Dichotomy of two CD8+ lymphocyte subsets in HIV infection. Depletion of CD8+ CD3‐ and expansion of CD8+ CD3+ subsets: consequence on the CD4/CD8 ratio
In order to highlight the underlying mechanism(s) of the CD8 lymphocyte expansion in the HIV infection, two distinct CD8 subsets were analysed: T CD8bright+ CD3+ with MHC‐restricted activity, and non‐T CD8dim+ CD3‐, which performs natural killer (NK) activity. It consists of a cross‐sectional study including 168 HIV‐infected patients (74 CDC stage II, 48 CDC stage III and 46 CDC stage IV) compared among them and to 60 healthy individuals. We observed an expansion of CD8+CD3+ cells which masks a depletion of CD8+CD3‐. The comparative study showed that the expansion of the CD8+CD3+ is relatively higher than that of total CD8+ lymphocytes and that the depletion of the CD8+ CD3‐ subset is severe, begins early and remains constant through the HIV progression. The comparison of CD4/CD8 and CD4/CD8+ CD3+ ratios showed that the latter could possibly be a better indicator in the HIV infection. The mechanism of inverted CD4/CD8 ratio in healthy individuals was also clarified. The CD8+CD3+, CD8+CD3‐ and CD4/CD8+CD3+ parameters would be more specific markers than total CD8 and CD4/CD8 ratio especially in therapy trials.