The effect of glucocorticoid administration on bacterial translocation. Evidence for an acquired mucosal...

Adherence of bacteria to intestinal epithelial cells may be the crucial initiating event for translocation and is normally prevented by both specific (secretory IgA) and nonspecific (mucus, bacterial antagonism, desquamation) mucosal defense mechanisms. The purpose of this study was to examine the effect of dexamethasone administration on mucosal immunity; specifically bacterial adherence and IgA. Twenty Fischer rats were randomly assigned to two groups of 10 animals each. Group I received 0.5 mL saline injection intraperitoneally (IP); and group II, 0.8 mg/150 g body weight dexamethasone IP per day for 2 consecutive days. The cecum mesenteric lymph nodes, and bile were aseptically collected, and bacterial adherence, bacterial translocation, and IgA concentration were determined. Results indicate that, compared with saline-treated animals, dexamethasone-treated animals had a fall in IgA (54 +/- 24 versus 232 +/- 41 micrograms/mg protein), an increase in bacterial adherence (8.2 +/- 0.5 versus 3.4 +/- 0.6 cfu (log10)/g cecum), and an increased incidence of bacterial translocation to the mesenteric lymph nodes (60% versus 0%). These data suggest that glucocorticoids may promote bacterial translocation by impairment of mucosal IgA synthesis.