Prognosis and risk factors for idiopathic membranous nephropathy with nephrotic syndrome in Japan

Japan Renal Biopsy Registry and Japan Kidney Disease Registry: Committee Report for 2009 and 2010

The Japan Renal Biopsy Registry (J-RBR) was started in 2007 and the Japan Kidney Disease Registry (J-KDR) was then started in 2009 by the Committee for Standardization of Renal Pathological Diagnosis and the Committee for the Kidney Disease Registry of the Japanese Society of Nephrology. The purpose of this report is to describe and summarize the registered data from 2009 and 2010. For the J-KDR, data were collected from 4,016 cases, including 3,336 (83.1 %) by the J-RBR and 680 (16.9 %) other cases from 59 centers in 2009, and from 4,681 cases including 4,106 J-RBR cases (87.7 %) and 575 other cases (12.3 %) from 94 centers in 2010, including the affiliate hospitals. In the J-RBR, 3,165 native kidneys (94.9 %) and 171 renal grafts (5.1 %) and 3,869 native kidneys (94.2 %) and 237 renal grafts (5.8 %) were registered in 2009 and 2010, respectively. Patients younger than 20 years of age comprised 12.1 % of the registered cases, and those 65 years and over comprised 24.5 % of the cases with native kidneys in 2009 and 2010. The most common clinical diagnosis was chronic nephritic syndrome (55.4 % and 50.0 % in 2009 and 2010, respectively), followed by nephrotic syndrome (22.4 % and 27.0 %); the most frequent pathological diagnosis as classified by the pathogenesis was IgA nephropathy (31.6 % and 30.4 %), followed by primary glomerular diseases (except IgA nephropathy) (27.2 % and 28.1 %). Among the primary glomerular diseases (except IgA nephropathy) in the patients with nephrotic syndrome, membranous nephropathy was the most common histopathology in 2009 (40.3 %) and minor glomerular abnormalities (50.0 %) were the most common in 2010 in native kidneys in the J-RBR. Five new secondary and longitudinal research studies by the J-KDR were started in 2009 and one was started in 2010.

Immunosuppressive treatment for nephrotic idiopathic membranous nephropathy: a meta-analysis based on Chinese adults

Background

Idiopathic membranous nephropathy (IMN) is the most common pathological type for nephrotic syndrome in adults in western countries and China. The benefits and harms of immunosuppressive treatment in IMN remain controversial.

Objectives

To assess the efficacy and safety of different immunosuppressive agents in the treatment of nephrotic syndrome caused by IMN.

Methods

PubMed, EMBASE, Cochrane Library and wanfang, weipu, qinghuatongfang, were searched for relevant studies published before December 2011. Reference lists of nephrology textbooks, review articles were checked. A meta-analysis of randomized controlled trials (RCTs) meeting the criteria was performed using Review Manager.

Main Results

17 studies were included, involving 696 patients. Calcineurin inhibitors had a better effect when compared to alkylating agents, on complete remission (RR 1.61, 95% CI 1.13, to 2.30 P = 0.008), partial or complete remission (effective) (CR/PR, RR 1.29, 95% CI 1.09 to 1.52 P = 0.003), and fewer side effects. Among calcineurin inhibitors, tacrolimus (TAC) was shown statistical significance in inducing more remissions. When compared to cyclophosphamide (CTX), leflunomide (LET) showed no beneficial effect, mycophenolate mofetil (MMF) showed significant beneficial on effectiveness (CR/PR, RR: 1.41, 95% CI 1.16 to 1.72 P = 0.0006) but not significant on complete remission (CR, RR: 1.38, 95% CI 0.89 to 2.13 P = 0.15).

Conclusions

This analysis based on Chinese adults and short duration RCTs suggested calcineurin inhibitors, especially TAC, were more effective in proteinuria reduction in IMN with acceptable side effects. Long duration RCTs were needed to confirm the long-term effects of those agents in nephrotic IMN.

Idiopathic membranous nephropathy: clinical and histologic prognostic features and treatment patterns over time at a tertiary referral center

BACKGROUND

Idiopathic membranous nephropathy (i-MN) is a leading cause of nephrotic syndrome in adults and results in end-stage renal disease in approximately one third of patients. There are few large, long-term US studies evaluating clinical and histologic prognostic factors in i-MN.

