11 Bronchoalveolar Lavage Fluid Cytokine and Chemokine Profiles in Ventilated Preterm Infants

Abstract

Background and aims: Pulmonary inflammation is historically regarded a key element of the pathophysiology of bronchopulmonary dysplasia (BPD). We aimed to determine the temporal cytokine and chemokine patterns in bronchoalveolar lavage fluid (BALF) from ventilated pretem infants in the first postnatal week. Associations with exposure to chorioamnionitis and development of BPD were determined. Methods: BALF was collected in ventilated preterm infants (≤ 32 wks) on days 0, 1, 3 and 7. Using multiplex immunoassay, individual levels of 32 inflammatory mediators were quantified in each sample. Results: 93 BALF samples were obtained from 59 infants. Levels were within the detection range for the vast majority of mediators and samples. Histological chorioamnionitis was associated with significantly increased BALF cytokine and chemokine levels, most prominently so on day 0 (Figure 1A). IL-10, TNF-α, IL-1α, and IL-1β had the highest predictive ability for chorioamnionitis on day 0 (area under ROC curve >0.90; p<.01). Increased cytokine and chemokine levels were not predictive of BPD development (Figure 1B). In contrast, BPD was associated with significantly decreased levels of several chemokines during the first postnatal week (CCL5, -19 and -22, CXCL8, and MIF (all p<.05). Conclusions: BPD was not preceded by increased pulmonary levels of inflammatory mediators during the first postnatal week in preterm infants. This is in accordance with the concept of ‘new BPD’ characterised by lung developmental arrest rather than lung injury and inflammation.