Endocapillary proliferative glomerulonephritis in a patient with parvovirus B19 infection

A 45-year-old woman developed acute nephritic syndrome after erythema infec tiosum. Laboratory data on admission showed decreased serum C3, C4, and CH5 0 levels and the presence of both immunoglobulin (Ig) M and IgG antibodies to human parvovirus B19 (HPV). A renal biopsy showed diffuse endocapillary proliferative glomerulonephritis. immunofluorescence microscopy indicated 2 + granular staining for IgG, IgM, and C3 over the mesangial area and along glomerular capillary walls. HPV antigen was also detected in glomeruli by i mmunohistochemistry. Electron microscopy showed electron-dense deposits in the subendothelial space and the paramesangial area. These findings suggest that immune complex-type glomerulonephritis is caused by glomerular deposi tion of HPV antigen-antibody complexes in some patients with HPV infection, (C) 2000 by the National Kidney Foundation, Inc.