Reversed Clinical and Morphologic Characteristics of Idiopathic Childhood Nephrotic Syndrome

Background and Aims: Minimal change disease (MCD) is uncommon in Nigeria; in the sixties and eighties quartan malaria nephropathy accounted for more than 80.0% of all cases of childhood nephrotic syndrome (CNS). There is paucity of current clinical and morphologic data on CNS. This study therefore determined the incidence and prevalence of CNS, pre-treatment glomerular pathology of idiopathic CNS (ICNS), renal and patient outcome in steroid sensitive ICNS. Methods: A non-randomized prospective study of consecutive cases of Nigerian children with idiopathic nephrotic syndrome was conducted over a 9-year period. Results: CNS accounted for 1.26% of pediatric admissions. Fifty-four of 78 (69.2%) nephrotic children had ICNS (incidence, 0.44/100000/year). Median NS onset age was 7.1 (2.5-14.0) years. Male: female ratio was 1.7. The histopathologic lesions were membranoproliferative glomerulonephritis (MPGN, 44.4%), focal segmental glomerulosclerosis (FSGS, 25.9%), MCD (18.5%), mesangial proliferative glomerulonephritis (7.4%) and membranous nephropathy (3.7%). Overall cumulative complete remission (CR) rate 4 to 8 weeks post prednisolone treatment was 49.6%. Twenty-two of 25 with CR were early steroid responders while 3 were late responders. Median time to CR was 12.0 (3.0 – 46.0) days. Thirty relapses occurred; median time to first relapse was 11.0 months. Cumulative five-year relapse-free rate was 26.6%. Five-year renal survival was 16.1%. All patients with CR were followed-up for 6-93 (median, 22.0) months. Conclusions: Prevalence of non-MCD was very high with significant resistance to prednisolone; poor renal survival was due to high frequency of MPGN and FSGS. Pre-treatment renal biopsy is advocated in our kind of patients so that steroid-sparing agents can be started early.