Background: Acetaminophen (APAP)-induced acute liver failure (ALF) is associated with significant mortality. To date, prog-
nostic scores lack discrimination in identifying patients who will die without liver transplant (LT), and those who will sur-
vive with medical management. Liver-type fatty acid binding protein (L-FABP) is a 15 kDa cytoplasmic protein expressed in
hepatocytes with potential prognostic value in APAP-ALF. Meth-ods: With serial serum samples (early; day 1 and late; day
3-5) from 198 APAP-ALF patients (99 survivors, 99 non-survi-vors), we examined whether L-FABP levels, measured using sol-
id-phase enzyme-linked immunosorbent assay, were associated with 21-day mortality in the absence of LT. Results: APAP-ALF
survivors had significantly lower L-FABP levels early (238.6 vs. 690.8 ng/ml, p<0.0001) and late (148.4 vs. 612.3 ng/ml,
p<0.0001) compared with non-survivors (Fig 1). Using logistic regression, elevated L-FABP early (Log L-FABP Odds Ratio (OR)
1.31, p=0.027) and late (Log L-FABP OR 1.50, p=0.005) were associated with significantly increased 21-day mortality
after adjusting for covariates (MELD, vasopressor use). Area under the receiver operating curve (AUROC) for early and
late models were 0.778 and 0.907. The addition of L-FABP significantly improved (p<0.01) the AUROC of the King’s Col-
lege Criteria (KCC) (Early: 0.552 alone, 0.711 with L-FABP; Late: 0.604 alone, 0.797 with L-FABP) as well as the ALFSG
prognostic index (Early: 0.686 alone, 0.766 with L-FABP; Late: 0.711 alone, 0.815 with L-FABP). Conclusion: Serum L-FABP
levels were significantly higher at serial time points in APAP-ALF non-survivors. After adjusting for covariates, serum L-FABP was
significantly associated with 21-day mortality. L-FABP improved prognostic discrimination (AUROC) when combined with KCC
and the ALFSG prognostic index which may potentially help identify APAP-ALF patients with higher potential of recovery.