METHODS

We describe 132 patients with biopsy-proven i-MN who were followed for a mean period of 68 months at our tertiary referral center from 1977 to 2009, and we analyzed clinical and histologic features that predicted renal outcomes.

RESULTS

The presence of hypertension and treating physician's decision to institute immunosuppression were negative predictors of attaining complete or partial remission. Among clinical variables, impaired renal function (eGFR <60 ml/min/1.73 m(2)) at time of presentation was the only variable at presentation associated with an increased risk of reaching end-stage renal disease. The use of statins and RAAS blockers were protective. The choice of corticosteroids as the initial immunosuppressive agent by referring physicians decreased over time but even in the most recent era (2000-2008) was significant (33%).

CONCLUSION

Renal function at presentation and non-white race were the main predictors of a worse renal outcome. Corticosteroid therapy is still being adopted as first-line therapy in a significant number of patients in this era. The development of guidelines may help clarify the treatment strategies of i-MN.

Membranous nephropathy in Japan: analysis of the Japan Renal Biopsy Registry (J-RBR)

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults. The J-RBR/J-KDR registry developed by the Japanese Society of Nephrology provides nationwide cohort data for epidemiological studies of MN. MN was present in 36.8% of 1,203 primary nephrotic syndrome patients in Japan. In addition, 633 (77.9%) out of 813 MN patients were referred to as "idiopathic," whereas 22.1% were classified as "secondary" and involved conditions such as systemic lupus erythematosus, drug exposure, infections, cancer, and various collagen diseases. The mean age of the MN patients was 62.2 (2-88) years old, their mean eGFR was 76.7 (7.6-154.6) ml/min/1.73 m(2), and 63.3% had hypertension at the time of renal biopsy. On the basis of these findings, half of Japanese idiopathic MN patients have risk factors (age >60, male, or lower eGFR) for end-stage renal failure, and 10% belong to the high-risk group (daily proteinuria of over 8.0 g). Further studies with high-grade evidence should resolve the natural history and therapeutic problems of idiopathic MN in elderly Japanese.

Low glomerular density is a risk factor for progression in idiopathic membranous nephropathy

BACKGROUND

The adverse histological features predicting a progressive loss of renal function in idiopathic membranous nephropathy (IMN), before the establishment of impaired renal function with advanced glomerulosclerosis and/or interstitial fibrosis, are still poorly understood. The present study examined the relationship between the glomerular density (GD; non-sclerotic glomerular number/renal cortical area of biopsy) and the renal prognosis in IMN patients, especially in those without any apparent renal dysfunction at the time of diagnosis.

METHODS

The predictive value of the factors at biopsy, including the GD, on the renal outcome was retrospectively analyzed in the 65 IMN patients with an estimated glomerular filtration rate (eGFR) of ≥ 60 mL/min/1.73 m(2) (mean, 80 mL/min/1.73 m(2)) at biopsy.

RESULTS

The individual values for GD ranged from 1.6 to 6.5/mm(2) with 4-fold variation. A lower GD was associated with progression based on a ≥ 50% reduction in eGFR or reaching to end-stage renal disease. An association between a lower GD and progression was observed, especially in patients with persistent proteinuria of ≥ 1 g/day at follow-up. In contrast, any patients who achieved proteinuria of <1 g/day at follow-up did not show progression regardless of their GD levels. In addition, among the various clinicopathological factors observed, the GD was the only factor at biopsy that independently predicted the slope of the renal function during the observation periods.

CONCLUSION

These results suggest that low GD is a plausible risk factor for progression in IMN patients, especially in those that do not achieve a remission of proteinuria during the follow-up.

Japan Renal Biopsy Registry: the first nationwide, web-based, and prospective registry system of renal biopsies in Japan

BACKGROUND

The Committee for the Standardization of Renal Pathological Diagnosis and the Working Group for Renal Biopsy Database of the Japanese Society of Nephrology started the first nationwide, web-based, and prospective registry system, the Japan Renal Biopsy Registry (J-RBR), to record the pathological, clinical, and laboratory data of renal biopsies in 2007.

