Case report: late relapse in a case of mesangioproliferative glomerulonephritis

A case of atypical proliferative glomerulonephritis (PGN) without mesangial immunoglobulin (Ig) A deposition (so-called non-IgA PGN) showing exacerbation of heavy proteinuria under long-term observation is reported. Examinations of first renal biopsy specimens revealed membranoproliferative glomerulonephritis (MPGN)-like findings. Urinary protein excretion completely disappeared after treatment with prednisolone (PSL) and an antiplatelet drug, i.e., dipyridamole. Negative reaction for urinary protein continued for more than 10 years. Fourteen and a half years after the first biopsy, the patient had heavy proteinuria again. Results of the second renal biopsy showed marked proliferation of glomerular mesangial cells. Under electron microscopy, lobulation and double contours of the glomerular capillary walls were also observed segmentally. Depositions of IgG, IgM, IgA, and C3 were observed mainly in the glomerular capillary walls, but not in the mesangial areas; however, these findings were not compatible with IgA nephropathy or MPGN. No hypocomplementemia was observed during the clinical course. The patient was treated with 30 mg of PSL and 75 mg of dipyridamole daily and showed a good response to such treatment. It appears that this patient had a rare case of atypical non-IgA PGN.