Cytomegalovirus is not specifically associated with immunoglobulin A nephropathy.

Cytomegalovirus (CMV) has been suspected to be involved in the pathogenesis of IgA nephropathy (IgAN). Whether CMV is present in renal tissue of IgAN, however, remains controversial. To determine the presence of CMV in IgAN, compared with other glomerulonephritis (GN) as disease control, polymerase chain reaction amplifying a 159-base-pair fragment of the immediate early gene of CMV and indirect immunofluorescence staining with anti-CMV monoclonal antibody were performed on 10 IgAN and 14 non-IgAN GN renal tissues. CMV DNA was detected in 6 of 10 IgAN tissues and 10 of 14 other GN by polymerase chain reaction, whereas no CMV antigen was detected in all renal tissues by immunofluorescence. This frequent observation of CMV DNA in various types of GN as well as in IgAN would suggest that CMV is not specifically associated with the pathogenesis of IgAN seen in endemic areas of CMV infection.