Inborn errors of immunity can be detected by evaluating circular DNA (cDNA) fragments of T- and B-cell receptors (TREC and KREC) resulting from the receptor gene rearrangement in T and B cells. Maturation and activation of the fetal immune system is known to proceed gradually according to the gestational age, which highlights the importance of the immune status in premature infants at different gestational ages. In this article, we evaluated TREC and KREC levels in infants of various gestational ages by real-time PCR with taking into account the newborns weight and sex. The 95% confidence intervals for TREC and KREC levels (expressed in the number of cDNA copies per 105 cells) were established for different gestational groups. The importance of studying immune system development in newborns is informed by the discovered dependence of the level of naive markers on the gestational stage in the early neonatal period.

Around 20,000 children with heart defects are born annually in the Russian Federation, among which around 5,000 children are manifested by its critical course that requires surgical correction within the first days after birth. Although timely pre- and postnatal diagnostics of congenital heart pathology allows to provide proper therapeutic and surgical assistance for such patients, it is hard to minimize severe complications at any stage of the child’s treatment. Quite often, post-surgery patients are unable to cope with serious complications caused by infectious diseases of the respiratory tract, endocardium and meninges. A special place is taken by cases of severe postoperative period: long-term non-healing postoperative wounds and septic disorders leading to patient death. Here we put forward an idea that congenital heart disease may serve as a marker of primary immunodeficiency characterized by lowered parameters of cellular and humoral immunity. Current retrospective study included 29 children died within the first year of life, whose medical records demonstrated confirmed congenital heart disease and manifested signs of immune-dependent pathology. There were analyzed data regarding pregnancy course in order to identify factors contributing to early diagnostics of immune-related pathology associated with CHD. The analysis of existing problems affecting proper diagnostics and treatment of children with congenital heart disease coupled to “covert” PID form was performed. It was noted that among twenty described syndromes manifested with congenital heart disease, seven are currently referred to the group of primary immunodeficiencies. Types of congenital heart defects in the study group ranged from disorders of the valve apparatus to the non-functional opening between heart chambers. Signs of immune-related pathology included decreased thymus size revealed by ultrasound examination as well as lowered value of genetic markers TREC and KREC, retrospectively obtained from neonatal dry blood spots. Finally, we name a key element for successful differential diagnostics of PID with congenital heart disease – awareness of various medical workers about such pathology for developing algorithms for their interaction with regard to management of such comorbid patients.

In the modern world, inborn errors of immunity (IEIs), or primary immunodeficiencies (PIDs), are among of the main causes of childhood disability and mortality, determining the demographic state of mankind not only at present, but also in the future. In the Sverdlovsk Region over the past 5 years, there were about 30% of children who died from severe combined primary immunodeficiency. This retrospective study is devoted to the study of the nosological profile of mortality in the children with immune-dependent disorders in the Sverdlovsk Region, as well as to assess information significance of extrachromosomal circular DNA molecules (TREC and KREC) analysis. Some anamnestic data on the course of prenatal period in the current and previous pregnancies were considered the signs of suggested diagnosis of primary immunodeficiencies, i.e., threats of pregnancy loss at the early terms, documented cases of early childhood death, persistent viral and bacterial infections in the mother, complicated course of pregnancy in the mother, as well as some clinical manifestations, including fungal-bacterial sepsis, generalized viral infection, repair disorders, reduced physiological tolerance accompanied by autoimmune organ damage and uncontrolled systemic inflammation. The study demonstrated a wide range of nosological entities of innate errors of immunity in the structure of early childhood mortality, including both classical forms of primary immunodeficiencies and the disorders not directly related to innate errors of immunity, but those showing phenotypically pronounced immunodeficiency and their immediate role in statistical deviations. Among the main criteria that may presume possible presence of an immune-dependent pathology in the early neonatal period we considered the molecular markers of naive T and B cells (TREC and KREC, respectively) revealed in 70% of the cases studied, with, at least, one of these indexes found to be reduced. It is important to understand that primary immunodeficiencies are not as rare as previously thought. Therefore, it is necessary to carry out timely and high-quality diagnostics, in order to avoid unavoidable deaths.