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1.  B lymphocytes and B-cell activating factor promote collagen and profibrotic markers expression by dermal fibroblasts in systemic sclerosis 
Arthritis Research & Therapy  2013;15(5):R168.
Introduction
B lymphocytes might play a pathogenic role in dermal fibrosis in systemic sclerosis (SSc). B-cell activating factor (BAFF), a key cytokine for B-cell activation, is increased in the serum and the skin of patients with SSc. However, the ability of B cells directly to stimulate dermal fibroblasts and the role of BAFF are not fully understood. We therefore investigated the involvement of B cells and BAFF in the expression of collagen and profibrotic markers by dermal fibroblasts.
Methods
Cocultures of blood B cells from healthy blood donors and normal or SSc dermal fibroblasts stimulated with anti-IgM and BAFF were performed. Alpha-SMA, TIMP1, MMP9, COL1A1, COL1A2, and COL3A1 mRNA expression were determined by quantitative RT-PCR. Soluble collagen, BAFF, IL-6, IL-1β, TGF-β1, and CCL2 protein secretion were assessed.
Results
Coculture of blood B cells and dermal fibroblasts isolated from SSc patients induced IL-6, TGF-β1, CCL2, and collagen secretion, as well as Alpha-SMA, TIMP1, and MMP9 expression in dermal fibroblasts. Transwell assays demonstrated that this induction was dependent on cell-cell contact. Addition of anti-IgM and BAFF to the coculture increased IL-6, CCL2, TGF-β1, and collagen secretion. B cell- and BAFF-induced collagen secretion was highly reduced by anti-TGF-β1 antibodies.
Conclusions
Our results showed for the first time a direct role of B cells on the production of collagen by dermal fibroblasts, which is further enhanced by BAFF. Thus, these results demonstrate a new pathogenic role of B cells and BAFF in fibrosis and systemic sclerosis.
doi:10.1186/ar4352
PMCID: PMC3978899  PMID: 24289101
2.  Innate immunity triggers IL-32 expression by fibroblast-like synoviocytes in rheumatoid arthritis 
Arthritis Research & Therapy  2010;12(4):R135.
Introduction
Interleukin-32 (IL-32) is a recently described cytokine that is a strong inducer of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, IL-1β, IL-6, and IL-8. The expression of this cytokine is highly increased in the rheumatoid synovium and correlated with the severity of joint inflammation. Little is known regarding the innate immune-related regulation of IL-32 by fibroblast-like synoviocytes (FLSs). We therefore investigated the effect of innate immune stimulation by ligands of Toll-like receptor (TLR)2, TLR3, and TLR4, and cytokines such as TNF-α and interferon (IFN)-γ, on IL-32 expression by FLSs.
Methods
FLSs were isolated from patients with rheumatoid arthritis (RA) according to the ACR criteria. Quantitative RT-PCR, confocal analysis, and ELISA were performed to evaluate IL-32 mRNA induction and IL-32 release by FLSs stimulated with TLR2 (BLP), TLR3 (poly I:C), and TLR4 (lipopolysaccharide) ligands, TNF-α and IFN-γ.
Results
TLR2, -3, and -4 ligands as well as IFN-γ and TNF-α induced IL-32 β, γ and δ mRNA expression by RA FLSs. Mature IL-32 was expressed intracellularly and released by cells stimulated with the various activators. The IL-32α isoform was expressed intracellularly in response to TNF-α and poly I:C and not released in culture supernatants. Stimulation of FLS with TNF-α, BLP, lipopolysaccharide, or poly I:C concomitant with IFN-γ increased IL-32 expression compared with stimulation with IFN-γ alone.
Conclusions
IL-32 synthesis by FLSs is tightly regulated by innate immunity in rheumatoid arthritis. Thus TNF-α, IFN-γ, double-strand RNA, hyaluronic acid, or other damage-associated molecular patterns (DAMPs), highly secreted in synovial tissues of RA patients, might trigger IL-32 secretion by FLSs. IL-32 might therefore represent a relevant therapeutic target in RA.
doi:10.1186/ar3073
PMCID: PMC2945025  PMID: 20615213
3.  Decreased B cell activating factor receptor expression on peripheral lymphocytes associated with increased disease activity in primary Sjögren's syndrome and systemic lupus erythematosus 
Annals of the Rheumatic Diseases  2006;66(6):790-797.