METHODS

The patient data including age, gender, laboratory data, and clinical and pathological diagnoses were recorded on the web page of the J-RBR, which utilizes the system of the Internet Data and Information Center for Medical Research in the University Hospital Medical Information Network. We analyzed the clinical and pathological diagnoses registered on the J-RBR in 2007 and 2008.

RESULTS

Data were collected from 818 patients from 18 centers in 2007 and 1582 patients from 23 centers in 2008, including the affiliated hospitals. Renal biopsies were obtained from 726 native kidneys (88.8%) and 92 renal grafts (11.2%) in 2007, and 1400 native kidneys (88.5%) and 182 renal grafts (11.5%) in 2008. The most common clinical diagnosis was chronic nephritic syndrome (47.4%), followed by nephrotic syndrome (16.8%) and renal transplantation (11.2%) in 2007. A similar frequency of the clinical diagnoses was recognized in 2008. Of the native kidneys, the most frequent pathological diagnosis as classified by pathogenesis was immunoglobulin (Ig) A nephropathy (IgAN) both in 2007 (32.9%) and 2008 (30.2%). Among the primary glomerular diseases (except IgAN), membranous nephropathy (MN) was the most common disease both in 2007 (31.4%) and 2008 (25.7%).

CONCLUSIONS

In a cross-sectional study, the J-RBR has shown IgAN to be the most common disease in renal biopsies in 2007 and 2008, consistent with previous Japanese studies. MN predominated in the primary glomerular diseases (except for IgAN). The frequency of the disease and the clinical and demographic correlations should be investigated in further analyses by the J-RBR.

Application of artificial neural networks in estimating predictive factors and therapeutic efficacy in idiopathic membranous nephropathy

Idiopathic membranous nephropathy (IMN) is one of the most frequent causes of the nephrotic syndrome in adults and one of the most common cause of chronic renal failure among primary glomerular diseases. The aim of this study was to develop artificial neural networks (ANN) to investigate factors of poor outcome for IMN and to evaluate the efficacy of different therapeutic protocols. Data were collected retrospectively for 124 patients with IMN (82 males, mean based on the received therapy patients were divided into three groups: corticosteroids only (group 1), cyclophsophamide with corticosteroids (group 2), and so called Ponticelli protocol (group 3). After achieving satisfactory truthfulness of the transcription function of ANN through clustering, we have applied the efficacy analysis to all patients and then compared them to each group separately, and evaluated the influence of initial characteristics on disease outcome as well as the therapy efficacy. The greatest therapy inefficiency was recorded for isolated corticosteroid therapy (29.41%) and the smallest inefficiency for Ponticelli protocol, for which the greatest accuracy of prognosis was recorded (82.09%). The greatest negative prognostic influence had kidney insufficiency (22%), quantitative proteinuria (15%) and index of interstitial infiltration (14%). Based on our results, we can recommend that patients diagnosed with IMN with renal insufficiency, nephrotic syndrome or a high degree of interstitial infiltration at the time of diagnosis should be treated concomitantly with cytotoxic drugs and corticosteroids, particularly with the Ponticelli protocol.

Management of idiopathic membranous nephropathy

IMPORTANCE OF THE FIELD

Idiopathic membranous nephropathy (IMN) can have a variable natural course. Treatments able to induce remission can improve the long-term prognosis. However, the optimal therapy for IMN remains controversial.

AREA COVERED IN THIS REVIEW

We reviewed the historical and current literature from 1979 to 2010 regarding the natural course of IMN and the possible treatments giving special emphasis to randomized controlled trials and to more recent approaches.

WHAT THE READER WILL GAIN

The reader will gain a comprehensive review of the available treatments of IMN. A personal therapeutic algorithm for nephrotic patients with IMN is also provided.

TAKE HOME MESSAGE

At least five different treatments showed efficacy in many (but not all) patients with IMN.

