Significance of T-receptor and kappa-deletion recombina- tion excision rings as molecular markers in the assessment of newborns of different gestational ages

Currently, there is a large number of studies indicating that preterm infants have reduced levels of T-receptor and kappa-deletion recombination excision rings (TREC and KREC) as indicators of impaired T- and/or B-cell immunity. Studies aimed at in-depth study of the causative factors that led to the decrease in the estimated indicators remain relevant. Purpose. Determination of the influence of somatometric parameters and prenatal factors on the level of TREC and KREC in newborns, as well as evaluation of the dynamics of these indicators from gestational age. Material and methods. The study included 203 neonates with gestational ages ranging from 22 to 41 weeks. TREC and KREC were isolated by PCR from dried blood spots on Guthrie cards. Blood sampling was performed as part of neonatal screening. The estimated parameters were analyzed according to gestational age, somatometric data and prenatal factors (mode of delivery, number of fetuses in pregnancy). Statistical analysis was performed using the StatTech v. 4.1.4 software. Results. It was found that the increase in gestational age by 1 week increases the KREC level by 44.610·105 (rxy = 0.271, p < 0.001), TREC level by 27.274·105 (rxy = 0.264, p = 0.002). Linear regression analysis showed weak direct relationships between TREC and KREC levels and anthropometric data. Children from multiple pregnancies had significantly higher TREC values than infants from singleton pregnancies (p < 0.001). Conclusion. The immune system of premature newborns is capable of producing adequate amounts of TREC and KREC. Between 22 and 28 weeks of age, the most intense increase in the assessed indicators occurs, after which their levels relatively stabilize. Since TREC and KREC levels tend to decrease in preterm newborns, a comprehensive evaluation of the dynamics of these indicators depending on significant prenatal and somatometric data is extremely important.