Single-dose Rituximab Therapy for Refractory Idiopathic Membranous Nephropathy: A Single-center Experience

Successful treatment of patients with refractory idiopathic membranous nephropathy with low-dose Rituximab: A single-center experience

BACKGROUND

The recognition of idiopathic membranous nephropathy (IMN) as an autoimmune disease has paved the way for the use of B-cell-depleting agents, such as Rituximab (RTX), which is now a first-line drug for treating IMN with proven safety and efficacy. Nevertheless, the usage of RTX for the treatment of refractory IMN remains controversial and challenging.

AIM

To evaluate the efficacy and safety of a new low-dose RTX regimen for the treatment of patients with refractory IMN.

METHODS

A retrospective study was performed on refractory IMN patients that accepted a low-dose RTX regimen (RTX, 200 mg, once a month for five months) in the Xiyuan Hospital of Chinese Academy of Chinese Medical Sciences’ Department of Nephrology from October 2019 to December 2021. To assess the clinical and immune remission data, we performed a 24 h urinary protein quantification (UTP) test and measured the serum albumin (ALB) and serum creatinine (SCr) levels, phospholipase A2 receptor (PLA2R) antibody titer, and CD19⁺ B-cell count every three months.

RESULTS

A total of nine refractory IMN patients were analyzed. During follow-up conducted twelve months later, the results from the 24 h UTP decreased from baseline [8.14 ± 6.05 g/d to 1.24 ± 1.34 g/d (P < 0.05)] and the ALB levels increased from baseline [28.06 ± 8.42 g/L to 40.93 ± 5.85 g/L (P < 0.01)]. Notably, after administering RTX for six months, the SCr decreased from 78.13 ± 16.49 μmol/L to 109.67 ± 40.87 μmol/L (P < 0.05). All of the nine patients were positive for serum anti-PLA2R at the beginning, and four patients had normal anti-PLA2R titer levels at six months. The level of CD19⁺ B-cells decreased to 0 at three months, and CD19⁺ B-cell count remained at 0 up until six months of follow-up.

CONCLUSION

Our low-dose RTX regimen appears to be a promising treatment strategy for refractory IMN.

Clinical efficacy and safety of rituximab with membranous nephropathy: a meta-analysis

INTRODUCTION

Membranous nephropathy (MN) is an organ-specific autoimmune disease, and its prevalence is increasing. B lymphocytes activated by T cells produce antibodies. CD19+/CD20+ plasma cells may contribute to autoantibody and alloantibody production. Rituximab has been effective in treating MN in many clinical trials. Thus, we conducted a meta-analysis to explore the clinical efficacy and safety of rituximab with MN.

MATERIAL AND METHODS

We searched Embase, PubMed, Cochrane Library and ClinicalTrials.gov without language or publication date limitations. Studies were classified in high-risk, medium-risk and low-risk groups based on baseline proteinuria. Follow-up periods and different administrations of rituximab were also compared. Complete remission (CR) and partial remission (PR) were assessed to measure the efficacy of rituximab, and adverse effects were also extracted. Dichotomous data were expressed by the odds ratio (OR), and the 95% confidence intervals (95% CI) were used for the recruited studies.

RESULTS

Fourteen articles, including 17 studies, were included in this meta-analysis. The pooled OR of overall PR and CR remission rate was 0.58 (95% CI: 0.53-0.63; p = 0.003). No studies belonged to the low-risk group. The overall PR and CR remission rate in the medium-risk group was 0.56 (95% CI: 0.36-0.73; p = 0.57). The pooled OR of overall PR and CR remission rate in the high-risk group was 0.59 (95% CI: 0.53-0.65; p = 0.03). At the 12-month follow-up, the pooled OR of overall PR and CR remission rate was 0.51 (95% CI: 0.43-0.59; p = 0.72). At the 24-month follow-up, the pooled OR of overall PR and CR remission rate was 0.71 (95% CI: 0.48-0.86; p = 0.07). The pooled OR of efficacy of rituximab at 375 mg/m² × 4 was 0.63 (95% CI: 0.55-0.70; p = 0.001). Rituximab was tolerated in MN, and most adverse effects were mild. The pooled OR of infusion reaction rate of rituximab was 0.25 (95% CI: 0.13-0.44; p = 0.01) in MN. The pooled OR of cardiovascular-related event rate of rituximab in MN was 0.04 (95% CI: 0.02-0.11). The pooled OR of infection rate of rituximab in MN was 0.06 (95% CI: 0.03-0.12; p < 0.00001).

CONCLUSIONS

Rituximab is safe and effective in MN and a promising alternative treatment. More randomized control trials and studies on the role of MN are expected.

Tripterygium wilfordii multiglycosides combined with prednisone in the treatment of idiopathic membranous nephropathy: A protocol for a systematic review and meta-analysis

AIM

The aim of this review is to assess the efficacy and safety of tripterygium wilfordii multiglycosides combined with prednisone in the treatment of idiopathic membranous nephropathy.

BACKGROUND

Tripterygium wilfordii multiglycosides, a Chinese patent medicine, is widely in-depth research in China, and is proved to have anti-inflammatory and immunosuppressive effect. It has been extensively used in China for the treatment of autoimmune diseases, such as idiopathic membranous nephropathy (IMN). However, there has no relevant systematic review studied on its effects and safety been reported. We plan to perform a systematically reviewing to assess the efficacy and safety of tripterygium wilfordii multiglycosides combined with hormones in the treatment of IMN.

