The Effect of Hepatitis C on Progression to AIDS in the Pre- and Post-HAART Eras

The aim of the current study was to assess the effect of infection with hepatitis C virus (HCV) on the progression of HIV disease, before and after the introduction of HAART.

The investigators used data from a multi-center prospective study of HIV seroconverters. Survival analyses were performed to compare the progression to AIDS by HCV serostatus in the period before HAART (i.e. June 1991-May 1996) and in the HAART era (i.e. June 1996-June 2001), controlling for duration of HIV infection.

Results

Among the 1052 persons enrolled, 595 (56.6%) were co-infected; the median follow-up time was 9.7 years.

Adjusting for demographic variables (age at HIV seroconversion and gender), HCV infection had no effect on the progression to AIDS in the pre-HAART era, whereas it increased the risk in the HAART era.

In the HAART era, the proportion of person-time spent on HAART out of the total time at risk was significantly lower among co-infected persons (30 versus 40% for non-co-infected persons; P-value = 0.001).

No significant difference was found for dual-therapy (29 versus 25%, respectively; P-value = 0.205). A significant difference was found for mono-therapy (15 versus 8%, respectively; P-value < 0.001).

Conclusions

The authors conclude, “HCV infection was not a determinant of HIV disease progression in the pre-HAART era, whereas since the introduction of HAART, co-infected individuals seem to have had a faster disease progression. This may in part be explained by differences in person-time spent on different antiretroviral regimens.”

Discussion

“To the best of our knowledge,” note the authors, “this is the first study to consider the duration of HIV infection in evaluating the effect of HIV-HCV co-infection on HIV disease progression, allowing an unbiased comparison of co-infected and non-co-infected individuals to be performed before and after the introduction of HAART.

“When comparing disease progression in the two groups, we found an effect of calendar period, which, as in other studies, was used as a surrogate of the use of HAART. Whereas we found no association between co-infection and disease progression before HAART, we did observe an association in the HAART era.

The results obtained in the HAART era are conflicting. In two European studies, the probability of progressing to AIDS was significantly higher for co-infected persons, although only persons undergoing HAART were considered and neither study was able to totally attribute the increased probability of progressing to AIDS to a reduced responsiveness to HAART.

These results are in contrast with those of Sulkowsky et al., who found no difference in the risk of death or of developing AIDS when comparing co-infected and non-co-infected persons in the HAART era.

In conclusion, the authors write, “The results of this study confirm that HCV was not a determinant of progression of HIV disease in the pre-HAART era. However, co-infection appears to have had an effect since the introduction of HAART, although it remains to be determined whether this effect is directly due to HCV co-infection (i.e. a different response to HAART) or to differences in HAART use.”

12/08/04

Reference
M Dorrucci and others (and the Italian HIV Seroconversion Study). The effect of hepatitis C on progression to AIDS before and after highly active antiretroviral therapy. AIDS 18(17): 2313-2318, November 19, 2004.