Frequency and clinicopathological correlations of histopathological variants of pediatric idiopathic focal segmental glomerulosclerosis

There is no information on the frequency and clinicopathological correlations of the histopathological variants of primary focal segmental glomerulosclerosis (FSGS) in children presenting with idiopathic nephrotic syndrome (INS) in Pakistan. All consecutive children (≤17 years) who presented with INS, and in whom the histological diagnosis of FSGS was made on renal biopsies, were included in this prospective study. Their clinical, laboratory, and histopathological features at the time of presentation were noted from the case files and the biopsy reports for analysis and clinicopathological correlations. Out of 138 children, 93 (67.4%) were males and 45 (32.6%) were females. The mean age was 8.95 ± 4.14 (range: 1.5-17) years. All had NS, with steroid dependant NS (SDNS) in 45 (32.6%) and steroid resistant NS (SRNS) in 93 (67.4%) cases. Renal dysfunction at the time of presentation was found in six (4.3%) children. Global glomerulosclerosis was found in 68 (49.3%) cases. The mean number of glomeruli involved by segmental scarring was 2.98 ± 2.44. FSGS, not otherwise specified (NOS) was the most prevalent variant, comprising 89.1% of all cases. Collapsing variant comprised 8%, tip variant 1.4%, perihilar 0.7%, and cellular 0.7%. Hyaline arteriolosclerosis was found in 13 (9.4%) cases. Mild interstitial fibrosis/tubular atrophy was found in 95 (68.6%) cases, moderate in 18 (13%), and severe in two (1.4%) cases. In conclusion, FSGS, NOS variant was the highly prevalent variant, while collapsing type was also found in small but significant number of cases. Remaining three variants were distinctly rare in our children.