Time to remission in childhood steroid sensitive nephrotic syndrome: a change in perspective.

Time to remission (TTR) has been largely considered one of the predictive factors for the risk of relapse and steroid dependency in childhood steroid-sensitive nephrotic syndrome, yet conflicting opinions exist. However, the factors influencing TTR have never been studied. We performed a post-hoc analysis of the prospective pediatric cohort enrolled in a previous multicenter study (ClinicalTrials.gov Id: NCT01386957) to evaluate the possible influence of some clinical and laboratory parameters at INS onset on the timing of TTR. A total of 136 children were evaluated. In simple linear regression models, TTR was directly correlated with serum uric acid, urea, potassium, and urinary protein levels at onset. TTR showed a non-linear inverse correlation with age at onset. A multiple linear regression model of TTR showed that hyperuricemia (p = 0.0000007), non linear age (p = 0.0006) and proteinuria (especially in binary form) (p = 0.02) were significant predictors of TTR, and that there was a significant positive interaction between uricemia and proteinuria as predictors of TTR (p = 0.004). Conclusions: In our analysis, TTR appears to be associated to a nephrotic status at clinical diagnosis characterized by more severe proteinuria and hyperuricemia. Moreover, younger age at onset, notably associated with prognosis, is also associated with a longer TTR. What is Known: • Corticosteroids are the first-line treatment in childhood nephrotic syndrome. • Over the years, time to remission has been considered a potential predictive factor for the risk of relapse and steroid dependency in childhood nephrotic syndrome, with conflicting results. What is New: • Clinical and laboratory parameters at nephrotic syndrome onset are associated with prolonged time to remission in children.