Serum tryptophan metabolites are associated with erosive hand osteoarthritis and pain: results from the DIGICOD cohort.

OBJECTIVE: To investigate host and gut-microbiota related Tryptophan metabolism in hand osteoarthritis (HOA). METHODS: The baseline serum concentration of 20 Tryptophan metabolites was measured in 416 HOA patients in a cross-sectional analysis of the DIGICOD cohort. Tryptophan metabolites levels, metabolite-ratios and metabolism pathway activation were compared between erosive (N = 141) and non-erosive HOA (N = 275) by multiple logistic regressions adjusted on age, BMI and sex. The association between Tryptophan metabolite levels and HOA symptoms was investigated by a Spearman's rank correlation analysis. RESULTS: Four serum Tryptophan metabolites, eight metabolite ratios and one metabolism pathway were associated with erosive HOA. Erosive HOA was negatively associated with Tryptophan (odds ratio (OR) = 0.41, 95% confidence interval [0.24-0.70]), indole-3-aldehyde (OR = 0.67 [0.51-0.90]) and 3-OH-anthranilic acid (OR = 1.32 [1.13-1.54]) and positively with 5-OH-Tryptophan levels (OR = 1.41 [1.13-1.77]). The pro-inflammatory kynurenine-indoleamine 2,3-dioxygenase pathway was upregulated in erosive HOA (OR = 1.60 [1.11-2.29]). Eleven metabolites were correlated with HOA symptoms and were mostly pain-related. Serotonin and N-acetyl serotonin levels were negatively correlated with number of tender joints. Indole-3-aldehyde level was negatively correlated and 3-OH-anthranilic acid, 3-OH-kynurenine and 5-OH-Tryptophan levels were positively correlated with number of patients-reported painful joints. Quinolinic acid and 3-OH-kynurenine levels correlated positively with AUSCAN pain. CONCLUSIONS: Tryptophan metabolites disturbance is associated with erosive HOA and pain and emphasize the role of low-grade inflammation and gut dysbiosis in HOA.

Serum carboxymethyllysine concentration is associated with erosive hand osteoarthritis.

OBJECTIVE: Carboxymethyllysine (CML) and homocitrulline (HCit) are the products of two non-enzymatic post-translational modifications of protein, a process related to age. We investigated whether serum CML and HCit concentrations were associated with hand osteoarthritis (HOA), especially erosive HOA. DESIGN: Serum CML and HCit were measured by using liquid chromatography coupled with tandem mass spectrometry at inclusion in 386 patients included in the DIGItal Cohort Design (DIGICOD) cohort. We investigated whether serum CML and/or HCit concentrations were associated with erosive HOA or with HOA clinical and radiological features. Moreover, we compared the tissular concentrations of CML and HCit in OA and non-OA cartilage from proximal interphalangeal and metacarpo-phalangeal (MCP) joints from human cadaveric donors. RESULTS: Median (IQR) serum CML concentration was lower in patients with erosive HOA than those with non-erosive HOA (178.7 [157.1-208.8] vs 194.7 [168.9-217.1] µmol/mol Lys, P = 0.002), but median HCit concentration did not differ between the groups (193.9 [162.9-232.0] vs 193.9 [155.9-224.6] µmol/mol Lys). Cartilage HCit and CML concentrations were not correlated with clinical features. Serum CML concentration was higher in OA than non-OA MCPs (7.0 vs 4.0 mmol/mol Lys, P = 0.01). CONCLUSIONS: Serum CML concentration was lower in erosive HOA than non-erosive HOA, and cartilage CML concentration was higher in OA than non-OA cartilage. These results encourage further studies to test whether serum CML could be a new prognostic biomarker in HOA.

Dunnigan lipodystrophy syndrome: French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins).

