Use of Rituximab in Childhood Idiopathic Nephrotic Syndrome.

Rituximab is an established therapy in children with idiopathic nephrotic syndrome to sustain short to medium term disease remission and avoid steroid toxicities. Recent trials focus on its use as a first-line agent among those with milder disease severity. Rituximab is used in multi-drug refractory nephrotic syndrome and post-transplant disease recurrence, although the evidence is much less substantial. Available data suggest that the treatment response to rituximab depends on various patient factors, dosing regimen and the concomitant use of maintenance immunosuppression. Following repeated treatments, patients are found to have an improving response overall with longer relapse-free period. The drug effect, however, is not permanent and 80% of patients eventually relapse and many will require an additional course of rituximab. This underpins the importance to understand the long-term safety profile upon repeated treatments. Although rituximab appears to be generally safe, there are concerns of long-term hypogammaglobulinaemia, especially in young children. Reliable immunophenotyping and biomarkers are yet to be discovered to predict treatment success, risk of both rare and severe side-effects, persistent hypogammaglobulinaemia and to guide on re-dosing strategy. In this review, we highlight recent advances on the use of rituximab for childhood nephrotic syndrome and how the therapeutic landscape is evolving.