Objective
To analyse B cell activating factor (BAFF) receptor (BAFF‐R) expression on peripheral lymphocytes from patients with primary Sjögren's syndrome (pSS) and systemic lupus erythematosus (SLE).
Patients and methods
Peripheral blood mononuclear cells from 20 patients with pSS, 19 patients with SLE and 15 controls were examined by flow cytometry to investigate BAFF‐R mean fluorescence intensity (MFI) on lymphocytes. BAFF‐R mRNA level from isolated blood B cells of nine patients with pSS and eight controls was assessed by real‐time quantitative reverse transcription‐PCR. BAFF serum level was determined by ELISA.
Results
In all subjects, BAFF‐R was expressed on all naïve CD27− and memory CD27+ B‐cells and was present on <0.5% of T cells. The expression of BAFF‐R on B cells was significantly decreased in patients with pSS as compared with controls (MFI = 7.8 vs 10.6, p = 0.001), and was intermediate in patients with SLE (MFI = 9.5). Serum BAFF level was inversely correlated with BAFF‐R MFI (p = 0.007), but not because of competition between endogenous BAFF (at observed concentrations in patients) and the monoclonal antibody (11C1) detecting BAFF‐R. BAFF‐R mRNA levels did not differ between patients with pSS and controls (p = 0.48). BAFF‐R MFI decreased after overnight culture with recombinant human BAFF (from 32.5 to 25.4, p = 0.03). Contrary to the serum BAFF level, BAFF‐R expression was correlated with extraglandular involvement in pSS and SLE Disease Activity Index.
Conclusions
BAFF‐R expression is reduced on peripheral B cells of patients with pSS and SLE. This down‐regulation occurs through a post‐transcriptional mechanism and could be the consequence of chronic increase in BAFF. BAFF‐R levels on B cells could be a novel activity biomarker in autoimmune diseases.
doi:10.1136/ard.2006.065656
PMCID: PMC1954659  PMID: 17185325
4.  Increase of B cell‐activating factor of the TNF family (BAFF) after rituximab treatment: insights into a new regulating system of BAFF production 
Annals of the Rheumatic Diseases  2006;66(5):700-703.
Background
The cytokine B cell‐activating factor of the TNF family (BAFF) is involved in the pathogenesis of autoimmune diseases.
Objective
To access changes in serum protein and mRNA levels of BAFF after rituximab treatment.
Methods
Serum and peripheral blood mononuclear cells (PBMCs) were isolated from five patients (two with lupus, two with Sjögren's syndrome, one with rheumatoid arthritis) before and 12 weeks (range 7–17) after a first course of rituximab infusion. Monocytes and B cells were selected from healthy controls and cocultured for 72 h. BAFF protein and mRNA levels were assessed by ELISA and real‐time PCR, respectively.
Results
After rituximab treatment, median serum BAFF protein level and BAFF to actin mRNA ratio in PBMCs significantly increased. In monocytes cocultured with autologous B cells, BAFF protein level decreased, whereas the mRNA level was stable. In one closely monitored patient, the mRNA ratio of BAFF to actin in PBMCs increased later than the BAFF serum level.
Conclusions
Two distinct mechanisms are probably involved in the increase in BAFF level after B cell depletion: (1) the decrease in its receptors leading to a release of BAFF; (2) a delayed regulation of BAFF mRNA transcription. This could favour the re‐emergence of autoreactive B cells.
doi:10.1136/ard.2006.060772
PMCID: PMC1954605  PMID: 17040963
5.  Tolerance and efficacy of rituximab and changes in serum B cell biomarkers in patients with systemic complications of primary Sjögren's syndrome 
Annals of the Rheumatic Diseases  2006;66(3):351-357.
Objective
To investigate the safety and efficacy of rituximab (RTX) for systemic symptoms in patients with primary Sjögren's syndrome (pSS), and changes in B cell biomarkers.
Patients and methods
The records of 16 patients with pSS according to the American European consensus group criteria were reviewed retrospectively.
