Mycophenolate mofetil in steroid-dependent idiopathic nephrotic syndrome.

Abstract

Prospective studies have established the mycophenolate mofetil (MMF) efficiency in childhood idiopathic nephrotic syndrome (INS) but reports on the long-term outcome are lacking. Moreover, the search for factors influencing its efficiency would be useful to define its place among the other treatments. We performed a monocentric retrospective study including 96 children with steroid-dependent INS followed for 4.7years (median) (IQ 3-6) after the onset of MMF treatment. The characteristics of responder patients (n = 74), as defined by a 50% decrease of relapse rate and/or a 60% decrease of steroid dose, and of non-responder patients (n = 22) were compared by univariate analysis and multivariate logistic regression. Withdrawal of prednisone was achieved in 48/96 patients after a median duration of 18.1months (IQ 7.8-30.0) of MMF. Only 26/48 patients did not relapse under MMF alone. After MMF was stopped in these patients, only six remained in remission without any treatment at last follow-up. Responders had a shorter time to remission at the first flare (9.5 vs. 15days, p = 0.02), a shorter disease duration prior tothe onset of MMF (22.2 vs. 94.5months, p = 0.001), and were younger at the MMF initiation (6.7 vs. 10.1years, p = 0.02) than non-responder patients. The age of MMF initiation was an independent factor associated with efficiency (OR = 0.80, 95% CI [0.69, 0.93], p < 0.01). MMF is more efficient in young patients treated early in the diseasecourse. Nevertheless, MMF has no remnant effect while nearly all patients relapsed after withdrawal of the drug.