Using hepatitis C virus (HCV) core-antigen testing to screen for acute hep C cases among HIV-positive people is reliable and saves time, money and resources when compared with polymerase chain reaction (PCR) testing. Publishing their findings in Clinical Infectious Diseases, researchers conducted a study comparing the capacity of PCR and core-antigen tests to diagnose recent HCV infections among people living with HIV.

There is an epidemic of sexually transmitted HCV among HIV-positive men who have sex with men (MSM). So the need is great for effective means of detecting cases as early as possible, especially because acute HCV has a tendency to lead to rapid liver damange among people coinfected with HIV.

The study drew participants from a pool of over 2,000 people with HIV who had routine liver function tests conducted every four to six months. During the 20 months of the study, 111 people (5 percent) who had alanine transaminase levels above normal received hep C tests using core-antigen, PCR and antibody screens.

The PCR test identified 15 cases of acute hep C, as did the core-antigen screen, for a sensitivity of 100 percent. While core-antigen yielded no false-positive results, it did result in two intermediate cases.

One of the participants was retested on the same day; both the core-antigen and PCR screens found that he did not have hep C. The second participant tested positive through all three methods five months later. The researchers were not able to determine if the first test was a false-intermediate read or a detection of a very early infection with the virus.

Considering these uncertainties, core-antigen testing had a 98 percent specificity, an 88 percent positive predictive value and a 100 percent negative predictive value when compared with the PCR test.

Using the core-antigen test instead of a PCR screen would have saved $8,160 in test kits and $3,116 in staff time for all the study participants. Also, core-antigen results were available the same day, while PCR results took up to a week to process.

To read the aidsmap story, click here.

To read the study abstract, click here.

 For a feature on sexually transmitted hep C, click here.