Changes in the amino acid profile of cord blood plasma preceding the respiratory distress syndrome in premature newborns

Background: Respiratory distress syndrome plays an important role in the structure of pathologies that have a significant impact on the life and health prognosis in premature infants,. Among neonatal respiratory disorders, its frequency is up to 46%. Improvement of the disease prognosis, prevention of complications, and pathogenetically based therapy requires a detailed study of metabolic disorders in this group of children.

Aim: The study aimed to identify changes in the amino acid spectrum of cord blood plasma preceding respiratory distress syndrome in premature infants.

Materials and methods: The study was conducted from May 2023 to September 2024. Cord blood was collected during vaginal and operative deliveries of premature babies at ≤36 weeks of gestation, taking into account the mother’s informed consent and non-inclusion/exclusion criteria. The included children were followed up until discharge. A confirmed diagnosis of respiratory distress syndrome was recorded based on patient follow-up. Concentrations of amino acid in cord blood plasma were determined by capillary electrophoresis. Based on the patient follow-up and disease diagnosis, 2 groups were retrospectively formed: the comparison group included premature newborns who did not develop respiratory distress syndrome during the entire follow-up period (n = 49); the main group included patients with respiratory distress syndrome (n = 14).

Results: In the main group, respiratory distress syndrome was diagnosed within 24 hours after birth. Disease development was preceded by an increase in alanine concentration (by 61.1%), р = 0.007, and a decrease in relative levels of tryptophan (by 15.0%), histidine (by 12.1%), and citrulline (by 14.7%); p = 0.020, p = 0.007 and p = 0.016, respectively.

Conclusion: Intrauterine amino acid metabolism disorders in premature infants become the basis for the development of severe diseases in the first days after birth. This study demonstrates changes in the amino acid profile of cord blood plasma reflecting the role of metabolic disorders of ornithine cycle-related amino acid metabolites, heterocyclic amino acids, and energy metabolism disorders in the respiratory distress syndrome.