Monocyte CD14 response following endotoxin exposure in cotton spinners and office workers

Background Monocyte cell surface CD14 acts as the major lipopolysaccharide (LPS) binding structure, and as such is of interest in the etiology of LPS induced disease. Methods The objective was to assess change in monocyte cell surface CD14 and CD4 + CD25 + lymphocytes in a group of cotton workers exposed to LPS over a working week, and to compare this to changes in office workers. Twenty-five cotton workers and nine office workers were studied. Monocyte CD14 fluorescence was measured by flow cytometry, on samples taken pre-shift on a Monday morning (baselinelpre-exposure), and subsequently after 6 and 72 hr The majority of cotton workers were exposed to at least 1 EU/m(3) of endotoxin over a working shift, and some highly exposed (between 100 and 400 EU/m(3)). Results After 6 hr of work in the mill, cotton workers developed a significant upregulation in CD14 in comparison to office workers (P=0.016), whereas CD,14 expression had returned to levels not significantly differing from the office workers at 72 hr after first work exposure (P = 0.426). Conclusions We propose that CD14 expression on monocytes may help to determine the mechanism of action of lipopolysaccharide in producing respiratory ill health, and may ultimately play a role in monitoring the health effect associated with LPS exposure in the workplace. Published 2002 Wiley-Liss, Inc.(dagger)