Serum total bilirubin levels and renal function prognosis in Chinese kidney transplant recipients during outpatient follow-up

Objective Renal function is critical in kidney transplant recipients, as it is a key indicator of graft health and patient prognosis. The present study aims to explore the prognostic value of serum total bilirubin levels in predicting renal function outcomes in this population. Methods We conducted a retrospective analysis of 264 stable kidney transplant recipients from the Second Affiliated Hospital of Guangxi Medical University. The study's primary endpoint was the development of chronic renal allograft dysfunction. Multiple linear regression analysis was used to evaluate whether total bilirubin and Cystatin C were independently related. Binary logistic regression analysis was performed using the lowest total bilirubin group as an outcome variable. The Kaplan-Meier (K-M) curve was plotted to describe the survival period. The relationship between serum total bilirubin and renal outcomes in renal transplant recipients was evaluated using multiple Cox regression analysis. Results Multiple linear regression analysis showed a negative correlation between total bilirubin and cystatin C(β=-0.924; p = 0.03). Our analysis revealed a significant negative correlation between serum total bilirubin and cystatin C levels, suggesting that higher bilirubin levels are associated with better renal function. Binary logistic regression analysis suggested a correlation between glomerular filtration rate and low total bilirubin levels (OR = 0.962, 95%CI = 0.937~0.988, p = 0.004). The K-M curve suggested that higher total bilirubin levels were associated with better survival outcomes (p = 0.003). Multiple Cox regression analysis demonstrated that high total bilirubin levels predicted better postoperative outcomes in kidney transplant recipients (HR, 0.468; 95CI, 0.235~0.931; p = 0.03). The Kaplan-Meier curve and Cox regression analysis further confirmed the protective role of higher bilirubin levels in post-transplant renal function. Conclusions The findings indicate that serum total bilirubin may serve as a prognostic biomarker for renal function in kidney transplant recipients, offering a potential tool for early identification of those at risk for renal insufficiency.