Clinical course and outcome of adult patients with primary focal segmental glomerulosclerosis with kidney function loss on presentation.

Background: Kidney function loss or renal insufficiency indicated by elevated creatinine levels and/or an estimated glomerular filtration rate (eGFR) < 60 mL/minute/1.73 m² at presentation in patients with primary focal segmental glomerulosclerosis (FSGS) is commonly seen as a poor prognostic marker for kidney survival. However, a pre>vious study from our center suggested this may be due to hemodynamic factors.

Aim: To observe the clinical and biochemical parameters, treatment response, kidney survival, and overall outcomes of adult patients with primary FSGS presenting with kidney function insufficiency.

Methods: This retrospective observational study was conducted at the Department of Nephrology, Sindh Institute of Urology and Transplantation, Karachi, Pakistan, from January 1995 to December 2017. During this period, 401 biopsy-proven primary FSGS patients were identified, of which 98 (24.4%) presented with kidney function loss or renal insufficiency defined as eGFR < 60 mL/minute/1.73 m² at presentation and were studied in detail.

Results: Among the 98 patients with renal function loss on presentation, the mean age was 30.9 years ± 13.6 years with a male-to-female ratio of 2.5:1. The mean serum creatinine level was 2.2 mg/dL ± 1.3 mg/dL and mean eGFR 37.1 mL/minute/1.73 m² ± 12.8 mL/minute/1.73 m². The mean 24-hour urinary protein excretion was 5.9 g/day ± 4.0 g/day, and the mean serum albumin was 2.1 g/dL ± 1.0 g/dL (median: 1.5 g/dL). The mean systolic blood pressure (BP) was 132.7 mmHg ± 19.8 mmHg, and the mean diastolic BP was 87.4 mmHg ± 12.7 mmHg. Steroid treatment was given to 81 (82.6%) of 98 patients for an average duration of 19.9 weeks ± 14.4 weeks, with a mean total steroid dose of 4.4 g ± 1.5 g. Treatment response showed that 20 (24.6%) patients achieved complete remission, 9 (11.1%) achieved partial remission, and 52 (64.1%) did not respond. The baseline eGFR was significantly lower in the non-responsive group (P = 0.006). The distribution of FSGS variants was also significantly different among steroid-responsive and non-responsive groups (P = 0.012).

Conclusion: Renal function loss in FSGS patients at presentation does not necessarily indicate irreversible kidney function loss and a significant number of patients respond to appropriate treatment of the underlying disease.