The association of development of chronic lung disease of newborns with neonatal colonization ofUreaplasmaand Interleukin-8 level of cord blood

Background: The aim of the present study was to investigate the association of chronic lung disease (CLD), neonatal Ureaplasma colonization, and interleukin-8 (IL-8) level of cord blood in preterm infants. Methods: In 77 infants of < 32 weeks gestation, the relationship between IL-8 level of cord blood, neonatal colonization of Ureaplasma, histological chorioamnionitis (CAM), and development of CLD was studied. Results: Five infants died and 29 infants developed CLD. The CLD group had significantly lower gestation (mean +/- SD: 26.6 +/- 1.8 weeks) compared with the infants without CLD (28.9 +/- 1.9 weeks, P < 0.0001). Logistic analysis showed that the development of CLD was associated with gestational age (odds ratio [OR], 0.5; 95% confidence interval (CI): 0.4-0.8) and Ureaplasma colonization (OR, 4.1; 95%CI: 1.2-14.4). Ureaplasma colonization was also associated with CAM (OR, 6.5; 95%CI: 1.8-23.5), absence of respiratory distress syndrome (OR, 6.2; 95%CI: 1.3-30.5), and development of CLD (OR, 4.0; 95%CI: 1.1-15.3). Elevated cord blood IL-8 >= 100 pg/mL was associated with female sex and the isolation of microorganisms (OR, 49.4; 95%CI: 4.6-525). Conclusion: The development of CLD defined by oxygen requirement at 36 weeks was associated with neonatal Ureaplasma colonization but not with IL-8 level of cord blood. Elevated cord blood IL-8 was associated with neonatal microorganisms isolation.