Results
Patients, all women, had a median age of 58.5 (range 41–71) years and a disease duration of 9.5 (range 0–25) years. RTX was prescribed for lymphoma (n = 5), refractory pulmonary disease with polysynovitis (n = 2), severe polysynovitis (n = 2), mixed cryoglobulinaemia (n = 5), thrombocytopenia (n = 1) and mononeuritis multiplex (n = 1). The median follow‐up duration was 14.5 (range 2–48) months. Three patients experienced adverse events, including one mild serum sickness‐like reaction with the presence of human antichimeric antibodies. Efficacy of treatment was observed in 4 of 5 patients with lymphomas and in 9 of 11 patients with systemic involvement. Dryness was improved in only a minority of patients. Corticosteroid dose was reduced in 11 patients. RTX induced decreased rheumatoid factor, γ‐globulin and β2‐microglobulin levels, and the level of B cell activating factor of the tumour necrosis factor family (BAFF) increased concomitantly with B cell depletion. Five patients were re‐treated, with good efficacy and tolerance, except for one with probable serum sickness‐like reaction.
Conclusion
This study shows good efficacy and fair tolerance of RTX for systemic features. In addition, RTX allows for a marked reduction in corticosteroid use. Except for BAFF, the level of which increases, serum B cell biomarker levels decrease after taking RTX. Controlled trials should be performed to confirm the efficacy of RTX in pSS.
doi:10.1136/ard.2006.057919
PMCID: PMC1856024  PMID: 16950808
6.  Increased levels of circulating microparticles in primary Sjögren's syndrome, systemic lupus erythematosus and rheumatoid arthritis and relation with disease activity 
Arthritis Research & Therapy  2009;11(5):R156.
Introduction
Cell stimulation leads to the shedding of phosphatidylserine (PS)-rich microparticles (MPs). Because autoimmune diseases (AIDs) are characterized by cell activation, we investigated level of circulating MPs as a possible biomarker in primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).
Methods
We measured plasma levels of total, platelet and leukocyte MPs by prothrombinase capture assay and flow cytometry in 43 patients with pSS, 20 with SLE and 24 with RA and in 44 healthy controls (HCs). Secretory phospholipase A2 (sPLA2) activity was assessed by fluorometry. Soluble CD40 ligand (sCD40L) and soluble P-selectin (sCD62P), reflecting platelet activation, were measured by ELISA.
Results
Patients with pSS showed increased plasma level of total MPs (mean ± SEM 8.49 ± 1.14 nM PS equivalent (Eq), P < 0.0001), as did patients with RA (7.23 ± 1.05 n PS Eq, P = 0.004) and SLE (7.3 ± 1.25 nM PS Eq, P = 0.0004), as compared with HCs (4.13 ± 0.2 nM PS Eq). Patients with AIDs all showed increased level of platelet MPs (P < 0.0001), but only those with pSS showed increased level of leukocyte MPs (P < 0.0001). Results by capture assay and flow cytometry were correlated. In patients with high disease activity according to extra-glandular complications (pSS), DAS28 (RA) or SLEDAI (SLE) compared with low-activity patients, the MP level was only slightly increased in comparison with those having a low disease activity. Platelet MP level was inversely correlated with anti-DNA antibody level in SLE (r = -0.65; P = 0.003) and serum β2 microglobulin level in pSS (r = -0.37; P < 0.03). The levels of total and platelet MPs were inversely correlated with sPLA2 activity (r = -0.37, P = 0.0007; r = -0.36, P = 0.002, respectively). sCD40L and sCD62P concentrations were significantly higher in pSS than in HC (P ≤ 0.006).
Conclusions
Plasma MP level is elevated in pSS, as well as in SLE and RA, and could be used as a biomarker reflecting systemic cell activation. Level of leukocyte-derived MPs is increased in pSS only. The MP level is low in case of more severe AID, probably because of high secretory phospholipase A2 (sPLA2) activity, which leads to consumption of MPs. Increase of platelet-derived MPs, sCD40L and sCD62P, highlights platelet activation in pSS.
doi:10.1186/ar2833
PMCID: PMC2787287  PMID: 19832990
7.  Cognitive Dysfunction and Dementia in Primary Sjögren's Syndrome 
ISRN Neurology  2013;2013:501327.
