Phagocyte activation in preterm infants following premature rupture of the membranes or chorioamnionitis.

Phagocyte activation was studied in 48 preterm infants, gestational age 27.3 +/- 0.3 wk, birthweight 968 +/- 40 g, during the first postnatal week. Human neutrophil lipocalin as a marker of neutrophil activation was measured in plasma and tracheal aspirate fractions; and lysozyme, as a marker of monocyte and macrophage activation, in plasma. The concentration of plasma human neutrophil lipocalin was 69 (46-126) microg/l (median and quartiles), tracheal aspirate fraction fluid 213 (71-433) microg/l and plasma lysozyme 1337 (923-1764) microg/l. Infants born to mothers with premature rupture of the membranes or clinical chorioamnionitis (group A, n = 20) had significantly higher plasma [73 (58-151) vs 53 (38-108) microg/l; p=0.027], and tracheal aspirate fraction human neutrophil lipocalin [319 (129-540) vs 190 (57-324) microg/l; p = 0.019], and plasma lysozyme [1739 (1356-2021) vs 1140 (739-1557)microg/l; p=0.0001] than did infants whose mothers had intact membranes and who had no suspicion of infection (Group B, n = 28). In infants born to mothers receiving corticosteroids ante partum, correlations existed between time from treatment to delivery and plasma (r =0.322, p = 0.0256) and tracheal aspirate fraction human neutrophil lipocalin (r = 0.314, p = 0.0096).