BANFF, ALTA. — Occult hepatitis B coinfection appears to be common in HIV-positive individuals, based on the first study of its kind to test for hepatitis B in peripheral blood mononuclear cells, reported Dr. Carla S. Coffin at the Canadian Digestive Diseases Week.
Of the 46 HIV-infected patients included in the study, 12 (26%) tested positive for hepatitis B virus (HBV) genomes in peripheral blood mononuclear cells (PBMCs). Interestingly, all of the study's participants tested negative for HBV genomes in plasma, indicating that the lymphoid system may be an important site for maintenance of HBV replication, even when the serum or plasma is apparently HBV nonreactive.
Dr. Coffin reported that, to her knowledge, this is the first study to undertake parallel analysis for occult HBV in both plasma and PBMC samples from HIV-infected individuals. “All of the previous studies that I was able to find looked for the virus only within plasma or serum.”
The findings suggest that “the lymphoid system is of vital importance in determining the presence of occult HBV infection,” Dr. Coffin explained.
Further testing of the coinfected patients revealed that their mean alanine aminotransferase (ALT) level was higher than that of their counterparts who tested negative for occult HBV, indicating possible ongoing hepatic necroinflammatory activity.
Dr. Coffin and her colleagues at the University of Calgary (Alta.) and Memorial University in St. John's, Nfld., also found that coinfected patients had lower median CD4+ T-cell counts (203 vs. 251 cells/mm
Preliminary sequence analysis revealed that coinfected patients had HBV and HIV viral diversity. This suggests a possible synergistic effect of coinfection on viral molecular evolution.
These data suggest the potential for serious pathogenic ramifications in HIV infection, said Dr. Coffin, a clinical scholar in the department of medicine. “In chronic HIV infection, HBV coinfection increases the risk of end-stage liver disease.”
“Case reports have reported an association with chronic transaminitis, HAART [highly active antiretroviral treatment]-related flares, and hepatotoxicity in coinfected patients,” she added.
“Moreover, in the pre-HAART area, there was one report [in which] antigen-negative patients with antibodies to HBV were found to have a more rapid progression to AIDS. Finally, the risk of reactivation of occult HBV and possible severe clinical consequences have been described.”
Dr. Coffin said that she had no relevant financial interests regarding this topic.
CDDW is sponsored by the Canadian Association of Gastroenterology and the Canadian Association for the Study of the Liver.
