Prognosis of idiopathic membranous nephropathy: a methodologic meta-analysis

Relapse and its remission in Japanese patients with idiopathic membranous nephropathy

BACKGROUND

The prognosis in patients with idiopathic membranous nephropathy (IMN) is diverse. However, the prognosis after relapse and factors affecting relapse remain unclear.

METHODS

A total of 146 Japanese patients with IMN who had been followed up for at least 3 years, or until end-stage renal failure or death were enrolled in this retrospective study. The initial clinicopathological factors were examined between the patients with and without relapse. The patients were assigned to two groups based on the electron microscopic findings: homogeneous type with synchronous electron-dense deposits and heterogeneous type with various phases of dense deposits.

RESULTS

A total of 105 of the 146 patients (72 %) achieved complete remission (CR) or incomplete remission (ICR) I after initial treatment. Twenty-six of the 105 patients relapsed after CR or ICR I (25 %). There were no differences in initial clinical findings or data between the patients with and without relapse, except for the higher degree of proteinuria at onset in patients with relapse. The relapse rate of the heterogeneous group (43 %) was higher than that in the homogeneous group (20 %). There were no significant associations between relapse rate and immunosuppressive therapy at onset. Eleven of 26 patients showing relapse (42 %) achieved CR or ICR I, which was lower than the rate for patients with initial remission.

CONCLUSION

Our results suggest that patients with relapse achieved CR or ICR I and that electron microscopic findings demonstrating heterogeneous type indicated susceptibility to relapse.

Reporting of prognostic studies of tumour markers: a review of published articles in relation to REMARK guidelines

Background:

Poor reporting compromises the reliability and clinical value of prognostic tumour marker studies. We review articles to assess the reporting of patients and events using REMARK guidelines, at the time of guideline publication.

Methods:

We sampled 50 prognostic tumour marker studies from higher impact cancer journals between 2006 and 2007. The inclusion criteria were cancer; focus on single biological tumour marker; survival analysis; multivariable analysis; and not gene array or proteomic data. Articles were assessed for the REMARK profile and other REMARK guideline items. We propose a reporting aid, the REMARK profile, motivated by the CONSORT flowchart.

Results:

In 50 studies assessed for the REMARK profile, the number of eligible patients (56% of articles), excluded patients (54%) and patients in analyses (98%) was reported. Only 50% of articles reported the number of outcome events. In multivariable analyses, 54% and 30% of articles reported patient and event numbers for all variables. Of the studies, 66% used archival samples, indicating a potentially biased patient selection. Only 36% of studies reported clearly defined outcomes.

Conclusions:

Good reporting is critical for the interpretability and clinical applicability of prognostic studies. Current reporting of key information, such as the number of outcome events in all patients and subgroups, is poor. Use of the REMARK profile would greatly improve reporting and enhance prognostic research.

Estudios de precisión diagnóstica (STARD) y pronóstica (REMARK)

Deficiencies in how research studies are reported are both well-documented and widespread across all medical specialties and study designs. Although randomised trials have received the most attention in this regard, similar concerns have been expressed about reporting of other types of research including diagnostic and epidemiological studies. If a journal article describes in enough detail what was done at each stage of a study, readers will have enough information to allow them to decide on the merits of the results for themselves. From this simple idea comes the scientific rationale of developing guidelines on how to report research. Recommended processes to produce reporting guidelines have evolved over several years during the preparation of a sequence of reporting guidelines starting with CONSORT and QUOROM in the 1990s. We describe initiatives to develop reporting guidelines for diagnostic accuracy studies (STARD) and tumour marker prognostic studies (REMARK).

Immunosuppressive treatment for idiopathic membranous nephropathy in adults with nephrotic syndrome

BACKGROUND

Idiopathic membranous nephropathy (IMN) is the most common form of nephrotic syndrome in adults. The disease shows a benign or indolent course in the majority of patients, with a rate of spontaneous complete or partial remission of nephrotic syndrome as high as 30% or more. Despite this, 30-40% of patients progress toward end-stage renal failure (ESRF) within 5-15 years.

OBJECTIVES

To assess the benefits and harms of immunosuppressive treatment for IMN in adults.

