Temporal profile of serum total bile acid levels and their value in the evaluation of early graft dysfunction in living donor liver transplantation: a prospective cohort study

Background: Early graft dysfunction (EGD) after liver transplantation is currently defined using clinical and laboratory parameters. This study aimed to characterize serum total bile acid (STBA) trends in the early posttransplant period following living donor liver transplantation (LDLT) and to evaluate their utility in detecting EGD and acute cellular rejection (ACR). Methods: STBA levels were measured preoperatively and daily from postoperative day (POD) 1 to POD 14 in LDLT recipients. EGD was defined using Olthoff's criteria, and ACR was diagnosed using pragmatic clinical criteria. Results: Among 63 LDLT recipients, EGD occurred in 25.4% and ACR in 26.9%. The median baseline STBA level in cirrhotic patients awaiting LDLT was 95.1 μmol/L (range, 15.5-578.6 μmol/L). STBA levels decreased to near-normal values on POD 1 and remained relatively stable through POD 14. The median STBA value on POD 1 was 10.43 µmol/L (interquartile range [IQR], 6.725-33.635 µmol/L), and on POD 14 was 11.92 µmol/L (IQR, 8.57-44.098 µmol/L). In patients with EGD, STBA levels were consistently higher and demonstrated a rising trend from POD 3 to POD 14. In cases of ACR, STBA levels increased 24 to 48 hours prior to elevations in liver enzymes, suggesting early biochemical changes preceding conventional markers. The sensitivity and specificity of rising STBA for predicting ACR were 94.1% and 61.9%, respectively, with an area under the receiver operating characteristic curve of 0.78 (95% confidence interval, 0.65-0.87). Conclusions: Elevated and progressively rising STBA levels during the first postoperative week are associated with EGD. Trends in STBA may also aid in the early differentiation of ACR from sepsis, offering a useful adjunct in posttransplant monitoring.