Alpha-fetoprotein is a predictor of outcome in acetaminophen-induced liver injury

Abstract

An increase in alpha-fetoprotein (AFP) following hepatic necrosis is considered indicative of hepatic regeneration. This study evaluated the prognostic value of serial AFP measurements in patients with severe acetaminophen-induced liver injury. Prospectively, serial measurements of AFP were performed in 239 patients with acetaminophen intoxication and a peak alanine aminotransferase (ALT) level above 1000 U/L. AFP was measured using an enzyme-linked immunoassay (EIA) with a detection limit below 0.4 microg/L. The optimum threshold of AFP to discriminate nonsurvivors was identified. An increase in AFP above 4 microg/L occurred in 158 (79%) of 201 survivors compared with 11 of 33 nonsurvivors (33%; P < .00001). The increase in AFP occurred a mean of 1.0 days (range, -2 to +6 days) after peak ALT in survivors compared with 4.1 days (range, +2 to +7 days) in nonsurvivors (P < .00001). Starting on the day of peak ALT, AFP values were significantly higher in survivors than in nonsurvivors. A threshold AFP of 3.9 microg/L on day +1 after peak ALT to identify nonsurvivors had a sensitivity of 100%, a specificity of 74%, a positive predictive value of 45%, and a negative predictive value of 100%. In conclusion, an increase in AFP was strongly associated with a favorable outcome in patients with acetaminophen-induced liver injury. AFP may be useful as a supplement to existing prognostic criteria. We suggest that the introduction of highly sensitive EIAs for the detection of AFP will require a reevaluation of AFP as a prognostic marker in acute nonneoplastic liver disease.