Amniotic fluid soluble CD93 is elevated in the presence of intra-amniotic inflammation in preterm prelabor rupture of the fetal membranes

Abstract

Objective: To determine the soluble form of CD93 (sCD93) concentration in amniotic fluid from pregnancies complicated by preterm prelabor rupture of membranes (PPROM) based on the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation. Methods: A total of 144 women with a singleton pregnancy complicated by PPROM were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis. MIAC was determined by the combination of cultivation and non-cultivation techniques. Intra-amniotic inflammation was characterized as a concentration of interleukin-6 ≥ 3,000 pg/mL in amniotic fluid. Women were categorized in the following groups: i) intra-amniotic infection (both MIAC and intra-amniotic inflammation), ii) sterile intra-amniotic inflammation (intra-amniotic inflammation perse), iii) colonization of the amniotic cavity (MIAC perse), and iv) negative amniotic fluid (without both MIAC and intra-amniotic inflammation). Levels of sCD93 in amniotic fluid were assessed by ELISA. Results: A difference in the levels of sCD93 in amniotic fluid was found among the groups of women with intra-amniotic infection, sterile intra-amniotic inflammation, colonization of the amniotic cavity, and negative amniotic fluid (intra-amniotic infection: median 22.3 ng/mL, sterile intra-amniotic inflammation: median 21.0 ng/mL, colonization of the amniotic cavity: 8.7 ng/mL, negative: median 8.7 ng/mL; P < 0.0001). Conclusions: Intra-amniotic inflammation in PPROM, irrespectively of the presence or absence of MIAC, is associated with the elevation of the level of sCD93 in amniotic fluid. Key words: apoptosis – interleukin-6 – monocytes – neutrophils – preterm delivery – receptor