Association of infectious mononucleosis with nephrotic syndrome.

A patient had infectious mononucleosis (IM) associated with transient nephrotic syndrome (NS). A kidney biopsy sample studied by light and electron microscopy demonstrated minimal glomerular lesions. Immunofluorescent studies revealed mainly granular mesangial deposits of IgM, and to a lesser extent, deposits of IgG and of C4 and C3. No Epstein-Barr virus-related antigen could be detected in the kidney. This, and three other cases reported in the literature, suggest a causal relationship between IM and NS.