Transitory Expansion of a CD3 + TcR γ/δ + CD16 + Lymphocytic Population in Two Patients with Advanced Human Immunodeficiency Virus Infection and High Levels of Natural Killer Activity

In the present study, we describe an expansion of CD16⁺ cells with a CD3⁺ TcR γ/δ⁺ phenotype, in the presence of normal numbers of "classic" CD3-CD16⁺ natural killer (NK) cells, in two patients with human immunodeficiency virus (HIV) infection in late stage. The NK activity of the two subjects was substantially higher then that of HIV+ subjects in the same stage of infection. A second evaluation of one of the patients showed levels of NK activity consistent with the clinical stage of HIV infection, concomitant with a remarkable reduction in the percentage of double-positive CD3/TcR γ/δ cells. The number of CD16⁺ cells also reached values comparable to those of the control group. In conclusion, we have identified a population of CD3⁺TcR γ/δ⁺CD16⁺ cells that have the capability to lyse an NK-sensitive target in two patients with unusually high levels of NK activity.