Race/ethnicity differences previously seen
Liver specialist Anna Suk-Fong Lok, MD, professor of medicine at the University of Michigan in Ann Arbor, who was not involved in the study, said that the findings are not especially surprising.
“When the studies came out from Asian countries showing that patients who were taken off treatment had a higher rate of S antigen loss than patients who stayed on treatment, the rate of S antigen loss was not all that impressive, but when you look at the European studies the rate of S antigen loss was very high,” she said in an interview.
“The question of course is ‘Why?’ I don’t think we understand completely why. We can speculate, but none of these type studies give us a definitive answer,” she said.
Possible reasons for the racial differences in HBsAg loss include differences in hepatitis B genotype, she said.
“Another possibility is that Asian patients may have been infected either at the time of birth or as a young kid, so they may have been infected for a much longer period of time than [Whites], who usually acquire infections as adults,” Dr. Lok said.
There may also be differences between patient populations in immune responses following cessation of antiviral therapy, she added.
The study was supported by the RETRACT-B group. Ms. Hirode and Dr. Lok reported no relevant disclosures.
SOURCE: Hirode G et al. AASLD 2020. Abstract 23.