Resolution versus persistence of childhood idiopathic nephrotic syndrome-A population-based study

To determine the duration of relapsing childhood idiopathic nephrotic syndrome (INS).

In this population-based study, we retrospectively analysed the computerised database of Israel's largest health maintenance organisation. Children (age 2-10 years) with a new INS diagnosis and a corticosteroid (CS) prescription between 2000 and 2010 were included. NS category was determined, according to CS and/or steroid-sparing agents (SSA) purchases.

Out of 1 669 977 eligible children, 608 fulfilled inclusion criteria. Patients in the fourth quartile of purchases (n = 132) had an older age at last relapse (17.9 ± 6.3 vs. 11.3 ± 5.9 years, p < 0.001) and more SSA use (78.8% vs. 20%, p < 0.001) compared to the remaining three quartiles. A single episode occurred in 84 patients. Of the remaining 524 patients (males 66%, diagnosis age: 4.8 ± 2.2 years, SSA prescribed: 35%) who were followed for 15.5 ± 5.1 years, 113 (21.6%) had a continuing disease at an age of 19.3 ± 6.3 years. The leftover 411 entered long-lasting treatment-free remission at age 11.2 ± 5.7 years.

In this multicentre study, we identified INS disease course by medication delivery. NS long-standing remission occurs at age 11.2 ± 5.7 years in most cases. However, the disease continues into adulthood in a fifth of the relapsing patients, implicating the need for proper transition to adult care.