Natural history and therapy of 66 patients with mixed cryoglobulinemia.

Cryoglobulinemia, a relatively uncommon disorder, is classified into types I, II, and III, with type II consisting of a monoclonal immunoglobulin possessing activity toward a polyclonal component. Many disease associations and therapies have been described but clinical trials are few, and the natural history, causes, therapy, and pathways of cryoglobulinemia require further investigation. Here, we describe the symptoms, comorbidities, treatments, and response of 66 patients with type II cryoglobulinemia by examining the records of all patients evaluated at Mayo Clinic, Rochester, Minnesota, between 3/2/1994 and 11/27/2000, using our prospective dysproteinemia database. Symptoms varied greatly among patients and during the disease course. Most common were purpura (55% of patients), renal disease (26%), edema (24%), neuropathy (18%), and arthralgia (21%). Renal disease required the most aggressive intervention. Laboratory findings did not correlate with disease manifestations or severity. Only age was a significant predictor of mortality. Ten patients had cryoglobulinemia without an identified comorbidity. Thirty-three patients had viral hepatitis alone, 6 had a lymphoproliferative disorder alone, and 5 had a rheumatologic disease alone. Ten patients had a combination of disorders, such that hepatitis C was identified in a total of 40 patients, lymphoproliferative disorders in 16, and rheumatologic disease in 8. Twenty-two different treatments were administered. Corticosteroids were the most common treatment, followed by interferon with or without ribavirin. Type II cryoglobulinemia is a nonfatal disease most frequently associated with hepatitis C. Treatment is generally directed at the underlying condition. Not all patients require treatment, and many can be followed and treated symptomatically.