Influence of hepatitis C virus coinfection on CD4⁺ T cells of HIV-infected patients receiving HAART.

OBJECTIVE: The effects of hepatitis C virus (HCV) coinfection on immune homeostasis and immune restoration in treated HIV infection are not well understood.
METHODS: We studied 79 HIV-infected patients who had been receiving HAART for more than 2 years and who had HIV viral load below 50 copies/ml. Four patient groups were studied: HIV/HCV, CD4⁺ cells above 350/μl; HIV/HCV, CD4 cells below 350/μl; HIV/HCV, CD4 cells above 350/μl; HIV/HCV, CD4⁺ cells below 350/μl. Controls comprised 20 healthy volunteers. Naive, central memory, effector memory, and terminal effector CD4⁺ T cells were enumerated. Naive CD4CD31 T cells were counted as recent thymic emigrants (RTEs). Activation state and ex-vivo apoptosis of CD4⁺ T cells, levels of liver enzymes, and aspartate aminotransferase-to-platelet ratio index were evaluated.
RESULTS: CD4⁺ T-cell counts and the numbers of all circulating CD4 T-cell maturation subsets were diminished in HIV infection; CD4⁺ T-cell activation and apoptosis were increased in HIV infection, but none of these indices was affected by HCV coinfection. RTE numbers were diminished in HIV infection, were inversely related to age, and were increased in women and lower in HIV/HCV patients than in singly HIV-infected patients. In coinfected patients, RTE numbers were inversely related to levels of liver enzymes, but not to HCV viral load.
CONCLUSION: Whereas we could find no relationship between HCV infection and most indices of CD4⁺ T-cell homeostasis or activation, CD4⁺ RTEs are diminished in the circulation of HCV coinfected persons and appear to be related to indices of ongoing hepatic damage or inflammation. 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins