Collapsing FSGS: a clinicopathologic study of 10 cases from Pakistan

Idiopathic collapsing focal segmental glomerulosclerosis (FSGS), a rare variant of FSGS, is of interest because of its increasing incidence, frequent association with black race, HIV-1 infection, and intravenous (IV) drug abuse. This lesion has not been reported from Pakistan until now.

We reviewed our 14-year native renal biopsies record and identified 10 cases of this entity (July 1995-July 2009). Patients' demographic and clinicopathologic data were collected from case files. Renal biopsies were studied by light microscopy, immunofluorescence microscopy, and electron microscopy. A control group of 124 patients with noncollapsing FSGS was selected for comparison of clinical, laboratory, and outcome parameters.

All the patients were young adults (mean age: 22.4 +/- 4.6 years). The majority were males (9 vs. 1 female). All presented with nephrotic syndrome (24-h urinary protein: 6.7 +/- 9.22 g). In addition, 8 had mild to moderate renal failure (serum creatinine: 4.12 +/- 4.6 mg/dl). No history of heroin or IV drug abuse was elicited and all tested negative for HIV. Only two patients (20%) responded to steroid treatment, while eight (80%) did not. Five of the patients (50%) developed endstage renal disease after a mean interval of 18 months.

Idiopathic collapsing FSGS is increasingly being reported in patients who have no HIV infection or history of IV drug abuse. There is a need for increased awareness among pathologists all over the world to diagnose this condition to guide nephrologists and patients regarding the poor prognosis of this form of FSGS.