Report of the ASFA Apheresis Registry Study on Focal Segmental Glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is one of the causes of end-stage kidney disease. The etiology is not fully understood, and standardized treatments are not established. We created a registry on apheresis for post-transplant FSGS through the Renal Subcommittee in the Research Committee in the American Society for Apheresis (ASFA), and here is our first report. Members of the renal subcommittee from seven centers in the United States contributed data collection on demographic, clinical course, and overall outcomes of patients with post-transplant recurrence of FSGS treated with therapeutic plasma exchange (TPE) between 2015 and 2020. The TPE data, including frequency and replacement fluid for TPE, are also investigated. The median age at diagnosis of FSGS and first transplantation among 26 patients was 12.7 and 21 years, respectively. The FSGS recurred at a median of 1 day after transplantation, and TPE was performed daily or every other day in the first month and continued at some frequency beyond a year in some cases. Most procedures used albumin as a replacement fluid and citrate anticoagulation, with 1-1.5 plasma volumes exchange. Twelve patients had complete/partial remission by 6 months. The median urine protein/creatinine ratio improved from 4.47 to 1.4 mg/mg within 3 months, and eGFR improved from 26 to 78 mL/min/1.73 m² in a year after TPE started. The study revealed some uniformity in the prescription of TPE, primarily using albumin as replacement fluid and performing 1-1.5 plasma volume exchanges. Observed complication rates were minimal. TPE can be one of the treatments to consider in this condition.