TNF alpha production by whole blood from HIV-1 infected patients

Production of cytokines by immunocompetent cells in vitro may be assessed after stimulation with polyclonal activators. Because it mimics the natural environment, diluted whole blood (WB) culture may be the most appropriate milieu in which to study cytokine production in vitro. We tested TNF alpha production by small volume of whole blood (25 microliters) from HIV-1 positive patients by using a one-step procedure that combines WB stimulation with LPS and PHA and cytokine measurement. We studied 30 patients without secondary infection or at distance of secondary infection staged according to the classification proposed by the CDC and 12 healthy seronegative subjects. The mean values of TNF alpha from patients were not statistically different from those from normal controls however in certain patients at different stages of the disease higher values than the mean +2 SD of controls and lower values than the mean -2 SD of controls were obtained. Heparinized blood from 5 control subjects had been collected sequentially during a period of 5 months. The individual variation of TNF alpha production were limited for all these individuals. For each of 6 HIV-1 patients, whole blood samples were collected sequentially during a period of 5 months and in most of patients large variations of levels of TNF alpha were observed from one sample to another one. Our method can detect abnormal cytokine production in HIV-1 positive individuals and can become a useful tool to investigate the role of cytokines in the outcome of HIV-1 infection.