Background. Primary Sjögren's syndrome (PSS) is a frequent systemic autoimmune disease. In this study, we aimed to explore the cognitive impairment and the correlations with brain MRI. Methods. Twenty-five patients (mean age 55 ± 11.8 years, 21 females) with PSS were prospectively selected and tested with a French translation of the Brief Repeatable Battery for Neuropsychological Examination. The results were compared with the scores for 25 matched patients with multiple sclerosis (MS) and 25 controls. Brain lesions were assessed by brain MRI using the Wahlund classification. Results. Fifteen of the 25 PSS patients (60%) presented with cognitive disorders versus 19/25 MS patients (76%). Five patients had dementia in the PSS group. Speed of information processing, attention, immediate and long-term memory, and executive functions were frequently impaired. The mean duration of cognitive complaints was 5.6 ± 6.1 years, and the mean duration of PSS was 15.8 ± 14.0 years. A trend towards a correlation was found between the severity of cognitive impairment and the degree of white matter lesions (WML) (P = 0.03, rho = 0.43). Conclusion. Cognitive impairment—mild or dementia—exists in patients with PSS. Further MRI studies are needed to better understand the precise neural basis of cognitive impairment in PSS patients.
doi:10.1155/2013/501327
PMCID: PMC3793286  PMID: 24224097
8.  Serum Levels of Beta2-Microglobulin and Free Light Chains of Immunoglobulins Are Associated with Systemic Disease Activity in Primary Sjögren’s Syndrome. Data at Enrollment in the Prospective ASSESS Cohort 
PLoS ONE  2013;8(5):e59868.
Objectives
To analyze the clinical and immunological characteristics at enrollment in a large prospective cohort of patients with primary Sjögren's syndrome (pSS) and to investigate the association between serum BAFF, beta2-microglobulin and free light chains of immunoglobulins and systemic disease activity at enrollment.
Methods
Three hundred and ninety five patients with pSS according to American-European Consensus Criteria were included from fifteen centers of Rheumatology and Internal Medicine in the “Assessment of Systemic Signs and Evolution of Sjögren's Syndrome” (ASSESS) 5-year prospective cohort. At enrollment, serum markers were assessed as well as activity of the disease measured with the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI).
Results
Patient median age was 58 (25th–75th: 51–67) and median disease duration was 5 (2–9) years. Median ESSDAI at enrollment was 2 (0–7) with 30.9% of patients having features of systemic involvement. Patients with elevated BAFF, beta2-microglobulin and kappa, lambda FLCS had higher ESSDAI scores at enrollment (4 [2]–[11] vs 2 [0–7], P = 0.03; 4 [1]–[11] vs 2 [0–7], P< 0.0001); 4 [2]–[10] vs 2 [0–6.6], P< 0.0001 and 4 [2–8.2] vs 2 [0–7.0], P = 0.02, respectively). In multivariate analysis, increased beta2-microglobulin, kappa and lambda FLCs were associated with a higher ESSDAI score. Median BAFF and beta2-microglobulin were higher in the 16 patients with history of lymphoma (1173.3(873.1–3665.5) vs 898.9 (715.9–1187.2) pg/ml, P = 0.01 and 2.6 (2.2–2.9) vs 2.1 (1.8–2.6) mg/l, P = 0.04, respectively).
Conclusion
In pSS, higher levels of beta2-microglobulin and free light chains of immunoglobulins are associated with increased systemic disease activity.
doi:10.1371/journal.pone.0059868
PMCID: PMC3663789  PMID: 23717383
9.  miR-346 Controls Release of TNF-α Protein and Stability of Its mRNA in Rheumatoid Arthritis via Tristetraprolin Stabilization 
PLoS ONE  2011;6(5):e19827.
