Fig. 1Light microscopy findings in renal biopsy (patient 1). Most glomeruli show diffuse endocapillary hypercellularity and neutrophilic infiltration with cellular crescents. Tubulointerstitial changes are mild (periodic acid-Schiff [PAS]) (A). In high-power views, the glomerulus shows a cellular crescent as well as endocapillary hypercellularity (PAS) (B), diffuse mesangial and endocapillary hypercellularity (methenamine silver) (C), and subepithelial, 'hump'-like deposits (arrow) (Masson's trichrome) (D).
Fig. 2Representative photomicrographs of immunofluorescence (IF) staining (patient 2). IF staining for IgG (A) is negative, but there is conspicuous coarsely granular positive IF staining for IgA (B) and C3 (C) along the glomerular capillary wall (3+), and segmentally in the mesangial areas (2+). IF staining for kappa (D) is weakly positive, and lambda (E) shows 1+ segmentally staining in mesangial areas and peripheral capillary walls.
Fig. 3Electron microscopic features of two renal biopsies (patients 3 and 5). (A, B) Patient 3 show subepithelial electron dense deposits ('humps'), intramembranous and mesangial deposits. (C) Patient 5 shows a large subepithelial deposit with proliferation of endothelial and mesangial cells, and a neutrophil in the lumen. Partially resorbed subepithelial 'hump' with electron lucency. In (D), there is a broad based subepithelial deposit (arrows) attracting neutrophil in the capillary lumen (A, B, ×8,000; C, ×7,000; inset in C, ×15,000; D, ×12,000).
Table 1IgA-dominant acute postinfectious glomerulonephritis: demographic and clinical features
Table 2IgA-dominant acute postinfectious glomerulonephritis: light microscopic findings in renal biopsy
Table 3IgA-dominant acute postinfectious glomerulonephritis: immunofluorescence and electron microscopic findings in renal biopsy
Table 4Review of literatures: previously reported 85 cases of IgA-dominant acute postinfectious glomerulonephritis