Response to Rituximab in Type II Cryoglobulinemia.

Introduction: Type II Cryoglobulinemia (CG) is a heterogeneous disorder caused by a monoclonal antibody with activity against polyclonal antibodies. No standard therapy exists, but two small recent studies have suggested a role for rituximab. We describe our experience with 8 patients with Type II CG who were treated with Rituximab.

Methods: The data was obtained from a prospectively held dysproteinemia database and by directly reviewing patient records. Follow up time ranged from 7 to 63 months. All patients had symptomatic disease with a monoclonal IgMκ Type II cryoglobulin and had undergone previous therapy for CG.

Results: Six of the patients had an underlying lymphoproliferative disorder (LPD), with two of these also having hepatitis C, and two others having Sjogren syndrome. One patient had essential CG and one had Gaucher disease with hyperslpenism. A total of 14 courses of treatment were given, as some patients received rituximab on multiple occasions. Five patients received rituximab either alone or with low dose prednisone initially, with one of these later receiving rituximab with cyclophosphamide and prednisone. One patient was treated initially with R-CHOP and subsequently with rituximab alone, one received rituximab with chlorambucil and prednisone, and one received rituximab with plasma exchange and prednisone. The patients were treated for a variety of indications including cutaneous ulcers, progressive renal failure, the underlying LPD, and biochemical recurrence of disease. Six of 8 patients experienced an improvement in their clinical status. Of the two patients who did not improve, one had end stage liver disease at the time of rituximab and died 2 years later, and the other had a progressive chronic B cell lymphoproliferative disorder leading to sepsis and death. Though lab values were not available on one patient, 4 of the remaining 7 demonstrated improvement in cryocrit, total complement, C4, and/or rheumatoid factor. The lab values correlated well with the clinical response, as treatment failures showed no laboratory changes. Cutaneous manifestations including rash and ulceration were the most responsive to treatment. Renal disease generally failed to improve, and the response of LPDs were variable. No adverse events associated with rituximab were reported, including no flares of hepatitis.

Conclusion: The high prevalence of LPD associated cryoglobulinemia distinguishes our results from the previous studies which had focused on patients with hepatitis C. Given the lack of any cryoglobulinemia specific therapy, and the potential toxicity of other immunosuppressive or anti viral therapies, rituximab remains a reasonable, safe, and effective therapeutic choice.