ANCA-mediated crescentic glomerulonephritis with linear deposition of IgG along the glomerular basement membrane

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides is an important cause of rapidly progressive glomerulonephritides (RPGN),and they are classically described as pauci-immune diseases as evidenced by the absence of immune deposits on immunofluoresence microscopy of the kidney biopsy. We report two patients with RPGN,pulmonary-renal syndrome,positive ANCA serology and linear Immunoglobulin G (IgG) staining on glomerular basement membrane in the absence of detectable anti-glomerular basement membrane (anti-GBM) antibodies in the serum.