No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Laboratory Parameters for Monitoring Hematopoietic Engraftment and Immune Reconstitution after Autologous Stem Cell Transplantation
Abstract
Autologous bone marrow or peripheral blood stem cell transplantation are well-recognized treatments for certain malignant hematological diseases. Therapy-induced pancytopenia and immunodeficiency that lead to increased rates of bleeding complications and higher susceptibility to bacterial, viral, and fungal infections often occur following transplantation. Infections during or shortly after transplantation are more likely to be associated with the severe depression of mononuclear cells and neutrophil granulocytes, whereas post-engraftment infections in the long term are probably due to numerical and functional impairment of primarily CD4+ T-helper-cells and B-lymphocytes. A prompt and sustained engraftment of the hematopoiesis and a complete and functionally intact recovery of the immune system are necessary for a good patient outcome. The quality of reconstitution depends upon several factors, including the underlying disease, the intensity of prior therapy, and the graft source. The faster hematopoietic engraftment as well as the larger mononuclear cell inoculum transfused to recipients of blood stem cell products might be superior to bone marrow transplantation with respect to lymphohematopoietic reconstitution. In this review, data published more recently on immune reconstitution after autologous stem cell transplantation are discussed, and laboratory parameters useful for monitoring states of deficiency of cellular and humoral immunity are evaluated.
ResearchGate has not been able to resolve any citations for this publication.
High-dose chemotherapy followed by autologous bone marrow transplantation is a therapeutic option for patients with chemotherapy-sensitive non-Hodgkin's lymphoma who have relapses. In this report we describe a prospective randomized study of such treatment.
A total of 215 patients with relapses of non-Hodgkin's lymphoma were treated between July 1987 and June 1994. All patients received two courses of conventional chemotherapy. The 109 patients who had a response to chemotherapy were randomly assigned to receive four courses of chemotherapy plus radiotherapy (54 patients) or radiotherapy plus intensive chemotherapy and autologous bone marrow transplantation (55 patients).
The overall rate of response to conventional chemotherapy was 58 percent; among patients with relapses after chemotherapy, the response rate was 64 percent, and among those with relapses during chemotherapy, the response rate was 21 percent. There were three deaths from toxic effects among the patients in the transplantation group, and none among those in the group receiving chemotherapy without transplantation. The two groups did not differ in terms of prognostic factors. The median follow-up time was 63 months. The response rate was 84 percent after bone marrow transplantation and 44 percent after chemotherapy without transplantation. At five years, the rate of event-free survival was 46 percent in the transplantation group and 12 percent in the group receiving chemotherapy without transplantation (P = 0.001), and the rate of overall survival was 53 and 32 percent, respectively (P = 0.038).
As compared with conventional chemotherapy, treatment with high-dose chemotherapy and autologous bone marrow transplantation increases event-free and overall survival in patients with chemotherapy-sensitive non-Hodgkin's lymphoma in relapse.
In 1995, a total of 12,101 blood or marrow transplants, performed in Europe by 343 teams from 31 countries, were reported to the European Group for Blood and Marrow Transplantation (EBMT). Of these, 3858 (32%) were allogeneic, 8243 (68%) autologous transplants. Of the autologous transplants 1384 (17%) were bone marrow derived, 6504 (79%) from peripheral blood stem cells and 355 (4%) combined bone marrow and peripheral blood stem cell transplants. Of the allogeneic transplants, 571 (15%) were peripheral blood stem cell transplants, the remainder, 3287 (85%) bone marrow transplants. Main indications were leukemias with 4408 transplants (36%), 2977 allogeneic (68%) and 1431 autologous (32%); lymphomas with 4671 transplants (39%), 272 allogeneic (6%) and 4399 autologous (94%); severe aplastic anemia with 237 transplants (2%), 237 allogeneic (100%) and 0 autologous (0%); solid tumors with 2399 transplants (20%), 17 allogeneic (1%) and 2382 autologous (99%); and congenital disorders with 294 transplants (2%), 294 allogeneic (100%) and 0 autologous (0%) and others with 92 transplants (1%), 61 allogeneic (66%) and 31 autologous (34%). There were major differences between participating countries. The absolute numbers of teams and transplants per country differ widely and range from 0.2 to 33.3 teams per 10 million inhabitants (median 5.8); 3.2 to 733.3 total transplants per 10 million (median 200); 0.7 to 210 allogeneic transplants per 10 million (median 65); 0.3 to 700 autologous transplants per 10 million (median 122); 0 to 47.7 unrelated transplants per 10 million inhabitants (median 8.7). There is also a difference in the relative number of transplants for the individual indications. The coefficient of variation for selected diseases was calculated for those 14 countries with a minimum of 100 transplants. A narrow coefficient of variation indicates consensus amongst grafting physicians. It is narrowest for chronic myeloid leukemia in allogeneic transplants (36.7%) and for Hodgkin's disease in autologous transplants (44.8%). These data reflect the present status of blood and marrow transplantation in Europe and provide a basis for patient counselling and health care planning.
