Purified blood monocytes from HIV 1-infected patients produce high levels of TNF alpha and IL-1.

The production of tumor necrosis factor alpha (TNF alpha) and interleukin 1 (IL-1) was measured in supernatants of cultured peripheral blood monocytes that were obtained from patients with human immunodeficiency virus type 1 (HIV 1) infection and that were purified by counterflow centrifugal elutriation (86-92% purity). TNF alpha levels were significantly higher in monocytes isolated from symptomatic HIV 1-infected patients as compared to normal controls. Although IL-1 levels were also elevated in this group of symptomatic patients they did not reach statistical significance. The production of the two monokines was intermediate in asymptomatic HIV 1-infected individuals. The increase of TNF alpha was observed in the absence of in vitro stimulation as well as in the presence of interferon-gamma plus lipopolysaccharide. TNF alpha and IL-1 were measured by radioimmunoassay and by bioassay, the results of the two methods being highly correlated for both cytokines. The levels of TNF alpha and IL-1 were also positively correlated. These data suggest that IL-1 and TNF alpha may be involved in the pathogenesis of HIV 1 infection.