Pulmonary Function and Symptoms after Inhalation of Endotoxin

TLDR

Prior studies have shown a strong correlation between airborne bacterial endotoxin levels and acute respiratory reactions to organic dusts. In this study, 77 naïve volunteers were exposed to either isolated endotoxin or endotoxin bound to bacterial cells from *Enterobacter agglomerans*. Endotoxin exposure produced dose‑dependent reductions in carbon monoxide transfer factor, fever in half the subjects, chest tightness in a third, modest FEV1 decline, transient bronchial hyperreactivity, and marginal changes in minute volume, confirming endotoxin as the trigger of acute reactions to organic dusts.

Abstract

In previous experiments, a good relationship was demonstrated between the amount of airborne bacterial endotoxin and acute reactions after exposure to organic dusts. In the present study, 77 naive subjects were exposed to isolated endotoxin (IE) or endotoxin attached to bacterial cells (CE). Both preparations were obtained from Enterobacter agglomerans, which is a major bacterial species in many organic dusts. The major physiologic effect caused was a dose-related decrease in transfer factor, as measured by carbon monoxide diffusion. Half of the subjects reported fever and about one-third a subjective feeling of chest tightness. The exposure also caused a dose-related but small decrease in FEVV1 A slightly increased bronchial reactivity was demonstrated at 4 h after endotoxin exposure. The minute volume after CO2 exposure was marginally affected. The results further support the conclusions from epidemiologic and experimental studies that the bacterial endotoxin is responsible for the acute reactions seen after exposure to many organic dusts, includinig that derived from cotton.