and fifteen patients with diagnosis of APIGN were identified. Clinicopathologic Features of IgA-Dominant Postinfectious

Acute postinfectious glomeruonephritis (APIGN) is an im-mune complex-mediated form of glomerulonephritis that fol-lows non-renal infection, often caused by Streptococci. It mostly affects children after an upper respiratory tract infection or im-petigo. The typical histological pattern of APIGN includes: diffuse endocapillary proliferative and exudative glomerulone-phritis (GN) on light microscopy (LM), coarsely granular depo-sition of IgG and C3 in a predominantly capillary wall distri-bution on immunofluorescence (IF), and characteristic subepi-thelial hump-shaped deposits on electron microscopy (EM). Over recent decades, the spectrum of the disease has been changed. Not only Streptococci but also other bacterial, viral, and parasitic organisms have been implicated in the pathogene-sis of postinfectious glomerulonephritis (PIGN).1-3 Extensive use of renal biopsy has demonstrated the presence of atypical histological features of PIGN. Recently, there have been several reports of PIGN with IgA-dominant immune complex deposi-tion, mostly related to staphylococcal infection, especially in patients with underlying diabetic nephropathy.4-19 IgA-domi-nant PIGN is characterized by diffuse endocapillary prolifera-tive GN on LM, intense deposits of IgA as the dominant or co-dominant immunoglobulin on IF, along with mesangial and subepithelial electron dense deposits on EM.9 However, there have been additional reports of IgA-dominant PIGN that lacked typical features such as diffuse endocapillary hypercellularity, subepithelial deposits, underlying diabetes mellitus and history of infection.11,12,15,17-19 Therefore, to avoid potential ambiguity, the clinicopathological features of IgA-dominant PIGN need to be investigated. Here we present seven cases of APIGN which showed IgA-dominant deposition on renal biopsy. Clinical features and renal pathologic findings were analyzed and discussed with a review of the literature