Abstract: Objective Cell-free DNA (cfDNA) was shown to be a prognostic marker for diverse pathological states in the Intense
Care Unit, but little is known of the role of cfDNA in HBV-related acute-on-chronic liver failure (ACLF). We hypothesize that
cfDNA can also be a promising prognostic as well as a diagnostic marker in patients with HBV-related ACLF. Methods
Thirty-eight patients with HBV-related ACLF admitted in the Intense Care Unit were enrolled in the study. The patients were
divided, according to the improvement of liver function at discharge, into favorable prognosis group (group 1, n=17) and poor
prognosis group (group 2, n=19). Plasma samples were collected from each patient at hospitalization and at discharge to
measure cfDNA by real-time quantitative PCR. MELD score was calculated at the same time points. Results The average level
of cfDNA of group 1 was lower than that of group 2 both at the time of hospitalization (P=0.044) and at discharge (P<0.001).
There was no difference in MELD score between the two groups at hospitalization. Significant correlations were found of
cfDNA levels with the MELD score, TBIL, CRE and INR both at hospitalization (γ=0.662, P<0.001; γ=0.356, P=0.033; γ=0.360, P=
0.031; γ=0.570, P<0.001, respectively) and at discharge (γ=0.854, P<0.001; γ=0.821, P<0.001; γ=0.650, P<0.001; γ=0.638, P<0.001,
respectively). The ROC curve showed that cfDNA level at discharge was optimal in diagnosing ACLF with an area under curve
(AUC) value of 0.96, followed by ΔcfDNA (AUC value of 0.923) and cfDNA level at hospitalization (AUC value of 0.667). The
MELD scores had an AUC value of only 0.545 at the time of hospitalization. Conclusion cfDNA may serve as a promising
prognostic and diagnostic marker for predicting in-hospital prognosis of HBV-related ACLF within 2 to 8 weeks.