Serum concentrations of soluble B7-H4 in early pregnancy are elevated in women with preterm premature rupture of fetal membranes

Problem To determine the association between maternal soluble B7-H4 (sB7-H4) and the preterm premature rupture of the amniotic membranes (pPROM), the blood serum concentration levels of sB7-H4 were studied. Method of study Maternal serum levels of sB7-H4 were determined with enzyme-linked immunosorbent assay (ELISA) in patients between 11 and 13 weeks’ gestation who later on in the pregnancy developed pPROM (n=21), premature rupture of the amniotic membranes at term (n=18), and in control group (n=27). Results The highest serum levels of sB7-H4 were found in patients who developed pPROM. An OR of 1.39 (95%-CI: 1.17–1.77; P=.002) per ng/mL sB7-H4 indicated an increased risk for developing pPROM, with some predictive ability to discriminate between pPROM cases and controls (AUC=.81). Conclusion Increased serum levels of sB7-H4 in early pregnancy in pPROM cases may indicate the dynamics of the immune response at the feto-maternal interface and, thus, may serve as a predictive marker for this pregnancy complication.