Apheresis in Adult With Refractory Idiopathic Nephrotic Syndrome on Native Kidneys

Efficacy of extracorporeal plasma therapy for adult native kidney patients with Primary FSGS: a Systematic review

PURPOSE

This study aimed to assess efficacy of extracorporeal plasma therapy (EPT), including plasmapheresis (PE), immunoadsorption (IA), low-density lipoprotein apheresis (LDL-A), and lymphocytapheresis (LCAP) for adult native kidney patients with primary focal segmental glomerulosclerosis (FSGS).

METHODS

A literature search was conducted using MEDLINE, EMBASE and Cochrane Databases through August 2022. Studies that reported outcomes of EPT in adult native kidneys with primary FSGS were enrolled.

RESULTS

18 studies with 104 therapy-resistant or refractory primary native FSGS patients were identified. Overall EPT response rate was 56%, with long-term benefit of 46%. Of the 101 non-hemodialysis (HD) patients, 54% achieved remission, with 30% complete remission (CR) and 23% partial remission (PR). Of 31 patients with PE, response rate was 65%; CR and PR rates were 27% and 37% in 30 non-HD patients. Of 61 patients with LDL-A, the response rate was 54%; CR and PR rates were 41% and 3% in 29 non-HD patients. Of 10 patients with IA, response rate was 40%. Of 2 patients with LCAP, 1 achieved CR, and one developed renal failure. All 3 HD patients showed increase in urine output and gradual decrease in urine protein excretion following PE (n = 1) or LDL-A (n = 2). 2 of 3 HD patients ultimately discontinued dialysis.

CONCLUSION

EPT with immunosuppressive therapy showed benefit in some patients with refractory primary FSGS, and PE appeared to have a higher response rate.

Current understanding of the molecular mechanisms of circulating permeability factor in focal segmental glomerulosclerosis

The pathogenetic mechanisms underlying the onset and the post-transplant recurrence of primary focal segmental glomerulosclerosis (FSGS) are complex and remain yet to be fully elucidated. However, a growing body of evidence emphasizes the pivotal role of the immune system in both initiating and perpetuating the disease. Extensive investigations, encompassing both experimental models and patient studies, have implicated T cells, B cells, and complement as crucial actors in the pathogenesis of primary FSGS, with various molecules being proposed as potential "circulating factors" contributing to the disease and its recurrence post kidney-transplantation. In this review, we critically assessed the existing literature to identify essential pathways for a comprehensive characterization of the pathogenesis of FSGS. Recent discoveries have shed further light on the intricate interplay between these mechanisms. We present an overview of the current understanding of the engagement of distinct molecules and immune cells in FSGS pathogenesis while highlighting critical knowledge gaps that require attention. A thorough characterization of these intricate immune mechanisms holds the potential to identify noninvasive biomarkers that can accurately identify patients at high risk of post-transplant recurrence. Such knowledge can pave the way for the development of targeted and personalized therapeutic approaches in the management of FSGS.

Efficacy of intravenous combined immunosuppression with plasmapheresis in adult patients with refractory primary focal segmental glomerulosclerosis

BACKGROUND

Primary focal segmental glomerulosclerosis (FSGS) treatment is based on immunosuppressive therapies. Since refractory disease is common, alternative methods are emerging. One of these methods is plasmapheresis with intravenous cyclosporine and corticosteroids, and it could be an option in post-transplant recurrent FSGS. We retrospectively investigated the efficacy of this combined treatment in adult patients with refractory primary FSGS.

METHODS

Seven refractory primary FSGS patients were included. Demographics, estimated glomerular filtration rates, serum albumin levels, urine protein/creatinine ratios, and previous treatments were evaluated. Also, complications and remission rates were assessed.

RESULTS

Median patient age was 23 years. Median duration of diagnosis was 2 years. Median number of plasmapheresis sessions was 14. Five of seven patients (71.4%, one complete, four partial remissions) were responders after the protocol. Changes in serum albumin levels and proteinuria after protocol were statistically significant (P = 0.018 and P = 0.018, respectively). eGFR levels did not change statistically (P = 0.753). Median follow-up duration after the treatment was 17 months. However, two patients experienced disease relapse (28.5%). End-stage kidney disease was developed in two patients. Sustained remission rate was 42.8% during follow-up (One complete and two partial remissions). Also, 42.8% of patients experienced catheter infections. Catheter-associated thrombosis that required surgery was observed in a patient.

CONCLUSIONS

Plasmapheresis combined with intravenous cyclosporine and corticosteroids could be an option in refractory primary FSGS. High response rates after this protocol were encouraging. However, the relapsing disease was observed after the cessation of apheresis. Also, complications of the protocol could limit the applicability.