IGA NEPHROPATHY PRESENTING CLINICOPATHOLOGICAL FEATURES OF ACUTE POSTSTREPTOCOCCAL GLOMERULONEPHRITIS

A 5-year-old Japanese girl was affected with acute nephritis. The pati ent had hypo-complementaemia and an elevation of anti-streptolysin O w ith positive throat culture of Group A streptococci. Four weeks after onset of the disease, serum complement level returned to normal, but p roteinuria increased into the nephrotic range with a deterioration in renal function. Four weeks after onset, light microscopy of a renal bi opsy showed diffuse endocapillary proliferation, and immunofluoroscopy revealed predominant IEA deposition in the mesangium. Electron micros copy showed electron dense deposits in the mesangial and subendothelia l area, but subepithelial deposits were not found in the glomeruli. Hi stological diagnosis was IgA nephropathy, while her clinico-serologica l features were typical of acute post-streptococcal glomerulonephritis Conclusion These results suggest that in some patients, IgA nephropat hy may be triggered by streptococcal infection and misdiagnosed as acu te post-streptococcal glomerulonephritis if renal histological examina tions are not done.