Role of innate errors of immunity in the group of children with fatal outcomes during the first year of life

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.