Mycoplasma pneumonia associated with acute glomerulonephritis.

An 11-year-old girl who presented with pneumonia, pleural effusion, hematuria, and red blood cell casts is described. Mycoplasma pneumoniae complement fixation titers were elevated. The pneumonia resolved following therapy with tetracycline. Light microscopy of renal biopsy tissue revealed an acute glomerulonephritis; immunofluorescent studies showed deposits of IgG, C3 and mycoplasma antigen along the glomerular capillary walls and in the mesangium; subendothelial and subepithelial deposits were seen by electron microscopy. This is the first report of acute glomerulonephritis associated with M. pneumoniae infection with evidence of mycoplasma-induced immune complex nephritis.