Clinical Outcome of Patients With Coexistent Antineutrophil Cytoplasmic Antibodies and Antibodies Against Glomerular Basement Membrane

Antineutrophil cytoplasmic antibodies (ANCA) and antibodies against glomerular basement membrane (anti-GBM) rarely coexist. Both antibodies may be associated with rapidly progressive glomerulonephritis and pulmonary hemorrhage. We describe the clinical, serological and histological features of our patients with dual antibodies. From 1977 to 2008, 48 patients with anti-GBM antibody-associated renal disease were observed. Eight out of the 30 tested patients (26.7%), all females, had positive myeloperoxidase (MPO)-ANCA coexistent with anti-GBM antibodies. The patients' mean age was 63.4 +/- 7.8 years. Five presented with pulmonary-renal syndrome, all but one were dialysis-dependent on admission. They had constitutional symptoms and different organ involvement. The kidney biopsies revealed intense linear staining for immunoglobulin G and C3 along the glomerular and distal tubular basement membrane associated with irregular diffuse or focal extracapillary crescentic glomerulonephritis with necrosis of varying extent. Lesions of varying ages were characteristically expressed. Seven patients were treated with methylprednisolone and plasma exchange, four with cyclophosphamide, and one with intravenous immunoglobulin. After 28-74 months, there were three dialysis-dependent survivors and one patient with stable chronic renal disease. Two clinical relapses with pulmonary involvement and MPO-ANCA positivity without anti-GBM antibodies occurred in two dialysis-dependent patients. In summary, screening for ANCA and anti-GBM antibodies should be undertaken in patients with clinical signs of systemic vasculitis. In dialysis-dependent patients, the goal of treatment is to limit the damage of other involved organs and not to preserve renal function. Careful follow-up is necessary due to the relapsing nature of the ANCA component of the disease.