at 1% (Gibco) and 1ng/ml human
fibroblast growth factor (bFGF) (Sigma-Aldrich, St.
Louis, MO, USA). e flasks were maintained in culture
at 37°C in 5 % CO2 atmosphere. e growth medium
was changed every 3–4 days. About 10–15 days later,
colonies were formed and the cells were split with Try-
pLE Select (Life Technologies) and seeded at 3000–
5000 cells/cm2. Once 70–80% confluence was reached,
cells were split again and cultured until they were
available at the amounts required to be administered
to patients. Finally, cells were harvested with TrypLE
Select, washed three times with PBS and resuspended
in Ringer’s lactate buffer (Grifols, Barcelona, Spain) con-
taining 1% human albumin (Grifols), to be administered
within 24h of harvesting of the cells. Cells were charac-
terized according to ISCT criteria. Cells were then ana-
lyzed by flow cytometry (FACSCalibur, BD Biosciences,
San José, CA, USA) with the appropriate antibodies (BD
Biosciences) to confirm expression of surface markers
CD90, CD73 and CD44, as well as absence of CD34 and
Cell injection
Cell injection was performed without radiographic guid-
ance through a lateral patellar approach by three differ-
ent orthopaedic surgeons from both involved centers
(Additional file1: Figure S1), 3–4weeks after the iliac
crest biopsy had been performed. In 90% of the patients,
cells were administered within the first hour after being
harvested. For this purpose, a 19G needle was used in
two consecutive intraarticular injections. In the first one,
10×106 (low dose) or 100×106 (high dose) BM-MSCs
were administered in 1.5 and 3 ml doses respectively.
Subsequently, 4ml HA (Hyalone®) were injected using
the same via.
Outcomes ofinterest
e occurrence of complications and/or adverse effects
during the study was registered. In addition, the response
to the intra-articular infusion of HA with or without BM-
MSCs was assessed using the following procedures:
A goniometer-based evaluation of the articular range of
motion at baseline i.e. before treatment administration,
and 3, 6 and 12months after treatment.
Two scale-based methods Visual Analog Scale (VAS)
[25] and the Likert version of the Western Ontario and
McMaster Universities Osteoarthritis Index (WOMAC)
[26, 27], evaluated at baseline and 3, 6 and 12months
after treatment, to clinically assess pain and function.
VAS ranges from 0 (maximum relief, i.e., no pain) to 10
(no relief, i.e., maximal pain). WOMAC comprises three
subscores: pain, which includes 5 items; stiffness, with 2
items; and physical function, with 17 items. According to
previous literature, patients were considered WOMAC
responders when they reported an improvement of 20%
in at least two items together with an improvement of ten
points in the overall scale [28].
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Lamo‑Espinosa et al. J Transl Med (2016) 14:246
Rosenberg X-ray projections at baseline and 6 and
12months afterwards to provide a radiographic assess-
ment of the joint space width. A custom methacrylate
patient positioner was used to achieve a comparative
view (Additional file2: Figure S2).
A magnetic resonance imaging (MRI) study at baseline
and 6 and 12months after treatment. Two experienced
radiologists evaluated MRI images in a blinded manner
by assessing the number and location of the lesions, car-
tilage thickness, signal intensity, and subchondral bone
alteration and volume, following the Whole-Organ Mag-
netic Resonance Imaging Score (WORMS) protocol, in
which higher score values indicate more damage [29].
3T Magnetom TRIO equipment (Siemens, Erlangen,
Germany) was used following a protocol which included
an axial T1 weighted image (WI) with slice thickness of
5mm, coronal T1 WI (4mm), sagittal T1 WI (4mm),
sagittal T2 FS WI (4mm) and sagittal gradient echo 3D
(DESS) (2mm).
e analyses were performed according to treatment
assignment, and all available data from all patients were
included in the analyses, following the intention-to-treat
principle. Descriptive data summaries are presented
as median [interquartile range (IQR)] or percentages.
Within each group, the comparison of each clinical
and radiographic endpoint between the value obtained
at 6 or 12months and the baseline value, i.e. the one
obtained immediately before the administration of the
treatment, was performed using the Mann–Whitney
U test. Changes in the same end points over time were
determined calculating the differences between the
measurements collected at the 6 or 12-month follow-up
visit and the baseline visit. Subsequently, comparisons
between treatment groups were carried out using the
Kruskal–Wallis test and the Mann–Whitney U test. All
tests were two-tailed. A p value of 0.05 was considered
to indicate statistical significance, without adjustment
for multiple testing. All analyses were performed using
Stata 14 (StataCorp. 2015. Stata Statistical Software:
Release 14. College Station, TX: StataCorp LP) and IBM
SPSS Statistics 20 (IBM Corp. Released 2011. IBM SPSS
Statistics for Windows, Version 20.0. Armonk, NY: IBM
Demographics ofpatients
irty-two patients were assessed for eligibility, and were
consecutively randomized to treatment groups (Fig. 1).
Two patients who had been randomly assigned to the
control group withdrew consent and were excluded from
the trial. All the groups showed similar baseline charac-
teristics of age and body mass index. Patients in the three
groups showed an uneven distribution according to the
Kellgren–Lawrence scale but without statistical signifi-
cance (p=0.585, Table1).
No serious adverse events or complications derived from
the procedures or treatments were noted. ere were
no clinically important trends in the results of physical
examination, vital signs and laboratory tests during the
study. Articular pain requiring anti-inflammatory treat-
ment during the first 24h after infiltration was observed
in 1, 3 and 6 patients in the control, low-dose BM-MSC
and high-dose BM-MSC groups respectively. All patients
recovered completely without sequelae and no treatment
group-dependent differences were detected in the dose
of required anti-inflammatory drug or in the time that
passed until recovery.
Clinical assessment ofpain andfunction
VAS and WOMAC clinical scores were used in order to
obtain the best picture of how patients perceived their
own evolution. Evaluations were performed before the
administration of treatment and 3, 6 and 12 months
afterwards, and the results are summarized in Fig. 2,
Additional file3: TableS1 (VAS) and Table2 (WOMAC).
e patients that were solely given HA did not show
changes during follow up in their pain status according
to VAS (Fig.2; Additional file3: TableS1). Furthermore,
although they initially perceived some improvement
according to the WOMAC pain and physical function
subscores, this perception was not significantly sustained
in the long term (Table2). Inatraarticular delivery of BM-
MSCs, specially when used at high dose, enabled patients
to perceive an improvement in their perception of pain in
their daily activity. On one hand, the VAS score value was
significantly reduced upon treatment with low and high
BM-MSC doses at all follow-up times (Fig.2; Additional
file3: TableS1). Furthermore, treatment with 100×106
cells was associated with a significant improvement in all
WOMAC subscores at 12months (Table2). It is impor-
tant to note that, when the overall WOMAC value at
12months was subtracted from the baseline value in each
patient, the median decrease in the score, i.e. the relief of
the symptoms, was notably larger if patients had been
treated with BM-MSCs [6.5 (19, 4), 14 (27, 4), and
14 (15, 8), median (IQR), for control, low-dose and
high-dose BM-MSCs groups respectively]. us, only the
patients who had been treated with BM-MSCs met cri-
teria to be considered WOMAC responders in the long
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Lamo‑Espinosa et al. J Transl Med (2016) 14:246
Eect oftreatments onthe range ofknee motion
e knee flexion and extension ranges of motion were
significantly improved in the patients who were treated
with BM-MSCs and the effect was seen earlier in patients
receiving the higher doses of BM-MSC. No improvement
was seen in patients receiving HA alone (Fig.3; Addi-
tional file4: TableS2).
