Published online May 6, 2019. doi: 10.12998/wjcc.v7.i9.1021
Peer-review started: February 26, 2019
First decision: March 10, 2019
Revised: March 20, 2019
Accepted: April 9, 2019
Article in press: April 9, 2019
Published online: May 6, 2019
Processing time: 72 Days and 19.8 Hours
In paediatric patients with complicated nephrotic syndrome (NS), rituximab (RTX) administration can induce persistent IgG hypogammaglobulinemia among subjects showing low basal immunoglobulin G (IgG) levels.
To evaluate the effect of RTX on IgG levels and infections in patients with complicated NS and normal basal IgG levels.
We consecutively enrolled all patients with complicated NS and normal basal IgG levels undergoing the first RTX infusion from January 2008 to January 2016. Basal IgG levels were dosed after 6 wk of absent proteinuria and with a maximal interval of 3 mo before RTX infusion. The primary outcome was the onset of IgG hypogammaglobulinemia during the follow-up according to the IgG normal values for age [mean ± standard deviation (SD)].
We enrolled 20 patients with mean age at NS diagnosis of 4.2 ± 3.3 years. The mean age at the first RTX infusion was 10.9 ± 3.5 years. Eleven out of twenty patients (55%) developed IgG hypogammaglobulinemia. None of these patients showed severe or recurrent infections. Only one patient suffered from recurrent acute otitis media and underwent substitutive IgG infusion. Three patients undergoing only the two “starting doses” experienced normalization of IgG levels. Using Kaplan-Meier analysis, the cumulative proportion of patients free of IgG hypogammaglobulinemia was 57.8% after the first RTX dose, 51.5% after the third dose, 44.1% after the fourth dose, and 35.5% after the fifth dose.
RTX can induce IgG hypogammaglobulinemia in patients with pre-RTX IgG normal values. None of the treated patients showed severe infections.
Core tip: In paediatric patients with complicated nephrotic syndrome (NS), rituximab (RTX) administration can induce persistent immunoglobulin G (IgG) hypogammaglobulinemia among subjects showing low basal IgG levels. Our case series shows that RTX can induce IgG hypogammaglobulinemia also in patients with pre-RTX IgG normal values and that persisting IgG hypogammaglobulinemia could be dose-dependent. When evaluating a patient with complicated NS and post-RTX IgG hypogammaglobulinemia, IgG supplementation may not be needed because, to date, no severe infections have been detected and the possibility of adverse events related to IgG supplementation exists.