Dunnigan syndrome, or Familial Partial Lipodystrophy type 2 (FPLD2; ORPHA 2348), is a rare autosomal dominant disorder due to pathogenic variants of the LMNA gene. The objective of the French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins), is to provide health professionals with a guide to optimal management and care of patients with FPLD2, based on a critical literature review and multidisciplinary expert consensus. The PNDS, written by members of the French National Reference Center for Rare Diseases of Insulin Secretion and Insulin Sensitivity (PRISIS), is available on the French Health Authority website (in French). Dunnigan syndrome is characterized by a partial atrophy of the subcutaneous adipose tissue and by an insulin resistance syndrome, associated with a risk of metabolic, cardiovascular and muscular complications. Its prevalence, assessed at 1/100.000 in Europe, is probably considerably underestimated. Thorough clinical examination is key to diagnosis. Biochemical testing frequently shows hyperinsulinemia, abnormal glucose tolerance and hypertriglyceridemia. Elevated hepatic transaminases (hepatic steatosis) and creatine phosphokinase, and hyperandrogenism in women, are common. Molecular analysis of the LMNA gene confirms diagnosis and allows for family investigations. Regular screening and multidisciplinary monitoring of the associated complications are necessary. Diabetes frequently develops from puberty onwards. Hypertriglyceridemia may lead to acute pancreatitis. Early atherosclerosis and cardiomyopathy should be monitored. In women, polycystic ovary syndrome is common. Overall, the management of patients with Dunnigan syndrome requires the collaboration of several health care providers. The attending physician, in conjunction with the national care network, will ensure that the patient receives optimal care through regular follow-up and screening. The various elements of this PNDS are described to provide such a support.

The cholinergic system in joint health and osteoarthritis: a narrative-review.

Osteoarthritis (OA) poses a major health and economic burden worldwide due to an increasing number of patients and the unavailability of disease-modifying drugs. In this review, the latest understanding of the involvement of the cholinergic system in joint homeostasis and OA will be outlined. First of all, the current evidence on the presence of the cholinergic system in the normal and OA joint will be described. Cholinergic innervation as well as the non-neuronal cholinergic system are detected. In a variety of inflammatory diseases, the classic cholinergic anti-inflammatory pathway lately received a lot of attention as via this pathway cholinergic agonists can reduce inflammation. The role of this cholinergic anti-inflammatory pathway in the context of OA will be discussed. Activation of this pathway improved the progression of the disease. Secondly, chondrocyte hypertrophy plays a pivotal role in osteophyte formation and OA development; the impact of the cholinergic system on hypertrophic chondroblasts and endochondral ossification will be evaluated. Cholinergic stimulation increased chondrocyte proliferation, delayed chondrocyte differentiation and caused early mineralisation. Moreover, acetylcholinesterase and butyrylcholinesterase affect the endochondral ossification via an acetylcholine-independent pathway. Thirdly, subchondral bone is critical for cartilage homeostasis and metabolism; the cholinergic system in subchondral bone homeostasis and disorders will be explored. An increase in osteoblast proliferation and osteoclast apoptosis is observed. Lastly, current therapeutic strategies for OA are limited to symptom relief; here the impact of smoking on disease progression and the potential of acetylcholinesterase inhibitors as candidate disease-modifying drug for OA will be discussed.

Identification of TGFß signatures in six murine models mimicking different osteoarthritis clinical phenotypes.