Fig. 1 Study flow diagram. Patients were screened in the two participating centers by using the inclusion and exclusion criteria
Table 1 Baseline characteristics ofpatients
Unless specied, data are presented as median [interquartile range (IQR)]. OA
osteoarthritis, K–L Kellgren and Lawrence grading scale of severity of knee OA
Control BM-MSCs
Low-dose High-dose
N 10 10 10
Age (years) 60.3 (55.1, 61.1) 65.9 (59.5, 70.6) 57.8 (55.0, 60.8)
Males, n (%) 7 (70) 4 (40) 8 (80)
BMI (kg/m2) 29.6 (26.2, 30.8) 27.1 (24.4, 31.2) 28.5 (25.8, 31.0)
Time since OA
diagnosis (years) 6 (2, 8) 9 (4, 12) 10 (7, 15)
K‑L 2, n (%) 4 (40) 1 (10) 3 (30)
K‑L 3, n (%) 2 (20) 2 (20) 3 (30)
K‑L 4, n (%) 4 (40) 7 (70) 4 (40) Fig. 2 VAS scores along the study. The median values of VAS in
the three groups before administration of treatments and 3, 6 and
12 months afterwards are presented. *p < 0.05; **p < 0.01 with
respect to the baseline value of the same group
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Lamo‑Espinosa et al. J Transl Med (2016) 14:246
Radiological andMRI ndings
e analysis of the knee joint space by X-rays during fol-
low up showed a borderline reduction in the control group
(p=0.05 at 12months), which was not observed in patients
treated with high dose BM-MSC (Table3; Additional file5:
TableS3). e assessment in the low dose group was not
possible because the baseline value was 0. ese results
suggest that BM-MSC may halt the progressive loss of car-
tilage observed in patients with OA despite the use of HA.
Consistent with the X-Ray results, the analysis of the MRI
following the WORMS protocol showed a reduction in the
score value during follow up (Table4). Patients treated with
high dose BM-MSCs showed a median improvement of 4
points at 12months, with an improvement of 22 points in
25% of patients, while there were no signs of improvement
either in the control or in the low BM-MSC group.
e interest in the clinical use of MSCs for the treatment
of knee OA has recently grown. However, the optimal
dose and source of cells, as well as the use of coadjuvants,
are not yet established. In the present clinical trial we used
two single doses of BM-MSCs, 10 and 100 × 106 cells,
coadministered with HA, and compared their effects with
the single administration of HA in patients with knee OA.
Table 2 WOMAC score beforeadministration oftreatments
and3, 6 and12months afterwards
The values of each one of the three WOMAC subscales as well as the overall
WOMAC score at baseline and 3, 6 and 12months afterwards are presented.
Data are the median (IQR) of each group. Function means physical function.
*p<0.05, **p<0.01 with respect to the baseline value of the same group
WOMAC Time Control BM-MSCs
Low-dose High-dose
Pain Baseline 5.5 (5, 6) 7.5 (5, 9) 4.5 (4, 5)
3 months 3 (1, 3)* 3.5 (3, 7) 3 (2, 5)
6 months 2.5 (1, 5)* 3.5 (3, 7) 3.5 (2, 5)
12 months 2 (1, 6) 3.5 (3, 5) 2.5 (2, 4)*
Stiffness Baseline 2 (1, 3) 4 (2, 5) 2.5 (2, 4)
3 months 2 (1, 2) 2 (0, 4) 2 (1, 2)
6 months 0.5 (0, 2) 1.5 (1, 3)* 2 (1, 3)
12 months 2 (1, 2) 2 (1, 2)* 2 (1, 2)*
Function Baseline 21 (13, 24) 26.5 (23, 32) 19 (12, 25)
3 months 9 (7, 11)* 17.5 (8, 26) 10 (7, 18)
6 months 7.5 (2, 13)* 18 (10, 23) 14.5 (8, 17)
12 months 9.5 (5, 23) 17 (10, 20) 11 (9, 14)*
Overall Baseline 29 (19, 38) 37 (32, 42) 28 (16, 34)
3 months 12 (11, 14)* 25.5 (11, 37) 13 (11, 26)*
6 months 10 (4, 20)* 24 (13, 31) 20 (13, 23)
12 months 13.5 (8, 33) 21.5 (15, 26) 16.5 (12, 19)**
Fig. 3 Knee range of motion along the study. The median values
expressed in degrees of the goniometric measurements of the
knee flexion (top) and extension (bottom) ranges of motion before
administration of treatments and 3, 6 and 12 months afterwards are
presented. *p < 0.05; **p < 0.01 with respect to the baseline value of
the high‑dose group. #p < 0.05 with respect to the baseline valued of
the low‑dose group
Table 3 X-ray measurement ofthe evolution of the knee
articular interline at6 and12months afterthe administra-
tion oftreatments
For each group of treatment, variation for knee joint space width, which was
measured in mm, was calculated by subtracting, for each patient of the group,
the value at 6 or 12months from the baseline value. Data are presented as the
median (IQR) of each group
Time Control BM-MSCs
Low-dose High-dose
6 months 3 (6, 0) 0 (1, 0) 0 (1, 1)
12 months 4 (18, 0) 0 (0, 3) 0 (1, 2)
Table 4 WORMS score beforeadministration oftreatments
and6 and12months afterwards
The overall WORMS scores at baseline and 6 and 12months afterwards are
presented as the median (IQR) of each group. The evolution within each
treatment group at 12months is also presented, and was calculated by
subtracting for each patient the values at 12months from the corresponding
baseline values. Data are the median (IQR) of each group
Time Control BM-MSCs
Low-dose High-dose
Baseline 79 (41, 94) 75 (64, 107) 60 (53, 84)
6 months 78 (34, 107) 70 (57, 126) 53 (51, 90)
12 months 83 (25, 95) 90 (67, 140) 53 (46, 82)
12 months evolution 0.5 (16, 15) 2.5 (3, 25) 4 (22, 2)
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Lamo‑Espinosa et al. J Transl Med (2016) 14:246
We found that the use of BM-MSCs resulted in a signifi-
cant relief of pain symptoms in the long term. According
to the VAS scores, when BM-MSCs had been adminis-
tered, an improvement was seen from the earliest evalua-
tion and was maintained until the last one, at 12months,
at which time point the highest effect was observed.
Interestingly, this pain reduction was independent of the
dose of BM-MSCs administered. On the other hand, no
significant changes in VAS were detected in the control
group, and the value at 12months was similar to the one
registered before the administration of the treatments.
Accordingly, the analysis of the information provided by
WOMAC score confirmed that BM-MSCs induced relief
of pain symptoms. It is interesting to note that, although
treatment with HA alone was able to reduce the WOMAC
score during the first 6months, this improvement was not
sustained in the long term, but when patients received
BM-MSCs, a significant reduction in WOMAC score
was detected at 12months. In addition, unlike what was
observed with VAS, only the high dose of BM-MSCs
showed an efficient reduction in the WOMAC score.
Furthermore, it is notable that only patients treated with
high-dose BM-MSCs met the criteria to be considered
WOMAC responders [28].
e effect of MSCs on pain improvement in knee OA
is controversial and the literature provides differing
accounts. One metaanalysis and a comprehensive review
have been recently published on this topic. Xia etal. [17]
performed a metaanalysis by managing the results of
seven clinical trials, concluding that cell treatments were
not able to reduce pain scores. Unfortunately, the heter-
ogeneity in the methodology used in the different stud-
ies, with different cell production methods and dosage,
precludes these authors from drawing solid conclusions.
On the other hand, Rodríguez-Merchán [30] reviewed
25 articles that reported the use of intra-articular injec-
tion of MSCs in knee OA, finding that MSCs induce pain
relief and functional improvement in three randomized
clinical trials which, however, were not comparable to
ours methodologically. One of them used bone marrow
concentrate, another used peripheral blood progenitor
cells, while the third one used cultured autologous BM-
MSCs together with a high tibial osteotomy, which is a
surgical treatment with a well-known impact on pain
relief [3133]. e number of clinical randomized tri-
als comparing different treatment and dosage is limited.
