Cyclophosphamide provides no additional benefit to steroid therapy in the treatment of idiopathic membranous nephropathy

Immunosuppressive treatment for idiopathic nephrotic syndrome with corticosteroids and cyclophosphamide: factors associated with a favourable outcome

OBJECTIVE

We report the results of a combined immunosuppressive schedule for the treatment of patients with idiopathic nephrotic syndrome, in which prednisone and cyclophosphamide were given in four phases: induction, maintenance, tapering and discontinuation.

PATIENTS AND OUTCOME MEASURES

Sixty-seven patients with nephrotic syndrome, followed for an average of 7.1 +/- 4.5 years, were studied. Treatment outcomes were remission, progression, end-stage renal disease and death.

RESULTS

At the end of the follow-up, 72% of patients maintained a complete remission. Stepwise logistic regression showed that the cumulative dose of cyclophosphamide was the only independent predictor of a favourable outcome, being associated both with complete remission of the nephrotic syndrome and with lack of progression to chronic renal failure.

CONCLUSION

We suggest that the combination treatment may be indicated in all histological subgroups of nephrotic syndrome, provided that prednisone is given at high doses on alternate days, cyclophosphamide is given for 6 months, and relapses are treated with the same schedule. The adverse effects of treatment, however, require the adoption of a programme to prevent bone loss, infertility, bladder cancer and infections.

Idiopathic Membranous Nephropathy: Outline and Rationale of a Treatment Strategy

Idiopathic membranous nephropathy is a common cause of nephrotic syndrome. The treatment of patients with idiopathic membranous nephropathy is heavily debated. Based on literature data and our own experience, we propose a rational treatment strategy. Patients with renal insufficiency (serum creatinine level > 1.5 mg/dL [> 135 micromol/L]) are at greatest risk for the development of end-stage renal disease and should receive immunosuppressive therapy. In patients with normal renal function (serum creatinine level < 1.5 mg/dL [< 135 micromol/L]), risk for developing end-stage renal disease can be estimated by measuring urinary excretion of beta2-microglobulin or alpha1-microglobulin and immunoglobulin G. For low-risk patients, a wait-and-see policy is advised. High-risk patients likely benefit from immunosuppressive therapy. Currently, combinations of steroids with chlorambucil or cyclophosphamide are the best studied. We prefer cyclophosphamide in view of its fewer side effects. Cyclosporine may be an alternative option in patients with well-preserved renal function, although long-term data are lacking. Other immunosuppressive agents, such as mycophenolate mofetil or rituximab, currently are under study; however, data are insufficient to support their routine use.

Treatment of idiopathic membranous nephropathy (IMN)

The best treatment of idiopathic membranous nephropathy remains an area of clinical controversy. At the moment only patients with nephrotic syndrome and/or declining renal function should be treated. Despite the negative trials, prolonged oral administration of corticosteroids alone may be a safe and an effective first-line treatment in nephrotic patients. If corticosteroids are ineffective, prolonged use of cyclosporine in low-doses can be recommended as an alternative treatment, that diminishes rapidly proteinuria in the majority of patients. Both treatments (intravenous high doses of corticosteroids and cyclosporine) may also be effective in patients with declining renal function. Because of their toxicity, the routine use of alkylating agents for patients with nephrotic syndrome is not justified. They may be retained for patients, in whom other treatment modalities have failed. Chlorambucil may be preferred over cyclophosphamide since it carries less toxicity. A lower dose of chlorambucil, than that usually suggested, for a short period of time seems to be prudent in an effort to avoid serious side-effects.

Treatment and long-term follow-up of patients with stage II to III idiopathic membranous nephropathy

