Rituximab as a first-line agent for the treatment of dermatomyositis

Abstract

B cells may play a pivotal role in the pathophysiology of DM, and reports have claimed that targeting B cells is a viable treatment option in patients with dermatomyositis. A 20-year-old girl presented in October 2007, with few weeks' history of proximal muscle weakness. Gottron's papules were noted on her knuckles. She had normal inflammatory markers and negative autoantibody screen. Her CPK was 7,000 U/L (normal range 0-170) with an LDH of 1,300 U/L (normal range 266-500). EMG and muscle biopsy was consistent with active myositis. She had normal pulmonary function tests. HRCT showed no interstitial lung disease. She was started with 60 mg glucocorticoids (1 mg/kg), with a good clinical response. However, any attempt to taper down the steroid dose led to recurrence of her symptoms. The options of available immunosuppressive therapies, including the experimental usage of rituximab, were discussed with her; averse to long-term systemic treatments, she opted to try a course of rituximab. She had rituximab 1,000 mg on days 0 and 14, and her glucocorticoids were tapered in next few weeks. Now, 24 months since her rituximab infusions, she remains in complete clinical and biochemical remission and is naïve to other immunosuppressive agents apart from glucocorticoids and rituximab. Depleting peripheral B cells with rituximab (one course) in our patient has led not only to complete resolution of muscle and skin disease (induction) but also remains off all immunosuppressives including glucocorticoids.