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To investigate whether the functional variant Q63R of the cannabinoid 2 (CB2) receptor is associated with susceptibility to oligo/poly-articular juvenile idiopathic arthritis (JIA) and with its clinical features. A total of 171 Italian children with oligoarticular/rheumatoid factor negative poly-articular JIA and 600 healthy controls were enrolled in the study and genotyped. A significant difference in genotype distribution of the CB2 Q63R variant (CNR2 rs35761398) between oligo/poly-articular JIA patients and controls was found (p = 0.001). The R63 variant was associated with increased rates of relapse (p = 0.0001). This study indicates that the CB2 receptor contributes to susceptibility to oligo/polyarticular JIA and to the severity of its clinical course.
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Association between cannabinoid receptor type 2 Q63R variant and
oligo/polyarticular juvenile idiopathic arthritis
GBellini
1
,ANOlivieri
2
, A Grandone
2
,MAlessio
3
, MF Gicchino
2
, B Nobili
2
,LPerrone
2
, S Maione
1
, E Miraglia del Giudice
2
,
FRossi
2
1
Department of Experimental Medicine, Second University of Naples (SUN),
2
Department of Women, Child and General and Specialist
Surgery, SUN, and
3
Department of Translational Medical Sciences, University of Naples Federico II, Naples, Italy
Objectives: To investigate whether the functional variant Q63R of the cannabinoid 2 (CB2) receptor is associated with
susceptibility to oligo/poly-articular juvenile idiopathic arthritis (JIA) and with its clinical features.
Method: A total of 171 Italian children with oligoarticular/rheumatoid factor negative poly-articular JIA and 600 healthy
controls were enrolled in the study and genotyped.
Results: A significant difference in genotype distribution of the CB2 Q63R variant (CNR2 rs35761398) between oligo/
poly-articular JIA patients and controls was found (p¼0.001). The R63 variant was associated with increased rates of
relapse (p¼0.0001).
Conclusions: This study indicates that the CB2 receptor contributes to susceptibility to oligo/polyarticular JIA and to the
severity of its clinical course.
Juvenile idiopathic arthritis (JIA) is an inflammatory
chronic disease affecting joints and other structures.
Sevensubtypesofarthritiscanbeidentifiedbyassociation
with the number of joints and the type of extra-articular
involvement occurring in the first 6 months of the disease:
systemic, oligoarticular (<5 joints), polyarticular (5
joints) rheumatoid factor (RF) positive or negative, psor-
iatic, enthesitis-related, and undifferentiated arthritis (1,2).
Although crucial or initiating antigens have not yet
been determined, enhanced proliferation of T-cells from
synovial fluid of pediatric JIA, correlating with disease
phenotype, has been shown (3).
T cells express cannabinoid receptors 1 and 2 (CB1 and
CB2). These receptors and the endocannabinoids with the
enzymes for their metabolism, represent the endocanna-
binoid (EC) system. The ECsystem is involved in a
plenty of physiological functions, including suppression
of cell activation, Th1 and Th2 balance, inhibition of pro-
inflammatory cytokine production. CB2 receptors, highly
expressed by all immune cells, regulate their develop-
ment, migration, proliferation and effector functions,
representing the key component of the ECsystem for
immune function modulation (4).
A common variant, rs35761398, of the CNR2 gene
encoding for the CB2 receptor, is associated to autoim-
munity unbalance (5). The relative glutamine-arginine
substitution at codon 63 (Q63R), affects the response of
CB2 to cannabinoid, differently modulating the EC-
induced inhibition of lymphocytes proliferation (6).
Lymphocytes from RR subjects had two-fold reduction
of EC-induced inhibition of proliferation compared to
those from QQ, suggesting the R variant as the less func-
tional (6). This less functional variant has been asso-
ciated, in childhood, with increased risk of chronic
immune thrombocytopenic purpura and celiac disease
(7,8). Drugs selectively acting on cannabinoid receptors
can ameliorate the symptomatology of several diseases
with unbalance of the innate or adaptative immune
response (9). CB2 Q63R variant has been found to influ-
ence the evolution of some liver diseases (1012).