Rapid recovery of CD4+ T cells after intensive chemotherapy is limited by an age-dependent decline in thymopoiesis. Here we sought to determine whether similar limitations exist for CD8+ T-cell regeneration. After intensive chemotherapy, CD8+ T cells had a faster effective doubling time than CD4+ T cells (median, 12.6 v 28.2 days, P < .05). Accordingly, at 3 months posttherapy, mean CD8+ T-cell number had returned to baseline, whereas mean CD4+ T-cell number was only 35% of pretherapy values (P < .05). These differences were primarily due to very rapid expansion of CD8+CD57+ and CD8+CD28- subsets. At 3 months posttherapy, there was no relationship between age and CD8+ T-cell number (R = -.02), whereas CD4+ T-cell number was inversely related to age (R = -.66) and there were no discernible differences in CD8+ recovery among patients with or without thymic enlargement, whereas CD4+ recovery was enhanced in patients with thymic enlargement after chemotherapy (P < .01). Therefore thymic-independent pathways of T-cell regeneration appear to rapidly regenerate substantial numbers of CD8+, but not CD4+ T cells, resulting in prolonged T-cell subset imbalance after T-cell depletion. These inherent distinctions between CD4+ v CD8+ T-cell regeneration may have significant implications for immunotherapeutic strategies undertaken to eradicate minimal residual neoplastic disease after cytoreductive chemotherapy.
We measured the concentration of CD34+ cells in peripheral blood (PB) (1/2) h prior to and (1/2), 1, 3, 6, and 12 h following hematopoietic stem cell (HSC) infusion in 34 breast cancer patients treated with high-dose chemotherapy (HDC). The decrease in these concentrations over time enabled us to determine the clearance kinetics of CD34+ cells from PB. The absolute number of CD34+ cells in PB generally peaked at (1/2) h after infusion, then rapidly declined from 1 to 3 h post infusion and continued to fall until 12 h post transplant, but more slowly. In univariate analysis, CD34+cells/kg infused, CFU-GM/kg infused, the CD34+ count at (1/2) h, and the 12-h clearance of CD34+ cells from PB were predictors of hematologic recovery, as were each of the two phases of clearance when the slope was divided into rapid and slow phases (from (1/2) to 3 and from 3 to 12 h post transplant, respectively). We then stratified our population by the number of CD34+ cells/kg infused. In group 1, patients received </=7.5 x 10(6) CD34+ cells/kg; in group 2, >7.5 x 10(6) CD34+ cells/kg. After adjusting for CD34+ cells injected, age, and purged or unpurged graft in multivariate analysis, the 12 h clearance remained a predictor of hematologic recovery in group 1. In addition, the second phase of clearance (from 3 to 12 h after infusion) was an even better predictor than the 12 h clearance. In group 2, however, no statistically significant correlation was observed, even with the number of HSC injected. Results suggest that rapidity of clearance of CD34+cells from PB is an independent indicator of hematologic recovery in patients receiving lower doses of CD34+ cells. When the cell dose injected is over a threshold, PB clearance correlations with hematologic recovery are masked.
In human leukocyte antigen haplotype–mismatched transplantation, extensive T-cell depletion prevents graft-versus-host disease (GVHD) but delays immune recovery. Granulocyte colony-stimulating factor (G-CSF) is given to donors to mobilize stem cells and to recipients to ensure engraftment. Studies have shown that G-CSF promotes T-helper (Th)-2 immune deviation which, unlike Th1 responses, does not protect against intracellular pathogens and fungi. The effect of administration of G-CSF to recipients of mismatched hematopoietic transplants with respect to transplantation outcome and functional immune recovery was investigated. In 43 patients with acute leukemia who received G-CSF after transplantation, the engraftment rate was 95%. However, the patients had a long-lasting type 2 immune reactivity, ie, Th2-inducing dendritic cells not producing interleukin 12 (IL-12) and high frequencies of IL-4– and IL-10–producing CD4+ cells not expressing the IL-12 receptor β2 chain. Similar immune reactivity patterns were observed on exposure of donor cells to G-CSF. Elimination of postgrafting administration of G-CSF in a subsequent series of 36 patients with acute leukemia, while not adversely affecting engraftment rate (93%), resulted in the anticipated appearance of IL-12–producing dendritic cells (1-3 months after transplantation versus > 12 months in transplant recipients given G-CSF), of CD4+ cells of a mixed Th0/Th1 phenotype, and of antifungal T-cell reactivity in vitro. Moreover, CD4+ cell counts increased in significantly less time. Finally, elimination of G-CSF–mediated immune suppression did not significantly increase the incidence of GVHD (< 15%). Thus, this study found that administration of G-CSF to recipients of T-cell–depleted hematopoietic transplants was associated with abnormal antigen-presenting cell functions and T-cell reactivity. Elimination of postgrafting administration of G-CSF prevented immune dysregulation and accelerated functional immune recovery.
Varicella-zoster virus (VZV) frequently causes severe infections in patients who have undergone bone marrow transplantation.
