Liver stiffness is a strong predictor of
hepatic complications and all-cause mortality in people co-infected with HIV
and hepatitis C virus (HCV), Spanish investigators report in the online edition of AIDS. Liver stiffness was assessed using
an ultrasound-based technique called transient elastometry (FibroScan). This can assess liver
stiffness, an accurate proxy for fibrosis without the need for a liver biopsy.
“We found that baseline liver stiffness was
the strongest predictor of developing hepatic events and of all-cause mortality
and death in HIV/HCV-coinfected patients,” write the investigators. “The
strength of our study is the large size of the study population…and the long
follow-up.”
The availability of safe and potent
antiretroviral therapy means that the prognosis for many people with HIV is
now a normal life expectancy. However, people co-infected with HIV and hepatitis C continue to
have markedly elevated mortality rates and liver disease is an important cause
of death in these patients.
Glossary
- ascites
An accumulation of fluid in the abdomen; may be caused by liver damage, especially cirrhosis.
- encephalopathy
-
A disease or infection affecting the brain.
- FibroScan
A non-invasive test, used instead of a biopsy, to measure the stiffness
or elasticity of the liver using an ultrasound probe.
- varices
Stretched veins which may burst and cause severe bleeding; a complication of cirrhosis.
Liver fibrosis is a predictor of the risk
of liver disease and death in co-infected people. The standard assessment
tool for fibrosis is liver biopsy. However, this is an invasive procedure, has
a risk of complications and is unpopular with patients. Therefore, alternative
tests have been developed, one of which is FibroScan. This test uses a handheld ultrasound scanning device to measure the stiffness of the liver. A liver scarred by fibrosis is stiffer than a healthy liver.
Investigators at the Hospital Carlos III in
Madrid wanted to see if liver stiffness as assessed by FibroScan was a predictor of liver disease and death in their
co-infected patients. FibroScan has
been in routine use at their centre since 2004.
Their observational, retrospective study
involved 545 co-infected patients. Most (71%) were men, their mean age was 41
years, 81% had a history of injecting drug use and 4% were also infected with
hepatitis B. All but three of the participants were taking antiretroviral therapy
and 88% had an undetectable viral load. The mean duration of follow-up was 71
months.
Liver stiffness below 7.5 kPa was
considered to equate to the Metavir F0-F1 stages (no or very mild fibrosis);
7.5-9.4 to Metavir F2 (mild fibrosis); 9.5-12.4 kPa to Metavir 3; and above
14.5 kPa as Metavir F4. Advanced fibrosis was classified Metavir F3-F4.
The investigators explored the relationship
between baseline liver stiffness and the incidence of death and liver-related
events (defined as ascites – fluid in the abdominal cavity; encephalopathy –
damage to the brain; oesophageal varices – enlarged veins in the oesophagus; and
hepatocellular carcinoma).
Over a third of participants (34%) had advanced
fibrosis at baseline. Almost two-thirds of individuals received hepatitis C
therapy during follow-up and 39% achieved a sustained virological response. Twelve
participants (2%) died. Four deaths were attributed to liver disease. Liver-related
events occurred in 53% participants (10%).
After taking into account potential
confounders, the investigators established that baseline liver stiffness was
the strongest predictor of liver-complications (OR = 1.12; 95% CI, 1.08-1.16; p
< 0.0001). Moreover, liver stiffness was the only factor associated with
all-cause mortality (OR = 1.09; 95% CI, 1.01-1.19; p = 0.02).
Other factors associated with liver-related
events were male gender (p = 0.01), CD4 cell count (p = 0.02) and glucose
levels (p = 0.006).
Hepatitis C therapy that achieved a
sustained virological response was protective against liver events (p = 0.01).
“Baseline liver stiffness is the strongest
predictor of liver-related complications and of all-cause mortality in
HIV/HCV-coinfected patients on antiretroviral therapy,” conclude the authors.
“Clearance of HCV with antiviral therapy significantly reduces the risk of
developing liver decompensation events in this population.”