Antiretroviral therapy helps preserve the CD4 cell counts of HIV-positive patients undergoing treatment for hepatitis C, Austrian investigators report in the June 15th edition of the Journal of Infectious Diseases.
Treatment with anti-HIV drugs was also associated with a faster recovery in CD4 cell count after the completion of hepatitis C treatment. The benefits of concomitant HIV therapy were more notable for patients whose baseline CD4 cell count was above 500 cells/mm3, which the investigators believe supports the early initiation of antiretroviral therapy by co-infected patients.
The retrospective study was undertaken by investigators at the Medical University of Vienna. It involved 94 co-infected patients who received treatment for hepatitis C (pegylated interferon and ribavirin) between 2003 and 2010.
CD4 cell counts are known to decline during this treatment, and the investigators were concerned that this could leave patients vulnerable to potentially dangerous illnesses.
They therefore designed a study with three aims:
To describe CD4 cell changes during and after hepatitis C therapy.
To evaluate the impact of concomitant antiretroviral therapy on CD4 cell changes during hepatitis C therapy.
To investigate the influence of HIV treatment on CD4 cell recovery after the cessation of therapy for hepatitis C.
At baseline, three-quarters (n = 70) of patients were taking antiretroviral treatment, and 97% of these individuals had an undetectable hepatitis C viral load.
CD4 cell counts at the time hepatitis C treatment was started were similar in the patients receiving HIV treatment and those who were not (500 vs. 588 cells/mm3).
Hepatitis C therapy was provided for 48 weeks.
Overall, mean CD4 cell counts fell from 512 cells/mm3 at the start of this therapy to 312 cells/mm3 at its completion.
CD4 cell count falls between weeks 24 and 48 of treatment were significantly steeper for patients who were not receiving HIV therapy (p = 0.027).
More robust increases in CD4 cell count were observed in patients taking antiretroviral therapy than those who were not one month after hepatitis C treatment was completed (p = 0.019), a difference which was sustained at months three (p = 0.07) and six (p = 0.003).
A subgroup analysis involving patients with a baseline CD4 cell count above 500 cells/mm3 showed that concomitant HIV therapy was especially beneficial for both the preserving immune function during hepatitis C treatment (p < 0.05), and the restoration of CD4 cell count once this therapy was completed (month six, p < 0.01).
“These findings provide further evidence for a beneficial effect of ‘early’ start of HAART [highly active antiretroviral therapy] in HIV-HCV coinfected patients,” write the authors.
There was some evidence that taking HIV therapy at the same time as treatment for hepatitis C had clinical benefits.
Opportunistic infections developed in 3% of patients taking HIV therapy, compared to 8% of individuals who were not taking this treatment. However, the difference was not statistically significant.
There was no evidence that taking HIV treatment increased the chances of a successful response to hepatitis C therapy, and overall 52% of patients achieved a sustained virological response.
“This study demonstrates the beneficial effects of concomitant HAART [highly active antiretroviral therapy] treatment in HIV-HCV coinfected patients undergoing antiviral combination therapy with pegylated interferon plus ribavirin,” comment the authors.
Limitations of the study include the small sample size and its retrospective design.
Nevertheless, the investigators conclude, “our data suggest that most patients would benefit from initiation and continuation of concomitant HAART during antiviral therapy with pegylated interferon plus ribavirin for prevention of profound decreases in CD4 cell counts and acceleration of immune reconstitution after antiviral therapy ends.”
They call for “prospective evaluation of benefits, costs, and potential harmful side effects of concomitant HAART in HIV-HCV coinfected patients with well-preserved CD4 cell count undergoing antiviral therapy in randomized trials.”
Reiberger T et al. Concomitant highly active antiretroviral therapy leads to smaller decline and faster recovery of CD4 cell counts during and after pegylated interferon plus ribavirin therapy in HIV-hepatitis C virus coinfected patients. J Infect Dis 203: 1802-06, 2011 (click here for the free abstract).