INFLAMMATORY BRONCHOPULMONARY RESPONSE OF PRETERM INFANTS WITH MICROBIAL COLONIZATION OF THE AIRWAYS AT BIRTH

The inflammatory indicators in the tracheobronchial aspirate (TA) of 8 1 ventilated preterm infants with microbial colonisation of the ah-way s and in non-colonised neonates were analysed on the first day of life . TA was assessed for chemotactic activity, neutrophil cell count, and concentrations of leukotriene B-4, C5a, interleukin-1, interleukin-8, elastase-alpha(1)-proteinase inhibitor, free elastase and albumin. Co ncentrations of mediators were related to concentrations of the secret ory component ofIgA. The infants' gestational age was mean (SD) 27.9 ( 2.0) weeks, birthweight 945 (179) g. In 12 infants (15%) microbial col onisation of the airways was present (Ureaplasma urealyticum n=7; bact eria n=5). Compared with non-colonised neonates (n=69), chemotactic ac tivity, neutrophil count, and concentrations of interleukin-1, leukotr iene B-4 and elastase-alpha(1)-proteinase inhibitor were significantly higher in the colonised group. The difference was most pronounced for IL-1 concentrations, both with and without correction for secretory c omponent. There was also a trend towards increased concentrations of i nterleukin-8 in the latter group. There were no differences for concen trations of C5a and albumin in the TA of both groups. It is concluded that airway colonisation with U urealyticum or bacteria at birth is as sociated with a clinically relevant bronchopulmonary inflammatory resp onse. Increased concentrations of interleukin-1 in TA on the first day of life may be a marker of perinatal colonisation of the airways.