Idiopathic membranous nephropathy: management strategies

Therapies for Membranous Nephropathy: A Tale From the Old and New Millennia

Primary Membranous Nephropathy (PMN) is the most frequent cause of nephrotic syndrome in adults. If untreated, PMN can lead to end-stage renal disease; moreover, affected patients are at increased risk of complications typical of nephrotic syndrome such as fluid overload, deep vein thrombosis and infection. The association of PMN with HLA-DQA1 and the identification in around 70% of cases of circulating autoantibodies, mainly directed towards the phospholipase A2 receptor, supports the autoimmune nature of the disease. In patients not achieving spontaneous remission or in the ones with deteriorating kidney function and severe nephrotic syndrome, immunosuppression is required to increase the chances of achieving remission. The aim of this review is to discuss the evidence base for the different immunosuppressive regimens used for PMN in studies published so far; the manuscript also includes a section where the authors propose, based upon current evidence, their recommendations regarding immunosuppression in the disease, while highlighting the still significant knowledge gaps and uncertainties.

Efficacy and safety of cyclosporine A in the treatment of idiopathic membranous nephropathy in an Asian population

INTRODUCTION

The efficacy of cyclosporine A (CsA) in the treatment of idiopathic membranous nephropathy (IMN) is unclear. This meta-analysis was conducted to assess the efficacy and the safety of CsA in the treatment of IMN in Asians.

METHODS

We searched the Pubmed, China Biomedical Database, CNKI, Wanfang Data, VIP, and EMBASE (November 30, 2018) systematically to identify the appropriate randomized controlled trials (RCTs) reporting the efficacy and the safety of CsA and glucocorticoid (GC) treatment vs other immunosuppressants and GC on patients with IMN in Asian populations.

RESULTS

The CsA treated group entered complete remission (CR) faster (3 months) than a cyclophosphamide (CTX) group. While the CsA group lower inefficacy rates and higher total remission (TR, CR, or partial remission) than the CTX group in the total treatment (3 months, 6 months, and 12 months), it had a higher relapse rate. As for the CsA group vs the tacrolimus (TAC) group, the TAC had a significant effect in increasing the CR and the TR, with decreased no remission. With the therapeutic regimens of CsA+GC vs CTX+GC, the CsA exhibited better efficacy in lowering the proteinuria levels only at 12 months, not at 3 months or 6 months. Severe events like leucopenia, hemorrhagic cystitis, and alopecia were observed in the CTX group. Gingival hyperplasia, hirsutism, and elevated blood pressure were reported only in the CsA group. Gastrointestinal syndrome, liver function lesion, happened more frequently in the CTX group, and elevated uric acid was more common in the CsA group.

CONCLUSIONS

In brief, the CsA has better efficacy than the CTX group in the Asian population, with mild adverse effects but higher relapse rates in short-term treatment.

Increased ratio of ICOS(+) /PD-1(+) follicular helper T cells positively correlates with the development of human idiopathic membranous nephropathy

To identify the frequencies of different subsets of peripheral blood follicular helper T (Tfh) cells in human idiopathic membranous nephropathy (IMN), 39 patients with new onset IMN and 18 age- and gender-matched healthy controls (HC) were enrolled for this study. The frequency of Tfh cells in venous blood were measured by flow cytometry, while concentration of serum IL-21 was detected by enzyme-linked immunosorbent assay. Correlation between the clinical features of IMN and Tfh cells was assessed by Spearman's rank correlation test. Overall, the frequencies of total, ICOS(+) , and PD-1(+) Tfh cells were increased in IMN patients, while the ratio of ICOS(+) /PD-1(+) Tfh cells positively correlated with IMN progression. However, the elevated serum IL-21 level in three subgroups of IMN patients, stratified based on 24-h urine protein levels, was not statistically significant compared to HC. Nonetheless, intracellular IL-21 in Tfh cells was generally increased in all IMN patients, and closely correlated with IMN development. Finally, the frequency of IL-21(+) Tfh cells and the ratio of ICOS(+) /PD-1(+) Tfh cells were positively correlated with the estimated 24-h urine protein of IMN patients. The data indicated that Tfh cells contribute to the pathogenicity of IMN. The ratio of ICOS(+) /PD-1(+) Tfh cells and the frequency of IL-21(+) Tfh cells may be indicators for evaluating the IMN development.

Two cases of idiopathic membranous nephropathy treated with rituximab

Idiopathic membranous nephropathy is a common cause of nephrotic syndrome, and has been reported as a cause of idiopathic primary glomerulonephropathy in up to 90% of patients. However, the treatment options remain controversial. We report two cases of idiopathic membranous nephropathy that were treated with rituximab. A 54-year-old man and a 64-year old man were admitted for rituximab therapy. They had previously been treated with combinations of immunosuppressive agents including cyclophosphamide, cyclosporine, mycophenolate, and steroids. However, the patients' heavy proteinuria was not resolved. Both patients received rituximab therapy, 2 weeks apart. After several months of follow-up and a second round of rituximab treatment for each patient, their proteinuria decreased and partial remission of disease was achieved in both patients.