SEARCH STRATEGY

We searched the Cochrane Renal Group Specialised Register (December 2003), The Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 4, 2003), MEDLINE and Pre-MEDLINE (1966 - December 2003), EMBASE (1980 - December 2003), reference lists of nephrology textbooks, review articles, prospective trial registers, relevant trials and abstracts from nephrology scientific meetings and the internet without language restriction. We also contacted principal investigators of controlled studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing any immunosuppressive interventions for the treatment of IMN in adults.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed and extracted information. Information was collected on method, participants, interventions and outcomes (death, ESRF, proteinuria, serum creatinine, GRF, remission, adverse events).

MAIN RESULTS

A total of 18 trials with 1025 patients were included. No differences were found when we combined data of all treatment categories as a group and compared them with placebo or no treatment. Oral glucocorticoids. No beneficial effect on any of the end points chosen for efficacy was observed. Alkylating agents showed a significant beneficial effect on complete remission (RR 2.37, 95%CI 1.32 to 4.25, P = 0.004) but not on partial remission (RR 1.22, 95%CI 0.63 to 2.35, P = 0.56) or complete or partial remission (RR 1.55, 95%CI 0.72 to 3.34, P = 0.27). Cyclophosphamide treatment resulted in significantly lower rate of discontinuations due to adverse events as compared to chlorambucil (RR 2.34, 95%CI 1.25 to 4.39, P = 0.008). There was no evidence of clinically relevant differences in favour of cyclosporin and there was insufficient data on anti-proliferative agents.

REVIEWERS' CONCLUSIONS

This review failed to show any long-term effect of immunosuppressive treatment on patient and/or renal survival. There was an increased number of discontinuations due to adverse events in immunosuppressive treatment groups. Within the class of alkylating agents there is weak evidence supporting the efficacy of cyclophosphamide as compared to chlorambucil. On the other hand, cyclophosphamide had fewer side effects leading to patient withdrawal than chlorambucil.

Pathologic findings of initial biopsies reflect the outcomes of membranous nephropathy

BACKGROUND

A considerable diversity of prognosis is seen with idiopathic membranous nephropathy (IMN). The initial factors affecting long-term outcome remain unclear.

METHODS

We studied retrospectively 105 patients with IMN who had been followed up for at least 5 years, or until end-stage renal failure (ESRF) (primary outcome), or death (secondary outcome). We analyzed the initial clinicopathologic factors affecting primary and secondary outcomes. We assigned the patients to two groups and one subgroup, based on the electron microscopic findings. The groupings were: homogeneous type with synchronous electron dense deposits; homogeneous type with large dense deposits (deep subgroup); and heterogeneous type with various phases of dense deposits.

RESULTS

No differences in the initial clinicopathologic states were seen between the homogeneous (N= 60) and heterogeneous types (N= 45), apart from hypertension and disease history before biopsy. In the homogeneous type, only one patient developed ESRF, which was drug-induced, and remission occurred earlier than in the heterogeneous type. With regard to secondary outcomes, increased age, male gender, heterogeneous type, and deep subgroup were independent risk factors. There were no significant differences attributable to therapeutic regime with respect to primary or secondary outcome in either group.

CONCLUSION

Our results indicate that an electron microscopic classification, at initial biopsy, as heterogeneous type or deep subgroup type with dense deposits are independent indicators of poor prognosis in IMN.

Idiopathic membranous nephropathy: Definition and relevance of a partial remission

BACKGROUND

Membranous nephropathy (MGN) remains the most common cause of adult onset nephrotic syndrome, and within the primary glomerulonephritis group is a leading cause of renal failure. A complete remission (CR) confers an excellent long-term prognosis, but the quantitative benefits of partial remissions (PR) have not been defined.

METHODS

This study evaluated the rate of renal function decline (slope), relapse, and renal survival in nephrotic MGN patients with CR, PR, or no remission (NR). Multivariate analysis included clinical and laboratory data at presentation and over follow-up, blood pressure control and agents employed, and immunosuppressive therapy.

RESULTS

The study cohort consisted of 348 nephrotic MGN patients with a minimum of 12 months follow-up identified from the Toronto Glomerulonephritis Registry. Over a median follow-up of 60 months, 102 experienced a CR, 136 had a PR, and 110 had no remission. A PR was independently predictive of slope and survival from renal failure by multivariate analysis (hazard ratio 0.08, 95% CI 0.03-0.19, P < 0.001). Benefit from immunosuppression could only be shown in a subset of high-risk patients. Treatment-related PR had the same long-term implication as spontaneous ones. Relapses from PR were high (47%) but often reversible.

CONCLUSION

A partial remission is an important therapeutic target with implications for both progression rate and renal survival.

