Markers of permeability and functional state of the placental barrier in pregnant women with chlamydial infection

Objective: To investigate the permeability of the placental barrier and the functional state of the placenta in pregnant women with chlamydial infection. Materials and methods: The study analyzed amniotic fluid and serum from 124 pregnant women at 38 to 40 weeks' gestation who had different courses of Chlamydia trachomatis infection. Group 1 included 83 pregnant women with acute infection, asymptomatic course (PCR+; IgM+; IgG titer <1:60), of whom 39 had children born with congenital infectious disease (CID) and 44 had healthy children. Group 2 included 41 pregnant Chlamydia trachomatis carriers (PCR-, IgM-, IgG titer >1:60) of whom 22 had CID babies and 19 had healthy babies. The control group comprised 37 healthy pregnant women of similar gestational age. High-molecular-weight alpha2-macroglobulin (a2-MG, 720 kDa) and low-molecular-weight albumin (68 kDa) were measured by enzyme immunoassay and quantitative rocket immunoelectrophoresis, respectively. Serum concentrations of a2-MG were determined by quantitative rocket immunoelectrophoresis, albumin by biochemical method. Placental proteins [pregnancy-associated protein A (PAPP-A) and trophoblastic в 1-globulin (TBG)] were analyzed by immunoassay. Results: Women who gave birth to babies with CID had elevated levels of amniotic fluid albumin regardless of the course of the infection [5.5 (2.3-11.5) g/L vs 1.8 (1.2-2.9) g/L for carriers and 3.3 (2.3-7.4) g/L vs 1.8 (1.0-2.2) g/L for acute form]. The a2-MG level in the amniotic fluid was elevated only in chlamydia infection carriers; its concentration was highest in those who gave birth to babies with CID [55.0 (25.4-111.4) mg/L vs 13.8 (5.5-37.2) mg/L in Chlamydia trachomatis carriers who gave birth to children without CID]. In women with acute chlamydia infection, serum levels of a2-MG was increased among those in Group 1 who gave birth to babies with CID [3.3 (2.9-3.6) g/L vs 2.5 (2.3-2.7) g/L in women who gave birth to children without CID]. Pregnant Chlamydia trachomatis carriers showed a significant reduction in blood placental protein PAPP-A levels compared with controls and women who gave birth to children without CID. Conclusion: Determination of a2-MG and albumin in the amniotic fluid of pregnant Chlamydia trachomatis carriers and patients with acute chlamydial infection can be used to evaluate placental barrier permeability. Elevated blood levels a2-MG in pregnant women with acute chlamydia infection are indicative of fetal/newborn CID.

Chlamydia trachomatis, infection, Chlamydia trachomatis, congenital infectious diseases, alpha-2-macroglobulin, albumin