Increased frequency of antibodies to ubiquitous viruses in essential mixed cryoglobulinaemia.

Antibodies to ubiquitous Herpes viruses have been studied in 13 patients with type II essential mixed cryoglobulinemia (EMC), and in two different control groups. All the EMC patients had monoclonal IgM kappa in their cryoprecipitates. IgM antibodies to the viral capsid antigen (VCA) of Epstein-Barr virus (EBV) were found in the sera of 11 EMC patients but all the cryoprecipitates were negative. IgG antibodies were also present in the sera of all and in the cryoprecipitates of some patients. In contrast, the number of subjects with antibodies to Cytomegalovirus (CMV) and Hepatitis B Virus (HBV) was not higher than in controls. Possible correlations between EMC and EBV infection are discussed.