Percutaneous renal artery embolization in a patient with severe nephrotic syndrome which continued after the introduction of hemodialysis

We treated a woman with membranous nephropathy in whom serious nephrotic syndrome (NS) continued even after the introduction of hemodialysis (HD). No response was seen with conservative treatment, including administration of steroids and albumin transfusion and body fluid management with HD. Hypoalbuminemia continued, and management of her general condition was problematic because of the hypotension, edema, pleural and peritoneal effusions. We performed percutaneous renal artery embolization (RAE), voluntary urine output disappeared for a short time, and good clinical course was subsequently seen with sustainable serum albumin levels of around 3 g/dL.

Triple therapy with single daily dose of cyclosporine in Japanese patients with idiopathic membranous nephropathy

OBJECTIVE

The optimal therapeutic approach to patients with idiopathic membranous nephropathy (IMN) remains controversial. In this study, we assessed the efficacy of single daily dose cyclosporine (CsA) combined with low-dose prednisolone (PSL) and an angiotensin II receptor blocker (ARB) in patients with IMN.

METHODS

We studied 13 nephrotic patients (8 men, 5 women) with IMN diagnosed on biopsy. An initial single daily dose of 2 mg/kg, but not exceeding 150 mg, CsA was given for 12 months, tapered by a 25 mg reduction every 2 months. An initial twice-daily dose of 0.5 mg/kg PSL was given for 2 months and was also tapered. An ARB was given to all patients and the same dosage was used throughout the study. Patients were followed up for 6 to 66 months.

RESULTS

Nine patients achieved complete remission at 6.7±2.9 months, and incomplete remission was obtained in the remaining patients. After a follow-up period of 32.7±20.0 months, their serum creatinine and estimated glomerular filtration rate values were similar to baseline levels. The 9 patients who completed the treatment course have not relapsed. Moreover, there were no adverse effects requiring discontinuation of this triple therapy.

CONCLUSION

A single daily dose of CsA combined with a low dose of PSL and an ARB in new-onset nephrotic patients with IMN induced a high remission rate of nephrotic syndrome, with a low incidence of relapse and a low risk of adverse effects. The triple therapy and prospective follow-up shows potential as a treatment approach for patients with IMN.

Assessment of renal fibrosis with diffusion-weighted MR imaging: study with murine model of unilateral ureteral obstruction

PURPOSE

To test, in a murine model of unilateral ureteral obstruction (UUO), whether the magnetic resonance (MR) imaging-derived apparent diffusion coefficient (ADC) changes during the progression of renal fibrosis and correlates with the histopathologic changes observed in renal fibrogenesis.

MATERIALS AND METHODS

This study was approved by the institutional animal care and use committee. A UUO was created in each of 14 mice. In five mice, longitudinal diffusion-weighted (DW) imaging was performed before the UUO (day 0) and on days 3 and 7 after the UUO and was followed by histopathologic analysis. The nine remaining mice were examined with cross-sectional studies on days 0 (n = 4) and 3 (n = 5). ADCs were measured with a spin-echo echo-planar sequence at five b values ranging from 350 to 1200 sec/mm(2). Differences in ADC among the time points and between the sides were assessed by using Tukey-Kramer and Student t tests, respectively. ADC was correlated with cell density and alpha-smooth muscle actin (alpha-SMA, a marker of myofibroblasts) expression at linear regression analysis.

RESULTS

Histopathologic examination revealed typical renal fibrosis on the side with UUO. The ADC decreased over time on the UUO side, from (1.02 +/- 0.06 [standard deviation]) x 10(-3) mm(2)/sec on day 0 to (0.70 +/- 0.08) x 10(-3) mm(2)/sec on day 3 (P < .001) and (0.57 +/- 0.10) x 10(-3) mm(2)/sec on day 7 (P < .001). The percentage change in ADC was greater on the UUO side than on the contralateral side on days 3 (29% +/- 9, P = .05) and 7 (44% +/- 11, P < .01). ADC correlated with both increased cell density and increased alpha-SMA expression (P < .001 for both correlations).

CONCLUSION

An ADC decrease in renal fibrosis is associated with an increased number of cells, including fibroblasts. ADC has the potential to serve as a sensitive noninvasive biomarker of renal fibrosis.

