Diagnostic value of local factors for innate immunity in extremely premature neonates with intrauterine infection
Objective. To elaborate criteria for diagnosing the development of intrauterine infection (IUI) with extremely low and low birth weight neonates on the basis of comprehensive clinical and immunological examinations of pregnant women. Subjects and methods. A prospective study was conducted in 108 mother-neonate pairs. The inclusion criteria were premature births at 23 to 32 weeks gestation. The exclusion criteria were multiple pregnancy, severe extragenital abnormalities, and fetal malformations. All the patients enrolled in the study were examined by an obstetrician/gynecologist and their venous blood and smears from the posterior vaginal fornix were taken at 17-19 weeks gestation. Group 1 included 52 patients and their neonatal infants with IUI developing in the early neonatal period and verified by clinical and laboratory examinations; Group 2 consisted of 56 patients and their neonates without IUI. All the pregnant women and neonatal babies underwent microbiological examination of maternal vaginal smears and fetal nasopharyngeal discharge and feces. A solid-phase enzyme-linked immunosorbent assay using CytImmune kits (USA) was used to determine the levels of cytokines (IL-1P, IL-6, IL-8, IL-10, and TNF-a) in the serum and posterior vaginal fornix discharge in the pregnant women, acute-phase proteins (C-reactive protein (CRP) and procalcitonin (PCT)) in their venous blood prior to regular labor activity and in the neonates on day 3 of their life. Results. There is evidence for a significant increase in the serum levels of IL-8 (19.78 pg/ml; p = 0.022) and IL-6 (42.99pg/ml; p = 0.038) in the pregnant women who gave birth to babies with further IUI. Quantification of the level of pro- and anti-inflammatory cytokines in the posterior vaginal fornix discharge revealed a significant rise in the level of IL-6 (92.37pg/ml) and IL-1P (159.55pg/ml) in Group 1 pregnant women (p < 0.05). Analysis of the results of an investigation of the serum level of acute-phase proteins in the pregnant women showed that in Group 1 there was a significantly increased CRP level that was 22.6 mg/l (p = 0.018) whereas in Group 2 it was not greater than the age-related normal level (4.6 mg/l). Assessment of the results of examination of serum acute-phase proteins in the neonates on day 3 of life revealed that Group 1 had a significant increase in CRP (11.3 mg/l; p = 0.0057) and PCT(14.3 ng/ml; p = 0.0004). In Group 2, the concentrations of CRP (2.1 mg/l) and PCT (1.5 ng/ml) did not exceed the age-related normal level (5 mg/l and 2 ng/ml, respectively). Conclusion. The findings permit the screening of pregnant women forming a group at high risk for IUI and among their neonatal infants.