Does immunosuppression with prednisolone and azathioprine alter the progression of idiopathic membranous nephropathy?

The role of immunosuppressive drugs in the treatment of idiopathic membrano us nephropathy (IMN) remains controversial. The effect of treatment with pr ednisolone and azathioprine in patients with nephrotic-range protein-uria a nd biopsy-proven IMN from a single center (Sheffield Kidney Institute, Shef field, UK) is described. In this retrospective study, 58 patients with IMN and nephrotic-range proteinuria were followed up for 4 years. Thirty-eight patients were treated with prednisolone(1 mg/kg body weight/d) and azathiop rine (2 mg/kg body weight/d) orally for a median period of 26 months (range , 6 to 48 months). Twenty patients received no specific treatment for IMN a nd served as a control group. Clinical, biochemical, and histopathologic fe atures at presentation were similar between the groups. Renal function (RF) , measured by serum creatinine (Scr) level, deteriorated in both treated an d control groups during the follow-up period. The median initial and final Scr levels (at the end of follow-up) in the treated group were 1.6 and 2.1 mg/dL, respectively, and in the control group were 1.3 and 1.7 m/dL, respec tively (P = not significant). Neither the rate of RF decline (measured by t he slope of reciprocal of Scr against time) nor the proportion of patients with deteriorating RF differed significantly between the groups (37%, treat ed group; 30%, control group). A significant reduction in proteinuria was o bserved in both groups (P < 0.01, either group). Also, the rate of remissio n of nephrotic-range proteinuria was not significantly different between gr oups (55%, treated group; 65%, control group). The only prognostic factor t hat correlated with RF outcome (expressed by final Scr level) in a given pa tient was the mean proteinuria during follow-up in either group (r = 0.493; P < 0.01, treated group) r = 0.651; (P < 0.01, control group). Adverse eff ects of immunosuppressive treatment were observed in nine patients (24%). T hese were serious in four patients (10%) and included squamous cell carcino ma (two patients), bacterial meningitis (one patient), and septicemia (one patient). In conclusion, treatment with prednisolone and azathioprine for p atients with IMN did not show significant beneficial effects on the progres sion of disease. Furthermore, this treatment was associated with frequent a nd serious adverse effects. (C) 1999 by the National Kidney Foundation, Inc .