The frequency of, characteristics of, and risk factors for this infection were studied in 164 patients undergoing autologous
peripheral blood progenitor cell transplantation (PBPCT). Twenty-six patients (15.8%) developed VZV infection, and the actuarial
risk was 10% at 1 year. No patient had visceral dissemination or died because of VZV, although one-third of the patients developed
postherpetic neuralgia. By multivariate analysis, a CD4+ lymphocyte count of <200 cells/µL (P < .0001; odds ratio [OR], 2.0) and a CD8+ lymphocyte count of <800 cells/µL (P = .0073; OR, 2.0) at day 30 after transplantation were factors associated with VZV infection. Patients with both these adverse
factors had an actuarial risk of VZV of 48% at 1 year. Patients with deficiency in both CD4+ and CD8+ lymphocytes are at high risk of VZV infection. These patients should be considered as candidates for preventive therapy,
but whether for antiviral therapy or vaccination remains to be investigated.
Selection of CD34+ PBPCs has been applied as a method of reducing graft contamination from neoplastic cells. This procedure seems to delay lymphocyte recovery, while myeloid engraftment is no different from that with unselected PBPC transplants.
Lymphocyte recovery was studied in two groups of patients who underwent autologous CD34+ PBPC transplant with two different technologies (Ceprate SC, Cellpro [n = 17]; CliniMACS, Miltenyi Biotech [n = 13]). The median number of CD34+ cells transfused was 3.88 x 10(6) per kg and 3.32 x 10(6) per kg, respectively. Residual CD3 cells x 10(6) per kg were 4.97 and 0.58, respectively (p = 0.041). Residual CD19 cells x 10(6) per kg were 1.33 and 0.73, respectively (NS).
No differences were found between the two groups in total lymphocyte recovery to >0.5 x 10(9) per L, which achieved a stable count by Day 30. During the study period, the CD4+ cell count remained below 0.2 x 10(9) per L, and the B-cell subset showed a trend toward normalization. CD3/HLA-DR+ and CD16/56 increased markedly in both groups by Day 30. An increase in CMV (13%) and adenovirus (17.4%) infection was found in both groups.
Both CD34+ cell selection technologies used here determined an excellent CD34+ cell purity and an optimal depletion of T cells. The high rate of viral complications is probably due to the inability of residual T cells left from the CD34+ cell selection to generate, immediately after transplant, an adequate number of virus-specific lymphocytes.
We studied platelet recovery in relation to graft content in CFUs and CD34+ cells in 31 patients with multiple myeloma (21) or non-Hodgkin lymphoma (10) receiving marrow-ablative therapy followed by autologous transplantation with G-CSF mobilized CD34+ cells purified from leukapheresis products. Twelve patients had prolonged post-transplantation thrombopenia (> or = 14 days): their graft contents in CD34+ cells, CFU-GM and BFU-E were significantly inferior to those of patients with rapid platelet recovery. Although numbers of infused CD34+ cells and CFU-GM or BFU-E were well correlated, the graft content in CD34+ cells was the only parameter predictive of platelet recovery (r = -0.38, p = 0.04), with a threshold of 2.5 x 10(6) CD34+ cells/kg. However, because rapid platelet reconstitution was obtained for 4 of 16 patients re-infused with < 2.5 x 10(6) CD34+ cells/kg, we investigated whether the graft CFU-MK content might be a better predictor of platelet reconstitution than the CD34+ cell content. Eighteen CD34 grafts were studied for CFU-MK content: CD34 and CFU-MK contents were weakly correlated (r = 0.52, p = 0.03), but there was no correlation between numbers of infused CFU-MK and time to platelet recovery. We conclude that, for autologous CD34 grafts, CFU-MK assays, like CFU-GM or BFU-E assays, cannot be used to predict platelet recovery. A CD34+ cell content > or = 2.5 x 10(6)/kg remains the only reliable indicator of the platelet reconstitution capacity of a CD34 graft.
We have used limiting dilution culture methods to determine the frequency of mitogen-responsive T cells in peripheral blood of patients after bone marrow autotransplantation, and have compared their responsiveness to that of allotransplant recipients and normal controls. Autotransplant patients were found to have low responder cell frequencies in tests for lymphokine-secreting helper function, and for IL-2 dependent proliferator and cytotoxic function. Multiple regression analysis showed that function was lower in autotransplant patients than in allorecipients, and lower in male patients for all three functional assays. Patients with clinically significant infection tended to have lower proliferative function in both transplant groups and lower cytotoxic function in the allotransplant population. Graft-versus-host disease was associated with lower T-cell function, but was present only in the allotransplant group; therefore, it cannot account for the even lower levels of function observed in the autotransplant population. Because we observe deficits in T-cell regeneration in autotransplant recipients that are even more severe than in allorecipients, we postulate that cellular immunodeficiency after bone marrow transplantation may reflect limitations in thymic-dependent repopulation rather than an effect of genetic disparity between host and donor (eg, clinical or subclinical graft-versus-host).
