Rituximab use in children with complicated idiopathic nephrotic syndrome - a single centre experience

Abstract

Background: In children with idiopathic nephrotic syndrome, rituximab can maintain short-term remission allowing steroids and calcineurin inhibitors taper.
Methods: We retrospectively reviewed all children receiving rituximab for idiopathic nephrotic syndrome at a tertiary hospital. All patients, except one who received a single dose, had four infusions of 375mg/m2 of rituximab at a one-week interval, minimum follow-up duration of four and maximum 118 months.
Results: Eleven patients were included, three patients with steroid resistant nephrotic syndrome and eight steroid dependent or frequently relapsing nephrotic syndrome. Male:female ratio was 8:3 and median age at onset was 2.7 (minimum 1.7-maximum 9.9) years-old. All patients received a trial of calcineurin inhibitors, eight received cyclophosphamide and seven mycophenolate mofetil. Remission of proteinuria was observed in nine patients. Two patients were non-responders evolving to end-stage renal disease. Patients experienced in median three relapses during the six months preceding rituximab. Responders did not relapse in the following six months (p=0.013) and daily dose of prednisolone was significantly reduced (p=0.001). Two patients relapsed at 9 and 12 months after rituximab. Another patient experienced relapse immediately after kidney transplant, successfully treated with our protocol for focal and segmental glomerulosclerosis relapse. Recovery of CD19 cells counting was observed in six patients including two relapsing patients. No severe infection or neoplasia were reported.
Conclusions: Rituximab successfully reduced relapsing in complicated idiopathic nephrotic syndrome, steroid dose and enabled other immunosuppressants weaning off in most patients. Recovery of CD19 cells did not anticipate relapse, but may herald the need for additional rituximab infusions.