NEUTROPHILS FROM BURN PATIENTS ARE UNABLE TO INCREASE THE EXPRESSION OF CD11B CD18 IN RESPONSE TO INFLAMMATORY STIMULI/

Neutrophils (PMNs) from patients with thermal injury are dysfunctional for the CD11b/CD18-dependent functions of diapedesis, chemotaxis, and phagocytosis, The expression of CD11b/CD18 on normal PMNs is increase d after an inflammatory stimulus, We proposed that CD11b/CD18 expressi on on burn patient PMNs would respond abnormally to inflammatory stimu li, PMNs were obtained from nonseptic burn patients during the second week after thermal injury, PMNs from burn patients incubated with lipo polysaccharide (LPS), N-formyl-methionyl-leucyl-phenylalanine, phorbol myristate acetate, or A23187 did not increase the expression of CD11b /CD18 to the same degree exhibited by normal PMNs, This inability to i ncrease CD11b/CD18 was not due to differences in CD14 receptor express ion, LPS binding, or factors present in the serum of burn patients, Th e upregulation of CD35 also was decreased on burn patient PMNs, Wester n blot analysis revealed decreased quantities of CD11b protein in burn patient PMNs compared with normal control PMNs. The deficiency in CD1 1b/ CD18 expression after inflammatory stimuli may explain some of the abnormalities observed in burn PMN function.