A patient with refractory nephrotic syndrome withdrawn from peritoneal dialysis

A 67-year-old woman was admitted to our hospital because of anasarca due to refractory nephrotic syndrome and chronic renal insufficiency. Laboratory data indicated serum total protein of 4.8 g/dl, albumin of 1.5 g/dl, creatinine of 1.9 mg/dl and BUN of 17 mg/dl. Urinary protein excretion was 7.8 g/day. Because of severe atrophy of both kidneys, neither renal biopsy nor immunosuppressive treatment was performed. Since conservative management including bed rest, diet therapy, limitation of water intake and administration of diuretics was not effective, peritoneal dialysis therapy using icodextrin only at night was started. The amount of water removal was steadily secured without progressing renal dysfunction or decreasing urine volume. From day 290 onward, the urinary protein excretion was decreased to show complete remission and urine volume increased. On day 528, peritoneal dialysis was discontinued, and thereafter only peritoneal lavage was performed. On day 858, the catheter was removed from the abdominal cavity, and thereafter diuretics could be discontinued. The reason for the dramatic reduction of urinary protein in this patient is unclear. However, it is possible that the primary disease such as membranous nephritis showed remission while the patient was undergoing icodextrin peritoneal dialysis, which preserves renal function but not extracorporeal ultrafiltration or hemodialysis. Icodextrin peritoneal dialysis may be an alternative to hemodialysis for refractory fluid overload in patients with nephrotic syndrome and may have the advantage of preserving renal function.

The natural history of the non-nephrotic membranous nephropathy patient

BACKGROUND AND OBJECTIVES

Although early studies suggest that patients with idiopathic membranous nephropathy (MGN) and subnephrotic range proteinuria overall do well, these studies were small and follow-up was short or difficult to discern.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Three hundred ninety-five cases of idiopathic MGN with at least 12 mo of follow-up from the Toronto Glomerulonephritis Registry were reviewed to determine the outcome of the subgroup of patients that presented with subnephrotic range proteinuria. Onset and follow-up data included mean arterial pressure (MAP) and creatinine clearance (CrCl) as determined by the Cockcroft-Gault equation. Outcome variables included the rate of progression (slope of CrCl), 50% reduction in initial CrCl, and end-stage renal disease (ESRD).

RESULTS

One hundred eight (27% of the total) patients presented with subnephrotic proteinuria and almost 40% (42 of 108) of this subgroup remained subnephrotic. Their long-term slope was -0.93 ml/min/yr. In contrast, those who subsequently developed nephrotic range proteinuria had a progression rate almost four times faster (-3.52 ml/min/yr). The majority who developed nephrotic syndrome did so within the first year of follow-up. The only distinguishing baseline feature between the two groups was a higher level of urine protein in the group that subsequently developed nephrotic syndrome (1.98 [0.3 to 3.4] versus 2.43 [0.5 to 3.4] g/d).

CONCLUSIONS

Patients with MGN and sustained subnephrotic range proteinuria have an excellent prognosis. Conservative management with close monitoring is recommended given the difficulty predicting which patients will develop nephrotic range proteinuria and then progress more rapidly.

Controversies in the treatment of idiopathic membranous nephropathy

Optimum treatment of idiopathic membranous nephropathy is both controversial and challenging. The most extensively studied and frequently used immunosuppressive regimens for this disease comprise alkylating agents plus corticosteroids or ciclosporin. All of these treatment options have inherent problems: they are not effective in all patients, partial-rather than complete-remissions are common, adverse effects are worrisome, and relapses after treatment cessation remain problematic. Alternative immunosuppressive agents have been tested in an effort to overcome these unresolved issues. This paper reviews the available evidence regarding both established and new agents for the treatment of patients with idiopathic membranous nephropathy, with an emphasis on the results of the most recent clinical trials.

