Table 2.

Clinical applications and significance of dd-cfDNA in liver transplantation

Clinical Application	Changes in dd-cfDNA Levels	Significance	Reference
Early Diagnosis of AR	Early in acute rejection, dd-cfDNA shows a significant increase, usually higher than the normal range	Can serve as an early warning signal for acute rejection, providing higher sensitivity and earlier diagnostic capability compared to traditional liver biopsy	[5]
Monitoring of Graft Function	Positively correlated with the recovery or deterioration of liver function, particularly with the levels of ALT and AST	Can be used to monitor liver damage or functional recovery in real time, overcoming the limitations of traditional biochemical tests and biopsies	[3]
Prediction of IRI	Rise rapidly and are correlated with the severity of the damage	Predict the occurrence of IRI and its impact on liver function, offering an opportunity for early intervention	[51]
Infection Monitoring and Complication Diagnosis	In cases of infection or other complications, dd-cfDNA levels often increase significantly	Help identify bacterial or viral infections after transplantation	[52]
Long-term Monitoring and Prognostic Assessment	Are associated with chronic rejection and chronic graft dysfunction	Not only for short-term monitoring, but also for the prediction of long-term post-transplant rejection and chronic liver failure	[11]

Abbreviations AR Acute rejection, IRI Ischemia–reperfusion injury, ALT Alanine Aminotransferase, AST Aspartate Aminotransferase