Placental IL-10 dysregulation and association with bronchopulmonary dysplasia risk

Cytokine profiles in amniotic fluid, cord serum, and tracheal aspirate of premature infants suggest a shift toward a proinflammatory state. Cytokines also contribute to the pathogenesis of bronchopulmonary dysplasia (BPD). We hypothesize that the initiating events for BPD are reflected in the placenta and propose that placental expression of cytokines provide a blueprint of events leading to BPD. This is a retrospective, case-controlled study of placental cytokines of premature infants with (n = 49) and without (n = 49) BPD, matched for gender, birth weight, and year of birth at Women and Infants Hospital between 2003 and 2005. Cytokine expression, including IL-6 and IL-10, was determined by immunohistochemistry in membrane rolls, umbilical cords, and placentas. IL-6 was similarly expressed in all tissues of infants with and without BPD. In contrast, anti-inflammatory cytokine IL-10 was less prominent in the placenta of patients with BPD compared with those without BPD. IL-10 expression in the villous trophoblast layer was associated with a reduced odds ratio of developing BPD (adjusted OR 0.08, 95% CI 0.01-0.70, p = 0.02). These results suggest that a placental balance between inflammatory and anti-inflammatory cytokines is crucial to normal lung organogenesis. Importantly, IL-10 seems to be protective against the development of BPD.