T cells generated during a second round of ontogeny after autologous bone marrow transplantation (ABMT) represent a unique model of early T-cell ontogeny in an autologous situation. Since grafted bone marrows were pretreated in vitro with the cyclophosphamide derivative ASTA Z 7557, circulating T cells had to be regenerated from reinfused hematopoietic progenitor cells. The T-cell population derived from 25 patients post-ABMT was phenotypically characterized: an increase in CD8+ cells, a low percentage of CD4+ cells, and a median of 12% CD56+ (NKH1+) cells were found. When the T cells were stimulated with phytohemagglutinin (PHA) and phorbol myristate acetate (PMA), defective interleukin-2 (IL-2) secretion was observed. In addition, proliferative responses of the T cells after activation through the antigen-receptor-dependent CD3 pathway, through the CD2 dependent alternative T-cell pathway, and by the lectin PHA were investigated. Despite the presence of CD2, CD3, alpha/beta chains of the T-cell receptor, and CD25+ IL-2 surface receptors, abnormal proliferative responses were obtained even in the presence of exogeneous IL-2. In experiments where the T-cell population was separated into CD4+ cells and CD8+ cells, both the CD4- and CD8+ subsets were unable to respond to activating and proliferating signals. Thus, T cells at early stages of ontogeny not only possess an intrinsic defect in IL-2 synthesis but, in addition, were unable to express functional IL-2 receptors in response to mitogenic stimuli.
Sixty-seven consecutive patients with aplastic anemia or leukemia who had been treated by allogeneic marrow transplantation and had survived for more than 1 month were surveyed in order to determine the incidence of nonviral infections occurring from 1 month to 3 years after transplantation. Twenty-eight of the 67 patients had one or more infections during this period. Around 20% suffered from pulmonary infections and 20% were classified as having a systemic infection. Ten patients died of bacterial or fungal infection, of whom 6 had graft-versus-host disease. In multivariate analyses acute graft-versus-host disease (P less than 0.0009), splenectomy (P less than 0.02), cytomegalovirus infection (P less than 0.05), and a low marrow cell dose (P less than 0.07) were correlated with nonviral infections.
From our limited data in the present study, PBL and T lymphocytes recovered to normal levels earlier than mitogen responsiveness. Recovery of delayed hypersensitivity of the skin was further delayed. Recovery patterns from the posttransplant immunodeficiency showed a considerable dissociation between the various lymphocyte properties and functions among investigators depending on tests employed. Although etiologies of the immunodeficiency after allo-BMT are not well clarified, the difference in posttransplant immunologic reconstitution is apparent between allo-BMT and auto-BMT. This depends on whether marrow grafts are allogeneic or autologous. From these observations it is suggested that donor's lymphoid stem cells can mature to express surface markers but cannot develop into lymphocytes with specified functions for more than 1 year after allo-BMT. Thus, abnormal or delayed functional differentiation of lymphoid stem cells may be one of major factors responsible for the severe, prolonged immunodeficiency which characterizes allo-BMT in contrast with auto-BMT.
Inadequate reconstitution of CD4+ T lymphocytes is an important clinical problem complicating chemotherapy, human immunodeficiency virus infection, and bone marrow transplantation, but relatively little is known about how CD4+ T lymphocytes regenerate. There are two main possibilities: bone marrow-derived progenitors could reconstitute the lymphocyte population using a thymus-dependent pathway, or thymus-independent pathways could predominate. Previous studies have suggested that the CD45RA glycoprotein on CD4+ T lymphocytes is a marker for progeny generated by a thymus-dependent pathway.
We studied 15 patients 1 to 24 years of age who had undergone intensive chemotherapy for cancer. The absolute numbers of CD4+ T lymphocytes in peripheral blood and the expression of CD45 isoforms (CD45RA and CD45RO) on these lymphocytes were studied serially during lymphocyte regeneration after the completion of therapy. Radiographic imaging of the thymus was performed concomitantly.
There was an inverse relation between the patients' ages and the CD4+ T-lymphocyte counts six months after therapy was completed (r = -0.92). The CD4+ recovery correlated quantitatively with the appearance of CD45RA+CD4+ T lymphocytes in the blood (r = 0.64). There was a higher proportion of CD45RA+CD4+ T lymphocytes in patients with thymic enlargement after chemotherapy than in patients without such enlargement (two-sided P = 0.015).
Thymus-dependent regeneration of CD4+ T lymphocytes occurs primarily in children, whereas even young adults have deficiencies in this pathway. Our results suggest that rapid T-cell regeneration requires residual thymic function in patients receiving high-dose chemotherapy.
In the present study, we examined changes in the expression of CD45RA, CD31, and CD29 on total CD4 and CD8 lymphocytes in patients who had received CD6 T cell-depleted allogeneic marrow and received no immune suppressive drugs after engraftment in order to identify defects in reconstitution of immunoregulatory T cells after allogeneic BMT. Results following allo-BMT were compared with normal controls and patients following autologous BMT. We showed that CD4+CD45RA+, CD4+CD29+ (CD29high), and CD4+CD31+ cells were markedly decreased during the first 24 months after allo- and auto-BMT. CD8+CD45RA+ cells recovered to normal levels within the first month after auto-BMT, while after allo-BMT, the CD8+CD45RA+ cells were at slightly low levels during the first month, but gradually increased to normal levels by 12 months post-BMT. CD8+CD29+ cells were increased during the first 12 months both after allo- and auto-BMT although during the first month, a decreased percentage of CD8+CD29+ cells was observed in allo-BMT patients. More important, CD4+CD29+, CD8+CD29+, and CD8+S6F1+ cells were significantly increased in patients with moderate-to-severe acute GVHD (grades II-IV) compared with those with or without mild acute GVHD (grade I), suggesting that CD4 helper-inducer (CD4+CD29high) and CD8 killer-effector (CD8+CD29highS6F1+) cells play an important role in the pathophysiology of acute GVHD.