In an interesting study, Orozco etal. [24, 34] reported
an improvement in pain and function with the use of
a single intra-articular injection of 40 × 106 cultured
autologous MSCs in twelve patients. In a more compa-
rable randomized clinical trial, using allogenic MSCs,
Vega etal. reported good clinical outcomes in pain con-
trol and function when comparing the use of a single
intra-articular injection of 40 × 106 cultured allogenic
MSCs against a single intraarticular injection of HA [23].
Osteoarthritis is not considered a classical inflammatory
arthropathy due to the absence of neutrophils in the synovial
fluid and the lack of systemic manifestations of inflammation
[35]. However, it is frequently associated with inflammation
signs and symptoms such as joint pain, swelling and stiff-
ness, leading to significant functional impairment and dis-
ability [36]. e improvement in pain scores together with
the mild effect on function and MRI scores suggests that the
positive effect of BM-MSCs that we have observed may rely
on their paracrine function. In support of this notion, MSC
antiinflammatory properties have been correlated with pain
reduction elsewhere [3740]. In addition, the reduction
in pain scores may explain the positive changes in flexion
and extension. Although such changes are small, it must be
noted that a limitation of only a few degrees in flexo-exten-
sion may severely compromise the daily functional activity.
ese improvements together with the findings in the image
analyses, suggest that MSC-based therapies may be indicated
in asymptomatic patients with mild OA grade, in whom the
injected MSCs could be more effective through their parac-
rine function when a healthier cartilage is still present.
e maintenance of the knee joint space width has been
related to an appropriate cartilage thickness [41]. Unlike
what happened in the patients that were treated with HA
only, who experienced a reduction of this space over the
time of the study, the space width was preserved when
BM-MSC were also administered, even though the results
obtained in the patients that had received the low dose
must be taken cautiously since the baseline value in 25%
of them was already zero, which precludes suitable follow-
up. Nevertheless, a difference could be observed between
the high dose and control groups, which did exhibit com-
parable baseline values. is finding is consistent with
MRI observations and is in agreement with previous
reports that also investigated the role of cultured MSCs or
MSCs embedded in scaffolds in knee OA [23, 24, 4244].
e required dose of MSCs to treat knee OA efficiently is
a topic of active research. Recently Jo etal. [12] performed
a pilot study comparing three doses of cultured adipose
tissue-derived MSCs (1×106, n=3; 50×106, n=3; and
100×106, n= 3). ey found a significant reduction in
the VAS score only in the high dose group at 6months,
in spite of the small number of patients included. Since
results were better with the highest dose, they focused on
this in a second phase of the study 100×106 (n=9), with
promising results. Our findings also suggest that it is pref-
erable to administer 100×106 rather than 10×106 cells.
However, we have to bear in mind that, despite randomi-
zation, the OA degree at recruitment was more severe in
the patients who received only 10×106 cells, which may
obscure our interpretation of this result.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 8 of 9
Lamo‑Espinosa et al. J Transl Med (2016) 14:246
It is accepted that OA patients have a MSC deficit that
leads to a degenerative process, and the number, invitro
proliferation and differentiation potential of BM-MSCs
present in the subchondral bone decreases with age and
OA grade [10, 11, 45]. However, we were able to obtain a
sufficient amount of BM-MSCs in osteoarthritis patients,
regardless of their age or grade of disease [4649]. We
have not identified any problems during the process of
production of autologous BM-MSCs, achieving the num-
ber of autologous BM-MSCs proposed, even though the
mean age of patients was around 60years.
e present study is not exempt from limitations. First,
ethical issues prevented us from performing a double-blinded
trial. In order to minimize this inconvenience, subjective
clinical scores were contrasted with objective measures to
minimize bias. In addition, two independent radiologists
carried out the MRI analyses in a blinded manner. Second,
the relatively short duration of the study prevented us from
analyzing the efficiency of the treatments beyond 1 year
after the administration of the treatments. Finally, as antici-
pated, the severe initial condition of a portion of patients who
were going to be administered the low dose of cells may have
stopped these exerting more beneficial effects.
Our study shows that the single intraarticular injection
of invitro expanded autologous BM-MSCs together with
HA is a safe and feasible procedure that results in a clini-
cal and functional improvement of knee OA, especially
when 100×106 cells are administered. ese results pave
the way for a future phase III clinical trial.
Additional les
Additional le1: Figure S1. Pattern of treatment administration. BM‑
MSCs (bottom right inset) were administered in two consecutive intraar‑
ticular injections with a 19 G needle using a lateral patellar approach.
10 × 106 or 100 × 106 cells were injected in 1.5 and 3 ml respectively and
subsequently 60 mg hyaluronic acid were administered in 4 ml. Patients
randomized to the control group received solely the second injection.
Additional le2: Figure S2. A–C, methacrylate patient positioner to
permit a correct caption of Rosenberg X‑ray projections. The X ray tube
is placed behind the patient, at the level of the knee and at an angle of
10° with respect to the horizontal in order to evaluate the knee articular
width. D, examples of the X‑ray images, obtained at baseline and 6 and
12 months afterwards, of the knees of three of the recruited patients are
shown. For each patient, images are comparable to each other, which
makes it possible to obtain a valid and comparable value of the articular
Additional le3: Table S1. VAS before administration of treatments and
3, 6 and 12 months afterwards.
Additional le4: Table S2. Goniometric measurements of the knee flex‑
ion and extension ranges of motion before administration of treatments
and 3, 6 and 12 months afterwards.
Additional le5: Table S3. X‑ray measurement of the knee articular
interline before administration of treatments and 6 and 12 months
αMEM: alpha minimum essential medium; bFGF: fibroblast growth factor;
BM‑MSCs: bone marrow mesenchymal stromal cells; GMP: good manufacture
practices; HA: hyaluronic acid; ISCT: International Society for Cellular Therapy;
K‑L: Kellgren and Lawrence scale; MRI: magnetic resonance imaging; MSCs:
mesenchymal stromal cells; OA: osteoarthritis; VAS: visual analogue scale;
WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index;
WORMS: Whole‑Organ Magnetic Resonance Imaging Score.
Authors’ contributions
Study design: JML‑E, GM, JM‑NC, MCC, FP. Provision of study materials or
patients: JML‑E, GM, JFB, AV‑A, EMV, GS‑G, JRV‑N, EA, FP. Data collection and
assembly: JML‑E, GM, EA, JFB, JMN‑C, FG‑M, CS‑E, JMB, JD‑A. Obtaining of
funding: FG‑M, MCC and FP. Drafting manuscript: JML‑E, FG‑M, FP. JML‑E, FG‑M,
JMN‑C, FP take responsibility for the integrity of the data analysis. All authors
read and approved the final manuscript.
Author details
1 Department of Orthopaedic Surgery and Traumatology, Clínica Universidad
de Navarra, Pamplona, Spain. 2 Department of Orthopaedic Surgery and Trau‑
matology, IBSAL‑Hospital Universitario de Salamanca, Salamanca, Spain.
