Aim:

This study aims to evaluate the effectiveness of donor-derived cell-free DNA (ddcfDNA) as a predictive biomarker for rejection events in pediatric liver transplant recipients.

Materials and Methods:

Around 2 ml of peripheral blood was collected from paediatric liver transplant recipients who are undergoing for-cause biopsy with suspicion of rejection/infection before the procedure. Patented Trunome® GrafAssure™ Test was performed as described in Jana et al., 2024 to derive ddcfDNA levels. A comparative analysis was performed between ddcfDNA levels, Liver function tests (LFT) and biopsy results. Mann Whitney test was used to compare continuous variables and a two-sided p-value <0.05 was defined as significant.

Results:

A total of 32 subjects were recruited for the study out of which 3 subjects were excluded due to non-immunological reasons. ddcfDNA levels were significantly elevated (p=0.0092) in the biopsy proven rejection group (n=23; 8.29%; 2.43ng/ml) as compared to the biopsy proven non-rejection group (n=6; 2.88%; 0.44ng/ml). To compare the diagnostic performance of ddcfDNA levels (ddcfDNA% and absolute ddcfDNA levels) and LFTs, their levels were correlated with the biopsy findings. Spearman correlation revealed a positive correlation of 0.79 (p<0.0001) for ddcfDNA levels, 0.39 (p=0.04) for AST and 0.53 (p=0.003) ALT levels indicating ddcfDNA levels as a better diagnostic marker than LFTs. In addition, AUC-ROC analysis also revealed that the %ddcfDNA levels can predict graft health precisely (AUC-0.93; p=0.0005), than LFT’s (AST-AUC-0.83; p=0.01; ALT-AUC-0.71; p=0.12). The predictive accuracy of ddcfDNA for detecting rejection was found to be 93.1%, with a sensitivity of 95.65% and specificity of 83.33%. The positive and negative predictive values of the ddcfDNA levels were found to be 95.65% and 83.33% respectively.

Conclusion:

Our results revealed a significant correlation between increased ddcfDNA levels and the onset of graft rejection, suggesting that ddcfDNA levels can act as an early predictor of impending rejection events. Moreover, ddcfDNA levels can act as a surrogate biomarker for real-time assessment of graft health, which could lead to more personalized and effective transplant management strategies. This approach shows promise in improving both short- and long-term transplant outcomes for paediatric patients.