Decreased interleukin-10 in tracheal aspirates from preterm infants developing chronic lung disease.

Abstract

The inability to balance pulmonary injury with healing may predispose preterm infants to chronic lung disease (CLD). It is postulated that the production of interleukin (IL)-10, an anti-inflammatory cytokine, is gestationally influenced and that CLD-prone infants may have a reduced ability to produce IL-10. Methods: Tracheal fluid (TF) was collected at least twice weekly from 48 mechanically ventilated infants within the first 7 d of life while intubated. Results: A total of 87 TF specimens were obtained. None of the 11 CLD infants (24-31 wk of gestation) had TF IL-10 levels above 4 pg/ml (0/20 TF specimens), while 14 (70%) of the 20 non-CLD preterm infants (27-36 wk of gestation) had IL-10 levels above 5 pg/ml in one or more of their TF specimens (18/48 TF specimens, p < 0.001). Only the 5 term infants who were ventilated for severe lung disease had raised IL-10 levels (17 infants, 5/19 TF specimens). IL-10 levels, if detected, (range 6938 pg/ml) tended to be higher with increasing gestation (Spearman's rho coefficient = 0.43; p = 0.003). TF IL-10 detection was not associated with hyaline membrane disease, antenatal steroids or influenced by TF sample volume. Overall IL-8 levels were wide ranging but towards the end of week 1 the levels were significantly higher in CLD infants (CLD: median 34 184 ng/ml, preterm non-CLD: median 699 ng/ml, p < 0.001, term: 2961 ng/ml, p = 0.028). Conclusion: A gestationally influenced low IL-10 may predispose preterm infants to persistent pulmonary inflammation of CLD.