Many important aspects of the therapeutic approach to patients with idiopathic membranous nephropathy are still controversial. There are several reports that the effectiveness of therapy depends on histological staging and severity of interstitial mononuclear cell infiltration. We used several different treatments in 39 patients with stage II to III primary membranous nephropathy with proteinuria more than 2.5 g/d, without hypertension and chronic renal failure at biopsy. Ten patients were not treated, 13 were treated with only steroids, 13 with alternate use of steroids and chlorambucil, and three with cyclosporine A. The follow-up period was 5 to 10 years. Statistics included Kruskall-Wallis and one-way ANOVA analysis. A significant decrease in proteinuria was noted in patients treated with steroids (P < 0.01), from 8.45 +/- 1.04 g/d (mean +/- SEM) to 1. 42 +/- 0.45 g/d after follow-up of 5 years and in patients treated with steroids and chlorambucil (12.9 +/- 2.4 g/d [mean +/- SEM] to 2. 46 +/- 1.38 g/d). Compared with patients treated with steroids (15. 3%) and patients treated with steroids and chlorambucil (15.3%), untreated patients had a high frequency of chronic renal failure after 5 years of follow-up (70%) and had a significant increase in mean serum creatinine (P = 0.008). We conclude that steroid therapy alone, or associated with chlorambucil, is effective in patients with stage II to III membranous nephropathy. Patients responded with a decrease of proteinuria and stable renal function during the long-term follow-up period. The group of patients treated with cyclosporine A was too small to analyze.

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

The role of immunosuppressive drugs in the treatment of idiopathic membranous nephropathy (IMN) remains controversial. The effect of treatment with prednisolone and azathioprine in patients with nephrotic-range proteinuria and biopsy-proven IMN from a single center (Sheffield Kidney Institute, Sheffield, 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 azathioprine (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 and served as a control group. Clinical, biochemical, and histopathologic features at presentation were similar between the groups. Renal function (RF), measured by serum creatinine (Scr) level, deteriorated in both treated and 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, respectively (P = not significant). Neither the rate of RF decline (measured by the slope of reciprocal of Scr against time) nor the proportion of patients with deteriorating RF differed significantly between the groups (37%, treated group; 30%, control group). A significant reduction in proteinuria was observed in both groups (P < 0.01, either group). Also, the rate of remission of nephrotic-range proteinuria was not significantly different between groups (55%, treated group; 65%, control group). The only prognostic factor that correlated with RF outcome (expressed by final Scr level) in a given patient 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 effects of immunosuppressive treatment were observed in nine patients (24%). These were serious in four patients (10%) and included squamous cell carcinoma (two patients), bacterial meningitis (one patient), and septicemia (one patient). In conclusion, treatment with prednisolone and azathioprine for patients with IMN did not show significant beneficial effects on the progression of disease. Furthermore, this treatment was associated with frequent and serious adverse effects.

Management of idiopathic membranous nephropathy: evidence-based recommendations

Membranous nephropathy is a frequent cause of nephrotic syndrome in adults, and in one third of these patients, it leads to end-stage renal disease. Based on an extensive critical review of the literature, the following recommendations are offered. Oral high-dose corticosteroids are ineffective in producing either a sustained remission of nephrotic syndrome or in preserving renal function in patients with membranous nephropathy, and should not be used as the sole therapy (grade A recommendation). The use of azathioprine is not associated with any significant benefits, so its use is not justified (grade C). The alkylating agents cyclophosphamide and chlorambucil are both effective in the management of membranous nephropathy. Because of growing concern about long-term toxicity, especially with cyclophosphamide, these drugs should be reserved for patients who exhibit clinical features, such as severe or prolonged nephrosis, renal insufficiency, or hypertension, that predict a high likelihood of progression to end-stage renal disease. Chlorambucil in conjunction with oral steroids is the drug of first choice (grade A). Cyclophosphamide and oral steroids are alternatives (grade B). Cyclosporine may, in the future, become the agent of choice for membranous nephropathy. Currently, it is recommended (grade B) that cyclosporine use be considered in patients at high risk for progression in membranous nephropathy or if alkylating agents are contraindicated or ineffective.

Is membranous nephropathy only a glomerular disease?

Tubulointerstitial lesions represent not only a constant component of the pathology of a "classical" glomerular disease such as idiopathic membranous nephropathy but also the most important prognostic indicator and a new "target" for its treatment. Proper "quantification" of the cellular events occurring within the interstitium may enable us to accurately assess the amount of disease activity and identify patients who might benefit from treatment.