Long-term outcomes of idiopathic membranous nephropathy in Japanese patients treated with low-dose cyclophosphamide and prednisolone

BACKGROUND

Treatment with cyclophosphamide and steroids for idiopathic membranous nephropathy (IMN) is effective in Caucasian patients, but the cumulative cyclophosphamide dosage exceeds 10 g and includes steroid pulse therapy. Adverse effects and difficulties with repeating treatment are major limitations. We studied the long-term outcomes of low-dose cyclophosphamide and prednisolone therapy in Japanese patients, who were thought to have relatively benign IMN compared with Caucasian patients.

METHODS

This is a prospective cohort study of 103 consecutive Japanese patients with IMN and nephrotic syndrome. Patients were treated with cyclophosphamide (50 mg/day for the first 3 months and 25 mg/day for the next 3 months) and prednisolone (30 mg/day for the first week and the dosage was gradually tapered to withdraw by 2 years). Additional therapies were allowed for initial treatment failure or relapse.

RESULTS

With a mean observation period of 8.5 years, 90 patients (87.4%) achieved proteinuria of <1 g/day and 78 (75.7%) achieved complete remission. A total of 27 patients did not respond to initial treatment and 30 patients had relapses after remission. Of these patients, 39 received additional therapies. At the last observation, 12 patients had developed renal insufficiency (S-Cr >1.5 mg/dL) but only 2 patients had reached renal death. Multivariate analysis revealed that the duration without remission was the strongest risk factor for renal prognosis. There were 14 deaths, and 8 patients developed cancers during the observation period.

CONCLUSION

Treating nephrotic IMN in Japanese patients with low-dose cyclophosphamide and prednisolone is beneficial for long-term renal prognosis with relatively few adverse effects.

Gene expression profiling of peripheral blood mononuclear cells from patients with minimal change nephrotic syndrome by cDNA microarrays

BACKGROUND

It is hypothesized that minimal change nephrotic syndrome (MCNS) is a consequence of immune cell dysfunction that may lead to release of glomerular permeability factors. However, the nature of such factors remains uncertain.

METHODS

Using cDNA microarrays, we performed gene expression profiling of peripheral blood mononuclear cells (PBMC) from 2 MCNS patients during nephrosis and remission phases. To confirm the cDNA microarray results, we performed quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses in nephrosis and remission samples from 24 MCNS patients and 10 patients with membranous nephropathy (MN), and from 24 healthy subjects.

RESULTS

Out of 24,446 genes screened, 171 functionally known genes were up-regulated (at least 2-fold) in PBMC from MCNS patients during the nephrosis phase. 21 genes encoded proteins involved in signal transduction and cytokine response. For further examination, we selected two genes encoding provable secretory proteins, chemokine (C-C) ligand 13 (CCL13) and a novel galectin-related protein (HSPC159). The results of quantitative RT-PCR showed that expressions of CCL13 and HSPC159 mRNA in nephrosis PBMC samples were higher than those in remission samples from all 24 MCNS patients examined, while these mRNA expression patterns were variable among 10 MN patients. CCL13 and HSPC159 mRNA expressions in PBMC from MCNS patients in nephrosis were significantly higher than those in nephrotic MN patients and healthy controls.

CONCLUSION

We found that CCL13 and HSPC159 mRNA expressions in PBMC are up-regulated specifically in MCNS patients during the nephrosis phase. Further studies are necessary to clarify whether these expression changes are directly involved in the pathophysiologic processes of MCNS.

Cyclosporin in idiopathic glomerular disease associated with the nephrotic syndrome : workshop recommendations

Management of idiopathic glomerular disease associated with nephrotic syndrome (INS) remains controversial and one of the most complex areas relates to utilization of the drug cyclosporin. This is despite its demonstrated effectiveness in several histologic types of the INS in randomized controlled trials. Cyclosporin is effective in inducing remission of proteinuria in approximately 80% of steroid-sensitive cases of minimal change disease (MCD). Cyclosporin is also effective in both the induction of remission and long-term preservation of renal function in steroid-dependent/-resistant MCD and steroid-resistant focal segmental glomerulosclerosis (FSGS). The overall response rate in FSGS is lower than in MCD, and long-term therapy (>12 months) may be required to both achieve remission and sustain it. Cyclosporin therapy is also of benefit in reducing proteinuria in 70-80% of patients with steroid-resistant membranous nephropathy (MGN). In MGN, the maximum benefit is often delayed compared to MCD (>12 weeks). Cyclosporin is generally well tolerated and safe. The major concern remains the nephrotoxicity, but with careful monitoring of the patient's renal function; minimizing the maintenance dose and utilizing repeat renal biopsy in those receiving long-term therapy, this risk can be minimized. The algorithms have been developed derived from the best evidence in the literature in each of the histologic types to help provide a guide to the integration of cyclosporin into the management of INS for the practicing nephrologist.