We investigated T cell receptor (TCR) alpha/beta and gamma/delta repertoire reconstitution after autologous and allogeneic bone marrow transplantation (BMT) in humans using 13 monoclonal antibodies directed at constant and variable regions of the TCR. The TCR gamma/delta repertoire was studied kinetically during the first month and then 1 year post-BMT whereas alpha/beta peripheral blood T lymphocytes (PBTL) were studied within the first 3 months and 1 year post-BMT. Through these two studies, we found 7 of 26 patients with over-represented TCR gamma/delta subsets during the early period post-BMT. Moreover, during this period the V gamma 9V delta 2 frequency among gamma/delta T cells was found to be higher than among normal donors. Study on TCR alpha/beta T cells also revealed abnormally expanded V-specific subset (5 of 10 patients within 3 months following BMT) demonstrating that repertoire alteration early after BMT is a general phenomenon concerning potentially all T cell subsets. More surprisingly, the alpha/beta T cell repertoire was also found to be altered late after BMT (7 of 15 patients after 1 year post-BMT presented one or more overepresented alpha/beta TCR subset). These alterations of TCR combinatorial diversity should be taken into account in understanding the immunological status of patients after BMT.
Immune reconstitution after marrow transplantation has some characteristics of immune development in early life. Here we provide phenotypic data suggesting this may not be true for T cells (particularly CD4+ T cells) in the case of marrow transplantation into adults. T cells from 35 adult patients at 1 year after transplant, 14 normal neonates and 22 normal adults were studied by 3-color flow cytometry. Marked disparity between the phenotype of neonatal vs post-transplant T cells was found. Of the total CD4+ T cells, the neonates had supranormal percentages of CD45RAhigh, L-selectin+, CD29low/-, CD11alow/- and CD28+ cells whereas most patients at 1 year after transplant had subnormal percentages of these CD4+ T cell subpopulations. (sub/supra-normal denotes below/above normal adult values). Absolute blood counts of naive (CD45RAhigh, L-selectin+, CD29low/- and CD11alow/-) CD4+ T cells correlated inversely with patient age. Neonates had also supranormal percentages of CD45RAhigh, L-selectin+, CD29low/-, CD11alow/- and CD28+ CD8+ T cells whereas the patients (particularly those with chronic GVHD) tended to have subnormal percentages of these CD8+ T cell subpopulations. Contrary to the CD4+ T cells, there was no correlation between the absolute counts of CD45RAhigh, L-selectin+, CD29low/- or CD11alow/- CD8+ T cells and patient age. Whereas the vast majority of neonatal T cells were CD38high, most patient and normal adult T cells were CD38- or CD38intermediate (both CD4+ and CD8+ T cells). We conclude that, in contrast to early life, the production of naive CD4+ T cells is deficient in adult (and particularly elderly) transplant recipients.
While success of autologous bone marrow transplantation (BMT) for malignancies largely depends on the cytotoxicity of the ablative regimen, achievement of relapse-free survival after allogeneic BMT is thought to be enhanced by immunologic effects. We therefore investigated in vivo and in vitro production of interferon-gamma (IFN-gamma), soluble interleukin-2 (IL-2) receptor alpha-chain (sCD25), tumor necrosis factor-alpha (TNF-alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients before and during various time periods up to 2 years after autologous and allogeneic BMT. Cytokine levels were assessed in patient plasma and in supernatants of patient-derived peripheral blood mononuclear cells (PBMNC) cultured for 3 days in the presence of T cell-specific stimulation via CD3 plus IL-2. Our studies show that IFN-gamma plasma levels are decreased in autologous graft recipients before and during the first 30 days posttransplant. In allogeneic graft recipients, IFN-gamma plasma levels are also decreased during the first 30 days posttransplant, but otherwise are comparable to normal control (NC) values. In vitro stimulated PBMNC from autologous graft recipients also exhibit an IFN-gamma production defect before and during the first 30 days posttransplant. In contrast, before and up to 30 days after allogeneic BMT, stimulated IFN-gamma production is comparable to NC values but then gradually decreases, reaching its trough levels at between 61 and 180 days post-BMT. The IFN-gamma production defects in both patient groups seem to be specific, as sCD25, TNF-alpha, and GM-CSF production in stimulated PBMNC is normal or even enhanced at any time after autologous or allogeneic BMT. Deficient IFN-gamma production in patient-derived PBMNC does not correlate with variation in monocyte, T cell, or natural killer (NK) cell numbers during the posttransplantation course.
