Interleukin-2 restores natural killer activity inhibited by sera from HIV+ hemophilic patients.

Natural killer (NK) activity is impaired in patients with positive serology for the human immunedeficiency virus (HIV). We previously found an inhibitory effect of sera from hemophilic (He) HIV+ patients on normal NK activity. In the present study, we have further characterized this effect by studying its reversibility, temperature and time incubation dependence. Since interleukin 2 (IL-2) is able to enhance NK levels, we analized the capacity of this lymphokine to reverse the effect of He HIV+ sera. We found that when IL-2 activation of NK activity occurred simultaneously or after HIV+ serum-treatment, a significant restoration of NK function was observed. In contrast, preincubation with IL-2 did not affect the inhibitory effect exerted by HIV+ sera.