This article is more than 5 years old. Information may no longer be current.

Alleles of APOE gene may protect non-Hispanic blacks from HEV

Certain alleles of the apolipoprotein E gene were found to protect non-Hispanic blacks from hepatitis E virus infection, according to newly published findings in Hepatology.

“We determined variations in the genetic makeup of humans potentially associated with increased risk for HEV infection in a large candidate gene study using a cross-sectional study of the three major racial/ethnic populations,” the researchers wrote. “A better understanding of the genetic influence on susceptibility to HEV infection can help identify and target high-risk populations appropriate for prevention.”

Researchers analyzed data of 2,434 non-Hispanic whites, 1,919 non-Hispanic blacks and 1,919 Mexican Americans in the U.S. who participated in the Third National Health and Nutrition Examination Survey between 1991 and 1994. The researchers searched for associations between anti-HEV immunoglobulin G (IgG) seropositivity and host genetic factors. They also investigated 497 single-nucleotide polymorphisms (SNP) across 190 genes, more specifically, those associated with lipid metabolism, and used the genomic control method for adjusting for potential population stratification, according to the research.

Anti-HEV seropositivity was found to be strongly associated with increasing age across all groups of patients and peaked in patients who were at least 65 years of age. Seropositivity was also associated with poverty income ratio, education, country of birth and region of residence.

Of the three groups, non-Hispanic blacks had the lowest seroprevalence of anti-HEV IgG (15.3%; 95% CI, 12.3%-19%) compared with non-Hispanic whites (22.3%; 95% CI, 19.1%-25.7%) and Mexican Americans (21.8%; 95% CI, 19%-25.3%; P < .01).

Univariate analysis showed non-Hispanic blacks as the only group to have an association between anti-HEV seropositivity and functional epsilon3 and epsilon4 alleles of the apolipoprotein E (APOE) gene, encoding the APOE protein that mediates lipoprotein metabolism, according to the researchers.

Of the patients with APOE, seropositivity of anti-HEV was lower in those carrying APOE epsilon4 (OR = 0.5; 95% CI, 0.4-0.7; P = .00004) and epsilon3 (OR = 0.6; 95% CI, 0.4-0.8; P = .001) compared with those carrying APOE epsilon2.

The researchers did not observe any associations between other SNPs and anti-HEV seropositivity in non-Hispanic blacks, or any between any SNPs and anti-HEV seropositivity in non-Hispanic whites or Mexican Americans.

The researchers concluded: “Both APOE [epsilon3] and [epsilon4] are significantly associated with protection against HEV infection in non-Hispanic blacks; additional studies are needed to understand the basis of protection so that preventive services can be targeted to at-risk persons.” – by Melinda Stevens

Disclosures: The researchers report no relevant financial disclosures.