TNF-α is a major cytokine implicated in rheumatoid arthritis. Its expression is regulated both at the transcriptional and posttranscriptional levels and recent data demonstrated that miRNAs are implicated in TNF-α response in macrophages. LPS-activated FLS isolated from RA patients express TNF-α mRNA but not the mature protein. This prompted us to look for miRNAs which could be implicated in this anti-inflammatory effect. Using a microarray, we found two miRNAs, miR-125b and miR-939 predicted to target the 3′-UTR of TNF-α mRNA, to be up-regulated in RA FLS in response to LPS, but their repression did not restore mature TNF-α expression in FLS. We showed previously that miR-346, which is upregulated in LPS-activated FLS, inhibited Btk expression that stabilized TNF-α mRNA. Blocking miR-346 reestablished TNF-α expression in activated FLS. Interestingly, transfection of miR-346 in LPS-activated THP-1 cells inhibited TNF-α secretion. We also demonstrated that TTP, a RNA binding protein which inhibited TNF-α synthesis, is overexpressed in activated FLS and that inhibition of miR-346 decreases its expression. Conversely, transfection of miR-346 in LPS-activated THP-1 cells increased TTP mRNA expression and inhibited TNF-α release. These results indicate that miR-346 controls TNF-α synthesis by regulating TTP expression.
doi:10.1371/journal.pone.0019827
PMCID: PMC3096642  PMID: 21611196
10.  Updated consensus statement on the use of rituximab in patients with rheumatoid arthritis 
Annals of the Rheumatic Diseases  2011;70(6):909-920.
Background
Since initial approval for the treatment of rheumatoid arthritis (RA), rituximab has been evaluated in clinical trials involving various populations with RA. Information has also been gathered from registries. This report therefore updates the 2007 consensus document on the use of rituximab in the treatment of RA.
Methods
Preparation of this new document involved many international experts experienced in the treatment of RA. Following a meeting to agree upon the core agenda, a systematic literature review was undertaken to identify all relevant data. Data were then interrogated by a drafting committee, with subsequent review and discussion by a wider expert committee leading to the formulation of an updated consensus statement. These committees also included patients with RA.
Results
The new statement covers wide-ranging issues including the use of rituximab in earlier RA and impact on structural progression, and aspects particularly pertinent to rituximab such as co-medication, optimal dosage regimens, repeat treatment cycles and how to manage non-response. Biological therapy following rituximab usage is also addressed, and safety concerns including appropriate screening for hepatitis, immunoglobulin levels and infection risk. This consensus statement will support clinicians and inform patients when using B-cell depletion in the management of RA, providing up-to-date information and highlighting areas for further research.
Conclusion
New therapeutic strategies and treatment options for RA, a chronic destructive and disabling disease, have expanded over recent years. These have been summarised in general strategic suggestions and specific management recommendations, emphasising the importance of expedient disease-modifying antirheumatic drug implementation and tight disease control. This consensus statement is in line with these fundamental principles of management.
doi:10.1136/ard.2010.144998
PMCID: PMC3086093  PMID: 21378402
11.  EULAR Sjogren's syndrome disease activity index: development of a consensus systemic disease activity index for primary Sjogren's syndrome 
Annals of the Rheumatic Diseases  2009;69(6):1103-1109.
Objective
To develop a disease activity index for patients with primary Sjögren’s syndrome (SS): the European League Against Rheumatism (EULAR) Sjögren’s Syndrome Disease Activity Index (ESSDAI).
Methods
Thirty-nine SS experts participated in an international collaboration, promoted by EULAR, to develop the ESSDAI. Experts identified 12 organ-specific “domains” contributing to disease activity. For each domain, features of disease activity were classified in 3 or 4 levels according to their severity. Data abstracted from 96 patients with systemic complications of primary SS were used to generate 702 realistic vignettes for which all possible systemic complications were represented. Using the 0–10 physician global assessment (PhGA) scale, each expert scored the disease activity of 5 patient profiles and 20 realistic vignettes. Multiple regression modelling, with PhGA used as the dependent variable, was used to estimate the weight of each domain.
Results
All 12 domains were significantly associated with disease activity in the multivariate model, domain weights ranged from 1 to 6. The ESSDAI scores varied from 2 to 47 and were significantly correlated with PhGA for both real patient profiles and realistic vignettes (r=0.61 and r=0.58, respectively, p<0.0001). Compared to 57 (59.4%) of the real patient profiles, 468 (66.7%) of the realistic vignettes were considered likely or very likely to be true.
