Infection with hepatitis B virus (HBV) is
associated with a poorer prognosis for people living with HIV who are
co-infected with hepatitis C virus (HCV), Spanish investigators report in a
study published in the online edition of AIDS.
After taking into account other factors, people with HIV and hepatitis C co-infection
who were also infected with hepatitis B had a 75% increase in their mortality risk
compared to individuals who were only infected with HIV and hepatitis C.
“Our results provide the strongest evidence
to date that HBV infection significantly worsens the prognosis of HIV/HCV
co-infected patients,” write the authors.
HIV, hepatitis B and hepatitis C share
similar modes of transmission. A considerable amount is known about
co-infection with HIV and hepatitis C, as well as about co-infection with HIV
and hepatitis B. However, the consequences of infection with all three viruses are
Investigators from the Spanish VACH cohort
therefore designed a study involving 6342 people who were co-infected with
HIV and hepatitis C. The primary aim of the study was to see if chronic
hepatitis B virus infection (hepatitis B surface antigen [HBsAg] positive) was
associated with increased mortality risk.
The prevalence of hepatitis B virus
infection was 6%. People infected with all three viruses were slightly older (37 vs
36 years, p < 0.01), more likely to be male (87 vs 80%, p = 0.001), had a
lower CD4 cell count (251 vs 293 cells/mm3, p = 0.006) and had a
higher APRI score (AST to platelet index; 1.10 vs 0.82, p = 0.002) than people who were only infected with HIV and hepatitis C.
Overall, the study participants contributed almost
26,000 person-years of follow-up. There were a total of 543 deaths, providing a
mortality rate of 2.1 deaths per 100 person years.
However, mortality rates differed according
to hepatitis B virus infection status, and were 3.78 per 100 person-years for
those infected with hepatitis B, and 2.01 per 100 person-years for people who
were hepatitis B virus-negative.
Initial analysis therefore showed that
infection with hepatitis B increased mortality risk for people with HIV/hepatitis
C co-infection by 90% (1.90; 95% CI, 1.42-2.54).
Several other factors, including a prior
AIDS-defining illness, age, HIV and hepatitis C treatment histories, CD4 cell
count and viral load also affected mortality risk.
The investigators therefore performed a second
set of analysis which took these factors into account.
This showed that hepatitis B virus
infection increased mortality risk by approximately 75% (1.745; 95% CI,
1.41-2.67). Other factors associated with a worse outcome included older age
and a detectable HIV viral load. A higher CD4 cell count, HIV therapy,
treatment with tenofovir (Viread,
also in Truvada, Atripla and Eviplera), which is active against both
HIV and hepatitis B, and hepatitis C therapy were all associated with a
reduction in mortality risk.
The investigators highlighted the findings
of earlier research involving the same patient cohort that showed that
hepatitis B virus infection was the most important factor affecting the risk of
end-stage liver disease in people with HIV/hepatitis C co-infection. The results of
the present research showed that liver-related deaths were more common in those
infected with all three viruses than in people with HIV/hepatitis C co-infection
(42 vs 24%).
Findings of this study underline the
importance of hepatitis B vaccination for everyone with or at risk of infection