IAS: HCV therapy does not significantly effect immune recovery of patients taking HIV therapy

Treatment for hepatitis C virus coinfection does not impair immune recovery in HIV-positive individuals who are taking potent antiretroviral therapy at the same time, a study presented to the recent International AIDS Society Conference in Sydney found.

There are conflicting data about the effect of hepatitis C virus coinfection on the immunological status of people with HIV. Although two studies have found that coinfection essentially has no negative impact on the immune systems of people with HIV, a third found that HIV-positive individuals with hepatitis C had smaller increases in their CD4 cell count after starting HIV therapy than patients who were only infected with HIV.

Investigators in New Jersey in the USA therefore examined changes in key markers of immune status in coinfected patients who were taking therapy for hepatitis C. All the patients were taking anti-HIV treatment and had a viral load below 50 copies/ml. Treatment for hepatitis C consisted of pegylated interferon and weight-adjusted ribavirin.

At baseline, the end of hepatitis C treatment, and at treatment follow-up, 24 weeks after the last doses of anti-hepatitis C therapy, investigators measured the patients’ CD4+ and CD8+ naïve and memory cells.

As expected, only a minority of patients (33%) achieved a sustained virological response to hepatitis C therapy.

When the investigators examined changes in CD4+ and CD8+ naïve and memory cells, they found that these did not alter significantly between baseline and treatment follow-up.

Six months after the completion of anti-hepatitis C therapy, CD+4 naïve cells had fallen by a mean of 8 cells/mm³ in patients who achieved a response to anti-hepatitis C treatment, and by a mean of 26 cells/mm³ in individuals who did not respond to treatment. Mean CD4+ memory cells fell by a mean of 20 cells/mm³ in treatment-responders and by 33 cells/mm³ in non-responders. CD8+ naïve cells fell by a mean of 17 cells/mm³ in those achieving a sustained virological response and by a mean of 49 cells/mm³ in non-responders. CD8+ memory cells showed a mean increase of 90 cells/mm³ in treatment-responders and a mean increase of 16 cells/mm³. None of these changes were statistically significant.

“This study demonstrates that immunological progression of HIV as evidenced by a change in both CD4+ and CD8+ naïve and memory cells is not significantly influenced by treatment for hepatitis C coinfection”, conclude the investigators.