Genome wide association studies have shown a note-
worthy genetic component of JIA pathogenesis (13).
Based on these evidences, we have investigated the influ-
ence of the CB2 Q63R variant on the susceptibility to the
two most common subtypes of JIA, IgM rheumatoid
factor (RF)negative polyarticular JIA and oligoarticular
JIA (1), performing a case-control association analysis in
a cohort of 171 Italian children and adolescents with JIA
and in 600 healthy Italian controls.
Patients and Methods
Patients. This study includes 171 children (124 females, 47
males; mean age at diagnosis 5.93.8) with oligo-articular
and poly-articular JIA treated atthe Department of Women,
Child and General and Specialistic Surgery of the Second
Anna Grandone, Department of Women, Child and General and
Specialist Surgery, Second University of Naples, 80138 Naples, Italy.
E-mail: agrandone@gmail.com
Accepted 16 February 2015
Scand J Rheumatol 2015;iFirst article:14 1
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University of Naples from November 1999 to June 2011.
Diagnoses were made according to International League
Against Rheumatism (ILAR) criteria and treatment was
assigned according to recommendations from the
American College of Rheumatology (ACR) (1,14).
The number of affected joints, age of disease onset,
follow-up duration, presence of comorbidities, presence
of associated autoimmune diseases, and relapses were
evaluated. Clinical remission was defined according to
Wallaces criteria (15). Any symptom appearing after a
minimum of 6 months if on medication and for 12 months
if off medication was considered as relapse of arthritis.
The presence of uveitis was considered as a comorbidity;
coeliac disease, thyroidites, and diabetes mellitus were con-
sidered associated autoimmune diseases. Six hundred healthy
children, of the same ethnic origin, Caucasian, previously
genotyped for the CB2 Q63R (7,8), were used as controls.
The study was approved by the SUN Medical Ethics
Committee and was performed in accordance with the
Declaration of Helsinki. Written informed consent was
obtained from all patientsparents.
Molecular study
Genomic DNA extraction and TaqMan assay were per-
formed as described previously (7).
Statistical analysis
Aχ
2
test was used to determine HardyWeinberg equili-
brium and the differences in genotype frequencies between
patients and controls. Logistic regression was used to assess
the association with clinical findings, adjusted for age, sex,
disease duration, and year of recruitment. Odds ratios (ORs)
for JIA with respect to the different genotypes were calcu-
lated according to an additive model. An analysis of var-
iance (ANOVA) was performed for the age of onset
considered as a continuous variable. Associated p-values
<0.05 were considered significant. All the analysis were
conducted by using Statgraphics Centurion XV.II software
(Adalta, Arezzo, Italy; Statpoint Technologies, Inc,
Warrenton, VA, USA).
Results
In this study we genotyped 105 oligoarticular and 66
polyarticular JIA children for the CNR2 rs35761398
variant. Data for the same variant in 600 healthy
children were also included (7,8). The results are
summarized in Table 1. The genotype distribution
showed significant differences between patients and
controls: RR subjects showed a twofold risk for
developing JIA compared to QQ subjects and,
among patients, a fivefold risk for developing poly-
articular JIA (Table 1). Association of the CB2 Q63R
variant with clinical findings revealed significant cor-
relations with the relapse of arthritis (p ¼110
4
).
We considered the presence or the absence of extended
oligoarticular disease as a categorical variable in the
analysis and it did not influence the results, possibly
because of the low number of patients affected
(15 subjects).
