Mixed cryoglobulinemia in a heroin addict

Several forms of glomerulopathies have been described in patients who use intravenous heroin, including focal glomerulosclerosis, membranous nephropathy associated with chronic hepatitis B antigenemia, and immune complex proliferative glomerulonephritis. This report describes a patient who was a heroin addict for 15 years and who developed membranoproliferative glomerulonephritis and cutaneous vasculitis due to mixed cryoglobulinemia; he also had a positive hepatitis C virus (HCV) antibody. Recently, an association has been described between "essential" mixed cryoglobulinemia and chronic HCV infection, which has a high prevalence in intravenous drug addict population. It is possible that mixed cryoglobulinemia-associated glomerulonephritis, occurring with chronic HCV infection, came to be considered a major cause of renal disease in heroin abusers. The possibility that HCV infection can be responsible for other types of renal involvement in intravenous drug addicts deserves further attention.