Implication of cord blood myeloperoxidase but not of soluble p-selectin levels in preterm deliveries

Although maternal amniotic and vaginocervical cytokines are known to play a role in triggering preterm delivery, the effects of activating fetal phagocytes and platelets are not clear. In an attempt to clarify this issue, we measured levels of myeloperoxidase (MPO), a phagocyte activation marker, and soluble p-selectin (sCD62p), a platelet activation marker, in umbilical cord blood samples from 2200 consecutive cord blood collections, 106 of which were from preterm infants. MPO and sCD62p levels were correlated to gestational age and preterm delivery. It was found that MPO levels were significantly higher in preterm infants and were not significantly correlated to gestational age. In contrast, sCD62p levels were lower in preterm infants and were negatively correlated to gestational age. In summary, we showed that fetal phagocyte activation as demonstrated by higher cord blood MPO levels is associated with preterm delivery, but platelet activation as shown by lower sCD62p levels is not. This suggests that fetal phagocyte activation may be implicated in preterm delivery, and subsequently in prematurity-related inflammatory insults.