Conclusion
The ESSDAI is a clinical index designed to measure disease activity in patients with primary SS. Once validated, such a standardized evaluation of primary SS should facilitate clinical research and should be helpful as an outcome measure in clinical trials.
doi:10.1136/ard.2009.110619
PMCID: PMC2937022  PMID: 19561361
primary Sjogren's syndrome; outcome assessment; systemic features; activity index; clinical vignettes; disease activity
12.  Markers of B-lymphocyte activation are elevated in patients with early rheumatoid arthritis and correlated with disease activity in the ESPOIR cohort 
Arthritis Research & Therapy  2009;11(4):R114.
Introduction
Little is known about systemic B-cell activation in early rheumatoid arthritis (RA). We therefore evaluated the serum levels of markers of B-cell activation in patients included in the ESPOIR early arthritis cohort.
Methods
In the ESPOIR early arthritis cohort (at least 2 swollen joints for more than 6 weeks but less than 6 months), 710 patients were assessed at 1 year and either met the 1987 American College of Rheumatology criteria for RA (n = 578) or had undifferentiated arthritis (n = 132). Baseline serum samples of patients naïve to corticosteroid and disease-modifying antirheumatic drug treatment were assessed for beta2-microglobulin, IgG, IgA, IgM, immunoglobulin free light chains of immunoglobulins, and B-cell activating factor of the tumor necrosis factor family (BAFF). The BAFF gene 871T>C polymorphism was genotyped in all patients.
Results
All markers of B-cell activation except BAFF and IgM were significantly higher in patients with early RA than those with undifferentiated arthritis. Anti-cyclic citrullinated peptide (anti-CCP) and beta2-microglobulin were associated with a diagnosis of early RA in the multivariate analysis. Markers of B-cell activation, except BAFF, were associated with disease activity, rheumatoid factor and anti-CCP secretion. The BAFF gene polymorphism was not associated with early RA.
Conclusions
Markers of B-cell activation are elevated in patients with early RA, compared with undifferentiated arthritis, independently of any systemic increase in BAFF secretion, and correlate with disease activity. This study sheds new light on the early pathogenic role of B-lymphocytes in RA and suggests that targeting them might be a useful therapeutic strategy in early RA.
doi:10.1186/ar2773
PMCID: PMC2745796  PMID: 19627580
13.  Microparticle-induced release of B-lymphocyte regulators by rheumatoid synoviocytes 
Introduction
In the present study, we investigated the ability of microparticles isolated from synovial fluids from patients with rheumatoid arthritis or osteoarthritis to induce the synthesis and release of key cytokines of B-lymphocyte modulation such as B cell-activating factor, thymic stroma lymphopoietin, and secretory leukocyte protease inhibitor by rheumatoid fibroblast-like synoviocytes.
Methods
Microparticles were analyzed in synovial fluids from patients with rheumatoid arthritis, osteoarthritis, microcristalline arthritis, and reactive arthritis. In addition, microparticle release after activation from various cell lines (CEM lymphocyte and THP-1 cells) was assessed. Microparticles were isolated by differential centrifugation, and quantitative determinations were carried out by prothrombinase assay after capture on immobilized annexin V. B cell-activating factor, thymic stroma lymphopoietin, and secretory leukocyte protease inhibitor release was evaluated by enzyme-linked immunosorbent assay.
Results
Microparticles isolated from synovial fluids obtained from rheumatoid arthritis and osteoarthritis patients or microparticles derived from activated THP-1 cells were able to induce B cell-activating factor, thymic stroma lymphopoietin, and secretory leukocyte protease inhibitor release by rheumatoid arthritis fibroblast-like synoviocytes. Conversely, CEM-lymphocytes-derived microparticles generated by treatment with a combination of PHA, PMA and Adt-D did not promote the release of B cell-activating factor but favored the secretion of thymic stroma lymphopoietin and secretory leukocyte protease inhibitor by rheumatoid arthritis fibrobast-like synoviocytes. However, microparticles isolated from actinomycin D-treated CEM lymphocytes were not able to induce B cell-activating factor, thymic stroma lymphopoietin, or secretory leukocyte protease inhibitor release, indicating that microparticles derived from apoptotic T cells do not function as effectors in B-cell activation.