Table 1. Casecontrol association study of the CB2 Q63R polymorphism in oligo/polyarticular JIA Italian children: genotype distribution
comparison
Oligo/polyarticular JIA patients
(n ¼171)
Controls
(n ¼600) p-value
Genotype QQ QR RR QQ QR RR
No. of patients 16 75 80 96 307 194 0.001 (χ
2
¼13.900, df ¼2)
Oligo/polyarticular JIA vs. controls
(171 vs. 600 subjects) OR 95% CI p-value
QR vs. QQ 1.466 0.7892.754 0.215 (χ
2
¼1.648, df ¼1)
RR vs QQ 2.474 1.3264.668 0.002 (χ
2
¼9.461, df ¼1)
RR vs QR 1.688 1.3264.668 0.005 (χ
2
¼8.087, df ¼1)
Polyarticular JIA patients
(n ¼66)
Oligoarticular JIA patients
(n ¼105) p-value
Genotype QQ QR RR QQ QR RR
No. of patients 2 30 34 14 46 45 0.071 (χ
2
¼5.28, df ¼2)
Polyarticular vs. oligoarticular
(66 vs. 105 patients) OR 95% CI p-value
RR vs QQ 5.289 1.03436.218 0.025 (χ
2
¼5.272, df ¼1)
RR vs QR 1.159 0.5812.312 0.652 (χ
2
¼0.203, df ¼1)
QR vs QQ 4.565 0.88631.408 0.039 (χ
2
¼4.239, df ¼1)
2 G Bellini et al
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Discussion
No study has previously evaluated the role of the CNR2
rs35761398 variant in JIA. We show for the first time a
role of the CB2 receptor in determining JIA and its
clinical course.
The contribution to the synovial inflammation of oligo/
polyarticular JIA is driven by a T-cell imbalance, leading
to failure of T-cell tolerance to self-antigens and to the
synovial massive leucocyte inflammatory migration (4).
The CB2 Q63R functional variant modulates T-cell pro-
liferation differently, and then their tolerance to self-
antigens, with the minor inhibition exerted by the R63
variant (5). Indeed, we found an association between JIA
and the less functional R63 variant. According to an
additive model, RR subjects show a risk for developing
JIA more than twice that with respect to QQ subjects, and
QR subjects show a lower risk for developing JIA with
respect to RR.
Accordingly, RR homozygotes show a higher risk for
developing polyarticular disease compared to QQ, and
QR patients had an intermediate risk (Table 1). A signifi-
cant correlation of the Q63R variant with the relapse of
arthritis was found, corrected for age, sex, follow-up
duration, and year of recruitment, considered as a proxy
to account for changing treatment patterns.
Finally, considering the risk allele in the homozygous
state, homozygous RR patients showed an earlier onset of
the disease with about double the risk of developing
disease before 5 years of age compared to QQ/QR
patients [OR ¼1.89, 95% confidence interval (CI)
1.033.47, p ¼0.038]. No other association was found.
To date, the CNR2 locus has not been associated with
JIA in GWAS, but as GWAS are performed through silent
single nucleotide polymorphisms (SNPs), functional vari-
ants that contribute to a part of the heritability could have
been missed (16). Association of the interleukin (IL)-10
cytokine family cluster with JIA has been shown (17). The
CB2 receptor modulates production directly, increasing the
anti-inflammatory cytokines, such as IL-10 (18). A heredi-
tary predisposition to low IL-10 production in children
with extended oligoarticular JIA has been found. The less
functional R63 variant is significantly associated with
relapses of arthritis, suggesting that a facilitated T-cell
imbalance may drive the active inflammatory state. These
data were still significant when risk factors contributing to
arthritis relapse (duration of treatment, treatment starting
age, and year of recruitment) were included as covariates.
Quantification of some relapse risk biomarkers for the
predictionof JIA relapse has been validated (19), including
the neutrophil-derived S100A12, which induces monocyte
activationbinding to Toll-like receptor4 (TLR4). Selective
stimulationoftheCB2receptordown-regulatestheTLR4-
activated pathway, probably facilitating relapse in patients
carrying the less functional R63 variant (20). CB2 agonists
exert their anti-inflammatory properties inhibiting the acti-
vation of autoreactive T cells and the leucocyte trafficking
towards the inflamed site (21), suggesting that the
disinhibition of the regulatory mechanism of T-cell recruit-
ment can result in an earlier onset of the disease and a more
severe phenotype. Accordingly, we found that, as for
immune thrombocytopenic purpura (11), the homozygous
R63 genotype was significantly associatedwith an onset of
the symptoms before 5 years of age.