3 TerCel (Spanish Cell Therapy Network, Spanish National Institute of Health
Carlos III), Madrid, Spain. 4 Cell Therapy Area, Clínica Universidad de Navarra,
Pamplona, Spain. 5 Navarra Institute for Health Research (IdiSNA), Pamplona,
Spain. 6 Division of Biostatistics, Research Support Service, Central Clinical
Trials Unit, Clínica Universidad de Navarra, Pamplona, Spain. 7 Department
of Preventive Medicine and Public Health, Medical School, University of Nav‑
arra, Pamplona, Spain. 8 Department of Radiology, Clínica Universidad de
Navarra, Pamplona, Spain. 9 Department of Rheumatology, Clínica Universidad
de Navarra, Pamplona, Spain. 10 Department of Hematology, IBSAL‑Hospital
Universitario de Salamanca, Salamanca, Spain. 11 Department of Hematology,
Clínica Universidad de Navarra, Avenida Pío XII 36, 31009 Pamplona, Navarra,
Spain. 12 Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla
y León, Castilla y León, Salamanca, Spain.
Not applicable.
Competing interests
The authors declare that they have no competing interests.
Availability of data and materials
All the data presented is available upon request.
Ethics approval and consent to participate
All the procedures were approved by the Institutional Review Board of Navarra
and the Spanish Agency of Medicines and Medical Devices.
This work has been partially supported by Grants PI13/01633 (MINECO
through Instituto de Salud Carlos III to FG‑M) and RD12/0019/0017 (to MCC)
and RD12/0019/0031 (to FP) from Instituto de Salud Carlos III (red TerCel). EMV
is supported by Centro en Red de Medicina Regenerativa y Terapia Celular de
Castilla y León, Consejería de Sanidad, Junta de Castilla y León.
Received: 22 June 2016 Accepted: 2 August 2016
1. Ishiguro N, Kojima T, Poole AR. Mechanism of cartilage destruction in
osteoarthritis. Nagoya J Med Sci. 2002;65(3–4):73–84.
2. Mazor M, Lespessailles E, Coursier R, Daniellou R, Best TM, Toumi H.
Mesenchymal stem‑cell potential in cartilage repair: an update. J Cell Mol
Med. 2014;18(12):2340–50.
3. Simon LS. Osteoarthritis. Curr Rheumatol Rep. 1999;1(1):45–7.
4. Buckwalter JA, Saltzman C, Brown T. The impact of osteoarthritis: implica‑
tions for research. Clin Orthop Relat Res. 2004;427:S6–15.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 9 of 9
Lamo‑Espinosa et al. J Transl Med (2016) 14:246
5. Steinert AF, Ghivizzani SC, Rethwilm A, Tuan RS, Evans CH, Noth U. Major
biological obstacles for persistent cell‑based regeneration of articular
cartilage. Arthritis Res Ther. 2007;9(3):213.
6. Knutsen G, Drogset JO, Engebretsen L, Grontvedt T, Isaksen V, Ludvig‑
sen TC, Roberts S, Solheim E, Strand T, Johansen O. A randomized trial
comparing autologous chondrocyte implantation with microfracture.
Findings at five years. J Bone Joint Surg Am. 2007;89(10):2105–12.
7. Brittberg M, Lindahl A, Nilsson A, Ohlsson C, Isaksson O, Peterson L. Treat‑
ment of deep cartilage defects in the knee with autologous chondrocyte
transplantation. N Engl J Med. 1994;331(14):889–95.
8. Nejadnik H, Hui JH, Feng Choong EP, Tai BC, Lee EH. Autologous bone
marrow‑derived mesenchymal stem cells versus autologous chondro‑
cyte implantation: an observational cohort study. Am J Sports Med.
9. Caplan AI. Review: mesenchymal stem cells: cell‑based reconstructive
therapy in orthopedics. Tissue Eng. 2005;11(7–8):1198–211.
10. Caplan AI. Adult mesenchymal stem cells for tissue engineering versus
regenerative medicine. J Cell Physiol. 2007;213(2):341–7.
11. Murphy JM, Dixon K, Beck S, Fabian D, Feldman A, Barry F. Reduced
chondrogenic and adipogenic activity of mesenchymal stem
cells from patients with advanced osteoarthritis. Arthritis Rheum.
12. Jo CH, Lee YG, Shin WH, Kim H, Chai JW, Jeong EC, Kim JE, Shim H, Shin
JS, Shin IS, Ra JC, Oh S, Yoon KS. Intra‑articular injection of mesenchymal
stem cells for the treatment of osteoarthritis of the knee: a proof‑of‑
concept clinical trial. Stem Cells. 2014;32(5):1254–66.
13. Campagnoli C, Roberts IA, Kumar S, Bennett PR, Bellantuono I, Fisk NM.
Identification of mesenchymal stem/progenitor cells in human first‑
trimester fetal blood, liver, and bone marrow. Blood. 2001;98(8):2396–402.
14. Karp JM, Leng Teo GS. Mesenchymal stem cell homing: the devil is in the
details. Cell Stem Cell. 2009;4(3):206–16.
15. Horie M, Choi H, Lee RH, Reger RL, Ylostalo J, Muneta T, Sekiya I, Prockop
DJ. Intra‑articular injection of human mesenchymal stem cells (MSCs)
promote rat meniscal regeneration by being activated to express Indian
hedgehog that enhances expression of type II collagen. Osteoarthr Cartil.
16. Gupta PK, Das AK, Chullikana A, Majumdar AS. Mesenchymal stem cells
for cartilage repair in osteoarthritis. Stem Cell Res Ther. 2012;3(4):25.
17. Xia P, Wang X, Lin Q, Li X. Efficacy of mesenchymal stem cells injection for
the management of knee osteoarthritis: a systematic review and meta‑
analysis. Int Orthop. 2015;39(12):2363–72.
18. Qi Y, Feng G, Yan W. Mesenchymal stem cell‑based treatment for cartilage
defects in osteoarthritis. Mol Biol Rep. 2012;39(5):5683–9.
19. Dominici M, Le Blanc K, Mueller I, Slaper‑Cortenbach I, Marini F, Krause
D, Deans R, Keating A, Prockop D, Horwitz E. Minimal criteria for defining
multipotent mesenchymal stromal cells. The International Society for
Cellular Therapy position statement. Cytotherapy. 2006;8(4):315–7.
20. Simmons PJ, Torok‑Storb B. Identification of stromal cell precursors in
human bone marrow by a novel monoclonal antibody, STRO‑1. Blood.
21. Burger SR. Current regulatory issues in cell and tissue therapy. Cytother‑
apy. 2003;5(4):289–98.
22. Fekete N, Rojewski MT, Furst D, Kreja L, Ignatius A, Dausend J, Schrezen‑
meier H. GMP‑compliant isolation and large‑scale expansion of bone
marrow‑derived MSC. PLoS One. 2012;7(8):e43255.
23. Vega A, Martin‑Ferrero MA, Del Canto F, Alberca M, Garcia V, Munar
A, Orozco L, Soler R, Fuertes JJ, Huguet M, Sanchez A, Garcia‑Sancho
J. Treatment of knee osteoarthritis with allogeneic bone marrow
mesenchymal stem cells: a randomized controlled trial. Transplantation.
24. Orozco L, Munar A, Soler R, Alberca M, Soler F, Huguet M, Sentis J,
Sanchez A, Garcia‑Sancho J. Treatment of knee osteoarthritis with autolo‑
gous mesenchymal stem cells: two‑year follow‑up results. Transplanta‑
tion. 2014;97(11):e66–8.
25. Huskisson EC. Measurement of pain. Lancet. 1974;2(7889):1127–31.
26. Bellamy N. Outcome measurement in osteoarthritis clinical trials. J Rheu‑
matol Suppl. 1995;43:49–51.
27. Escobar A, Quintana JM, Bilbao A, Azkarate J, Guenaga JI. Validation of
the Spanish version of the WOMAC questionnaire for patients with hip or
knee osteoarthritis. Western Ontario and McMaster Universities Osteoar‑
thritis Index. Clin Rheumatol. 2002;21(6):466–71.
