It was hypothesized that
IL-8, a neutrophil
chemotaxin, contributes to the influx of neutrophils into the pleural cavity of patients with
pleural effusions. Pleural fluids were collected from 57 patients including 13 with effusions due to
congestive heart failure, 28 with pleural involvement by
carcinoma, 5 with
empyema, 4 with parapneumonic effusions complicating
bacterial pneumonia, 3 with
hemothorax, 3 with
tuberculosis, and 1 with
rheumatoid arthritis. All exudate groups had significantly higher
IL-8 concentrations than the CHF group (p < .001). In 18 of the exudate fluids, the concentrations of
IL-8 was equal to or in excess of the optimal concentration of
IL-8 which causes neutrophil chemotaxis in vitro. Between 20 and 90% of the chemotactic activity in the fluids was removed by absorbing the
IL-8 with an
IL-8 affinity column. These data showed that
IL-8 is a major
chemotaxin in the fluid. The percentage of neutrophils in the fluids was not correlated with the
IL-8 concentration. Although
TNF alpha, a potent stimulator of
IL-8 production, is present in some
pleural effusions, no correlation was found between the concentrations of
IL-8 and
TNF alpha in the fluids. The data suggest that
IL-8 contributes to the neutrophil influx into the pleural space of patients with pleural exudates in conjunction with other
chemoattractants. It is unlikely that
TNF alpha is the sole stimulus for the
IL-8 production in
pleural disease states.