The CD14 receptor is a binding site for lipopolysaccharide (LPS) and LPS binding protein, expressed in low levels on the neutrophil (PMN) cell surface. Glucocorticoids have been reported to decrease CD14 upregulation after LPS stimulation in adult PMNs in vitro(J Surg Research 55:632-9). We studied CD14 expression and response to LPS on PMNs from infants receiving steroids.
Methods: Blood samples were drawn from very low birth weight(VLBW) babies treated with low-dose hydrocortisone (1.2-2.4mg/kg/day) during the first week of life, from VLBW babies treated with dexamethasone(0.3mg/kg/day) for developing bronchopulmonary dysplasia, and from infants(<6 months old) treated with methylprednisolone (2mg/kg/day) for respiratory syncytial virus infection (RSV). Blood samples were drawn from each infant while on and off steroids, and results were analyzed by paired t test. Cells were spun down, then resuspended in RPMI 1640, and incubated±LPS (10ng/ml) for 45 minutes. Anti-CD14 (Becton-Dickinson (B-D)) was added for 15 minutes, cells washed, and LDS-751 (Exciton) added as a nuclear and viability marker. PMNs were defined by FACS (B-D) using forward and side scatter. Overlapping monocytes (CD14 bright cells) were gated out.
