Challenge for long-term discontinuation of immunosuppressants in children with idiopathic nephrotic syndrome: a single-center experience over 10 years

Background Despite adverse events associated with the long-term use of immunosuppressants, their long-term discontinuation remains challenging in children with idiopathic nephrotic syndrome. Relapse and resumption of immunosuppressants after discontinuation and associated risk factors were analyzed. Methods This single-center retrospective cohort study included 107 children with frequently relapsing/steroid-dependent nephrotic syndrome (FRNS/SDNS) or steroid-resistant nephrotic syndrome (SRNS) who initiated immunosuppressant treatment between 2010 and 2020. Patients treated with immunosuppressants for less than two years and those with genetic SRNS were excluded. Results Of 107 patients with FRNS/SDNS or SRNS, 68 (64%) discontinued immunosuppressants. Discontinuation of immunosuppressants was more frequently tried in patients with less relapse on initial immunosuppressants and less rituximab administration. Of 68 patients who discontinued immunosuppressants, 45 (66%) relapsed and 31 (46%) resumed immunosuppressants with a median follow-up of 39.8 months (IQR, 24.6–71.2 months) after discontinuation. The relapse-free survival rates were 40.0%, 35.3%, and 35.3% in 1, 2, and 3 years from discontinuation of immunosuppressants, respectively. The resumption-free survival rates were 59.0%, 52.2%, and 52.2% in 1, 2, and 3 years from discontinuation of immunosuppressants, respectively. Relapse on initial immunosuppressants was the risk factor for both relapse (HR 2.447, 95%CI 1.234–4.856, P = 0.011) and resumption of immunosuppressants (HR 3.070, 95༅CI 1.315–7.167, P = 0.010) after discontinuation, adjusting for sex, age at immunosuppressant treatment initiation, SRNS, and rituximab use. Conclusions Long-term discontinuation of immunosuppressants can be feasible in patients without a relapse on initial immunosuppressants and those without a relapse for one year after discontinuation of immunosuppressants. Trial registration: Not applicable