Efficacy and safety of mycophenolate mofetil versus cyclophosphamide for induction therapy of lupus nephritis: a meta-analysis of randomized controlled trials

INTRODUCTION

Whether mycophenolate mofetil is superior to cyclophosphamide as induction therapy for lupus nephritis (LN) remains controversial.

OBJECTIVE

Our objective was to investigate the efficacy and safety of mycophenolate mofetil compared with cyclophosphamide as induction therapy for LN patients.

METHODS

Randomized controlled trials (RCTs) on humans were identified in searches of PubMed/MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (all to 1 December 2011). Studies that compared the efficacy and safety between mycophenolate mofetil and cyclophosphamide as induction therapy in LN patients were selected. Methodological quality of the included trials was assessed according to Cochrane criteria and Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The fixed effects model was applied for pooling where there was no significant heterogeneity, otherwise the random effects model (Dersimonian and Laird method) was performed.

RESULTS

Seven trials were identified, including 725 patients. The Dersimonian and Laird method was applied for renal remission in the presence of significant heterogeneity, and no statistically significant differences were distinguished between mycophenolate mofetil and cyclophosphamide. To explore the possible source of heterogeneity, meta-regression was performed. It was suggested that no obvious study- or patient-level factors could explain interstudy heterogeneity with statistical significance. Among all these factors, the mode of administration of cyclophosphamide could explain most of the heterogeneity, although the coefficient was insignificant. Therefore, we performed a sensitivity analysis by excluding the trial in which cyclophosphamide was administered orally instead of intravenously, which suggested that mycophenolate mofetil was more effective than intravenous cyclophosphamide for inducing complete remission (relative risk [RR] 1.72; 95% CI 1.17, 2.55; p = 0.006) and complete or partial remission (RR 1.18; 95% CI 1.04, 1.35; p = 0.01). In addition, mycophenolate mofetil was superior to cyclophosphamide for significantly reducing end-stage renal disease (ESRD) or death (RR 0.64; 95% CI 0.41, 0.98; p = 0.04). For the safety comparison, lower risks of leukopenia, amenorrhoea and alopecia, and a higher risk of diarrhoea were found with mycophenolate mofetil. No statistical differences in infection and gastrointestinal symptoms were distinguished between mycophenolate mofetil and cyclophosphamide. The relatively small number and the open-label fashion of eligible RCTs may limit the value of our meta-analysis.

CONCLUSIONS

Mycophenolate mofetil is superior to intravenous cyclophosphamide for inducing renal remission, and has a significant advantage over cyclophosphamide for reducing ESRD or death. Furthermore, mycophenolate mofetil has lower risks of leukopenia, amenorrhoea and alopecia, but a higher risk of diarrhoea than cyclophosphamide. However, our conclusions need to be proved further in larger well designed trials.

Membranous nephropathy in a 13-year-old boy with common variable immunodeficiency

Various forms of hypogammaglobulinemia can occur in patients with autoimmune diseases and vice versa. We report a 13-yr-old boy with membranous nephropathy and common variable immunodeficiency. He presented with the nephrotic syndrome, pneumonia with bronchiectasis, and profound hypogammaglobulinemia. Renal biopsy showed diffusely thickened glomerular capillary walls with 'spikes' suggesting a membranous nephropathy. Secondary causes were ruled out by laboratory studies; however, heavy proteinuria persisted with steroid therapy. Cyclosporine and intravenous immunoglobulin were added, and the patient was discharged with decreased proteinuria. Hypogammaglobulinemia may have a deleterious impact on the immune dysregulation in some patients with membranous nephropathy.

Association of phospholipase A2 receptor 1 polymorphisms with idiopathic membranous nephropathy in Chinese patients in Taiwan

Background

Idiopathic membranous nephropathy (IMN) is one of the most common forms of autoimmune nephritic syndrome in adults. The purpose of this study is to evaluate whether polymorphisms of PLA2R1 affect the development of IMN.

Methods

Taiwanese-Chinese individuals (129 patients with IMN and 106 healthy controls) were enrolled in this study. The selected single nucleotide polymorphisms (SNPs) in PLA2R1 were genotyped by real-time polymerase chain reaction using TaqMan fluorescent probes, and were further confirmed by polymerase chain reaction-restriction fragment length polymorphism. The roles of the SNPs in disease progression were analyzed.

Results

Genotype distribution was significantly different between patients with IMN and controls for PLA2R1 SNP rs35771982 (p = 0.015). The frequency of G allele at rs35771982 was significantly higher in patients with IMN as compared with controls (p = 0.005). In addition, haplotypes of PLA2R1 may be used to predict the risk of IMN (p = 0.004). Haplotype H1 plays a role in an increased risk of IMN while haplotype H3 plays a protective role against this disease. None of these polymorphisms showed a significant and independent influence on the progression of IMN and the risk of end-stage renal failure and death (ESRF/death). High disease progression in patients having C/T genotype at rs6757188 and C/G genotype at rs35771982 were associated with a low rate of remission.

Conclusions

Our results provide new evidence that genetic polymorphisms of PLA2R1 may be the underlying cause of IMN, and the polymorphisms revealed by this study warrant further investigation.