Increased risk of treatment failure and end-stage renal disease in familial focal segmental glomerular sclerosis

Objective: Focal segmental glomerular sclerosis (FSGS) is one of the most important causes of end-stage renal disease (ESRD). The pathogenesis, clinical manifestation, pathological changes and treatment of FSGS differ in patients with and without a family history of the disease. Few studies have compared familial FSGS (FFSGS) and sporadic FSGS (SFSGS). The aim of this study was to assess the clinical and pathological features and the prognosis of FSGS in patients with and without a family history of the disease.

Methods: We enrolled 124 FFSGS patients and 124 age- and sex-matched SFSGS patients in the study. All patients underwent a renal biopsy to determine FSGS. The mean follow-up time was 28.3 ± 12.5 months for the FFSGS group and 26.5 ± 19.5 months for the SFSGS group (p > 0.05). Baseline clinical characteristics were recorded for all participants. The primary outcomes of the study were ESRD and remission of proteinuria (defined as a 50% reduction of the baseline urine protein level). The pathological changes were assessed by focal/global glomerulosclerosis and the tubulointerstitial lesion score.

Results: There were no age or gender differences between the two groups. A total of 43.75% of the FFSGS patients and 35.16% of the SFSGS patients had high blood pressure, but the difference was not statistically significant (p = 0.079). In addition, patients in the FFSGS group had a lower urine protein excretion rate (1.4 ± 1.4 vs. 2.0 ± 1.8 g/24 h) and a higher serum albumin value (3.6 ± 6.2 vs. 3.0 ± 1.1 g/dl) than patients in the SFSGS group (p < 0.01). A total of 62.9% of the FFSGS patients and 22.9% of the SFSGS patients had hematuria, and the difference was statistically significant (p = 0.0001). Nephrotic syndrome occurred less frequently in the FFSGS group than in the SFSGS group (13.3 vs. 22.6%, p = 0.003). The baseline serum creatinine, uric acid and eGFR values were similar in the two groups. When pathological changes were examined, the FFSGS patients showed more severe global glomerulosclerosis and tubular interstitial injury than the SFSGS patients. During the follow-up period, the FFSGS group had a lower proteinuria remission rate (23.08 vs. 48.39%, p = 0.006) and a lower median renal survival time (96 vs. 72 months, p = 0.04) than the SFSGS group.

Conclusions: Compared to SFSGS patients, FFSGS patients displayed distinct clinicopathological features that were associated with less response to treatment and worse renal outcomes.