Predictive value of initial histology and effect of plasmapheresis on long-term prognosis of rapidly progressive glomerulonephritis

Abstract

Intensive immunosuppressive therapy has improved the outcome of patients with rapidly progressive glomerulonephritis (RPGN), which progresses to end-stage renal failure in 90% of patients without intervention. However, it remains unclear which patients benefit most from immunosuppressive therapy and whether plasmapheresis improves long-term outcome. This prospective multicenter study randomized 39 patients with biopsy-proven RPGN (Couser type II, n = 6; pauci-immune type III, n = 33) to undergo either immunosuppressive therapy with prednisone and cyclophosphamide (n = 18) or plasmapheresis in addition to immunosuppression (n = 21). Patients were observed for a mean of 127 months or until reaching the end points of hemodialysis or death. Six of 11 patients who were initially dialysis dependent recovered renal function; however, 2 of those patients required dialysis therapy again after 10 and 105 months. Overall, 15 of 39 patients reached end-stage renal failure after a mean of 25 months, and 4 patients died before requiring hemodialysis therapy. Plasmapheresis had no significant effect on renal or patient survival in type II or pauci-immune (type III) RPGN, independently of age, sex, or serum creatinine level at the time of diagnosis. Overall, probabilities of dialysis-free survival were 0.80, 0.67, 0.55, and 0.48 after 12, 24, 60, and 120 months, respectively. Histological characteristics at the time of diagnosis predicted the effect of immunosuppression on renal outcome. All patients were dialysis dependent within 24 months if more than one third of glomeruli were totally sclerosed on the initial histological examination. Interstitial fibrosis also correlated significantly with the risk for progression to renal failure. Conversely, long-term dialysis-free survival was significantly more likely in patients with a greater number of crescents than in those with a low number of crescents. In conclusion, plasmapheresis does not add to the improvement in outcome reached by immunosuppression alone. Crescents on initial histological examination correlate with a favorable outcome. However, 90% of patients who initially have glomerular sclerosis present become dialysis dependent. Overall, approximately 50% of patients are alive and off dialysis therapy 10 years after the diagnosis of type II or type III RPGN using immunosuppression with cyclophosphamide and prednisone.