Clinical Significance of Hilar Hyalinosis in Glomeruli of Children with Idiopathic Nephrotic Syndrome

Abstract

Introduction: Hilar hyalinosis (HH) of glomeruli has been thought for a long time to be a precursor or a variant of focal glomerulosclerosis (FGS). In view of its implications on treatment and prognosis of nephrotic syndrome, a retrospective study of hilar hyalinosis in children with the idiopathic nephrotic syndrome (INS), but without any other histologic evidence of FGS, was performed to determine the clinic-pathologic significance of this lesion. Methods: A total of 92 Children with INS who had kidney biopsies for frequent relapses, steroid dependency or resistance were included. Eight of them had a biopsy-proven diagnosis of either minimal change disease or mild IgM nephropathy with HH in 6-25% of glomeruli were compared to control group consisting of 84 children with either minimal change disease (n=57) or IgM nephropathy (n=27) but without HH. Results: Clinically HH patients presented with NS and followed a steroid-dependent relapsing course prior to biopsy. Around 75% of the HH patients received at least one course of cytotoxic therapy after biopsy. At last visit, 6 patients were in remission, 2 were protein-free but on medication. None had hypertension or renal insufficiency. Apart from having a shorter interval between presentation and biopsy (P<0.001) and a lower remission rate (P<0.05), control patients followed a similar course. Pathologically HH patients showed less mesangial change (P<0.001) than the controls but similar mean glomerular size and tubuloinerstitial damage. Conclusion: The results do not support the concept of HH being a precursor lesion of FGS. Kibara [10] have reported HH in the kidneys of children without clinical evidence of renal disease. In view of the possibility that Hilar and perihilar hyalinosis is a precursor or a variant of FGS with its implications for treatment and prognosis, a retrospective study of HH in children with the nephrotic syndrome (NS) but without any other histologic evidence of FGS was performed to determine the clinic-pathologic significance of this lesion.