Validation of a predictive model of idiopathic membranous nephropathy: its clinical and research implications

Although a number of factors have consistently correlated with progression to chronic renal insufficiency (CRI) in idiopathic membranous glomerulonephropathy (IMGN), they appear late, are not quantitative in nature and have not been validated. We have determined that the highest sustained six-month period of proteinuria is an important predictor of progression. Using multiple logistic modelling, the only additional prognostic variables of importance in 184 Canadian patients were the initial creatinine clearance and the rate of change in function over this six-month interval. Independent data from Italy (101 patients) and Finland (78 patients) were obtained for comparison. Sensitivity, specificity, negative and positive predictive values and overall accuracy, as well as Pearson's goodness-of-fit and Harrell's "C" statistic were used to assess the fits of the model. Accuracy of prediction was > or = 85% in all three countries. Pearson's Chi-square goodness-of-fit showed good agreement across the spectrum and Harrell's "C" statistic was > or = 90%. Therefore, a predictive, semiquantitative algorithm in IMGN has been validated. Its relevance in patient management and in clinical trials is illustrated.

A review of therapeutic studies of idiopathic membranous glomerulopathy

The treatment of idiopathic membranous glomerulopathy remains an enigma. We have reviewed many of the important clinical trials concerning membranous glomerulopathy using a meta-analysis and a secondary pooled analysis to test the effects of corticosteroid or alkylating, therapy compared with no treatment on renal survival and complete remission of the nephrotic syndrome. A search was performed using MEDLINE (1968 through 1993) for articles on idiopathic membranous glomerulopathy and glomerulonephritis. Bibliographies of articles were reviewed for completeness. Sixty-nine articles were reviewed. Meta-analysis was performed for four trials that evaluated corticosteroids compared with no treatment and for three trials that evaluated alkylating therapy compared with no treatment. Pooled analysis was performed on randomized and prospective studies (10 studies) and then with 22 case series added. All studies evaluated renal biopsy-proven disease. Meta-analysis was performed on the relative chance of being in complete remission for each study. Renal survival could be evaluated by pooled analysis only. For pooled analyses, Cox's proportional hazard and logistic regression models were used to test the effect of therapy on renal survival and the nephrotic syndrome, respectively. Data concerning gender, nephrotic syndrome, and geographic region were used in all statistical models. Evaluation of renal survival revealed no differences by treatment group (P > 0.1). By meta-analysis, the relative chance of complete remission was not improved for corticosteroid-treated patients (1.55; 95% confidence interval, 0.99 to 2.44; P > 0.1), but was improved for patients treated with alkylating agents (4.8; 95% confidence interval, 1.44 to 15.96; P < 0.05) when compared with no treatment. Pooled analysis of randomized and prospective studies, as well pooled analysis with all studies, supported the findings of the meta-analysis. Corticosteroids or alkylating therapy did not improve renal survival in idiopathic membranous glomerulopathy. Complete remission of the nephrotic syndrome was observed more frequently with the use of alkylating agents.

A controlled trial of cyclosporine in patients with progressive membranous nephropathy. Canadian Glomerulonephritis Study Group

A controlled trial of cyclosporine in patients diagnosed with progressive membranous nephropathy (MGN) was carried out to determine whether cyclosporine (D) would be more effective than placebo (P) in reducing the rate of deterioration in renal function. Patients (N = 64) with MGN were placed on a restricted protein diet (< or = 0.9 g/kg) and followed closely for 12 months (Part 1). Patients at high risk of progression based on an absolute loss in creatinine clearance (CCr) of > or = 8 ml/min and persistent nephrotic range proteinuria (Pr) were selected and randomly assigned to either (D) (N = 9) or (P) (N = 8) for 12 months (Part 2). No differences in the two groups were noted at entry. After 12 months, the improvement in CCr slope in ml/min/month was significantly greater in the D patients (D + 2.1 vs. P + 0.5, mean difference 1.6; 95% CI 0.3 to 3.0, P < 0.02). This improvement was maintained in six of eight D (75%) over a mean follow-up period of 21 months. Daily Pr also improved with D (by month 3, D - 4.5 g/day vs. P + 0.7 g/day, P = 0.02) and was sustained in six of eight (75%) D patients. When Pr was expressed as a function of their concurrent CCr, the D versus P patients' time to halving was faster (P = 0.02) and absolute number higher (4/9 D vs 0/8 P). In the D group a trend towards worse hypertension and an increase in the number of transient rises in serum creatinine were noted.(ABSTRACT TRUNCATED AT 250 WORDS)