A significant difference in the Q63R genotype distribu-
tion was also found between oligoarticular and polyarti-
cular JIA, with increased frequency of RR homozygous
polyarticular patients. Considering the 105 oligoarticular
JIA (QQ ¼14, QR ¼46, RR ¼45) or the 66 polyarticular
JIA patients (QQ ¼2, QR ¼30, RR ¼34) alone, the
genotype distribution was still significantly different from
that of the controls (QQ ¼96, QR ¼307, RR ¼194) only
for the polyarticular form (oligoarticular vs. controls χ
2
¼
4.275, df ¼2, p ¼0.118; polyarticular vs. controls χ
2
¼
13.525, df ¼2, p ¼0.0012). Among JIA patients, QR
carriers and RR carriers showed an increased risk of four-
fold and fivefold, respectively, to be affected by a poly-
articular disease with respect to QQ subjects. These
findings are consistent with the hypothesis that, in the
polyarticular disease, there is a greater failure of a regu-
latory mechanism of T-cell recruitment and activation
(5) and could suggest a CB2 Q63R genotype contribu-
tion to this difference. This observation may lead
to important potential therapeutic consequences, as
development of drugs acting on the CB2 receptor for
clinical application represents a major topic of pharma-
ceutical research. These preliminary findings need to be
confirmed by independent studies. Despite this limita-
tion, our data suggest, for the first time, the CB2 receptor
as a possible molecular determinant contributing to the
susceptibility to oligo/polyarticular JIA and to its clin-
ical course.
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... Cannabinoids have been proposed as a promising immunomodulator to reduce the SARS-CoV-2 immunopathology (16). Variations in the cannabinoid CB2 receptor gene (CNR2) could affect intracellular signaling and reduce the ECs function, which has been associated with an unbalanced immune response and increased risk of various in ammatory diseases (17)(18)(19)(20)(21)(22)(23). The CB2-Q63R polymorphism is a missense mutation of the second and third bases at codon 63 of the CNR2 gene, which leads to a Q/R substitution, causing a different polarization state of the protein (24). ...
... The association between the CB2-Q63R variation and autoimmune conditions such as thrombocytopenic purpura (45), celiac disease (23), juvenile idiopathic arthritis (19), in ammatory bowel disease (46), and rheumatoid arthritis (22) has been reported. The data reported by the current authors have been implied the involvement of the Q63R variation in susceptibility to multiple sclerosis in Iranian patients (18). ...
... In the case of SARS-CoV-2 infection, while a robust innate immune response is essential to eliminate viral pathogens, a prolonged or dysregulated/exuberant manner can damage the respiratory tract (47). The current results are consistent with previous studies that showed a reduced EC-induced modulation of the immune system in human subjects carrying the RR variant of CB2 compared with those having the QQ variant (2,19,23,45,46). ...
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Full-text available
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... Cannabinoids have been proposed for use as immunomodulators to reduce the inflammatory effects of SARS-CoV-2 [17,18]. Variations in the cannabinoid CB2 receptor gene (CNR2) could affect intracellular signaling and reduce the effects of ECs, which has been associated with an unbalanced immune response and an increased risk of various inflammatory diseases [19][20][21][22][23][24][25]. The mammalian CB2 gene is highly conserved in most of the regions, but not at amino acid position 63 [26]. ...
... The co-dominant, recessive, and additive inheritance models showed a significant association between Q63R and COVID-19 severity (Table 3). According to the An association between the CB2-Q63R variation and autoimmune conditions such as thrombocytopenic purpura [47], celiac disease [25], juvenile idiopathic arthritis [21], inflammatory bowel disease [48], and rheumatoid arthritis [24] has been reported. The data from our previous study suggested an involvement of the Q63R variation in susceptibility to multiple sclerosis in Iranian patients [20]. ...
... In the case of SARS-CoV-2 infection, while a robust innate immune response is essential to eliminate viral pathogens, a prolonged, dysregulated, or excessive response can damage the respiratory tract [49]. The current results are consistent with previous studies that showed reduced EC-induced modulation of the immune system in human subjects carrying the RR variant of CB2 compared with those with the QQ variant [2,21,25,47,48]. ...