OBJECTIVE: TGFß is a key player in cartilage homeostasis and OA pathology. However, few data are available on the role of TGFß signalling in the different OA phenotypes. Here, we analysed the TGFß pathway by transcriptomic analysis in six mouse models of OA. METHOD: We have brought together seven expert laboratories in OA pathophysiology and, used inter-laboratories standard operating procedures and quality controls to increase experimental reproducibility and decrease bias. As none of the available OA models covers the complexity and heterogeneity of the human disease, we used six different murine models of knee OA: from post-traumatic/mechanical models (meniscectomy (MNX), MNX and hypergravity (HG-MNX), MNX and high fat diet (HF-MNX), MNX and seipin knock-out (SP-MNX)) to aging-related OA and inflammatory OA (collagenase-induced OA (CIOA)). Four controls (MNX-sham, young, SP-sham, CIOA-sham) were added. OsteoArthritis Research Society International (OARSI)-based scoring of femoral condyles and ribonucleic acid (RNA) extraction from tibial plateau samples were done by single operators as well as the transcriptomic analysis of the TGFß family pathway by Custom TaqMan® Array Microfluidic Cards. RESULTS: The transcriptomic analysis revealed specific gene signatures in each of the six models; however, no gene was deregulated in all six OA models. Of interest, we found that the combinatorial Gdf5-Cd36-Ltbp4 signature might discriminate distinct subgroups of OA: Cd36 upregulation is a hallmark of MNX-related OA while Gdf5 and Ltbp4 upregulation is related to MNX-induced OA and CIOA. CONCLUSION: These findings stress the OA animal model heterogeneity and the need of caution when extrapolating results from one model to another.

[Therapeutic strategy for the treatment of non-infectious uveitis proposed by an expert panel]. / Avis d'experts pour le traitement des uvéites non infectieuses.

Conventional immunosuppressive drugs, anti-TNF alpha and other biotherapies used in clinical practice are capable of controlling non-infectious anterior uveitis, posterior uveitis and panuveitis. The present work has been led by a multidisciplinary panel of experts, internists, rheumatologists and ophthalmologists and is based on a review of the literature. In case of corticodependency or sight-threatening disease, conventional immunosuppressive drugs (methotrexate, azathioprine and mycophenolate mofetil) and/or anti-TNF alpha (adalimumab, infliximab) are used to achieve and maintain remission. Interferon is an efficient immunomodulatory treatment, as a second-line therapy, for some therapeutic indications (refractory macular edema, Behçet's vascularitis). Other biologics, especially tocilizumab, are showing promising results. Local treatments (corticosteroids, sirolimus etc.) are adjuvant therapies in case of unilateral inflammatory relapse. Therapeutic response must be evaluated precisely by clinical examination and repeated complementary investigations (laser flare photometry, multimodal imaging, perimetry, electroretinography measures).

[Uveitis: Diagnostic work-up. Recommendations from an expert committee]. / Prise en charge diagnostique des uvéites : recommandations d'un groupe d'experts.

INTRODUCTION: Diagnostic work-up of uveitis involves many uncertainties. Search for an etiology should take into account the epidemiology of uveitis and focus on the most severe diseases or those, which can be treated. This work was undertaken to establish recommendations for the diagnosis work-up of uveitis. METHODS: Recommendations were developed by a multidisciplinary panel of 15 experts, including internists, ophthalmologists and a rheumatologist and are based on a review of the literature with regard to effectiveness of investigations and the results of the ULISSE study, which is the first prospective study assessing the efficiency of a standardized strategy for the etiological diagnosis of uveitis. Children, immunocompromised patients, severe retinal vasculitis and specific ophthalmological entities are excluded from these recommendations. RESULTS: Investigations should be first guided by the history and physical examination. Serological screening for syphilis is the only test appropriate in all forms of uveitis. If no diagnosis is made after this stage, we propose investigations guided by the anatomic characteristics of uveitis. It includes HLA B27 testing (in unilateral acute anterior non-granulomatous uveitis), serum angiotensin converting enzyme, interferon-gamma release assay and chest CT (chronic uveitis), cerebral MRI and anterior chamber tap with IL10 analysis (intermediate or posterior uveitis in patients over 40 years). Investigations ordered in the absence of orientation are almost always unhelpful. CONCLUSIONS: We propose a strategy for the etiologic diagnosis of uveitis. The recommendations should be updated regularly. The efficiency of more invasive investigations has yet to be evaluated.

Economic impact of lower-limb osteoarthritis worldwide: a systematic review of cost-of-illness studies.

