The natural history of fsgs in the german chronic kidney disease (gckd) cohort

Abstract Background and Aims FSGS is a heterogenic glomerular disease and a common cause of kidney failure in adults. Here we describe the natural history of individuals with FSGS in the German Chronic Kidney Disease (GCKD) cohort. Method From 2010 to 2012, 159 patients with biopsy-proven FSGS have been enrolled into the GCKD study, a prospective observational cohort study (N = 5217). Inclusion criteria were an estimated glomerular filtration rate (eGFR) of 30–60 mL/min/1.73 m2 or overt proteinuria in the presence of an eGFR>60 mL/min/1.73 m2. Baseline date was defined as first study visit. Endpoints were the composite renal endpoint (MAKE); eGFR decline >40%, eGFR< 15ml/min/1.73 m2 or initiation of kidney replacement therapy. The associations between the incidence of MAKE and clinical parameters were analyzed using the Cox proportional hazards regression model. Data relating to baseline demographics, laboratory, comorbidity, and mortality were used. Results The mean age at baseline of patients with FSGS was 52.1 ± 13.6 years. Median proteinuria at baseline was 0.7 g/g (Q1 0.1; Q3 1.8), while mean eGFR was 55.8 ± 23 mL/min/1.73 m². Mean duration of the disease before enrollment was 4.7 ± 6.8 years. The majority (101;63.5%) were male; 69 (43.4%) were diagnosed as primary FSGS using clinical and pathological criteria, 55 (34.6%) as secondary FSGS and for 35 (22%) the etiology was uncertain. At baseline, 37 (23.3%) were under immunosuppressive treatment. Over a follow-up of 6.5 years, 44 reached MAKE, in detail 19 (12%) initiated kidney replacement therapy, an additional 25 (15.8%) experienced a >40% eGFR decline. Albuminuria >0.7 g/g was associated with MAKE, with a HR of 1.47 (95% CI: 1.27-1.7) compared to <0.7 g/g. Higher eGFR at baseline (per 10 ml/min) protected from MAKE with a HR of 0.8 (95% CI: 0.68-0.95). Conclusion The GCKD cohort represents a large study population with lengthy and adjudicated follow-up data. Lower eGFR and higher albuminuria are significant risk factors for progressive kidney disease and ESKD in patients with FSGS.