L-SELECTIN EXPRESSION ON POLYMORPHONUCLEAR LEUKOCYTES AND MONOCYTES IN PREMATURE-INFANTS - REDUCED EXPRESSION AFTER DEXAMETHASONE TREATMENTFOR BRONCHOPULMONARY DYSPLASIA

We examined the effect of dexamethasone on the expression of the adhes ion molecule L-selectin on circulating polymorphonuclear leukocytes (P MLs) and monocytes from premature infants with bronchopulmonary dyspla sia (BPD). Nineteen infants who received dexamethasone (Dex group) and 28 who did not receive dexamethasone (no Dex group) were studied. L-s electin expression, measured as mean fluorescence intensity, was lower on circulating PMLs (5.7 +/- 0.6 vs 10.6 +/- 0.7, p < 0.001) and mono cytes (7.9 +/- 0.9 vs 12.5 +/- 0.9, p < 0.02) isolated from those who had received dexamethasone. Because L-selectin is important for the re cruitment of PMLs to inflammatory foci in the lungs, we speculate that one of the mechanisms by which dexamethasone reduces inflammation in BPD is by impairing the ability of leukocytes to migrate into the BPD lesions.