Rheumatoid Factor, Complement, and Mixed Cryoglobulinemia
Figure 2
Total hemolytic complement activity was determined after reconstitution of varied molar ratios of separated IgM and IgG from two type 2 cryoglobulins (Vi; Bu). Separated IgM was 100% monoclonal IgMk with RF activity; the IgG fraction had immunoblot reactivity to multiple HCV linear antigens. Isolated cryoglobulin was significantly (40 and 60% total serum RNA by RT-PCR) enriched in HCV RNA. Separated IgM and IgG fractions were mixed at 37 and cooled O/N to 4 C. Results are compared to control IgG and IgM, the latter from a patient with Waldenströms macroglobulinemia without RF activity. Both cryoglobulins were obtained from patients chronically infected with HCV, with active cutaneous vasculitis and membranoproliferative glomerulonephritis. (courtesy of Dr. B. Ghebrehiwet).
