Transitory expansion of a CD3+TcR gamma/delta+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 gamma/delta(+) 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 gamma/delta 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 gamma/delta(+)CD16(+) cells that have the capability to lyse an NK-sensitive target in two patients with unusually high levels of NK activity.