An increase in alpha-fetoprotein (AFP) following hepatic necrosis is considered indicative of hepatic regeneration.
Dr Schmidt and colleagues from Copenhagen in Denmark undertook a study in order to evaluate the prognostic value of serial AFP measurements in patients with severe acetaminophen-induced liver injury.
The researchers prospectively performed serial measurements of AFP in 239 patients with acetaminophen intoxication and a peak alanine aminotransferase (ALT) level above 1,000 U/L.
The investigators measured AFP using an enzyme-linked immunoassay (EIA) with a detection limit below 0.4 g/L.
The research team was able to identify the optimum threshold of AFP in order to discriminate nonsurvivors.
| Starting on the day of peak ALT, AFP values were significantly higher in survivors than in nonsurvivors|
The researchers found that an increase in AFP above 4 g/L occurred in 79% of survivors compared with 33% nonsurvivors.
The increase in AFP occurred after a mean of 1.0 days after peak ALT in survivors compared with 4.1 days in nonsurvivors.
The research team noted that starting on the day of peak ALT, AFP values were significantly higher in survivors than in nonsurvivors.
In addition, the researchers found that a threshold AFP of 3.9 g/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%.
Dr Schmidt concluded, "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."
The research team added, "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."