Efficacy of a second course of immunosuppressive therapy in patients with membranous nephropathy and persistent or relapsing disease activity

BACKGROUND

A single course of immunosuppressive treatment improves renal survival in patients with idiopathic membranous nephropathy (iMN) and renal insufficiency. However, not all patients respond and relapses occur within 5 years in 30% of patients. It is unknown if a second course of immunosuppressive therapy is effective in such patients.

METHODS

We have prospectively studied and evaluated the clinical course in 15 patients (14 male, one female; age: 52+/-12 years) with iMN who have received a repeated course of immunosuppressive therapy because of deteriorating renal function associated with relapsing or persistent nephrotic syndrome.

RESULTS

The first course of immunosuppression was started 8 months (range: 0-143 months) after renal biopsy and consisted of chlorambucil (n = 8) or cyclophosphamide (n = 7); the second course consisted of cyclophosphamide in all patients. The interval between the first and second course was 40 months (range: 7-112 months). Total follow-up was 110 months (range: 46-289 months). Renal function and proteinuria improved at least temporarily in all patients after the second course. During follow-up, an additional course of therapy was given in four patients. Status at the end of follow-up was complete remission (n = 2), partial remission (n = 8), persistent proteinuria (n = 3), end-stage renal disease (n = 1) and death (n = 1, due to cardiovascular disease while nephrotic). Renal survival was 86% at 5 and 10 years of follow-up. The repeated courses of immunosuppression have resulted in a gain of dialysis-free survival time of > or =93 months (range: 43-192 months).

CONCLUSIONS

Our results indicate that patients with iMN who do not respond well or relapse after a first course of immunosuppressive therapy and have renal insufficiency should be offered a second course of immunosuppression. Such a strategy maintains renal function in the majority of patients.

Mycophenolate mofetil and cyclosporine therapy in membranous nephropathy

Idiopathic membranous nephropathy (IMN) remains one of the most common causes of the nephrotic syndrome (NS) in adults. Although the natural history is extremely variable, approximately two thirds of the patients will have persistent high-grade proteinuria and/or develop renal failure over a decade of observation. On the other hand, the remaining third of patients will remit spontaneously and potentially toxic therapy should be avoided in this group. Our capacity to predict which patient will progress at an early stage of the disease has improved substantially in the past 10 years. We present the data from studies of cyclosporine (CSA) and mycophenolate mofetil (MMF) treatment of IMN with their level of evidence in support of efficacy. In addition, based on data related to predicting prognosis, we assign a risk for progression category to the trial patients at entry into these studies. The data are presented in this format so the reader will be able to better discern the risk benefit of treatment within each category and the rationale for our subsequent grade of recommendation for the use of these agents in IMN. CSA has been shown in randomized controlled trials in both the medium and high risk of progression categories of IMN patients to improve proteinuria and preserve renal function at least in the short term in up to two thirds of patients. Other studies suggest prolonged therapy beyond 6 months to 1 year may reduce the high relapse rate after CSA treatment supporting more long-term, continuous, or combination therapy in IMN treatment. The data in favor of MMF treatment of this disease is much weaker and are derived from pilot studies. Only one report applied MMF specifically to IMN patients. In these medium to high risk of progression patients, approximately one-half had a 50% reduction in their baseline proteinuria without a significant alteration in their serum creatinine level. MMF's role as a single agent or as adjunctive therapy in the treatment of IMN needs more rigorous evaluation.

Conservative versus immunosuppressive treatment of patients with idiopathic membranous nephropathy

BACKGROUND

Treatment of idiopathic membranous glomerulonephritis (MGN) is a controversial issue. Whereas some authors recommend early immunosuppressive treatment of all patients with nephrotic syndrome, others do not support aggressive therapies, based on the spontaneous long-term favorable outcome of most patients. However, 20 to 50% of untreated patients develop progressive renal insufficiency.

METHODS

All of the patients with biopsy-proven MGN who developed renal insufficiency at our Hospital during the period of 1975 to 2000 were studied. Selected patients (N=39) were separated into two groups according to the two different therapeutic policies followed at our department: a conservative approach during the first period, 1975 to 1989 (group I, N=20), and a course of immunosuppressive therapy (oral prednisone for six months and concurrent oral chlorambucil, 0.15 mg/kg/day, during the first 14 weeks) during the second period, 1990 to 2000 (group II, N=19).

