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Acute HEV rare in patients with acute liver failure

Acute hepatitis E virus infection was not prevalent in American patients with acute liver failure, according to published findings.

“These data demonstrate that previously unsuspected acute HEV infection is an exceedingly uncommon cause of [acute liver failure] in the United States. … Unsuspected acute HEV infection was not implicated in any of the intermediate, pregnancy nor autoimmune-related [acute liver failure] patients, and classic HEV RNA-positive [acute liver failure] was not recognized in any of our patients,” Robert J. Fontana, MD, professor of medicine, University of Michigan Health System, and colleagues wrote.

Robert J. Fontana

The researchers hypothesized that HEV-related ALF might be present and unrecognizable in patients with ALF since antibody testing for HEV is not a routine procedure. Therefore, they analyzed serum samples of 699 adults (mean age, 41.8 years; 32.9% men) enrolled in the U.S. ALF Study Group and tested them for anti-HEV immunoglobulin (Ig)M and anti-HEV IgG levels. If a patient presented with detectable anti-HEV IgM, they underwent additional testing for HEV RNA.

“Acute HEV infection is rarely encountered in most developed countries unless someone has a history of travel to an endemic area like Asia or Africa. However, as many as 20% of individuals in the general U.S. population have detectable anti-HEV IgG indicative of prior exposure with no antecedent history of hepatitis suggesting prior subclinical infection,” the researchers wrote.

The final analysis included 681 patients with a positive or negative value for anti-HEV IgM and only three patients (all men) tested positive for anti-HEV IgM. Follow-up testing of eight serum samples for each of the three patients showed they were HEV RNA-negative and had other putative diagnoses.

At baseline, 43.4% of all the patients without acute HEV were positive for anti-HEV IgG (n = 294). These patients tended to be older and less likely to have acetaminophen overdose. In addition, they were more likely to have grade 3 or 4 encephalopathy at baseline and underwent liver transplantation. The lower overall 3-week survival was also lower (60%) compared with patients negative for anti-HEV IgG (70%; P = .018).

The highest seroprevalence was in the Midwest (50%) and the lowest in the Southeastern part of the U.S. (28%).
The researchers concluded: “Acute HEV infection is very rare in adult Americans with ALF and could not be implicated in any indeterminate, autoimmune or pregnancy-related ALF cases. Prior exposure to HEV with detectable anti-HEV IgG was significantly more common in the ALF patients compared to the general U.S. population.”

Disclosure: The researchers report no relevant financial disclosures.