OBJECTIVE: An overview of the economic consequences - overall costs as well as cost breakdown (direct and indirect) - of hip and knee osteoarthritis (OA) worldwide. METHODS: A systematic literature search of EMBASE, MEDLINE, Scopus and Cochrane databases for articles was performed independently by two rheumatologists who used the same predefined eligible criteria. Papers without abstracts and in languages other than English or French were excluded. Extracted costs were converted to an annual cost and to 2013 euros (€) by using the Consumer Price Index of the relevant countries and the 2013 Purchasing Power Parities between these countries and the European Union average. RESULTS: A total of 45 abstracts were selected, and 32 articles were considered for the review. The studied populations were heterogeneous: administrative, hospital and national health survey data. Annual total costs per patient ranged from 0.7 to 12 k€, direct costs per patient from 0.5 to 10.9 k€ and indirect costs per patient from 0.2 to 12.3 k€. The weighted average annual costs per patient living with knee and hip OA were 11.1, 9.5 and 4.4 k€ for total, direct and indirect costs, respectively. CONCLUSIONS: This review highlights the heterogeneity of studies and lack of methodologic consensus to obtain reliable cost-of-illness estimates for lower-limb OA. However, costs induced by the disease seem substantial and deserve to be more extensively explored.

Body mass index and response to tocilizumab in rheumatoid arthritis: a real life study.

Several studies have suggested that obesity could have a negative effect on response to anti-tumor necrosis factor α (anti-TNFα) in rheumatoid arthritis (RA). Little is known about the impact of body mass index (BMI) on other biologic agents. We aimed to evaluate the effect of BMI on response to tocilizumab (TCZ) in RA. RA patients treated with TCZ were included in this multicenter retrospective study. BMI was calculated at the initiation of treatment. After 6 months of treatment, change from baseline in DAS28, pain on a visual analog scale, erythrocyte sedimentation rate and C-reactive protein level, and tender and swollen joints were analyzed. The primary endpoint was decrease in DAS28 ≥ 1.2. Secondary outcomes were good response and remission by EULAR criteria. At baseline, among 115 RA patients included, the median (interquartile range) BMI was 25.4 (22.0-28.8) kg/m(2). The number of patients with normal weight, overweight, and obesity was 53 (46 %), 37 (32 %), and 25 (22 %), respectively. Baseline characteristics did not differ between the three subgroups of BMI. The median BMI did not differ between responders and non-responders for DAS28 decrease ≥1.2 (25.7 [22.1-29.9] vs 24.9 [22.0-27.1], P = 0.38), EULAR good response (25.9 [22.8-30.0] vs 25.4 [22.0-28.4], P = 0.61), and remission (25.1 [22.5-28.6] vs 25.4 [22.0-28.9], P = 0.76). BMI did not affect the response to TCZ in RA. If confirmed, these results could be helpful for the selection of a biologic agent in obese RA patients.

Metabolic stress-induced joint inflammation and osteoarthritis.

Osteoarthritis (OA) is a heterogeneous disorder with several risk factors. Among them, obesity has a major impact on both loading and non-loading joints. Mechanical overload and activity of systemic inflammatory mediators derived from adipose tissue (adipokines, free fatty acids (FFA), reactive oxygen species (ROS)) provide clues to the increased incidence and prevalence of OA in obesity. Recently, research found greater OA prevalence and incidence in obese patients with cardiometabolic disturbances than "healthy" obese patients, which led to the description of a new OA phenotype - metabolic syndrome (MetS)-associated OA. Indeed, individual metabolic factors (diabetes, dyslipidemia, and hypertension) may increase the risk of obesity-induced OA. This review discusses hypotheses based on pathways specific to a metabolic factor in MetS-associated OA, such as the role of advanced glycation end products (AGEs) and glucose toxicity. A better understanding of these phenotypes based on risk factors will be critical for designing trials of this specific subset of OA.

Determinants of hydroxychloroquine blood concentration variations in systemic lupus erythematosus.