METHODS

Seven electronic databases will be searched to identify eligible trials. Randomized controlled trials (RCTs) that compared tripterygium wilfordii multiglycosides combined with prednisone versus standard therapy are included. Methodological quality is assessed using the Cochrane Collaboration Risk of Bias tool. A random- or fixed-effect model is used to analyze outcomes that are expressed as risk ratios (RRs) or mean differences (MD), and the I statistic is used to assess heterogeneity.

RESULTS

A high-quality synthesis of current evidence of tripterygium wilfordii multiglycosides combined with prednisone in the treatment of idiopathic membranous nephropathy will be provided in this study.

CONCLUSION

This systematic review will provide evidence of whether tripterygium wilfordii multiglycosides is an effective intervention for idiopathic membranous nephropathy.PROSPERO registration number: No.CRD42018118179.

Therapeutic efficacy of rituximab for the management of adult-onset steroid-dependent nephrotic syndrome: a retrospective study

BACKGROUND

Recent reports have described the efficacy of rituximab in treating steroid-dependent nephrotic syndrome (SDNS) in pediatric patients. However, few reports describe data regarding adult-onset SDNS. We investigated the efficacy of rituximab for the management of adult-onset SDNS.

METHODS

We performed a retrospective cohort study investigating eight patients with adult-onset SDNS who were treated with rituximab. Clinical data were obtained at the initiation of rituximab therapy. The primary outcomes evaluated were successful suppression of relapses and CD19+ cells after rituximab treatment. The corticosteroid- and immunosuppressant-sparing effect and adverse events were additionally evaluated.

RESULTS

All eight patients were diagnosed with minimal change nephrotic syndrome and received immunosuppressants in addition to corticosteroid. Total number of relapses was 10.5 times as a median value. Rituximab administration was repeated in two patients, whereas six received single-dose rituximab. Three of eight (37.5%) patients showed relapse after rituximab therapy. A rituximab-induced depletion in CD19+ cells noted initially was followed by their reappearance in all patients. There were cases with no relapse after the reappearance of CD19+ cells. The median relapse time pre- and post-rituximab therapy showed a decrease from 1 time/year (interquartile range [IQR] 1-3 times/year) to 0 time/year (IQR 0-1 time/year). Rituximab treatment induced a significant reduction in the required doses of corticosteroid and cyclosporine (P < 0.01). No serious adverse events were observed.

CONCLUSION

Rituximab treatment was effective not only in childhood-onset but also in adult-onset SDNS. Further studies are needed to establish optimal treatment regimens.

A case report of remission of refractory membranous nephropathy progressing to stage 4 chronic kidney disease using low-dose rituximab: A long-term follow-up

RATIONALE

As suggested by the 2012 KDIGO guidelines, persistent elevation of serum creatinine > 3.5 mg/dl (> 309 μmol/l) (or an estimated glomerular filtration rate < 30 ml/min per 1.73 m is one of contradictions for the use of immunosuppressive therapy in membranous nephropathy.

PATIENT CONCERNS

A 45-year-old man with membranous nephropathy negative for serum anti-phospholipase-A2-receptor antibody, showed no response to corticosteroids and cyclophosphamide. He progressed to chronic kidney disease stage 4 (CKD4) under tacrolimus and relapsed after withdrawal.

DIAGNOSES

The patient received repeated renal biopsy, comfirming the diagnosis of membranous nephropathy with progressive glomerular and tubulointerstitial scarring.

INTERVENTIONS

He was treated with successfully four times with lose-dose (180 mg/m every 2-3 months) rituximab (RTX) depending on his B cell counts, aiming to remain at 0-5 cells/μl.

OUTCOMES

The patient was followed-up for almost 6 years. He achieved a partial remission at 11 months and a complete remission of the nephritic range of proteinuria at 34 months following infusion of RTX. RTX was well tolerated and the patient's renal function improved. He had no edema and his dosage of corticosteroids could be discontinued.

LESSONS

This case strongly suggested that rituximab has promising therapeutic significance, even in patients progressing to CKD4.

Membranous Nephropathy and Anti-Podocytes Antibodies: Implications for the Diagnostic Workup and Disease Management

The discovery of circulating antibodies specific for native podocyte antigens has transformed the diagnostic workup and greatly improved management of idiopathic membranous nephropathy (iMN). In addition, their identification has clearly characterized iMN as a largely autoimmune disorder. Anti-PLA2R1 antibodies are detected in approximately 70% to 80% and anti-THSD7A antibodies in only 2% of adult patients with iMN. The presence of anti-THSD7A antibodies is associated with increased risk of malignancy. The assessment of PLA2R1 and THSD7A antigen expression in glomerular immune deposits has a better sensitivity than measurement of the corresponding autoantibodies. Therefore, in the presence of circulating anti-podocytes autoantibodies and/or enhanced expression of PLA2R1 and THSD7A antigens MN should be considered as primary MN (pMN). Anti-PLA2R1 or anti-THSD7A autoantibodies have been proposed as biomarkers of autoimmune disease activity and their blood levels should be regularly monitored in pMN to evaluate disease activity and predict outcomes. We propose a revised clinical workup flow for patients with MN that recommends assessment of kidney biopsy for PLA2R1 and THSD7A antigen expression, screening for circulating anti-podocytes antibodies, and assessment for secondary causes, especially cancer, in patients with THSD7A antibodies. Persistence of anti-podocyte antibodies for 6 months or their increase in association with nephrotic proteinuria should lead to the introduction of immunosuppressive therapies. Recent data have reported the efficacy and safety of new specific therapies targeting B cells (anti-CD20 antibodies, inhibitors of proteasome) in pMN which should lead to an update of currently outdated treatment guidelines.