Work

Persistent hypogammaglobulinaemia after rituximab in children with difficult-to-treat nephrotic syndrome: a multicentre cross-sectional observational study

Year: 2026

Type: article

Abstract: Background Rituximab is widely used for difficult steroid-dependent and frequently relapsing nephrotic syndrome (SDNS/FRNS). Persistent hypogammaglobulinaemia (PH) after rituximab is increasingly recognised, but data from low- and middle-income settings remain limited.Methods In this multicentre cross-sectional study, children <18 years with SDNS/FRNS who had received rituximab ≥12 months earlier were evaluated for serum immunoglobulin G (IgG) levels. PH was defined as IgG<2 SD below age-adjusted norms ≥12 months after the last rituximab dose. Logistic regression was performed to identify predictors of PH. Infection-related hospitalisation rates were compared between groups.Results Among 109 children (median age 10.2 years; median 24 months since last rituximab), 27 (25%) had PH. Younger age at first rituximab independently predicted PH (OR 0.968 per year (95% CI 0.947 to 0.990); p=0.005). PH prevalence declined progressively with increasing age at first exposure (71% in 2–3.9 years vs 12% in ≥8 years; p=0.005). Overall, 12% required hospitalisation for severe infections; infection-related hospitalisation rates were higher among children with hypogammaglobulinaemia (0.41 vs 0.07 per year; p=0.002).Conclusion In this cross-sectional cohort, hypogammaglobulinaemia was detected in one-quarter of children ≥12 months after rituximab exposure and was independently associated with younger age at first exposure. Hypogammaglobulinaemia was also associated with higher infection-related hospitalisation rates, although this exploratory association cannot establish causality. Prospective longitudinal studies are needed to define IgG recovery and infection risk after rituximab.

Source: BMJ Paediatrics Open

DOI: 10.1136/bmjpo-2026-005067