Clinical significance of determining trec and krec markers in dried blood spots in children with severe infectious diseases complicated by fatal outcome

The article presents the results of a study of the levels of T-lymphocyte receptor DNA recombination products (TREC) and B-lymphocyte receptor DNA recombination products (KREC) in children with severe infectious diseases complicated by a fatal outcome. Data from 18 children who died from infections associated with immune mechanism disorders were analyzed. TREC and KREC levels were successfully determined in 11 children from neonatal screening records using real-time PCR. Significant variability in marker levels was established: the TREC copy number ranged from 250,0 to 29 988,0, and KREC – from 1 759,0 to 33 214,0 copies per 106 leukocytes. Cases of both reduced marker levels and marker levels within the normal range were identified. The lowest TREC levels were observed in children with thymic hypoplasia and sepsis (250,0 and 746,0 copies per 106 leukocytes, respectively). These data suggest the need for a differentiated approach to interpreting TREC and KREC levels in critically ill newborns, taking into account the multiple factors affecting immune status

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