Systemic involvement in primary Sjogren's syndrome evaluated by the EULAR-SS disease activity index: analysis of 921 Spanish patients (GEAS-SS Registry).

OBJECTIVE: To evaluate systemic involvement in primary SS in a large cohort of Spanish patients using the EULAR-SS disease activity index (ESSDAI) definitions. METHODS: Systemic involvement was characterized using ESSDAI definitions for the 10 clinical domains (constitutional, lymphadenopathy, glandular, articular, cutaneous, pulmonary, renal, peripheral nervous system, central nervous system and muscular). ESSDAI scores at diagnosis, during follow-up and cumulated at the last visit were calculated. RESULTS: The cohort consisted of 921 patients. After a mean follow-up of 75 months, 77 (8%) patients still had an ESSDAI score of zero at the last visit. Organ by organ, the percentage of patients who developed activity during the follow-up (ESSDAI score ≥ 1 at any time) ranged between 1.4% and 56%, with articular, pulmonary and peripheral neurological involvement being the most common. Logistic multivariate regression analysis showed the following features at diagnosis and had the closest association with systemic activity (statistically significant independent variables in at least two domains): cryoglobulinaemia in five domains; anaemia, lymphopenia and low C3 levels in three domains each and age <35 years in two domains. Sicca features, ANA and RF at diagnosis were not associated with a higher cumulated activity score in any clinical domain. CONCLUSION: Primary SS is undeniably a systemic disease, with the joints, lungs, skin and peripheral nerves being the most frequently involved organs. Cytopenias, hypocomplementaemia and cryoglobulinaemia at diagnosis strongly correlated with higher cumulated ESSDAI scores in the clinical domains. Clinically the ESSDAI provides a reliable picture of systemic involvement in primary SS.

Association of the FCGR3A-158F/V gene polymorphism with the response to rituximab treatment in Spanish systemic autoimmune disease patients.

Rituximab is being used as treatment for systemic autoimmune diseases. The objective of this study was to determine whether the genetic variant in the Fc gamma-receptor III a (FCGR3A) gene, 158F/V, contributes to the observed variation in response to rituximab in patients with systemic autoimmune diseases. DNA samples from 132 Spanish patients with different systemic autoimmune diseases receiving rituximab were genotyped for FCGR3A-158F/V (rs396991) gene polymorphism using the TaqMan(®) allelic discrimination technology. Six months after infusion with rituximab we evaluated the response to the drug: 61% of the patients showed a complete response, partial 27% and 12% did not respond to the treatment. A statistically significant difference was observed in V allele frequency between responder (38%) and nonresponder (16%) patients (p=0.01; odds ratio [OR]=3.24, 95% confidence interval [CI] 1.17-11.1). Rituximab was also more effective in V allele carriers (94%) than in homozygous FF patients (81%): p=0.02; OR=3.96, 95% CI 1.10-17.68. These results suggest that FCGR3A-158F/V (rs396991) gene polymorphism play a role in the response to rituximab in autoimmune diseases. Validation of these findings in independent cohorts is warranted.

Association between -174 interleukin-6 gene polymorphism and biological response to rituximab in several systemic autoimmune diseases.

Rituximab has become a pivotal treatment for systemic autoimmune diseases. The aim of this study was to determine whether the genetic variant -174 IL-6 contributes to differences in the response to rituximab in patients with systemic autoimmune diseases, including systemic lupus erythematosus (SLE), inflammatory myopathies, anti-neutrophil cytoplasmic antibody-mediated vasculitis, systemic sclerosis, Sjöegren's syndrome, rheumatoid arthritis, and autoimmune hemolytic anemia. DNA samples from 144 Spanish patients with different systemic autoimmune diseases receiving rituximab were genotyped for -174 IL-6 (rs1800795) gene polymorphism using the TaqMan(®) allelic discrimination technology. Six months after the first infusion with rituximab, we evaluated the response to the drug: 60.4% of the patients showed a complete response, partial 27.8%, and 11.8% did not respond to the treatment. The CC genotype frequency was significantly increased in nonresponders with respect to responders (23.5% vs. 7.1%, respectively; p=0.049; odds ratio (OR)=4.03, 95% confidence intervals (CI) 0.78-16.97). According to the genotype distribution, rituximab was effective in 69.2% of the CC carriers, 91.9% of the CG carriers, and 88.4% of the GG carriers. A similar trend was observed when SLE patients were analyzed separately (27.3% carried CC homozygosis in nonresponders and 6.9% in responders; p=0.066; OR=5.10, 95% CI 0.65-31.73). Rituximab was effective in 62.5% of the CC carriers, 88.9% of the GC carriers, and 90% of the GG carriers. These results suggest that -174 IL-6 (rs1800795) gene polymorphism plays a role in the response to rituximab in systemic autoimmune diseases. Validation of these findings in independent cohorts is warranted.