Immune-complex glomerulonephritis associated with cytomegalovirus infection.

Histologic and immunopathologic studies were performed at autopsy on the kidneys of a patient in whom hematuria and proteinuria developed in association with cytomegalovirus (CMV) pneumonitis. Light microscopic examination of the kidneys revealed focal mesangial proliferative glomerulonephritis. Immunofluorescent microscopy revealed a granular deposition of IgG, IgA, C3, and C4, mainly in the mesangium. CMV antigens were also demonstrated in a similar immunofluorescent pattern. Glomerulus-bound immunoglobulins were eluted and demonstrated to contain antibodies to CMV antigens. These findings suggest that in some patients who have CMV infection immune-complex glomerulonephritis is induced by glomerular deposition of CMV antigen-antibody complexes.