Rituximab for the treatment of juvenile dermatomyositis: A report of four pediatric patients

Abstract

Juvenile dermatomyositis (DM) is a chronic inflammatory myopathy of childhood primarily affecting the muscles and skin. Treatment for juvenile DM is often difficult, and conventional therapies include corticosteroids and other immune suppressants. We reviewed the records of 4 patients with juvenile DM who received the B cell-depleting anti-CD20 monoclonal antibody rituximab to determine whether this therapy resulted in improved control of their juvenile DM. This is a retrospective review of 4 pediatric patients ages 10-17 years with juvenile DM who were treated with rituximab. All patients were tested for myositis autoantibodies and received weekly rituximab infusions for a total of 4 doses. Two patients received repeat courses of rituximab 1 year after their first dose. Patients were followed up between 12 and 24 months after their first course of rituximab, and their strength, muscle enzymes, and rash were reviewed. One patient was positive for a myositis-specific antibody, anti-Mi-2, and demonstrated striking reductions in her muscle enzyme levels for 1 year after rituximab therapy. Following a second course of rituximab, this patient remained disease free for 14 months before requiring a third course of rituximab. Two myositis antibody-negative patients showed clinical improvement and tolerated lower doses of corticosteroids following treatment with rituximab. Finally, 1 patient had worsening of her disease following rituximab. These cases highlight the potential for anti-B cell therapies in the treatment of juvenile DM in both myositis-specific autoantibody-positive and -negative patients.