A retrospective study on the efficacy of corticosteroid-alone therapy in membranous nephropathy patients

OBJECTIVE

Membranous nephropathy (MN) is the most common cause of adult-onset nephrotic syndrome and its management is still controversial. The aim of this study was to determine the effectiveness of corticosteroid-alone therapy for controlling proteinuria in MN.

METHODS

Twenty-three patients, which had moderate proteinuria (admission 24-hour urinary protein excretion 1.0 to 3.5 g/day) with primary MN were studied retrospectively.

RESULTS

Thirteen patients received corticosteroid-alone therapy combined with rest and dietary therapy (steroid group), while the other 10 patients were treated with rest and diet alone (non-steroid group). These two groups did not differ with respect to their laboratory features at the time of admission. After discharge, 5 of 13 patients of the steroid group dropped out . Therefore, only 8 patients could be followed up. As the result, 5 of 8 patients (62.5%) achieved complete remission (CR) and 3 of 8 patients (37.5%) had incomplete remission (ICR), so none of the patients failed to improve. On the other hand, 3 of 10 patients of the non-steroid group dropped out. Then, 7 patients were followed up. None of the 7 patients showed improvement during follow-up and 5 of these 7 patients were started on corticosteroids. Finally, as this result, 4 of 5 patients (80%) could achieve CR by 2 years after hospital discharge. Moreover, in the remaining 2 patients from the non-steroid group, no remission could be achieved even 2 years after discharge.

CONCLUSION

These results suggest that long-term corticosteroid-alone therapy is beneficial for controlling proteinuria in patients with MN.

Rituximab for Idiopathic Membranous Nephropathy: Who Can Benefit?

Rituximab effectively reduces proteinuria in patients with idiopathic membranous nephropathy (IMN), but response to treatment may vary from patient to patient. The association between baseline clinical, laboratory, and histology covariates and proteinuria reduction was evaluated retrospectively by multiple linear regression analysis at 3 mo after rituximab therapy in 14 patients with IMN with proteinuria > 3.5 g/24 h while on angiotensin-converting enzyme inhibition for at least 6 mo and no previous remissions. The association strength was expressed by standardized beta coefficients (SbetaC). Glomerular (SbetaC = 0.48, P = 0.049) and tubulointerstitial (TI) scores (SbetaC = 0.61, P = 0.003) predicted the outcome. Among glomerular and TI score components, tubular atrophy (SbetaC = 0.59, P = 0.003) and interstitial fibrosis (SbetaC = 0.60, P = 0.001) were significantly associated with 3-mo proteinuria. Urinary protein excretion decreased from 9.1 +/- 4.0 to 4.6 +/- 3.5 g/24 h (P < 0.001) in eight patients with TI score 1.7 but did not change in six with a score > or = 1.7. Nine additional patients with IMN then were allocated prospectively to rituximab treatment on the basis of a TI score < 1.7. Three-month proteinuria decreased in all patients from 8.9 +/- 5.3 to 4.9 +/- 3.9 g/24 h (P < 0.001) and serum albumin increased from 2.2 +/- 0.6 to 2.8 +/- 0.5 mg/dl (P < 0.01). Changes in serum albumin and cholesterol were inversely correlated (P < 0.02, r = -0.44). Rituximab achieved CD20 and CD19 depletion in all patients. In patients with IMN and nephrotic proteinuria despite angiotensin-converting enzyme inhibition therapy, renal biopsy findings may help in predicting response to rituximab and defining selection criteria for randomized trials that aim to assess the risk/benefit profile of B cell target therapy as compared with aspecific immunosuppressants and/or conservative therapy alone.