T-cell loss in HIV explained

It has been widely held that HIV depletes its primary target, CD4⁺ T cells, by blocking new T-cell production. But two independent studies published in December 17 and November 5 of Journal of Experimental Medicine show now that HIV does not block such production, but instead accelerates the division of existing T cells.

Joseph Kovacs and colleagues from National Institutes of Health, Bethesda, US examined, in vivo the effects of HIV on the turnover of CD4⁺ and CD8⁺ T cells in infected patients. They found that the viral load affects only the size of a rapidly proliferating pool of both CD4 and CD8 T cells with no effect on the slowly proliferating T cells. In addition, HAART (Highly Active Anti-Retroviral Therapy) decreased just the size of the rapidly proliferating T cells (J Exp Med 2001, 194:1731-1741).

These results confirm findings in a study by...