Natural killer cell function and modulation by alpha IFN and IL2 in AIDS patients and prodromal subjects.

We have examined the primary immune response, the numbers of the total T (T-11+) cells, T-helper (T4+) cells, T-suppressor (T8+) cells, NK cells (Leu7+) and the level of serum IgG in 83 healthy male heterosexuals and compared the data to those obtained from 12 clinically diagnosed AIDS patients and 92 asymptomatic male homosexuals. The absolute number of total T (T11) and T helper (T4) cell populations were significantly reduced among most of the asymptomatic homosexual males and even more decreased in the AIDS patients. In contrast, the absolute numbers of T suppressor cells (T8) remained virtually unaltered in the 3 study populations. The absolute numbers of circulating killer cells were similar in the controls and the homosexual subjects but significantly reduced in the AIDS patients. Furthermore, all 12 AIDS patients exhibited a significantly depressed NK cell activity which in most cases correlated with the reduced absolute number of NK (Leu7+) cells as well as T helper cells (T4) and T4/T8 ratios. The NK-cell activity in clinically diagnosed AIDS patients could not be normalized by addition of alpha IFN or IL2. Three distinctive subgroups with normal (N-NK), significantly heightened (H-NK) and markedly lowered (L-NK) NK activity could be readily identified among the apparently well homosexual male population. The subgroups responded to alpha IFN and IL2 in an apparently independent fashion. The N-NK and L-NK groups displayed a marginal to no response to in vitro treatment with alpha IFN and IL2. However, the NK cell activity in the H-NK group was moderately to strongly inhibited by inclusion of the 2 immunomodifiers.(ABSTRACT TRUNCATED AT 250 WORDS)