Autologous hematopoietic stem cell transplantation effectively results in restoration of hematopoiesis, but induces an often prolonged period of T cell dysfunction including redistribution of T cell subsets and defective T cell proliferation. Because IL-2 production is markedly decreased following autologous stem cell engraftment, and because IL-12 has direct stimulatory effects on TH1 cells, a major source of IL-2, we investigated the production and responsiveness of IL-12 of peripheral blood mononuclear cells (PBMC) of autologous stem cell recipients in the first 6 months following engraftment. When stimulated with S. aureus Cowan I (SAC), PBMC from autologous hematopoietic transplant recipients in the early months following engraftment show no decrease in production of IL-12 as compared to control PBMC. Furthermore, transplant-derived PBMC appear to be functionally responsive to exogenously provided IL-12 as indicated by several criteria. In vitro proliferation of total PBMC and of isolated CD4+ T cells from transplanted recipients to PHA (1 microgram/ml) + IL-12 (20 U/ml) was comparable to controls, excluding the possibility that only NK or CD8+ cells respond to IL-12. Culture of both control and transplant-derived PBMC in PHA + IL-12 (20 U/ml) or IL-2 (100 U/ml) + IL-12 (20 U/ml) combinations yielded comparable production of IFN-gamma, one of the major biological effects of IL-12 in vivo, as well as equal production of TNF-alpha, a costimulatory factor of IL-12-mediated induction of IFN-gamma by NK cells. Taken together, this in vitro evidence suggests that following autologous transplantation, PBMC do not appear to have either decreased production of endogenous IL-12 or defective functional responsiveness to exogenously provided IL-12.
The expression of CD45RA+ and CD45RO+ isoforms on T cells and the recovery of B lymphocytes and NK cells after autologous peripheral blood stem cell transplantation (PBSCT) were studied during the early period following transplantation. The same panel of monoclonal antibodies was used to analyze the lymphocyte subsets after allogeneic bone marrow transplantation (allo-BMT) and in cord blood. The CD4+ subsets regenerated differently from the CD8+ isoforms and the CD4+CD45RA+ subsets appears to be the only thymus-dependent regenerating population post-transplantation. Since the CD8+ CD45RA+ and CD8+ CD45RO+ isoforms recovered to normal levels within a month after PBSCT and within 3 months after allo-BMT, there seems to be no thymic influence on the regeneration of the immature CD8+CD45RA+ subset. The regeneration of the CD4+ cells was markedly delayed, but was faster in the PBSCT recipients, mainly because of the faster recovery of the mature CD4+ CD45RO+ subset. The pattern of surface antigens on T lymphocytes after transplantation did not resemble the antigen pattern on cord blood cells. The CD19+ CD20+ cells recovered earlier in the PBSCT group and remained compromised after allo-BMT during the time studied. The faster B lymphocyte regeneration correlates with the faster reconstitution of the mature CD4+CD45RO+ cells. The pattern of antigens CD38+, HLA-DR+, CD10+ on B lymphocytes of the recovery phase resembled the pattern on B cells of cord blood lymphocytes. The NK cells were not deficient at any time post-transplant in both groups.
Hematopoiesis after autologous bone marrow transplantation (BMT) is characterized by a prolonged and severe deficiency of marrow progenitors for several years, especially of erythroid and megakaryocyte progenitors, while the peripheral blood cells and marrow cellularity have reached relatively normal values within a few weeks. These anomalies are comparable to those reported for allogeneic BMT, despite the absence of any allo-immune reaction or post-graft immunosuppressive therapy. Post-graft hematopoietic impairment is the consequence of quantitative and qualitative changes involving both stem cell and stromal compartments which are expressed by an impaired capacity of stem cell self-renewal and commitment towards erythroid and megakaryocytic lineages. Besides the toxicity of conditioning regimens, hematopoietic reconstitution using autologous grafts is particularly dependent on a combination of factors related to the patient, such as underlying disease and pre-graft chemotherapy regimens, and to the graft processing itself, such as in vitro purging with chemotherapeutic agents.
The cytomegalovirus (CMV)-specific CD8+ cytotoxic T-lymphocyte (CTL) and CD4+ T-helper cell (Th) functions were characterized in 15 CMV seropositive recipients of autologous peripheral blood stem cell or bone marrow transplants. These immune functions were evaluated in peripheral blood specimens obtained before and at 1, 2, and 3 months after transplant. For study of CTL activity, blood mononuclear cells were cocultured with CMV-infected autologous fibroblasts for 2 weeks and then tested for cytotoxicity against CMV-infected or mock-infected autologous and HLA-mismatched fibroblasts. The Th response to CMV antigen was assessed by standard lymphoproliferative assay. CMV-specific CD8+ CTL and CD4+ Th responses were detectable in 12 (80%) and 14 (93%) patients, respectively, in the first 3 months after transplantation. A Th response to CMV was always present by the time of first CTL detection. During the posttransplant period, CMV infection occurred in 6 (40%) patients, and detection of CMV-specific CD8+ CTL activity was associated with protection from subsequent CMV infection (P = .002). Among CMV seropositive autograft recipients, CMV-specific CD8+ CTL and CD4+ Th responses are restored in a large proportion of patients in the first 3 months after transplantation, and the presence of a specific CD8+ CTL activity affords protection from CMV infection.
