Mesangial IgA/IgG Deposit Glomerulonephritis

ABSTRACT

Percutaneous renal biopsy was performed on a 34 year old male patient with mild proteinuria and microhematuria. Histopathologic examination showed a focal mesangiopathic glomerulonephritis, simulating a "minimal change" disease pattern by light microscope. Granular deposits of IgA, C3, IgG, IgM, and fibrinogen were present in the glomerular mesangial area by immunofluorescent technique. A special prevalence of IgA was found. The intensity of immunofluorescent staining was correlated with the mesangial proliferative reaction by light microscopy. Electron microscopy showed electron dense granular deposits in the mesangial areas. The glomerulonephritis in this patient was related with the IgA antibody associated mesangial immune complex deposit disease mediated by the classic complement pathway. This glomerulonephritis is known to have a good prognosis. The antigenic nature, the reason of predominant immune deposits in the mesangium, and the mechanism of a special prevalence of IgA and IgM immunoglobulin classes are discussed, and special attention to the value of immunofluorescent study of renal diseases, with a review of the literature, is given.