A Özön, SA Çamlar, G Erfidan, ÖÖ Şimşek, C Başaran, D Alaygut, F Mutlubaş, D Yılmaz, BK Demir

Abstract

Objectives: Nephrotic syndrome (NS) may lead to the loss of protective antibodies against infectious agents as a consequence of its underlying pathophysiology. This study aimed to evaluate immunoglobulin G levels specific to measles, mumps, rubella, and varicella in children with NS in remission. Methods: Children aged 2-18 years with NS who had completed the national immunisation schedule and were in remission were included. Exclusion criteria were age under two years, proteinuria, current infection, documented immunodeficiency, or incomplete vaccination. Seropositivity was defined using the following thresholds: >100 mIU/mL for varicella, >10 IU/mL for rubella, >250 mIU/mL for measles, and >25 mIU/mL for mumps. Results: Thirty-nine patients were included (51.4% male), with a median age of 13 years (range 3.7-18). Median follow-up duration was 50 months (range 12-120), and the mean number of relapses was 5.38 (range 1-17). Seropositivity rates were 56.4% for measles, 69.2% for rubella, 43.6% for mumps, and 71.8% for varicella. Patients receiving combined corticosteroid and immunosuppressive therapy showed lower seropositivity rates than those receiving corticosteroids alone; however, these differences were not statistically significant. Conclusion: Vaccine-induced immunity in children with NS may be compromised by both disease-related factors and immunosuppressive treatment. Periodic monitoring of vaccine-specific antibodies may be warranted during follow-up.