The recipients of hematopoietic stem cell transplants are characterized by an immunodeficiency of varying severity and duration. Their immunoincompetence is due in part to: 1) a lack of sustained transfer of donor immunity, 2) a recapitulation of lymphoid ontogeny, 3) the effects of graft-versus-host disease and its therapy, and 4) a reduction in thymic function. Recipients can have delays in the production of naive T lymphocytes following transplantation which result in defects in the production of new antigen-specific T lymphocytes and an inability to produce antibodies, especially to carbohydrate antigens.
The cytolytic T lymphocyte (CTL) response has often been used to assess the reconstitution of T cell function after allogeneic or autologous bone marrow transplantation (BMT). Less is known, however, about the reconstitution of the CTL response after peripheral blood stem cell transplantation (PBSCT). Therefore, we investigated the CTL response against Epstein-Barr virus (EBV) of patients undergoing autologous PBSCT. CTLs of six patients with relapsed non-Hodgkin's lymphoma and multiple myeloma were established before and at different times after PBSCT by in vitro stimulation of peripheral blood lymphocytes with autologous EBV-transformed lymphoblastoid cell lines (LCLs). The efficiency of T cell priming by LCLs was assessed at the time of initiation of CTL lines; the proliferative response was strongly reduced during the first 4 months and increased 5 months or more following PBSCT. Cytolytic activity was measured after three or four restimulations of CTLs. All patients investigated had a detectable EBV-specific CTL response which was poor during the first weeks after transplantation, accompanied by a strong non-MHC-restricted cytotoxic activity and a high proportion of CD56-positive T cells. Five or more months after PBSCT, a specific CTL response against EBV was seen which was similar to the situation prior to PBSCT, while the unspecific cytotoxic response decreased. Blocking experiments with monoclonal anti-CD3, anti-CD8 or anti-MHC I antibodies resulted in substantial inhibition of autologous LCL lysis, whereas anti-CD4 or anti-MHC II antibodies had no effect. Finally, autologous PHA blasts of a patient with the HLA haplotype A1/9+, B5/8+, Cw4/7+, were loaded with various EBNA-derived nonapeptides known to be presented by HLA B8 or A11, and exposed to autologous, EBV-directed CTLs. Specific lysis by CTLs only occurred with HLA B8-, but not with HLA A11-restricted nonapeptides. This demonstrated the existence of an MHC I-restricted anti-EBV CTL response after PBSCT. Taken together, the results show that the anlaysis of the EBV-directed CTL activity may serve as a surrogate marker to assess the reconstitution of the cellular immune response in patients undergoing autologous PBSCT.
High-dose therapy with autologous peripheral blood stem cell (PBSC) rescue is widely used for the treatment of malignant disease. CD34 selection of PBSC has been applied as a means of reducing contamination of the graft. Although CD34 selection results in a 2 to 3 log reduction in contaminating tumor cells without significantly delaying engraftment, many other types of cells are depleted from the CD34-enriched grafts and immune reconstitution may be impaired. In the present study, 31 cytomegalovirus (CMV)-seropositive patients who received myeloablative therapy followed by the infusion of CD34-selected autologous PBSC were assessed for the development of CMV disease in the first 100 days posttransplant. Seven patients (22.6%) developed CMV disease and 4 patients (12.9%) died from complications of their infection. In a contemporaneous group of 237 CMV-seropositive patients receiving unselected, autologous PBSC, only 10 patients (4.2%) developed CMV disease, with 5 deaths (2.1%). In a multivariate logistic regression analysis, the use of CD34-selected autologous PBSC after high-dose therapy was associated with a marked increase in the incidence of CMV disease and CMV-associated deaths.
Following high-dose chemotherapy (HDC) and peripheral blood progenitor cell transplantation (PBPCT), there are profound changes in leukocyte homeostasis and the immune system is compromised. Transplantation of purified CD34+ cells may further compromise immune recovery because the grafts are depleted of mature immune cells. However, a detailed monitoring of immune cell reconstitution has not been done. We monitored blood levels of antigen-presenting cells (APC) and of lymphocytes by multi-color flow cytometry at different times post CD34+ PBPCT. We found a rapid normalization of circulating levels of the antigen-presenting CD11c+ dendritic cells (defined as lineage- HLA-DR+ CD11c+ cells). There was a slight over-representation of lin- DR+ CD11c- cells at day 42 post transplantation suggesting that the composition of the APC population might be affected. Normal levels of total T, B and NK lymphocytes were rapidly achieved but the composition of the T cell population was abnormal. Patients had elevated levels of CD8+ T cells at early times and a persistent reduction in levels of naive CD8+ T cells (CD8+ CD4- CD45RA+ CD27+) and of naive CD4+ T cells (CD4+CD3+ CD8- CD45RA+). Thus, we found a rapid recovery of DC after CD34+ PBPCT but the specific numerical defects in naive T cells are likely to be a major cause of immune dysfunction in the patients. Bone Marrow Transplantation (2000) 25, 1249-1255.
