Tolerance and efficacy of rituximab and changes in serum B cell biomarkers in patients with systemic complications of primary Sjogren's syndrome

Objective: To investigate the safety and efficacy of rituximab (RTX) for systemic symptoms in patients with primary Sjogren'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, gamma-globulin and beta 2-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.