Modelling CD4 T Cell Recovery in Hepatitis C and HIV Co-infected Children Receiving Antiretroviral Therapy

BACKGROUND: The effect of hepatitis C virus (HCV) co-infection on CD4+ T cell recovery in treated HIV-infected children is poorly understood. OBJECTIVE: To compare CD4 T cell recovery in HIV/HCV co-infected children with recovery in HIV mono-infected children. METHOD: We studied 355 HIV mono-infected and 46 HIV/HCV co-infected children receiving ART during a median follow up period of 4.2 years (interquartile range: 2.7-5.3yrs). Our dataset came from the Ukraine pediatric HIV Cohort and the HIV/HCV co-infection study within the European Pregnancy and Paediatric HIV Cohort Collaboration (EPPICC). We fitted an asymptotic non-linear mixed-effects model of CD4+ T cell reconstitution to age-standardized CD4 counts in all 401 children and investigated factors predicting the speed and extent of recovery. RESULTS: We found no significant impact of HCV co-infection on either pre-ART or long-term age-adjusted CD4 counts (z-scores). However, the rate of increase in CD4 z-score was slower in HIV/HCV co-infected children when compared with their mono-infected counterparts (p<0.001). Both mono-infected and co-infected children starting ART at younger ages had higher pre-ART (p<0.001) and long-term (p<0.001) CD4 z-scores than those who started when they were older. CONCLUSIONS: HIV/HCV co-infected children receiving ART had slower CD4+ T cell recovery than HIV mono-infected children. HIV/HCV co-infection had no impact on pre-ART or long-term CD4 z-scores. Early treatment of HIV/HCV co-infected children with ART should be encouraged.