Objective: There is evidence to support a dominant role for B cells in the pathophysiology of primary Sjögren's syndrome (SS). Therefore, we evaluated the safety and efficacy of anti-CD20 monoclonal antibody.
Methods: Sixteen patients who met the new American-European Consensus Group criteria for primary SS and scored >50 on at least 2 of 4 visual analog scales (VAS; 100 mm) evaluating global disease, pain, fatigue, and global dryness received infusions of low-dose rituximab (375 mg/m(2)) at weeks 0 and 1 without steroid premedication.
Results: Slow rituximab infusions (100 mg/hour) were well tolerated, with only 1 patient experiencing serum sickness-like disease. There was a dramatic reduction in B cells of the blood and salivary gland (SG). At week 12, VAS scores with respect to fatigue and dryness (P < 0.05), tender point count (P < 0.035), and quality of life as evaluated by the Short Form 36 questionnaire (SF-36; P < 0.001) were significantly improved. At week 36, significant improvements were noted in the 4 VAS scores (P < 0.05), tender joint count (P = 0.017), tender point count (P = 0.027), and SF-36 (P < 0.03). Pulmonary manifestations were ameliorated in 1 patient. Patients with improvements on at least 3 of the 4 VAS scores at any visit (n = 11) had a shorter disease duration than the other patients (n = 5; mean +/- SD duration 3.8 +/- 5.4 versus 30.1 +/- 29.5 years; P = 0.02).
Conclusion: Low-dose rituximab infusions were well tolerated without the benefit of steroids. Infusions induced a rapid depletion of B cells in the blood and SG and could improve primary SS. Controlled studies are needed.