Course and prognosis of anti-basement membrane antibody (anti-BM-Ab)-mediated disease: report of 35 cases.

Anti-basement membrane antibody (anti-BM Ab) mediated disease is reported to be a rare disorder frequently leading to severe deterioration of renal function. It was our purpose to work out parameters necessary to predict the outcome reliably and to examine, who will benefit most from therapy. Data from 35 patients were evaluated retrospectively. Diagnosis was based on the detection of linear IgG staining (n = 28) along the glomerular basement membrane (GBM) in renal biopsies and/or on the demonstration of anti-BM Ab both by ELISA and immunoblotting (n = 35). Patients were followed up for at least 6 months. Several variables were analysed as to whether they are appropriate prognostic factors. Twenty patients (57%) presented with Goodpasture's syndrome, 13 (37%) had anti-GBM glomerulonephritis alone, whereas two patients suffered solely from pulmonary haemosiderosis. Frequent initial symptoms were haemoptysis (n = 18), haematuria (n = 26), proteinuria (n = 26) and elevated serum creatinine (n = 27). Among all, 10 patients improved, having stable renal function. Twenty-one patients developed end-stage renal failure and four died. Parameters indicating a poor prognosis were a serum(s)-creatinine greater than 600 mumol/l and crescent formation in more than 50% of the glomeruli on renal biopsy. By combining these two parameters the outcome could be reliably predicted. The initial antibody titre and cigarette smoking were without predictive value. In conclusion, the earlier therapy starts, the better will be the result. Patients presenting early with a serum creatinine < 200 mumol/l and without severe glomerular alterations gained the most benefit from therapy, indicating that outcome may be improved by early diagnosis.