Background: Cryoglobulinemia(CG) is a relatively uncommon disorder which has been recognized as a syndrome for nearly forty years. The further classification into types I, II, and III was established thirty years ago, with Type II consisting of a monoclonal immunoglobulin possessing activity towards a polyclonal component. In the interim, many disease associations have been described and various therapies tried, but clinical trials remain rare, and the natural history, causes, and pathways of CG require further investigation.
Methods: We examined the records of all patients seen at the Mayo Clinic, Rochester, with Type II CG between 3/2/1994 and 11/27/2000 using a prospectively held dysproteinemia database.
Results: Of 66 total patients 30 were male(45%) and 36 were female(55%) with mean ages of 52.7±11.0 and 60.9±12.6, respectively. 63 patients were Caucasian, with one each of African, Hispanic, and other. 34 patients(52%) presented with purpura, 16 with edema(24%), 12 with neuropathy(18%), 12 with fatigue, 10 with arthralgia(15%), 8 with weight loss(12%), 5 with livido reticularis(8%), 4 with leg ulcers(6%), and 2 with infarcted extremities(2%). Of our patients, 13 had Type II CG (20%) unassociated with infection or lymphoma. 38 patients(58%) had hepatitis C(HCV), of whom 12 underwent genotyping with 10 having genotype 1a or 1b and 2 having genotype 2a or 2b. No patients had isolated Hepatitis B(HBV) though 8 HCV patients were coinfected with HBV. One patient each had CMV and EBV. 7 patients(10%) had Sjogren’s disease, and 1 had scleroderma. 11 patients (17%) had a lymphoproliferative disorder (LPD), and 5 more went on to develop LPD. Of these, 7 patients had a B-cell LPD, 4 had a MALT lymphoma, 4 had a non specific LPD, one had a lymphoplasmacytic lymphoma, and one had Gaucher’s thrombocytopenia. Significant renal disease developed in 23 patients(35%), with 12 being membranoproliferative glomerulonephritis (18%) and 3 being mesangioproliferative glomerulonephritis. Pertinent laboratory finding included a mean cryocrit of 7.6%±12.5, a positive rheumatoid factor in 36 out of 36, and hypocomplementemia in 33 of 41(80%). Liver function testing was reflective of the patient’s hepatitis status. Serum electrophoresis in 48 patients revealed the following patterns: 22 were normal(46%), 15 had a γ peak(31%), 5 polyclonal patterns(10%), 5 hypogammaglobulinemia, and one a β-γ peak. Of 32 samples where a monoclonal antibody was isolated 29 were IgM (91%), and 3 IgG (9%). The light chains were 88% κ, with 12% λ. Treatment was generally guided by the comorbidities, and many (30%) required no specific treatment for Type II CG. In the 38 HCV patients, 17 received interferon with or without ribavirin and 18 were deemed not to need treatment, while 2 received steroids alone and 1 was lost to follow up. In 28 patients without HCV 20 received steroids(71%), while 5 received other treatments and 3 were untreated. Of 46 patients who received any treatment, 27 (59%) achieved no response or had disease progression and required a change in therapy. To date, 8 patients have died, with none of deaths specifically attributable to complications of cryoglobulinemia.
Conclusion: Type II CG is a non fatal disease most frequently associated with HCV. Optimal disease specific treatment is as yet undefined, and is generally directed at the underlying comorbidity when possible. Not all cases require treatment and many can be followed symptomatically.