The majority of patients with rapidly progressive crescentic glomerulonephritis show
histologic features of extensive necrosis and focal and segmental proliferation with fibrin
production, but little or absent Ig deposition in the glomerulus. This subcategory of the
disease, labeled “pauci-immune” glomerulonephritis, has recently been shown to be
associated with the presence of antineutrophil cytoplasmic antibody in the patient's
circulation (but not within the glomerulus). The absence of the effectors of humoral immunity …