Prospective study of anti-neutrophil cytoplasmic autoantibody tests in the diagnosis of idiopathic necrotizing-crescentic glomerulonephritis and renal vasculitis.
We prospectively assessed the value of anti-neurtrophil cytoplasmic autoantibodies (ANCA) and nuclear or perinuclear anti-neutrophil autoantibodies measured by indirect immunofluorescence microscopy and antimyeloperoxidase autoantibodies measured by a solid-phase assay in the diagnosis of idiopathic (pauci-immune) necrotizing-crescentic glomerulonephritis (NCGN) and renal vasculitis at our institution. A diagnosis was established on the basis of clinical and renal biopsy findings, and follow-up continued for at least 6 months. ANCA were measured at the conclusion of the study. Of the 111 study patients, 28 had NCGN and renal vasculitis. The immunofluorescence assay had 50% sensitivity and 79% specificity. The combination of the enzyme-linked immunosorbent assay for antimyeloperoxidase autoantibodies and the immunofluorescence assay for cytoplasmic ANCA had 78% sensitivity and 84% specificity. A firm diagnosis was established before the determination of ANCA in 26 of the 28 patients with NCGN and renal vasculitis. The antimyeloperoxidase autoantibody values would have suggested the diagnosis in the other two patients. Of these 28 patients, 5 had negative ANCA results. High antimyeloperoxidase autoantibody values were detected in patients with NCGN and renal vasculitis, whereas lower values were less specific and were detected mainly in patients with anti-glomerular basement membrane antibody disease and lupus glomerulonephritis.
Division of Nephrology and Internal Medicine, Mayo Clinic Rochester, MN 55905.
J A
JA
Velosa
H A
HA
Homburger
K E
KE
Holley
D019268:Antibodies, Antineutrophil Cytoplasmic; D001323:Autoantibodies / Q000032:analysis*; D015415:Biomarkers; D001706:Biopsy; D002196:Capillaries / Q000473:pathology; D005500:Follow-Up Studies; D005921:Glomerulonephritis / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007118:Immunoassay; D007678:Kidney Glomerulus / Q000098:blood supply / Q000276:immunology / Q000473:pathology; D008856:Microscopy, Fluorescence; D009336:Necrosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014657:Vasculitis / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology
D019268:Antibodies, Antineutrophil Cytoplasmic; D001323:Autoantibodies; D015415:Biomarkers