While kidney transplantation substantially improves patient outcomes, early post-transplant mortality remains a concern. Growth differentiation factor 15 (GDF-15) has recently been explored as a biomarker for predicting mortality in various clinical contexts. This study investigates whether pretransplant GDF-15 levels can serve as a prognostic indicator in kidney transplant candidates. The analysis included 395 recipients with stored serum samples obtained prior to transplantation. The median GDF-15 level was 5331.3 pg/mL (range: 50.49–16,242.3). Over an average follow-up of 90.6 ± 41.5 months, 82 patients (20.8%) died. Patients in the highest GDF-15 tertile faced approximately double the mortality risk, even after adjusting for clinical variables (p = 0.009). When accounting for the Estimated Post Transplant Survival (EPTS) score, elevated GDF-15 remained significantly associated with mortality: medium-risk tertile HR = 3.24 (95% CI: 1.2–8.8; p = 0.021) and high-risk tertile HR = 4.3 (95% CI: 1.65–11.54; p = 0.003). Addition of GDF-15 to the EPTS score improved predictive accuracy for 1-year (∆AUC = 0.09, p = 0.039) and 3-year mortality (∆AUC = 0.11, p = 0.036). These results suggest that higher pretransplant GDF-15 concentrations independently predict mortality and can enhance the prognostic performance of established risk assessment tools for kidney transplant candidates.