Recovery of immune function following stem cell transplantation is necessary for a good outcome. Immune recovery is facilitated by transplanting higher numbers of cells than neutrophil or platelet reconstitution requires. Estimates from studies in the allogeneic setting suggest the minimum stem cell dose to achieve optimal lymphocyte recovery is about 10(7) CD34+ cells/kg. Increasing the number of autologous stem cells infused potentially increases the risk of reinfusing tumor cells. Transplanted mature immune cells apparently have very limited early contribution to cellular immune recovery. Mobilizing cytokines permit collection of greater numbers of stem cells, but they also can polarize T cells with potentially significant consequences, for example, granulocyte colony-stimulating factor (G-CSF) decreases the antitumor cytotoxic effector functions of cells. Although this could be a disadvantage in the autologous setting, it might decrease graft versus host disease in the allogeneic setting. Thus, identification of cytokines, which alone or in combination provide the most potent mobilizing effect to permit the collection of the highest number of stem cells without inadvertent detrimental polarization of the responses of immune cells, and employment of cytokines posttransplantation, which direct differentiation of the stem cells along the most desirable pathways, for example, to generate antitumor immune responses, might improve immunological outcome. A future emphasis should be to better define the cytokines and target cell populations that provide optimal immune reconstitution rather than focusing solely on rapid hematological recovery. More complete immunological reconstitution in a greater proportion of patients should be accompanied by improvements in outcomes of blood stem cell transplantation.
Autologous hematopoietic stem cell transplantation has proved to be an effective treatment for certain hematologic malignancies. However, relapse rates are high during the first year after transplantation. These relapses are attributed to the failure of high-dose chemotherapy to eradicate minimal residual malignant disease. In allogeneic hematopoietic stem cell transplantation, the higher antitumor effects observed compared with those in autologous hematopoietic stem cell transplantation are based on the immunologically mediated graft-vs-tumor effect. Therefore, a better understanding of the mechanisms involved in immune reconstitution after hematopoietic stem cell transplantation may clarify the importance of various components of the recovery of the immune system as they pertain to eradication of residual tumor, as well as uncover possible interventions directed at maximizing this effect. This review focuses on immune reconstitution after autologous hematopoietic stem cell transplantation. Autologous hematopoietic stem cell transplantation is not affected by graft-vs-host disease or immunosuppressive therapy after transplantation to control graft-vs-host disease, providing a direct insight into the mechanisms involved in immune reconstitution after engraftment.
This review presents evidence-based guidelines for the prevention of infection after blood and marrow transplantation. Recommendations apply to all myeloablative transplants regardless of recipient (adult or child), type (allogeneic or autologous) or source (peripheral blood, marrow or cord blood) of transplant.
In Section I, Dr. Dykewicz describes the methods used to rate the strength and quality of published evidence supporting these recommendations and details the two dozen scholarly societies and federal agencies involved in the genesis and review of the guidelines.
In Section II, Dr. Longworth presents recommendations for hospital infection control. Hand hygiene, room ventilation, health care worker and visitor policies are detailed along with guidelines for control of specific nosocomial and community-acquired pathogens.
In Section III, Dr. Boeckh details effective practices to prevent viral diseases. Leukocyte-depleted blood is recommended for cytomegalovirus (CMV) seronegative allografts, while ganciclovir given as prophylaxis or preemptive therapy based on pp65 antigenemia or DNA assays is advised for individuals at risk for CMV. Guidelines for preventing varicella-zoster virus (VZV), herpes simplex virus (HSV) and community respiratory virus infections are also presented.
In Section IV, Drs. Baden and Rubin review means to prevent invasive fungal infections. Hospital design and policy can reduce exposure to air contaminated with fungal spores and fluconazole prophylaxis at 400 mg/day reduces invasive yeast infection.
In Section V, Dr. Sepkowitz details effective clinical practices to reduce or prevent bacterial or protozoal disease after transplantation. In Section VI, Dr. Sullivan reviews vaccine-preventable infections and guidelines for active and passive immunizations for stem cell transplant recipients, family members and health care workers.
Autologous or alloge-neic bone marrow transplantation compared with intensive chemo-therapy in acute myelogenous leukemia
- Zittoun Ra
- F Mandelli
- Willemze
Zittoun RA, Mandelli F, Willemze R et al. Autologous or alloge-neic bone marrow transplantation compared with intensive chemo-therapy in acute myelogenous leukemia N Engl J Med 1995;332:217±23.
Report on state of the art in blood and marrow transplantation ± the IBMTR/ABMTR summary slides with guide
- Horowitz
- Mm
Horowitz MM: Report on state of the art in blood and marrow transplantation ± the IBMTR/ABMTR summary slides with guide. IBMTR/ABMTR newsletter 2002.
Se-lective outgrowth of CD45RO+ Vg9+/Vd2+ T-cell receptor g/d T cells early after bone marrow transplantation
- Van
- D Harst
- Van A Brand
- Luxemburg-Heijs
- Sa
Van der Harst D, Brand A, Van Luxemburg-Heijs SA et al. Se-lective outgrowth of CD45RO+ Vg9+/Vd2+ T-cell receptor g/d T cells early after bone marrow transplantation. Blood 1991;78:1875± 81.