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... CBr2 (also known as the peripheral cannabinoid receptor) is another G protein-coupled receptor that has a 44% amino acid similarity with CBr1. It acts in a similar manner to CBr1 by inhibiting adenylate cyclase and activating MAPK, but its activation can also transiently increase intra-cellular calcium levels via phospholipase C [22,23]. It is primarily expressed on immune cells, but is also expressed on chondrocytes, osteocytes, fibroblasts, FLSs, dorsal root ganglia, and microglial cells, although the extent to which it is expressed in the human nervous system is still unclear [18,20,21]. ...
... Evidence of CBr2 mRNA has been found in rodent cerebellum, cortex, brainstem, spinal cord and glial cells, and it is worth noting that the Q63R variant is associated with autoimmune diseases such as celiac disease, immune thrombocytopenic purpura, and (of particular interest to rheumatologists) juvenile idiopathic arthritis [23]. ...
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... T1DM shares genetic and phenotypic comorbidity with other autoimmune diseases and CB2R activation can ameliorate symptoms of multiple sclerosis (Annunziata et al., 2017), thyroiditis autoimmune diseases (Alcigir et al., 2017), celiac disease (Tortora et al., 2020), Crohn's disease (Leinwand et al., 2017), and rheumatoid arthritis (Gui et al., 2014). Several human leukocyte antigen (HLA) gene polymorphisms of MHC class I and II (Noble and Valdes, 2011), insulin gene short VNTR (variable number tandem repeat) (Bennett et al., 1995), and a nonsynonymous CNR2 SNP (Q63R) are risk alleles that cosegregate with several autoimmune diseases (Rossi et al., 2012;Mahmoud Gouda and Mohamed Kamel, 2013;Bellini et al., 2015;Ismail and Khawaja, 2018;Strisciuglio et al., 2018). However, we could not find any study of CB2R and its level of activation in T1DM in the literature. ...
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... One missense polymorphism is the AA-GG conversion at positions 188-189 of the CB 2 R coding DNA, (rs2501432) which causes a glutamine-arginine amino acid change at position 63 of the protein (CB 2 R-Q63R). This mutation allele frequency seems to be 65% worldwide (28), and has been suggested to affect some conditions like depression, alcoholism (9,10), schizophrenia (8), autoimmune diseases (29,30), juvenile idiopathic arthritis (31), immune thrombocytopenic purpura in children (32,33), and others. In the case of another missense polymorphism (rs41311993), which involves a leucine-isoleucine exchange at position 133 (CB 2 R-L133I), a significantly higher mutant allele frequency was found in bipolar disorder patients in an Italian population sample (34). ...
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... This finding demonstrates the potential role of cannabinoids in OA treatment. The CB 2 receptor gene polymorphism Q63R is associated with increased arthritis risk [107,108]. CB 2 is also important for the regulation of osteoblast differentiation and bone formation. Mice with inactivated CB 2 receptors developed osteoporosis with relative uncoupling of bone resorption from bone formation, while in primary osteoblasts from CB 2 −/− mice, a reduced capacity to form bone nodules in vitro was observed (in wild-type osteoblast cell culture, the CB 2 agonist HU-308 promoted bone node formation) [27]. ...
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... This and many other alterations seem to contribute to the low-grade inflammation of white adipose tissue in obese people [70]. The same CB2 Q63R variant was associated also with liver necroinflammation in chronic hepatitis patients with HIV/HCV coinfection [48], synovium inflammation in juvenile idiopathic arthritis [71], liver damage in children with non-alcoholic fatty liver disease [72] and inflammation of gastro-intestinal tract in inflammatory bowel disease (Crohn's disease and ulcerative colitis) [73] and in celiac disease [74]. Moreover, it has been demonstrated that the cannabinoid CBD inhibits the production of the pro-inflammatory cytokines IL-6, IL-8 and TNF-α in in vitro models of allergic contact dermatitis [75], and in osteoarthritis, THC reduced TNF-α, IL-1 , IL-6 and IL-8 release in LPS-stimulated MG63 cells, demonstrating the anti-inflammatory CB2-mediated role [76]. ...
