Idiopathic Nephrotic Syndrome in Syrian Children: Clinicopathological Spectrum, Treatment, and Outcome

Abstract

Abstract Background: Idiopathic nephrotic syndrome (INS) is the most common glomerular disorder of childhood. We performed this study to report the histopathological findings, correlation between the clinical and histopathological features, with the response to steroids and other immunosuppressive drugs and outcome in Syrian children with INS. Methods: A single-center observational cohort study was conducted at Children’s University Hospital in Damascus, included all patients aged 1 – 14 years, admitted from January 2013 to December 2022 with INS and underwent kidney biopsy. Results: The study included 109 patients, with a male/female ratio of 1.13:1, and a mean age of 6.08 years ± 3.73 SD. The main indication of kidney biopsy was steroid-resistant nephrotic syndrome (SRNS) (57.8%). The main histopathological patterns were minimal change disease (MCD) (45%) and focal segmental glomerulosclerosis (FSGS) (37.6%). FSGS was the most common histopathological pattern in SRNS (44.3%). In SRNS, we used Tacrolimus in 49 patients with response rate of 69.4% and Cyclosporine in 20 patients with response rate of 50%. In steroid-dependent nephrotic syndrome (SDNS), we used MMF in 9 patients with response rate of 89% and Cyclophosphamide in 3 patients with response rate of 66.7%. Rituximab was used in four patients with FSGS, two SRNS patients and two SDNS patients, with response rate of 100% and continuous remission till now (more than two years). Fifteen patients (13.7%) progressed to chronic kidney disease stage V, of them 7 patients had FSGS and 8 patients had focal and global glomerulosclerosis, 14 patients of them were steroid resistant and one patient was steroid dependent, and all of them were resistant to immunosuppressants. The most common outcome was recovery (47%) in MCD and frequent relapses (31.7%) in FSGS. Conclusions: FSGS was the most common histopathological pattern in idiopathic SRNS and has the worst prognosis. Tacrolimus is the most effective second-line therapy in SRNS. Rituximab is an effective and safe treatment that induces prolonged remission mainly in SDNS and frequently relapsing NS, and even in SRNS.