28. Escobar A, Gonzalez M, Quintana JM, Vrotsou K, Bilbao A, Herrera‑Espi‑
neira C, Garcia‑Perez L, Aizpuru F, Sarasqueta C. Patient acceptable symp‑
tom state and OMERACT‑OARSI set of responder criteria in joint replace‑
ment. Identification of cut‑off values. Osteoarthr Cartil. 2012;20(2):87–92.
29. Peterfy CG, Guermazi A, Zaim S, Tirman PF, Miaux Y, White D, Kothari M, Lu Y,
Fye K, Zhao S, Genant HK. Whole‑organ magnetic resonance imaging score
(WORMS) of the knee in osteoar thritis. Osteoarthr Cartil. 2004;12(3):177–90.
30. Rodriguez‑Merchan EC. Intra‑articular injections of mesenchymal stem
cells for knee osteoarthritis. Am J Orthop. 2014;43(12):E282–91.
31. Wong KL, Lee KB, Tai BC, Law P, Lee EH, Hui JH. Injectable cultured
bone marrow‑derived mesenchymal stem cells in varus knees with
cartilage defects undergoing high tibial osteotomy: a prospective,
randomized controlled clinical trial with 2 years follow‑up. Arthroscopy.
32. Varma HS, Dadarya B, Vidyarthi A. The new avenues in the manage‑
ment of osteo‑arthritis of knee–stem cells. J Indian Med Assoc.
33. Saw KY, Anz A, Jee CSY, Merican S, Ng RC, Roohi SA, Ragavanaidu K.
Articular cartilage regeneration with autologous peripheral blood stem
cells versus hyaluronic acid: a randomized controlled trial. Arthroscopy.
34. Orozco L, Munar A, Soler R, Alberca M, Soler F, Huguet M, Sentis J, Sanchez
A, Garcia‑Sancho J. Treatment of knee osteoarthritis with autologous mes
enchymal stem cells: a pilot study. Transplantation. 2013;95(12):1535–41.
35. Goldring MB, Goldring SR. Osteoarthritis. J Cell Physiol.
36. Felson DT. Clinical practice. Osteoarthritis of the knee. N Engl J Med.
37. Uccelli A, Moretta L, Pistoia V. Mesenchymal stem cells in health and
disease. Nat Rev Immunol. 2008;8(9):726–36.
38. Doorn J, Moll G, Le Blanc K, van Blitterswijk C, de Boer J. Therapeutic
applications of mesenchymal stromal cells: paracrine effects and poten‑
tial improvements. Tissue Eng Part B Rev. 2012;18(2):101–15.
39. Salgado AJ, Reis RL, Sousa NJ, Gimble JM. Adipose tissue derived stem
cells secretome: soluble factors and their roles in regenerative medicine.
Curr Stem Cell Res Ther. 2010;5(2):103–10.
40. Abumaree M, Al Jumah M, Pace RA, Kalionis B. Immunosuppressive
properties of mesenchymal stem cells. Stem Cell Rev. 2012;8(2):375–92.
41. Buckland‑Wright JC, Macfarlane DG, Lynch JA, Jasani MK, Bradshaw CR.
Joint space width measures cartilage thickness in osteoarthritis of the
knee: high resolution plain film and double contrast macroradiographic
investigation. Ann Rheum Dis. 1995;54(4):263–8.
42. Centeno CJ, Busse D, Kisiday J, Keohan C, Freeman M, Karli D. Increased
knee cartilage volume in degenerative joint disease using percutane‑
ously implanted, autologous mesenchymal stem cells. Pain Physician.
43. Emadedin M, Aghdami N, Taghiyar L, Fazeli R, Moghadasali R, Jahangir S,
Farjad R, Baghaban Eslaminejad M. Intra‑articular injection of autologous
mesenchymal stem cells in six patients with knee osteoarthritis. Arch Iran
Med. 2012;15(7):422–8.
44. Kim YS, Choi YJ, Lee SW, Kwon OR, Suh DS, Heo DB, Koh YG. Assessment
of clinical and MRI outcomes after mesenchymal stem cell implantation
in patients with knee osteoarthritis: a prospective study. Osteoarthr Cartil.
2015. doi:10.1016/j.joca.2015.08.009.
45. Chua KH, Zaman Wan Safwani WK, Hamid AA, Shuhup SK, Mohd Haflah
NH, Mohd Yahaya NH. Retropatellar fat pad‑derived stem cells from older
osteoarthritic patients have lesser differentiation capacity and expression
of stemness genes. Cytotherapy. 2014;16(5):599–611.
46. Im GI, Jung NH, Tae SK. Chondrogenic differentiation of mesenchymal
stem cells isolated from patients in late adulthood: the optimal condi‑
tions of growth factors. Tissue Eng. 2006;12(3):527–36.
47. Dudics V, Kunstar A, Kovacs J, Lakatos T, Geher P, Gomor B, Monostori E,
Uher F. Chondrogenic potential of mesenchymal stem cells from patients
with rheumatoid arthritis and osteoarthritis: measurements in a microcul‑
ture system. Cells Tissues Organs. 2009;189(5):307–16.
48. Kafienah W, Mistry S, Dickinson SC, Sims TJ, Learmonth I, Hollander AP.
Three‑dimensional cartilage tissue engineering using adult stem cells
from osteoarthritis patients. Arthritis Rheum. 2007;56(1):177–87.
49. Scharstuhl A, Schewe B, Benz K, Gaissmaier C, Buhring HJ, Stoop R. Chon‑
drogenic potential of human adult mesenchymal stem cells is independ‑
ent of age or osteoarthritis etiology. Stem Cells. 2007;25(12):3244–51.
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... Se detectaron 9 estudios de duración superior a 6 meses de 6 diferentes AH (17)(18)(19)(20)(21)(22)(23)(24)(25). Un resumen esquemático de las publicaciones analizadas puede verse en la Tabla I del documento. ...
... Estos estudios de largo seguimiento se analizan a continuación (Tabla V), donde se plasma la descriptiva general de cada estudio y sus objetivos (18)(19)(20)(21)(22)(23)(24)(25). ...
... Si realizamos una revisión de los resultados en la literatura (18)(19)(20)(21)(22)(23)(24)(25), solo encontramos que Adant® Plus y Synvisc One® han demostrado una duración del efecto de 12 meses a través de estudios de largo seguimiento (> 6 meses). Adant® One, Crespine®Gel+ precisarían, por lo tanto, de reinfiltración alrededor de los 6-8 meses. ...
... Intra-articular injection of hyaluronic acid (HA) was conditionally recommended in patients with knee OA by the Osteoarthritis Research Society International (OARSI) for pain relief [13]. Previous clinical trial compared MSCs with HA in the treatment of OA, in which HA injection was also given to MSCs groups [14]. Clinical trials directly comparing MSCs and HA are limited. ...
... Unlike previous RCTs in which 80 ml bone marrow or more was aspirated for MSCs isolation [24,25], only 10 ml bone marrow was aspirated in this pilot study to reduce the possibility of obtaining low number of nucleated cells and potentially lower yield of MSCs in second aspirates [26]. Although this resulted in a lower MSC yield, this intervention with fewer MSCs still resulted in a similar clinical outcome compared with other RCTs that injected larger numbers of MSCs [14,25]. This suggests that a lower dose of injected MSC might not adversely affect clinical outcome. ...
