HIV/hepatitis B coinfection: closer treatment monitoring needed?

HIV care providers may not be monitoring markers of hepatitis B virus (HBV) infection closely enough in HIV/HBV coinfected patients, according to a study published in the April 1^st issue of Clinical Infectious Diseases. More comprehensive coinfection treatment guidelines are also needed, according to the authors.

In the US, up to 10% of people with HIV are coinfected with hepatitis B virus (HBV). Guidelines for managing HBV infection call for monitoring disease markers including hepatitis B antigen (HBeAg) and HBV viral load; current US guidelines for HIV management discuss factors to consider in HBV coinfection but do not specify how to monitor HBV infection status or response to treatment.

In this study researchers from the University of Texas, Southwestern Medical Center, reviewed the frequency of diagnostic procedures performed on HIV/HBV coinfected patients at their outpatient HIV clinic. The cohort consisted of 155 patients, new to the clinic between 1999 and 2003, who started antiretroviral therapy after 1999. (The median age was 38, median CD4 count 137 cells/mm³, and HIV viral load 4.81 log₁₀ copies/mL. Eighty-eight per cent were men; 65% MSM, 15% IDU; the group was racially mixed. Ninety-two per cent were on antiretrovirals which are also active against HBV, including 88% on 3TC.)

Chart reviews found that while HIV viral load testing was universally and frequently performed, HBV viral load testing was not. HIV viral load measurements were done for all but one patient before starting antiretroviral therapy (ART), and a median of 3.0 more times per patient during the following year; only 13% did not have an HIV viral load measurement during the first year of therapy. HBV viral load measurements were made in only 16% of the patients before ART initiation, and a median of less than once in the following year; 67% did not have their HBV viral load measured in that year. The frequency of HBV viral load testing did not vary with CD4 count or the overall frequency of follow-up visits.

The frequency of HBV-related testing did increase over time. Only 7% to 13% of those who started ART in 1999 or 2000 had some form of HBV testing in the following year. Between 2001 and 2003, that number had increased from 43% to 52% (p≤0.001). However, by 2003, nearly half of the coinfected patients were still not being monitored for HBV response.

This was a small, retrospective study of clinical practice at a single US outpatient clinic. However, the researchers believe their findings “suggest that HIV care providers did not understand the need for and use of viral and serologic markers to monitor HBV treatment response.” Guidelines for monitoring HIV/HBV coinfection were limited during the study period; several more have been published since (Lessells 2004, Brook 2005, Soriano 2005). The authors of this study believe that “[i]mproved physician adherence to [such guidelines] is needed.”