Primary FSGS is not associated with worse kidney outcome compared with other FSGS subtypes

Area of Science:

• Nephrology
• Pathology
• Clinical Medicine

Background:

• Limited comparative studies exist on kidney outcomes across different focal segmental glomerulosclerosis (FSGS) forms.
• Understanding prognostic factors in FSGS is crucial for patient management.

Purpose of the Study:

• To compare kidney outcomes, specifically annual estimated glomerular filtration rate (eGFR) slope and kidney failure rate, across various biopsy-proven FSGS etiologies.
• To identify clinical and histological factors influencing kidney prognosis in FSGS patients.

Main Methods:

• Retrospective analysis of 82 patients with biopsy-proven primary, maladaptive, genetic, and undetermined FSGS from 2010-2022.
• Utilized Cox and Fine and Gray models for kidney failure associations and linear mixed-effects models for eGFR slope estimation.

Main Results:

• Kidney failure occurred in 26.8% of patients.
• Primary FSGS showed higher baseline eGFR and less chronic changes.
• Annual eGFR slopes varied: -2.5 mL/min in primary, -2.5 mL/min in maladaptive, -4.6 mL/min in genetic, and -4.4 mL/min in undetermined FSGS.
• Female sex, higher baseline eGFR, and lower proteinuria were associated with better outcomes. Higher global sclerosis correlated with lower baseline eGFR, while segmental sclerosis predicted faster eGFR decline.

Conclusions:

• Primary FSGS patients, biopsied earlier, demonstrated favorable kidney outcomes.
• Prognosis in FSGS is more significantly influenced by sex, baseline eGFR, proteinuria, and glomerulosclerosis extent than by FSGS etiology alone.