Coexistent anti-neutrophil cytoplasmic antibody and antiglomerular basement membrane antibody associated disease = report of six cases.

From a series of 95 patients biopsied for rapidly progressive glomerulonephritis, twelve patients were identified with anti-glomerular basement membrane-mediated renal disease who were also tested for antineutrophil cytoplasmic antibody (ANCA). Six patients had both anti-glomerular basement membrane and ANCA antibodies. Three of the latter six patients had significant extrarenal disease, including severe hemoptysis, while the remaining three patients had only renal disease. The three patients with extrarenal disease had either a myeloperoxidase-positive perinuclear-ANCA (two patients) or a proteinase-3-positive cytoplasmic-ANCA (one patient). Two patients with renal disease alone had a myeloperoxidase-negative and proteinase-3-negative perinuclear-ANCA, and one patient had a proteinase-positive cytoplasmic-ANCA. Renal biopsy in all six patients showed a severe necrotizing and crescentic glomerulonephritis involving 94 to 100% of glomeruli. Renal arteritis was also noted in one perinuclear-ANCA patient. Despite aggressive therapy with steroids, cyclophosphamide, and plasma exchange, two of the six double-antibody patients died and four are on dialysis. We conclude that ANCA is commonly present in anti-glomerular basement membrane-associated disease and believe that this observation may have implications in the serologic evaluation of ANCA- and anti-glomerular basement membrane-positive patients.