[Idiopathic collapsing glomerulopathy in children: report of two cases]

Idiopathic collapsing glomerulopathy (ICG) is a clinically and pathologically distinct variant of focal segmental glomerulosclerosis, which is characterized by proteinuria (often nephrotic range) and rapid progression to end-stage renal failure. The typical pathological changes are global/segmental glomerular collapse, hypertrophy and hyperplasia of podocytes and severe tubulointerstitial lesions. Most ICG patients who have been reported in previous published papers are adults. ICG in children is rare. The study aimed to analyze and investigate clinical manifestations, renal histopathological findings, treatment and outcomes of ICG in children.

Data of two cases of ICG, a 7-year-old boy and a 12-year-old girl, were analyzed. Both of them were Chinese and Han. Clinical characteristics, results of laboratory tests, renal histopathological findings, treatment, outcomes and prognosis of the two children with ICG were retrospectively analyzed. Results were compared with published data.

These two children presented typical clinical features of nephrotic syndrome. The quantity of 24 hr urine protein was 7.6 g/d (0.47 g/kg x d for boy) and 10.67 g/d (0.35 g/kg x d for girl). Both of them had hypertension (blood pressure ranged from 130/90 to 150/110 mmHg) and hypercholesterolemia (15.4 mmol/L for the boy and 11.3 mmol/L for the girl). The serum albumin was 12 g/L for girl and 23 g/L for boy. The creatinine clearance rate gradually decreased from normal range to 30 ml/min for the girl. The histopathological changes in renal biopsy of them were focal segmental or global glomerular collapse, hypertrophy and hyperplasia of podocytes and severe tubulointerstitial lesions. These two cases were steroid-resistant and were treated with pulse intravenous methylprednisolone and pulse intravenous cyclphosphamade in one case, who rapidly progressed to end-stage renal failure and died half a year later. Another one was treated with cyclosporine. He showed continuous hypertention and heavy proteinuria for eight months.

ICG in the 2 children was a severe disease which presented steroid-resistant nephrotic syndrome and rapidly progressive renal failure. The pathological characteristics was global/segmental glomerular collapse, hypertrophy and hyperplasia of podocytes and severe tubulointerstitial lesions. In children with ICG treatment was difficult and the prognosis was poor.