Early Postnatal Surge of Serum Clara Cell Secretory Protein in Newborn Infants

Abstract

Background: Clara cell secretory protein (CCSP) is an anti-inflammatory mediator, but its role in neonatal lung adaptation and diseases is uncertain. Objective: To characterize postnatal changes in serum CCSP in relation to gestation, respiratory disease (RDS) and bronchopulmonary dysplasia (BPD) in comparison with other anti-inflammatory cytokines (IL-4, -10 and -13). Methods: Blood was collected from 76 infants (26 of 23–29 weeks’ gestation, 33 of 30–36 weeks’ gestation and 17 term infants) at birth (preterm cord blood); on admission; at 12, 24 and 48 h; and on days 3–4 and 7 of life. CCSP was assayed by ELISA and cytokines by Bio-Plex. Results: Median serum CCSP in extremely and moderately preterm infants rose from a baseline of 13.6 and 15.9 to 33.4 ng/ml (p = 0.04) and 59.8 ng/ml (p = 0.03) at 12 h of age, respectively. CCSP levels were highest in term infants (80.7 ng/ml at 12 h). CCSP then decreased to 22.5 ng/ml on days 3–4 (p = 0.001). CCSP of 37 RDS infants fell to a lower baseline on days 4 and 7 than that of the 22 non-RDS preterms. The 8 infants who developed BPD had persistently low serum CCSP (12.7 ng/ml at 12 h). In contrast, early postnatal changes were not seen in IL-4, -10 and -13 levels, but low IL-10 and -13 levels were found on day 7 in BPD infants. Conclusions: Serum CCSP levels were characterized by an early postnatal surge. This apparent gestation-influenced surge may represent an initiation of a protective cascade against postnatal lung injury during extrauterine adaptation.