RESULTS

There were no significant differences between both groups at the time of renal biopsy, nor at the onset of renal function decline. All group I patients showed a progressive renal insufficiency; at the end of the follow-up 13 patients (65%) were on chronic dialysis, 2 (10%) showed advanced renal failure, and 5 (25%) had died. In contrast, most of group II patients showed an improvement or stabilization of serum creatinine (SCr; 2.3 +/- 0.9 mg/dL at onset of treatment, 2 +/- 1.5 mg/dL at the end of follow-up) together with decreased proteinuria (11.2 +/- 3.3 vs. 5.2 +/- 6.7 g/24 h). At the end of the follow-up 58% of group II patients had a SCr value < or =1.5 mg/dL and 36% showed a complete or partial remission, whereas no patient in group I showed remission. After four years of follow-up the probability of renal survival without dialysis was 55% in group I and 90% in group II (P < 0.001), and after seven years the renal survival was 20% and 90%, respectively (P < 0.001). Side effects of immunosuppressive treatment were uncommon but severe, as two patients suffered Pneumocystis carinii pneumonia.

CONCLUSION

A course of immunosuppressive treatment administered early at the onset of renal function decline induces a favorable effect in most of patients with MGN and deteriorating renal function. Untreated patients progressed without exception toward advanced renal failure.

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.

Use of mycophenolate mofetil in resistant membranous nephropathy

Membranous nephropathy (MN) is a common cause of nephrotic syndrome. Optimal therapy for this disease is still debated. We report our experience using mycophenolate mofetil (MMF), an immunosuppressive agent widely used in transplant recipients, to treat 16 nephrotic patients with MN. All patients had biopsy-documented MN; secondary forms were ruled out. Fifteen patients had steroid-resistant disease; cytotoxic agents had failed in 6 patients and cyclosporine therapy had failed in 5 patients. Patients were treated with MMF (dose range, 500 to 2,000 mg) for a mean of 8 months. Six patients experienced a halving of proteinuria, which occurred after a mean duration of 6 months of therapy. Partial remissions occurred in 2 patients. There were no significant changes in mean values for serum creatinine, serum albumin, or proteinuria. Mean cholesterol levels were significantly less. Side effects of MMF were infrequent and generally mild. In summary, MMF appears to reduce proteinuria in some patients with idiopathic MN previously resistant to steroids, cytotoxic agents, or cyclosporine. Further trials with this agent are warranted.

Prediction in idiopathic membranous nephropathy

BACKGROUND

Results of the prognosis of idiopathic membranous nephropathy are conflictive and prevent an effective risk stratification. These conflicts are explained in part by insufficient consideration of methodological principles for prognostic research. This cohort study is aimed at identifying clinical predictors for risk stratification while paying particular attention to methodology.

METHODS

We studied 120 patients with idiopathic membranous nephropathy. Baseline data were extracted at the time of diagnostic renal biopsy, and patients were followed prospectively. Predictors were identified for the end points end-stage renal failure (ESRF) and ESRF or death.

RESULTS

From the 120 patients followed for a median of five years (1 to 24 years), 19% developed end-stage renal failure or deterioration of renal function. Proteinuria of more than 3.5 g/day persisted in 34%, and 47% were in complete or partial remission. The Kaplan-Meier estimated probability of renal survival was 91 +/- 3% at five years and 75 +/- 6% at ten years. The predictors for the primary outcome, ESRF, identified in a Cox proportional hazards model, were histological stage (Ehrenreich-Churg) III-IV (hazard ratio 5.3, CI 1.9 to 15.0, P = 0.002) and nephrotic syndrome (hazard ratio 7.9, CI 1.1 to 61.5, P = 0.04); the predictors for the secondary outcome, ESRF or patient death, were histological stage III-IV (hazard ratio 2.8, CI 1.3 to 6.0, P = 0.008), nephrotic syndrome (hazard ratio 3.0, CI 1.1 to 8.0, P = 0.003) and comorbidity (hazard ratio 2.8, CI 1.3 to 5.9, P = 0.007). Nephrotic syndrome and histological stage III-IV allowed the demarcation of the high-risk group from the remaining patients (P < 0.0001).

CONCLUSION

Histological stage, nephrotic syndrome, and comorbidity predict end-stage renal failure or death in idiopathic membranous nephropathy. Identification of the high-risk group at the time of diagnostic renal biopsy will permit appropriate treatment to be targeted to the patients who might benefit the most from the therapy in future clinical trials.