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Chapter
The endocannabinoid system plays a critical role in immunity and therefore its components, including cannabinoid receptors 1 and 2 (CB1 and CB2), are putative druggable targets for immune-mediated diseases. Whether modulating endogenous cannabinoid levels or interacting with CB1 or CB2 receptors directly, cannabinoids or cannabinoid-based therapeutics (CBTs) show promise as anti-inflammatory or immune suppressive agents. Herein we provide an overview of cannabinoid effects in animals and humans that provide support for the use of CBTs in immune-mediated disease such as multiple sclerosis (MS), inflammatory bowel disease (IBD), asthma, arthritis, diabetes, human immunodeficiency virus (HIV), and HIV-associated neurocognitive disorder (HAND). This is not an exhaustive review of cannabinoid effects on immune responses, but rather provides: (1) key studies in which initial and/or novel observations were made in animal studies; (2) critical human studies including meta-analyses and randomized clinical trials (RCTs) in which CBTs have been assessed; and (3) evidence for the role of CB1 or CB2 receptors in immune-mediated diseases through genetic analyses of single nucleotide polymorphisms (SNPs) in the CNR1 and CNR2 genes that encode CB1 or CB2 receptors, respectively. Perhaps most importantly, we provide our view of data gaps that exist, which if addressed, would allow for more rigorous evaluation of the efficacy and risk to benefit ratio of the use of cannabinoids and/or CBTs for immune-mediated diseases.
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We used the Immunochip array to analyze 2,816 individuals with juvenile idiopathic arthritis (JIA), comprising the most common subtypes (oligoarticular and rheumatoid factor-negative polyarticular JIA), and 13,056 controls. We confirmed association of 3 known JIA risk loci (the human leukocyte antigen (HLA) region, PTPN22 and PTPN2) and identified 14 loci reaching genome-wide significance (P < 5 x 10(-8)) for the first time. Eleven additional new regions showed suggestive evidence of association with JIA (P < 1 x 10(-6)). Dense mapping of loci along with bioinformatics analysis refined the associations to one gene in each of eight regions, highlighting crucial pathways, including the interleukin (IL)-2 pathway, in JIA disease pathogenesis. The entire Immunochip content, the HLA region and the top 27 loci (P < 1 x 10(-6)) explain an estimated 18, 13 and 6% of the risk of JIA, respectively. In summary, this is the largest collection of JIA cases investigated so far and provides new insight into the genetic basis of this childhood autoimmune disease.
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Background: The cytokine IL-10 and its family members have been implicated in autoimmune diseases and we have previously reported that genetic variants in IL-10 were associated with a rare group of diseases called juvenile idiopathic arthritis (JIA). The aim of this study was to fine map genetic variants within the IL-10 cytokine family cluster on chromosome 1 using linkage disequilibrium (LD)-tagging single nucleotide polymorphisms (tSNPs) approach with imputation and conditional analysis to test for disease associations. Methodology/principal findings: Fifty-three tSNPs were tested for association between Caucasian paediatric cohorts [219 systemic JIA (sJIA), 187 persistent oligoarticular JIA (pOJIA), and 139 extended OJIA (eOJIA) patients], and controls (Wellcome Trust control cohort, WTCCC2). Significant association with sJIA was detected at rs1400986 in the promoter of IL-20 (odds ratio 1.53; 95% CI 1.21-1.93; p = 0.0004), but in no other subtypes. Imputation analysis identified additional associated SNPs for pOJIA at IL-20 and IL-24, including a rare, functional, missense variant at IL-24 with a p = 0.0002. Penalised logistic regression analysis with HyperLasso and conditional analysis identified several further associations with JIA subtypes. In particular, haplotype analysis refined the sJIA association, with a joint effect at rs1400986 and rs4129024 in intron 1 of MAPKAPK2 (p = 3.2E-5). For pOJIA, a 3-SNP haplotype including rs1878672 in intron 3 of IL-10 showed evidence for association (p = 0.0018). In eOJIA, rs10863962 (3'UTR of FCAMR) and rs12409577 (intron of IL-19) haplotype showed some evidence of association (p = 0.0003). Conclusions: This study supports previous association of IL-20 with sJIA. Haplotype analyses provided stronger association signals than single point analyses, while a penalised logistic regression approach also suggested multiple independent association signals. Replication studies are required to confirm or refute these findings. The results indicate that combined effects with unknown/rare variants remain to be characterised in JIA, and represent a possible example of synthetic association in this region.