Full-text available
Objective This pilot study evaluated the efficacy of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) versus hyaluronic acid (HA) in surgically naïve patients with knee osteoarthritis (OA). Methods Single-centre, single-blind randomized study of patients with knee OA. Twenty patients were randomized into groups of 10 each for intra-articular injection of cultured BM-MSCs (6 ml of BM-MSCs at 1 × 10⁶ cells/mL) or HA (6 ml). Clinical assessments of pain, quality of life, radiographic imaging, and magnetic resonance imaging (MRI) compositional change were performed at baseline and 12 months follow-up. Results Compared with HA, BM-MSCs injection resulted in significant improvement in qualify of life and reduction in pain as reflected by visual analogue scale (VAS) pain score, Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and 36-Item Short Form Survey (SF-36) score collectively. T2-relaxation time tended to decrease more in the BM-MSCs group with a 38 ± 24.0% reduction in 6 out of 10 BM-MSC participants; while there was only a 12 ± 7.9% reduction in 4 out of 10 HA participants at the end of follow-up. The remaining participants showed either no response or had relaxation time increased on MRI assessment. Conclusions This pilot study found that autologous BM-MSCs significantly reduced pain, improved functional assessment score, and improved quality of life parameters comparing with HA at one year follow-up. Further clinical trial with larger sample size and longer follow up duration is warranted. The Translational Potential of this Article This pilot RCT demonstrated the feasibility and potential effectiveness of BM-MSCs advanced therapy for patients with knee OA compared to HA injection. Further multi-center clinical trial with a larger sample size and longer follow up duration in accordance with latest regulatory guidelines is warranted to ascertain the long term safety and effectiveness of MSCs therapy for cartilage regeneration in OA. Registration The study was registered in the Centre for Clinical Research Biostatistics - Clinical Trials Registry (CUHK_CCT00469).
... In recent clinical treatments, intra-articular (IA) injections of hyaluronic acid (HA) [8] and biopharmaceuticals such as platelet-rich plasma (PRP) or mesenchymal stem cells (MSCs) are used to reduce inflammation, repair articular cartilage defects, and restore joint mobility [9][10][11][12]. Studies have shown that IA injection is effective for treating arthritis because the paracrine substances of PRP and MSC play an important role [13]. ...
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Background: Extracellular vesicles (EVs) are derived from internal cellular compartments, and have potential as a diagnostic and therapeutic tool in degenerative disease associated with aging. Mesenchymal stem cells (MSCs) have become a promising tool for functional EVs production. This study investigated the efficacy of EVs and its effect on differentiation capacity. Methods: The characteristics of MSCs were evaluated by flow cytometry and stem cell differentiation analysis, and a production mode of functional EVs was scaled from MSCs. The concentration and size of EVs were quantitated by Nanoparticle Tracking Analysis (NTA). Western blot analysis was used to assess the protein expression of exosome-specific markers. The effects of MSC-derived EVs were assessed by chondrogenic and adipogenic differentiation analyses and histological observation. Results: The range of the particle size of adipose-derived stem cells (ADSCs)- and Wharton's jelly -MSCs-derived EVs were from 130 to 150 nm as measured by NTA, which showed positive expression of exosomal markers. The chondrogenic induction ability was weakened in the absence of EVs in vitro. Interestingly, after EV administration, type II collagen, a major component in the cartilage extracellular matrix, was upregulated compared to the EV-free condition. Moreover, EVs decreased the lipid accumulation rate during adipogenic induction. Conclusion: The results indicated that the production model could facilitate production of effective EVs and further demonstrated the role of MSC-derived EVs in cell differentiation. MSC-derived EVs could be successfully used in cell-free therapy to guide chondrogenic differentiation of ADSC for future clinical applications in cartilage regeneration.
... MRI on the high-dose group also revealed a small reduction in joint damage. 56 Additionally, MSCs in combination with other compounds with therapeutic potential were studied. A co-injection of synovial membrane derived MSCs and apigenin 0.3µM into knee OA rats has been reported to reduce the levels of several inflammatory cytokines such as TNF-a, MDA, and IL-1B while increasing the levels of SOD, Sox-9, COL2A1, and aggrecan. ...
The knee is the most common joint in adults associated with morbidity. Many pathologies are associated with knee damage, such as gout or rheumathoid arthritis, but the primary condition is osteoarthritis (OA). Not only can osteoarthritis cause significant pain, but it also can result in signficant disability as well. Treatment for this condition varies, starting off with oral analgesics and physical therapy to surgical total knee replacmenet. In the gamut of this various treatments, a conservative approach has included intra articular steroid injections. With time, researchers and clinicians determined that other components injected to the knee may additionally provide relief of this condition. In this investigation, we describe different types of knee injections such as platelet-rich plasma (PRP), hyaluronic acid, stem cells, and prolotherapy. Additionally, we describe the role of geniculate knee injections, radiofrequency, and periopheral nerve stimulation. These treatments should be considered for patients with knee pain refractory to conservative therapies.
... We looked at three different studies [25,27,34], and nine other studies [26,28,29,32,33,[37][38][39]41] have reported the VAS outcome of allogeneic and autologous sources of MSCs, respectively, at the 6-month time point. There was a substantial amount of heterogeneity among the studies that were included. ...
Study DesignMeta-analysis.Objectives Our objective is to review the randomized controlled trials (RCTs) that have been conducted previously on the topic of osteoarthritis of the knee to assess and compare the efficacy and safety of autologous and allogeneic sources of mesenchymal stromal cells (MSCs) in the treatment of osteoarthritis.Materials and methodsWe searched the electronic databases PubMed, Embase, Web of Science, and the Cochrane Library until August 2021 for randomised controlled trials (RCTs) analysing the efficacy and safety of autologous and allogeneic sources of MSCs in the management of knee osteoarthritis. These searches were conducted independently and in duplicate. The outcomes that were taken into consideration for analysis were the visual analogue score (VAS) for pain, the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), the Lysholm score, and adverse events. The OpenMeta [Analyst] software was utilised to carry out the analysis in the R platform.ResultsIn total, 21 studies with a total of 936 patients were considered for this analysis. Because none of the studies made a direct comparison of the autologous and allogeneic sources of MSCs, we pooled the results of all of the included studies of both sources and made a comparative analysis of how the two types of MSCs fared in their respective applications. Although both allogeneic and autologous sources of MSCs demonstrated significantly better VAS improvement after 6 months (p = 0.006, p = 0.001), this trend was not maintained after 1 year for the allogeneic source (p = 0.171, p = 0.027). When compared to their respective controls based on WOMAC scores after 1 year, autologous sources (p = 0.016) of MSCs performed better than allogeneic sources (p = 0.186).A similar response was noted between the sources at 2 years in their Lysholm scores (p = 0.682, p = 0.017), respectively. Moreover, allogeneic sources (p = 0.039) of MSCs produced significant adverse events than autologous sources (p = 0.556) compared to their controls.Conclusion Our analysis of literature showed that autologous sources of MSCs stand superior to allogeneic sources of MSC with regard to their consistent efficacy for pain, functional outcomes, and safety. However, we strongly recommend that further studies be conducted that are of a high enough quality to validate our findings and reach a consensus on the best source of MSCs for use in cellular therapy treatments for knee osteoarthritis.
... Some studies show the greatest benefits at the highest dose, ranging from 50 (Song et al., 2018) to 100 million cells (Jo et al., 2017), although this may also give rise to additional risks of pain, joint infection and swelling (Gupta et al., 2016). Others have reported greater therapeutic benefits of low-dose MSC injections, where 10 million bone marrow-derived MSCs outperformed 100 million (Lamo-Espinosa et al., 2016), or 2 million adipose-derived MSCs outperformed 10 and 50 million (Pers et al., 2016). The array of inconsistent clinical results raises uncertainty for the long-term benefits of periodic MSC treatment for OA. ...
