Response to rituximab in patients with type II cryoglobulinemia.

Type II cryoglobulinemia (CG) is a heterogeneous, generally indolent disorder caused by a monoclonal antibody with activity against polyclonal antibodies and is commonly associated with hepatitis C, lymphoproliferative disorders (LPDs), or autoimmune diseases. It can lead to substantial morbidity, including renal failure, cutaneous ulcers, or neuropathy. Medical records were reviewed for 8 patients with previously treated symptomatic CG who were part of a prospectively held dysproteinemia database. Patients subsequently received 14 total courses of rituximab treatment (standard infusion, 375 mg/m2 for 4 or 8 doses) between February 1999 and March 2005. One patient had essential CG, and 1 had Gaucher disease with hypersplenism. Six patients had an LPD, and 4 of them had concomitant disorders (2 with hepatitis C and 2 with Sjogren syndrome). Treatment indications included purpura, LPD, cutaneous ulcers, and renal failure. Clinical improvement was evaluated by improved cryocrit, total complement, C4, and rheumatoid factor. Six patients had some clinical improvement. Cutaneous manifestations were the most responsive; renal disease and lymphoma were more refractory. Laboratory values showed improvement after 7 of 12 available treatment courses. No adverse reactions were noted. Overall, rituximab appears to be a safe and effective therapy.