Risk factors can help spot people who need hep D screening

Last Updated: 2020-11-12

By Will Boggs MD

NEW YORK (Reuters Health) - Several risk factors associated with hepatitis D virus (HDV) infection can be used to identify people who should be screened, researchers report.

"It was interesting to find that the risk factors that were identified in our cohort support the current American Association for the Study of Liver Diseases (AASLD) recommendations on whom to screen, which were derived from experiences mostly outside of North America," said Dr. Christopher Koh of the National Institute of Diabetes and Digestive and Kidney Diseases, in Bethesda, Maryland.

"Our study not only is a description of a cohort of patients within North America, which is unique on its own, but it also expands on previous work by providing specific numerical values related to hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT)," he told Reuters Health by email.

HDV is a defective RNA virus that requires the presence of HBV, specifically the hepatitis B surface antigen (HBsAg), to be infectious in humans. There is a lack of evidence and clarity as to which patients with chronic HBV should be screened for HDV; as a result, most patients with HBV are not screened for HDV.

Dr. Koh and colleagues used data from a retrospective, cross-sectional study of 652 HBsAg-positive adult patients seen between 2000 and 2019 to identify risk factors associated with active HDV infection and to test whether current recommendations from the AASLD suffice.

AASLD recommends screening patients who are HIV positive, intravenous drug users, men who have sex with men, at risk for sexually transmitted diseases, or are immigrants from an HDV-endemic country.

Among the 588 HBsAg-positive patients tested for hepatitis D antibody (HDAb), 113 (19%) were considered HDV "exposed" (HDAb-positive), and most of these (91, 80.5%) were confirmed to have chronic HDV infection by the presence of serum HDV-RNA and/or HDV antigen staining in liver tissue, the researchers report in the American Journal of Gastroenterology.

The other 22 HDAb-positive individuals were considered HDV "cleared" by virtue of the absence of serum HDV-RNA.

On multivariate analysis, significant predictors of HDV infection included intravenous drug use, serum HBV-DNA <2000 IU/mL, ALT >40 U/L, and origins from an HDV-endemic country.

"Therefore," the authors conclude, "patients with HBV who have at least one of these risk factors should be screened for HDV infection with serum HDAb testing."

"This piece helps to bring more awareness of hepatitis D to care providers within North America," Dr. Koh said. "We hope that by increasing awareness, more care providers will consider testing for hepatitis D in their patients so they can receive the care that they need."

"Hepatitis D is a global disease with potentially devastating consequences which has known risk factors," Dr. Koh said. "Physician awareness is the key to helping our patients."

Dr. David E. Kaplan of the University of Pennsylvania and Corporal Michael J. Crescenz VA Medical Center, in Philadelphia, has studied hepatitis D within the VA medical system He told Reuters Health by email, "Most surprising is the high rate of active delta co-infection, but likely results from the referral population to the NIH and multicultural population of Washington, D.C. with higher rates of non-southeast Asian chronic HBV and larger African and central Asian referral base. The testing rate for HDAb was astronomically higher than that usually obtained (because this was the NIH)."

"If you don't look for delta, you won't find delta," said Dr. Kaplan, who was not involved in the new research. "All chronic HBV patients should probably get one-time antibody screening (which is my practice: I check for hepatitis A immunity, HCV, and delta exposure at the first visit). This is particularly true for patients from West Africa, Mongolia, Central Asia, and countries bordering the Black Sea."

"Always think hepatitis D if ALT is abnormal but HBV DNA is low," Dr. Kaplan added. "This phenotype should be presumed hepatitis D until proven otherwise."

SOURCE: https://bit.ly/3510ddQ American Journal of Gastroenterology, online October 7, 2020.