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Osteoarthritis (OA) is a leading cause of chronic pain and disability, for which there is no cure. Mesenchymal stromal cells (MSCs) have been used in clinical trials for treating OA due to their unique functions to send paracrine anti-inflammatory and trophic signals. Interestingly, these studies have shown mainly short-term effects of MSCs in improving pain and joint function, rather than sustained and consistent benefits. This may reflect a change or loss in the therapeutic effects of MSCs after intra-articular injection. This study aimed to unravel the reasons behind the variable efficacy of MSC injections for OA using an in vitro co-culture model. Osteoarthritic human synovial fibroblasts (OA-HSFs) exposed to MSCs showed short-term downregulation of pro-inflammatory and pro-catabolic genes, but the MSCs showed upregulation of pro-inflammatory genes and impaired ability to undergo osteogenesis and chondrogenesis in the presence of OA-HSFs. Moreover, short-term exposure of OA-HSFs to MSCs was insufficient for inducing sustained changes to their diseased behaviour. These findings suggest MSCs may not provide long-term effects in correcting the OA joint environment due to adopting the diseased phenotype of the surrounding tissues, which have important implications in the future development of effective stem cell-based OA treatments with long-term therapeutic efficacy.
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Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the destruction of the articular cartilage, sclerosis of the subchondral bone, and joint dysfunction. Its pathogenesis is attributed to direct damage and mechanical destruction of joint tissues. Mesenchymal stem cells (MSCs), suggested as a potential strategy for the treatment of OA, have shown therapeutic effects on OA. However, the specific fate of MSCs after intraarticular injection, including cell attachment, proliferation, differentiation, and death, is still unclear, and there is no guarantee that stem cells can be retained in the cartilage tissue to enact repair. Direct homing of MSCs is an important determinant of the efficacy of MSC-based cartilage repair. Recent studies have revealed that the unique homing capacity of MSCs and targeted modification can improve their ability to promote tissue regeneration. Here, we comprehensively review the homing effect of stem cells in joints and highlight progress toward the targeted modification of MSCs. In the future, developments of this targeting system that accelerate tissue regeneration will benefit targeted tissue repair. Graphical Abstract
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Objective: To evaluate the effectiveness and safety of mesenchymal stem cells (MSCs) in the treatment of osteoarthritis (OA). Methods: Chinese databases (such as CNKI and SinoMed) and English databases (such as PubMed and Embase) were searched to collect randomized controlled trials (RCTs) of MSCs in the treatment of OA. The retrieval time is from inception to October 10, 2021. The literature was strictly selected according to the inclusion and exclusion criteria, data was extracted, and the quality was evaluated. RevMan 5.3 software was used for meta-analysis. STATA was used to evaluate publication bias. The registration number of this systematic review and meta-analysis is CRD42021277145. Results: A total of 28 RCTs involving 1494 participants were included. The primary outcomes showed that MSCs may reduce WOMAC pain and VAS at the 3rd-month follow-up [WOMAC pain: -3.81 (-6.95, -0.68), P = 0.02. VAS: -1.11 (-1.53, -0.68), P < 0.00001], and the effect lasts for at least 12 months [WOMAC pain: -4.29 (-7.12, -1.47), P = 0.003. VAS: -1.77 (-2.43, -1.12), P < 0.00001]. MSCs may also reduce WOMAC stiffness and physical function at the 6th-month follow-up [WOMAC stiffness: -1.12 (-2.09, -0.14), P = 0.03. WOMAC physical function: -4.40 (-6.84, -1.96), P = 0.0004], and the effect lasts for at least 12 months [WOMAC stiffness: -0.99 (-1.95, -0.03), P = 0.04. WOMAC physical function: -3.26 (-5.91, -0.61), P = 0.02]. The improvement of WOMAC pain, VAS, WOMAC stiffness, and WOMAC physical function may be clinically significant. Meanwhile, after the MSC injection, Lequesne had been reduced compared with the control group [-4.49 (-8.21, -0.77), P = 0.002]. For adverse events, there is no significant difference in the safety of MSC injection and the control group [1.20 (0.97, 1.48), P = 0.09]. The quality of WOMAC physical function and adverse events were moderate. Conclusion: Based on current evidence, MSCs may be a safety therapy that have a good curative effect in the treatment of OA, the onset time is no later than 3 months, and the time to maintain the curative effect is no less than 12 months. However, these results should be generalized with caution due to the generally low quality of evidence and RCTs.
Over the last decade the clinical application of concentrated bone marrow or adipose tissue aspirates as well as culture-expanded stem cells has enhanced the clinical options for articular cartilage treatment. In particular, single-stage procedures with sampling of bone marrow or adipose tissue aspirates with intraoperative preparation of cell concentrates appear to be an attractive strategy and are advertised by various manufacturers as unproblematic point of care (PoC) procedures; however, one should be aware that by applying this technology, the surgeon automatically becomes the manufacturer of a drug within the statutory framework of the German Medicinal Products Act (AMG). Therefore, it is compulsory to notify the regulatory authorities of the clinical application of the cell product. The various procedures for production of cell products are then classified according to the form of processing (substantial or nonsubstantial) and the intended application (homologous or nonhomologous use). Cell products that are classified as advanced therapy medicinal products (ATMP) unconditionally necessitate permission for the sampling and manufacturing, which can only be acquired in cooperation with the competent authorities (e.g. Paul Ehrlich Institute, European Medicinal Agency). The knowledge of and compliance with the regulatory framework conditions for the application of intraoperatively harvested bone marrow and adipose tissue aspirates as well as culture-expanded cells are essential for the medical profession to ensure a legally compliant administration in the treatment of articular cartilage diseases. The clinical results on the application of cell concentrates or ex vivo expanded mesenchymal stem cells are difficult to compare due to the heterogeneous production techniques, the different study designs and the lack of randomized studies. Therefore, a conclusive assessment with respect to the effectiveness is currently not possible.
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Background: Osteoarthritis of the knee is one of the most common ailments worldwide, and pain management of this condition is critical. Methods: A multicentre randomized controlled trial RCT with three months of follow-up, conducted in parallel groups: hyaluronic acid (HA), dry needling (DN) and ultrasound (US) and isometrics of quadriceps. 60 participants took part in the RCT who were diagnosed with osteoarthritis (Grade 3) of the knee by MRI and active adults (age: 23.41 ± 1.68 years; height: 1.79 ± 0.08 m; body mass: 78.33 ± 9.03 kg; body mass index (BMI): 24.14 ± 1.45 kg/m2). After the assigned intervention, VAS, WOMAC, IPAQ and the Star Excursion Balance test were measured at baseline. At 24 h, 15 days, 30 days, 90 days and 180 days follow-up, all variables were measured again. Results: Comparing statistically significant differences between groups, VAS scores were significant at post-test measurement (HA vs. US + isometric and DN vs. US + isometric) at 24 h (HA vs. DN), at 15 days (HA vs. US + isometric and DN vs. US + isometric) and at 1 month (US + isometric vs. HA and US + isometric vs. DN). Conclusions: There is an improvement in pain intensity in knee osteoarthritis in the short term in patients undergoing DN and conventional US + isometric treatment, but in the long term the HA group shows an improvement in pain intensity. There is also a significant difference in the improvement of knee function at different phases of the study in the various intervention groups. The combination of DN and HA in clinical practice is the best option for the treatment of osteoarthritis.
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Background: The purpose of this study was to see if percutaneously injected autologous mesenchymal stem cells, platelet lysate, and dexamethasone could reduce this patient's knee cartilage defect size. Case Report: A study patient's mesenchymal stem cells were obtained from her iliac crest bone marrow, isolated and expanded in culture. They were then injected into her knee along with autologous platelet lysate to enhance growth, and nanogram doses of dexamethasone to promote differentiation to chondrocytes. Pre and post treatment MRI imaging, physical therapy and pain score data were then analyzed. Conclusions: This patient's MRI data showed a significant decrease in cartilage defect size. Along with this, her measured physical therapy outcomes and subjective pain and functional status all improved. Autologous mesenchymal stem cell injection, in conjunction with platelet lysate and low-dose dexamethasone are a promising minimally invasive therapy for osteoarthritis of the knee.
