Secretory phospholipase A2 (sPLA2) regulates the first step of inflammatory cascade and is involved in several pathological processes. sPLA2 also plays a role in preterm labor and parturition, since they are triggered by inflammatory mediators such as prostaglandins. Interestingly, chorioamnionitis (i.e., the presence of intrauterine inflammation) is also often associated with preterm birth. We aimed to verify if chorioamnionitis with fetal involvement modifies sPLA2 activity and expression profile in mothers and neonates delivered prematurely. We collected maternal plasma and amniotic fluid, as well as bronchoalveolar lavage fluid from preterm neonates born to mothers with or without clinical chorioamnionitis with fetal involvement. We measured concentrations of sPLA2 subtype-IIA and -IB, total enzyme activity, and proteins. Urea ratio was used to obtain epithelial lining fluid concentrations. Enzyme activity measured in maternal plasma (P < 0.001) and amniotic fluid (P < 0.001) was higher in chorioamnionitis cases than in controls. This was mainly due to the increased production of sPLA2-IIA, as the subtype -IB was present in a smaller amount and was similar between the two groups; sPLA2-IIA was increased in epithelial lining fluid (P = 0.045) or increased, although without statistical significance, in maternal plasma (P = 0.06) and amniotic fluid (P = 0.08) of chorioamnionitis cases. Cytokines that are known to increase sPLA2-IIA expression (TNF-α and IL-1β) or whose expression was increased by sPLA2-IIA (IL-8) were higher in histologically confirmed chorioamnionitis [TNF-α (P = 0.028), IL-1β (P < 0.001), and IL-8 (P = 0.038)]. These data represent the basis for future studies on sPLA2-IIA inhibition to prevent deleterious consequences of chorioamnionitis and preterm birth.
Keywords: chorioamnionitis; mother; neonate; prematurity; surfactant.