OBJECTIVE: Blood concentrations of hydroxychloroquine (HCQ) vary widely among patients with systemic lupus erythematosus (SLE). A pharmacokinetic/pharmacodynamic relationship has been found in different situations, and a very low blood concentration of HCQ is a simple marker of nonadherence to treatment. Therefore, interest in blood HCQ concentration measurement has increased, but little is known about factors that influence blood HCQ concentration variability. This study was undertaken to analyze determinants of blood HCQ concentrations. METHODS: We conducted a retrospective analysis of patient data, including data from the Plaquenil Lupus Systemic (PLUS) study, to determine the association of epidemiologic, clinical, and biologic factors with blood HCQ concentrations. Data for nonadherent patients (blood HCQ concentration <200 ng/ml) were excluded. RESULTS: To examine homogeneous pharmacologic data, we restricted the analyses of the PLUS data to the 509 SLE patients receiving 400 mg/day. We found no association of ethnicity or smoking with blood HCQ concentrations and no pharmacokinetic drug-drug interaction with antacids or with inhibitors or inducers of cytochrome P450 enzymes. On multivariate analysis, high body mass index (P = 0.008), no treatment with corticosteroids (P = 0.04), increased time between the last tablet intake and measurement of blood HCQ concentrations (P = 0.017), low platelet count (P < 0.001), low neutrophil count (P < 0.001), and high estimated creatinine clearance (P < 0.001) were associated with low blood HCQ concentrations. In 22 SLE patients with chronic renal insufficiency (median serum creatinine clearance 52 ml/minute [range 23-58 ml/minute]) who received 400 mg/day HCQ, the median blood HCQ concentration was significantly higher than that in the 509 patients from the PLUS study (1,338 ng/ml [range 504-2,229 ng/ml] versus 917 ng/ml [range 208-3316 ng/ml]) (P < 0.001). CONCLUSION: We provide a comprehensive analysis of determinants of blood HCQ concentrations. Because this measurement is increasingly being used, these data might be useful for clinicians.

Characterization of diabetic osteoarthritic cartilage and role of high glucose environment on chondrocyte activation: toward pathophysiological delineation of diabetes mellitus-related osteoarthritis.

OBJECTIVE: To examine the relationship between osteoarthritis (OA) and type 2 diabetes mellitus (DM). METHODS: OA cartilage from DM and non-DM patients undergoing knee replacement were stimulated by IL-1ß for 24 h and release of interleukin-6 (IL-6) and prostaglandin E2 (PGE2) was measured. Primary cultured murine chondrocytes were stimulated for 24 and 72 h with or without IL-1ß (5 ng/mL) under normal-glucose (5.5 mM) or high-glucose (25 mM) conditions. The expression and release of pro-inflammatory mediators (IL-6, cyclooxygenase 2 [COX2]/PGE2) were analyzed by quantitative RT-PCR and ELISA/EIA. Glucose uptake was assessed with ((14)C)-2-deoxyglucose. Reactive oxygen species (ROS) and nitric oxide (NO) production were measured. To analyze the mechanism of IL-1ß-induced inflammation, cells were pretreated or treated with inhibitors of glucose transport (cytochalasin B), the polyol pathway (epalrestat), mitochondrial oxidative stress (MitoTEMPO) or nitric oxide synthase (l-NAME). RESULTS: With IL-1ß stimulation, IL-6 and PGE2 release was greater in human DM than non-DM OA cartilage (2.7- and 3-fold, respectively) (P < 0.05). In vitro, with IL-1ß stimulation, IL-6 and COX2 mRNA expression, IL-6 and PGE2 release, and ROS and NO production were greater under high-than normal-glucose conditions in cultured chondrocytes. IL-1ß-increased IL-6 release was reduced with cytochalasin B, epalrestat, L-NAME or MitoTEMPO treatment (-45%, -62%, -38% and -40%, respectively). CONCLUSION: OA cartilages from DM patients showed increased responsiveness to IL-1ß-induced inflammation. Accordingly, high glucose enhanced IL-1ß-induced inflammation in cultured chondrocytes via oxidative stress and the polyol pathway. High glucose and diabetes may thus participate in the increased inflammation in OA.

