Systemic fetal inflammation and reduced concentrations of macrophage migration inhibitory factor in tracheobronchial aspirate fluid of extremely premature infants.

Objective: Macrophage migration inhibitory factor is a proinflammatory mediator of innate immunity, enhances cell growth, and plays a role in preterm delivery. We speculated that funisitis, reflecting fetal systemic inflammation, would be associated with higher concentrations of macrophage migration inhibitory factor in airways of extremely premature infants.

Study Design: We measured macrophage migration inhibitory factor by enzyme linked immunosorbent assay in tracheobronchial aspirate fluid of 35 ventilated infants less than 30 weeks' gestational age, throughout the first week of life. Three groups were distinguished histologically: chorioamnionitis, funisitis, and control.

Results: Unexpectedly, funisitis was associated with significantly decreased macrophage migration inhibitory factor in tracheobronchial aspirate fluid on day 1 (P < .01) and levels remained lower than in the chorioamnionitis group thereafter. For the 35 patients in total, macrophage migration inhibitory factor steadily declined.

Conclusion: Decreased macrophage migration inhibitory factor concentrations in airways of extremely premature infants with systemic fetal inflammation early in life might predispose them to pulmonary infection and interfere with maturation of the lung, contributing to adverse pulmonary outcome.