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Osteoarthritis is the most prevalent joint disease and a common cause of joint pain, functional loss, and disability. Conventional treatments demonstrate only modest clinical benefits without lesion reversal. Autologous mesenchymal stromal cell (MSC) treatments have shown feasibility, safety, and strong indications for clinical efficacy. We performed a randomized, active control trial to assess the feasibility and safety of treating osteoarthritis with allogeneic MSCs, and we obtain information regarding the efficacy of this treatment. We randomized 30 patients with chronic knee pain unresponsive to conservative treatments and showing radiological evidence of osteoarthritis into 2 groups of 15 patients. The test group was treated with allogeneic bone marrow MSCs by intra-articular injection of 40 × 10 cells. The control group received intra-articular hyaluronic acid (60 mg, single dose). Clinical outcomes were followed for 1 year and included evaluations of pain, disability, and quality of life. Articular cartilage quality was assessed by quantitative magnetic resonance imaging T2 mapping. Feasibility and safety were confirmed and indications of clinical efficacy were identified. The MSC-treated patients displayed significant improvement in algofunctional indices versus the active controls treated with hyaluronic acid. Quantification of cartilage quality by T2 relaxation measurements showed a significant decrease in poor cartilage areas, with cartilage quality improvements in MSC-treated patients. Allogeneic MSC therapy may be a valid alternative for the treatment of chronic knee osteoarthritis that is more logistically convenient than autologous MSC treatment. The intervention is simple, does not require surgery, provides pain relief, and significantly improves cartilage quality.
Murine IgM monoclonal antibody STRO-1 identifies a cell surface antigen expressed by stromal elements in human bone marrow (BM). STRO-1 binds to approximately 10% of BM mononuclear cells, greater than 95% of which are nucleated erythroid precursors, but does not react with committed progenitor cells (colony-forming unit granulocyte-macrophage [CFU-GM], erythroid bursts [BFU-E], and mixed colonies [CFU-Mix]). Fibroblast colony-forming cells (CFU-F) are present exclusively in the STRO-1+ population. Dual-color cell sorting using STRO-1 in combination with antibody to glycophorin A yields a population approximately 100-fold enriched in CFU-F in the STRO-1+/glycophorin A+ population. When plated under long-term BM culture (LTBMC) conditions, STRO-1+ cells generate adherent cell layers containing multiple stromal cell types, including adipocytes, smooth muscle cells, and fibroblastic elements. STRO-1+ cells isolated from LTBMC at later times retain the capacity to generate adherent layers with a cellular composition identical to that of the parent cultures. The STRO-1-selected adherent layers are able to support the generation of clonogenic cells and mature hematopoietic cells from a population of CD34+ cells highly enriched in so-called long-term culture-initiating cells. We conclude that antibody STRO-1 binds to BM stromal elements with the capacity to transfer the hematopoietic microenvironment in vitro.
Cartilage regenerative procedures using the cell-based tissue engineering approach involving mesenchymal stem cells (MSCs) have been receiving increased interest because of their potential for altering the progression of osteoarthritis (OA) by repairing cartilage lesions. The aim of this study was to investigate the clinical and magnetic resonance imaging (MRI) outcomes of MSC implantation in OA knees and to determine the association between clinical and MRI outcomes. Twenty patients (24 knees) who underwent arthroscopic MSC implantation for cartilage lesions in their OA knees were evaluated at 2 years after surgery. Clinical outcomes were evaluated according to the International Knee Documentation Committee (IKDC) score and the Tegner activity scale, and cartilage repair was assessed according to the MRI Osteoarthritis Knee Score (MOAKS) and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. The clinical outcomes significantly improved (P < 0.001 for both). The cartilage lesion grades (as described in MOAKS [grades for size of cartilage-loss area and percentage of full-thickness cartilage loss]) at follow-up MRI were significantly better than the preoperative values (P < 0.001 for both). The clinical outcomes at final follow-up were significantly correlated with the MOAKS and MOCART score at follow-up MRI (P < 0.05 for all). Considering the encouraging clinical and MRI outcomes obtained and the significant correlations noted between the clinical and MRI outcomes, MSC implantation seems to be useful for repairing cartilage lesions in OA knees. However, a larger sample size and long-term studies are needed to confirm our findings. Copyright © 2015. Published by Elsevier Ltd.
The purpose of this study was to access the efficacy of mesenchymal stem cells (MSCs) injection in the treatment of knee osteoarthritis (OA). Studies were identified from databases (Pubmed, Embase, Cochrane Library, Biosis Previews,, CBMdisc) searched to December 2014 using a battery of keywords. We included randomized controlled and controlled clinical trials of people with knee OA comparing the outcomes of pain and function for those receiving MSCs injection with those receiving no MSCs injection. Two reviewers independently selected studies, extracted relevant data and assessed study quality. Data were pooled and meta-analyses were performed. Seven randomized controlled and controlled clinical trials, studying a total of 314 participants with a diagnosis of knee OA were included. Overall, MSCs injection has no significant effect on pain [weighted mean difference (WMD) (95 % confidence interval (CI)) [-1.33(-3.08, 0.41), P = 0.13], and tends to improve self-reported physical function [standardized mean difference (SMD) (CI) = 2.35(0.92, 3.77), P = 0.001] at the last follow-up. But results from two high quality trials (94 patients) show a positive effect of MSCs injection on pain [WMD(CI) = -0.49 (-0.79, -0.19), P = 0.001]. Heterogeneity observed between studies regarding the effect of MSCs injection on pain and function was explained by the difference of follow-up time, outcome measures, control group, the source and dose of MSCs. The quality of evidence supporting these effect estimates was rated as low. MSCs injection could be potentially efficacious for decreasing pain and may improve physical function in patients with knee OA. The findings of this review should be confirmed using methodologically rigorous and adequately powered clinical trials.
Human mesenchymal stem/progenitor cells (MSCs) have been identified in adult bone marrow, but little is known about their presence during fetal life. MSCs were isolated and characterized in first-trimester fetal blood, liver, and bone marrow. When 106 fetal blood nucleated cells (median gestational age, 10+2 weeks [10 weeks, 2 days]) were cultured in 10% fetal bovine serum, the mean number (± SEM) of adherent fibroblastlike colonies was 8.2 ± 0.6/106 nucleated cells (69.6 ± 10/μL fetal blood). Frequency declined with advancing gestation. Fetal blood MSCs could be expanded for at least 20 passages with a mean cumulative population doubling of 50.3 ± 4.5. In their undifferentiated state, fetal blood MSCs were CD29+, CD44+, SH2+, SH3+, and SH4+; produced prolyl-4-hydroxylase, α-smooth muscle actin, fibronectin, laminin, and vimentin; and were CD45−, CD34−, CD14−, CD68−, vWF−, and HLA-DR−. Fetal blood MSCs cultured in adipogenic, osteogenic, or chondrogenic media differentiated, respectively, into adipocytes, osteocytes, and chondrocytes. Fetal blood MSCs supported the proliferation and differentiation of cord blood CD34+cells in long-term culture. MSCs were also detected in first-trimester fetal liver (11.3 ± 2.0/106 nucleated cells) and bone marrow (12.6 ± 3.6/106 nucleated cells). Their morphology, growth kinetics, and immunophenotype were comparable to those of fetal blood-derived MSCs and similarly differentiated along adipogenic, osteogenic, and chondrogenic lineages, even after sorting and expansion of a single mesenchymal cell. MSCs similar to those derived from adult bone marrow, fetal liver, and fetal bone marrow circulate in first-trimester human blood and may provide novel targets for in utero cellular and gene therapy.