Safety of surgery after rituximab therapy in 133 patients with rheumatoid arthritis: data from the autoimmunity and rituximab registry.

OBJECTIVE: We used data from the AutoImmunity and Rituximab (AIR) registry to investigate the safety of surgery for patients with rheumatoid arthritis receiving rituximab (RTX) in routine care. METHODS: Data for patients included in the AIR registry and undergoing surgery during the year following an infusion of RTX were reviewed to describe the frequency of postsurgical complications, compare patients with and without complications, and identify factors associated with complications. RESULTS: We examined data for 133 patients with a known date of surgery and at least 1 followup visit, corresponding to 140 procedures, including 94 orthopedic surgeries (67%) and 23 abdominal surgeries (16.5%). The median delay between surgery and the last RTX infusion was 6.4 months (interquartile range 4.3­ 8.7 months), without any difference between patients with and without complications. Nine patients (6.7%) experienced 12 complications (8.5%), including 8 surgical site infections (5.7%) and 1 death due to septic shock. Postoperative complications occurred after 4.3% of abdominal surgeries (1 of 23) and 7.4% of orthopedic surgeries (7 of 95). On univariate analysis, spine surgery was associated with postoperative complications (P = 0.048). CONCLUSION: In common practice, the risk of complications may be more important in case of spine surgery, but does not seem to be linked to the time between the last RTX infusion and surgery.

Rituximab therapy for systemic vasculitis associated with rheumatoid arthritis: Results from the AutoImmunity and Rituximab Registry.

OBJECTIVE: Rituximab improves articular symptoms in rheumatoid arthritis (RA) and it recently has been shown to be an effective induction therapy for antineutrophil cytoplasmic antibody-associated vasculitis. We assessed the efficacy and safety of rituximab in a real-life clinical setting among patients with systemic rheumatoid vasculitis (SRV). METHODS: We analyzed data from the AutoImmunity and Rituximab registry, which includes patients with autoimmune diseases treated with rituximab. RESULTS: Of the 1,994 patients with RA enrolled in the registry, 17 were treated with rituximab for active SRV. At baseline, the mean Birmingham Vasculitis Activity Score for RA (BVAS/RA) was 9.6, with a mean prednisone dosage of 19.2 mg/day. After 6 months of rituximab therapy, 12 patients (71%) achieved complete remission of their vasculitis, 4 had a partial response, and 1 died with uncontrolled vasculitis. Mean BVAS/RA was reduced to 0.6 and mean prednisone dosage to 9.7 mg/day. At 12 months, 14 patients (82%) were in sustained complete remission. Severe infection occurred in 3 patients, corresponding to a 6.4 per 100 patient-years rate. In the 6 patients who received further rituximab as maintenance therapy between months 6 and 12, no relapse of vasculitis was observed. However, among the 9 patients who did not, a relapse was observed in 3 patients who were treated with methotrexate alone. Remission was reestablished by reintroducing rituximab in 2 cases. CONCLUSION: Complete remission of SRV was achieved in nearly three-fourths of patients receiving rituximab in daily practice, with a significant decrease in daily prednisone dosage and an acceptable toxicity profile. Rituximab represents a suitable therapeutic option to induce remission in SRV, but maintenance therapy seems to be necessary.

Posterior reversible encephalopathy syndrome during systemic lupus erythematosus: four new cases and review of the literature.

