Hepatitis C co-infection does not increase the risk of
cardiovascular disease or non-AIDS cancers in people with HIV, an analysis of
the large EuroSIDA cohort published in Clinical Infectious Diseases has found.
Although the long-term impact of hepatitis C virus (HCV) infection on the risk
of end-stage liver disease in people with HIV is well established, the
long-term impact of HCV co-infection on risks of cardiovascular disease or
non-AIDS-defining cancers is unclear. The risks of cardiovascular disease or
cancers such as non-Hodgkin lymphoma, pancreatic cancer or cholangiocarcinoma are
elevated in people with HCV monoinfection but the effect of HCV infection on
these risks in people with HIV is unknown.
Furthermore, studies which have identified increased risks
of some conditions in people with HCV have been carried out in varying populations
with relatively small sample sizes. EuroSIDA is a large cohort that
collects comprehensive information on people in HIV care in Europe and
Argentina.
Glossary
- lymphoma
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type of tumour affecting the lymph nodes.
The analysis looked at the risk of cardiovascular disease,
non-AIDS malignancies and end-stage liver disease in people with HIV and HCV
antibodies, compared to people with HIV alone.
The analysis distinguished between four groups of people
with HCV antibodies: people who had cleared HCV spontaneously, people with
untreated chronic HCV infection, people cured of HCV by any treatment and
people with chronic HCV who had not been cured by treatment.
The analysis included all people with known HCV antibody and
RNA status followed in participating cohorts from January 2001, a total of
16,818 people. Sixty-two per cent were HCV antibody negative, 5.5% had cleared
HCV spontaneously, 22.3% were chronically infected with HCV but untreated, 4.9%
had been cured of HCV infection and 5.2% had experienced failure of HCV treatment.
Approximately three-quarters (74%) were male, 85% were white
and 83% had some exposure to antiretroviral therapy, 67.8% having a viral load
below 500 copies/ml (undetectable) at the beginning of the follow-up period.
People who inject drugs made up 25.7% of the entire cohort
but formed the majority in all HCV antibody-positive groups.
Among those with chronic HCV infection, advanced liver fibrosis
(stages 3 or 4) was most common in those who had experienced previous treatment
failure (18.2%) or those cured of HCV infection (19%).
Participants were followed for a median of 8.3 years. During
the follow-up period the most common clinical events were non-AIDS defining
cancers (902 cases, most commonly anal cancer, comprising 15.9% of all
malignancies, and lung cancer, comprising 10.6%) and cardiovascular events (887
cases, most frequently invasive cardiovascular procedure (39.6%) or stroke
(28.1%)).
The incidence rate of cardiovascular disease was 6.4 cases
per 1000 person-years of follow-up and incidence of cardiovascualr disease was slightly higher in
HCV-negative people and in people who had cleared hepatitis C spontaneously.
The incidence rate of non-AIDS-defining cancers was 6.5 per
1000 person-years of follow-up with no significant difference between the
groups in incidence rate.
The incidence rate of end-stage liver disease was 3.1 per
1000 person-years of follow-up. The highest rates of end-stage liver disease
occurred in untreated (9.6 per 1000 person-years) and treatment failure groups (9.9 per
1000 person-years) (both p < 0.0001).
People cured of hepatitis C by treatment did not have
significantly lower rates of cardiovascular disease, or of heart attack or stroke
when the results were broken down by cardiovascular disease event. The same was true for
non-AIDS-defining malignancies, and the investigators also found that the type
of HCV treatment that people had received did not affect these outcomes, regardless
of whether treatment resulted in a cure or not.