Can Kunxian Capsule, a Novel Tripterygium Preparation be Used as an Adjuvant Treatment of Early Recurrent Focal Segmental Glomerular Sclerosis After Renal Transplantation? A Case Report

Focal segmental glomerular sclerosis (FSGS) tends to recur after kidney transplantation, particularly when genetic testing is negative. Once the recurrence happens, the renal graft function can rapidly become impaired, following a massive urine protein loss. Despite intensive plasmapheresis and high-dose rituximab treatment, the complete remission rate remains below 50%. The Kunxian capsule, representing a new generation of tripterygium preparation, has shown promising results in controlling proteinuria in patients with IgA nephropathy. It is unclear whether Kunxian capsule treatment would also produce a favorable response in cases of FSGS recurrence. Here we report favorable results with this approach in a patient with early recurrent FSGS after kidney transplantation; we treated this patient successfully with a Kunxian capsule, a low dose of rituximab (200 mg), and reduced sessions of plasmapheresis. Complete remission, with a 90% reduction in total urine protein (0.81 g/24 h vs 8.3 g/24 h), was achieved within 2 weeks post-treatment. Of interest, the complete remission state in this patient has been maintained over 20 months with continuous administration of Kunxian capsules after the cessation of plasmapheresis. The potential mechanisms involved here include direct podocyte protection and the anti-inflammatory and immunosuppressive properties of triptolide in the Kunxian capsule. Our case may offer a new reference option for treating recurrent FSGS in the future.