Posterior reversible encephalopathy syndrome (PRES) associates various neurological manifestations (headaches, seizures, altered mental status, cortical blindness, focal neurological deficits, vomiting) and transient changes on neuroimaging consistent with cerebral edema. Posterior reversible encephalopathy syndrome mainly occurs in the setting of hypertension, eclampsia, renal failure and/or use of immunosuppressive drugs. We report four cases of PRES complicating systemic lupus erythematosus (SLE). In all our cases, renal involvement and hypertension were present. Neurological symptoms were typical. Magnetic resonance imaging showed posterior cerebral edema and in one case hemorrhagic complication. With symptomatic treatment and immunosuppressor withdrawal when they were previously used, symptoms fully resolved within 15 days in all cases, but one who had only partial regression related to cerebral hemorrhage. Including our cases, we reviewed a total of 46 patients with SLE and PRES. Their clinical and radiological presentation was not specific. The peculiar role of SLE itself in the occurrence of PRES was not clear, since hypertension (95%), renal involvement (91%), recent onset of immunosuppressive drugs (54%) and/or recent treatment with high intravenous dose of steroids (43%) were often present. The hypertension and other worsening factors should be treated. Finally, the evolution of this clinical and radiological spectacular syndrome is generally rapidly favorable.

Is Inhibitor of differentiation 3 involved in human primary Sjögren's syndrome?

OBJECTIVES: Inhibitor of differentiation 3 (Id3)-deficient mice show sicca symptoms, lymphocyte infiltration of exocrine glands and positive anti-Ro/SSA and anti-La/SSB antibodies, all hallmarks of primary Sjögren's syndrome (pSS). The impairment of Id3 in T cells and, possibly, in salivary glandular epithelial cells (SGECs) seems to be involved. This animal model prompted us to investigate the role of Id3 in human pSS. METHODS: Quantitative Id3 expression in peripheral T cells, cultured SGECs and in total minor salivary glands was assessed by RT-PCR in pSS patients and controls. After Id3 sequencing, we investigated two single nucleotide polymorphisms (SNPs) (c.313G>A and g.-156A>G) in a case-control study of 212 Caucasian pSS patients and 168 controls. RESULTS: Quantitative Id3 expression was not decreased in pSS patients nor in SGECs, in T cells or in minor salivary glands. As well, patients and controls did not differ in allele and genotype frequencies of Id3 SNPs (P = 0.67 and P = 0.71 for the c.313G>A and the g.-156A>G, respectively). Neither SNP was associated with a pattern of autoantibody secretion. CONCLUSION: Although the Id3-deficient mouse model represents an attractive model for human pSS, Id3 expression is not impaired in SGECs, peripheral T cells and in labial salivary glands in pSS patients and Id3-relevant SNPs do not give evidence of genetic predisposition in Caucasian pSS patients.

B-cell activating factor of the tumour necrosis factor family expression in blood monocytes and T cells from patients with primary Sjögren's syndrome.

We investigated B-cell activating factor of the tumour necrosis factor family (BAFF) level in peripheral blood mononuclear cells (PBMCs), monocytes and T cells from patients with primary Sjögren's syndrome (pSS) and controls both ex vivo and in vitro after cytokine stimulation. PBMCs, monocytes and T cells were isolated from 15 patients with pSS and 17 controls. Cells were cultured alone or with interferon (IFN)alpha, IFNgamma and interleukin 10 (IL-10). T cells were stimulated with phytohaemagglutin and anti-CD3. BAFF protein was assessed by enzyme-linked immunosorbent assay. Ex vivo, no difference was observed in BAFF mRNA level in PBMCs and monocytes from patients and controls. Blood monocytes were the main cell type secreting BAFF both in patients and controls. In vitro, after IFNalpha stimulation, BAFF mRNA level was significantly higher in cells from patients than from controls (63.8 versus 20.7, P = 0.03). T cells from patients secreted a higher level of BAFF protein than those from healthy donor cells (17.4 versus 2.9 pg/ml, respectively, P = 0.04) but at a lower level than that from monocytes. Stimulation of T cells did not change BAFF secretion level. The induction of Th17 cells showed no increased BAFF expression. In conclusion, similar to epithelial cells, blood monocytes in patients with pSS show increased production of BAFF under IFNalpha, which confirms the involvement of IFNalpha in pSS. BAFF expression is also increased in blood T cells of such patients, independently of T-cell stimulation.