Associations Between Cessation of Second-Line Therapies and Relapse Rates of Childhood Refractory Minimal-Change Nephrotic Syndrome: A Single-Center, Retrospective Chart Review

Most patients (≥85%) with minimal-change nephrotic syndrome (MCNS) respond to corticosteroid treatment. However, about 10% to 20% of patients with MCNS have steroid-resistant nephrotic syndrome and 25% to 43% of patients have steroid-dependent nephrotic syndrome or frequent-relapse steroid-sensitive nephrotic syndrome. Patients with refractory MCNS are treated with various second-line therapies.This study aimed to evaluate the associations between the use of various second-line therapies and relapse rates in Chinese patients with childhood refractory MCNS.In this study, patients with childhood nephrotic syndrome renal biopsy proved to be "minimal change" from a single tertiary-care center between January 2002 and July 2018 were identified. A Total of 56 medical charts of patients treated with 1 of these second-line immunosuppressors: cyclophosphamide (CYC), mycophenolate mofetil (MMF), or tacrolimus (TAC) were reviewed. Patients were divided into CYC (n = 24), MMF (n = 20), and TAC (n = 12) groups according to the second-line therapy administered. Baseline characteristics, immune status, immunocomplex deposition in the renal tissue, and treatment outcomes were analyzed.The ratio of patients with steroid-resistant nephrotic syndrome and steroid-dependent nephrotic syndrome in the CYC, MMF, and TAC groups did not differ significantly (In this small population of Chinese patients with childhood refractory MCNS, the relapse rate following TAC therapy was higher than that following MMF or CYC therapy. Different proportions of CD16