Treatment and outcome of congenital nephrotic syndrome.

Background Recommendations for management of Finnish-type congenital nephrotic syndrome (CNS) followed by many teams include daily albumin infusions, early bilateral nephrectomy, dialysis and transplantation. We aimed to assess the treatment and outcome of patients with CNS in France. Methods We conducted a nationwide retrospective study on 55 consecutive children born between 2000 and 2014 treated for non-infectious CNS. Results The estimated cumulative incidence of CNS was 0.5/100000 live births. The underlying defect was biallelic mutations in NPHS1 (36/55, 65%), NPHS2 (5/55, 7%), PLCE1 (1/55, 2%), heterozygous mutation in WT1 (4/55, 7%) and not identified in nine children (16%). Fifty-three patients (96%) received daily albumin infusions from diagnosis (median age 14days), which were spaced and withdrawn in 10 patients. Twenty children (35%) were managed as outpatients. Thirty-nine patients reached end-stage kidney disease (ESKD) at a median age of 11months. The overall renal survival was 64% and 45% at 1 and 2years of age, respectively. Thirteen children died during the study period including four at diagnosis, two of nosocomial catheter-related septic shock, six on dialysis and one after transplantation. The remaining 13 patients were alive with normal renal function at last follow-up [median 32months (range 9-52)]. Renal and patient survivals were longer in patients with NPHS1 mutations than in other patients. The invasive infection rate was 2.41/patient/year. Conclusions Our study shows: (i) a survival free from ESKD in two-thirds of patients at 1 year and in one-half at 2 years and (ii) a significant reduction or even a discontinuation of albumin infusions allowing ambulatory care in a subset of patients. These results highlight the need for new therapeutic guidelines for CNS patients.