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BACKGROUND: & Aims: The cannabinoid receptor 2 (CB2) has been implicated in liver disease. The single nucleotide polymorphism rs35761398 in CNR2, which encodes the CB2, substitutes glutamine (Q) 63 with arginine (R) and reduces the function of the gene product. We investigated the effects of CNR2 rs35761398 in patients with hepatitis C virus (HCV) infection. METHODS: We studied 169 consecutive patients with asymptomatic chronic hepatitis (tested positive for anti-HCV and HCV-RNA) at 2 liver units in southern Italy; first liver biopsy samples were collected from July 2009 through December 2011. All patients were naive to antiviral therapy; CNR2 genotype was determined by PCR analysis. RESULTS: Patients with CB2-63 QQ variant had higher serum levels of aminotransferase than those with CB2-63 QR or RR variants; they also had higher histologic activity index (HAI) scores (8.6±3.8) than patients without the CB2-63 RR variant (5.3±3.6; P0.005) or those with the CB2-63 QR variant (5.8±3.3, P<.001). Patients with the different variants of CNR2 did not differ in fibrosis stage or steatosis score. Moderate or severe chronic hepatitis (HAI>8) was identified more frequently (55.5%) in patients with the CB2-63 QQ variant than in those with the 63 QR (20%; P<.005) or RR variant (17.4%; P<.005). In logistic regression analysis, the CB2-63 QQ variant and fibrosis score were independent predictors of moderate or severe chronic hepatitis (HAI >8; P<.0001). CONCLUSIONS: The CB2-63 QQ variant of CNR2 is associated with more severe inflammation and hepatocellular necrosis in patients with HCV infection.
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Juvenile idiopathic arthritis (JIA) is not a disease, but an exclusion diagnosis that encompasses all forms of arthritis that begin before the age of 16 years, persist for more than 6 weeks, and are of unknown origin. This heterogeneous group of chronic arthritides has been classified on clinical and laboratory grounds to try to identify homogeneous, mutually exclusives categories suitable for etiopathogenic studies . Recent advances have shown that while some JIA categories identify quite definite disease entities, others still include heterogeneous conditions. Some aspects of JIA classification and nomenclature need therefore to be reconsidered.
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Diabetic neuropathy is a frequent complication of diabetes mellitus with a tremendous impact on patients' quality of life, and it remains poorly treated. Cannabinoids relieve the signs of diabetic neuropathy in different experimental models, including streptozotocin- (STZ-) induced type 1 diabetic rodents, and they may also relieve neuropathic signs in type 2 diabetic animals. This study compares the effect of the non-selective cannabinoid agonist WIN 55,212-2 (WIN) in Zucker Diabetic Fatty (ZDF) rats (type 2 diabetes) and in STZ-injected Wistar rats (type 1 diabetes). WIN (or its vehicle) was either systemically administered at a non-psychoactive dose or locally injected. Selective CB1 and CB2 cannabinoid antagonists were used to characterize WIN antineuropathic effects. Both type 1 and type 2 diabetic rats showed mechanical allodynia but not thermal hyperalgesia. WIN alleviated mechanical allodynia in both models of diabetes. In STZ-treated rats, both cannabinoid receptors were involved, whereas in ZDF rats, WIN effects seemed to mainly involve the activation of CB1 receptors. Higher doses of WIN were needed to significantly relieve mechanical allodynia upon intraplantar administration in ZDF vs. STZ-injected rats. Cannabinoids, acting on systemic and/or peripheral receptors, may serve as a new therapeutic alternative for symptom management in painful neuropathy associated with both type 1 and type 2 diabetes. Additionally, our results highlight the need for appropriate selection of diabetic experimental models because the results from studies in STZ-induced diabetic rodents might not be applicable in all diabetic situations.