Conclusions
These results demonstrate that microparticles are signalling structures that may act as specific conveyors in the triggered induction and amplification of autoimmunity. This study also indicates that microparticles have differential effects in the crosstalk between B lymphocytes and target cells of autoimmunity regarding the parental cells from which they derive.
doi:10.1186/ar2648
PMCID: PMC2688187  PMID: 19291304
15.  CTLA-4 +49A/G and CT60 gene polymorphisms in primary Sjögren syndrome 
CTLA-4 encodes cytotoxic T lymphocyte-associated antigen-4, a cell-surface molecule providing a negative signal for T-cell activation. CTLA-4 gene polymorphisms have been widely studied in connection with genetic susceptibility to various autoimmune diseases, but studies have led to contradictory results in different populations. This case-control study sought to investigate whether CTLA-4 CT60 and/or +49A/G polymorphisms were involved in the genetic predisposition to primary Sjögren syndrome (pSS). We analysed CTLA-4 CT60 and +49A/G polymorphisms in a first cohort of 142 patients with pSS (cohort 1) and 241 controls, all of Caucasian origin. A replication study was performed on a second cohort of 139 patients with pSS (cohort 2). In cohort 1, the CTLA-4 +49A/G*A allele was found on 73% of chromosomes in patients with pSS, compared with 66% in controls (p = 0.036; odds ratio (OR) 1.41, 95% confidence interval (CI) 1.02 to 1.95). No difference in CTLA-4 CT60 allelic or genotypic distribution was observed between patients (n = 142) and controls (n = 241). In the replication cohort, the CTLA-4 +49A/G*A allele was found on 62% of chromosomes in patients with pSS, compared with 66% in controls (p = 0.30; OR 0.85, 95% CI 0.63 to 1.16). Thus, the CTLA-4 +49A/G*A allele excess among patients from cohort 1 was counterbalanced by its under-representation in cohort 2. When the results from the patients in both cohorts were pooled (n = 281), there was no difference in CTLA-4 +49A/G allelic or genotypic distribution in comparison with controls. Our results demonstrate a lack of association between CTLA-4 CT60 or +49A/G polymorphisms and pSS. Premature conclusions might have been made if a replication study had not been performed. These results illustrate the importance of case-control studies performed on a large number of patients. In fact, sampling bias may account for some contradictory results previously reported for CTLA-4 association studies in autoimmune diseases.
doi:10.1186/ar2136
PMCID: PMC1906800  PMID: 17341301
16.  No evidence for an association between the -871 T/C promoter polymorphism in the B-cell-activating factor gene and primary Sjögren's syndrome 
Polyclonal B cell activation might be related to pathogenic over-expression of B-cell-activating factor (BAFF) in primary Sjögren's syndrome (pSS) and other autoimmune diseases. We therefore investigated whether BAFF over-expression in pSS could be a primary, genetically determined event that leads to the disease. The complete BAFF gene was sequenced in Caucasian pSS patients and control individuals. The only single nucleotide polymorphism frequently observed, namely -871 T/C in the promoter region, was then genotyped in 162 French patients with pSS and 90 French control individuals. No significant differences in allele (T allele frequency: 49.7% in patients with pSS versus 50% in controls; P = 0.94) and genotype frequencies of BAFF polymorphism were detected between pSS patients and control individuals. BAFF gene polymorphism was not associated with a specific pattern of antibody secretion either. T allele carriers had significantly increased BAFF protein serum levels (mean values of 8.6 and 5.7 ng/ml in patients with TT and TC genotypes, respectively, versus 3.3 ng/ml in patients with CC genotype; P = 0.01), although no correlation was observed between BAFF polymorphism and mRNA level. In conclusion, BAFF gene polymorphism is neither involved in genetic predisposition to pSS nor associated with a specific pattern of antibody production.
doi:10.1186/ar1884
PMCID: PMC1526574  PMID: 16507129

Results 1-16 (16)