BASIC LYMPHOCYTES SUBSETS DURING THE POST-TRAUMATIC PERIOD IN CHILDREN

Abstract

Severe trauma remains a leading cause of disability and mortality among children older than one year. This study aimed to assess the dynamics of peripheral blood lymphocyte subpopulations as indicators of injury severity, complication development, and prognosis in pediatric trauma. A total of 118 children with severe mechanical trauma (ISS≥16) were included. According to the Severe Injury Outcomes Scale (OISS), 60 patients had a favorable outcome, 51 an unfavorable outcome, and 7 a fatal outcome. Based on clinical course, subgroups with septic complications (PSC, n=23) and multiple organ dysfunction syndrome (MODS, n=19) were identified. Flow cytometric analysis of lymphocyte subpopulations (CD3⁺, CD19⁺, NK cells) was conducted on days 1, 3, 5, 7, 10, and 14 post-trauma, with normalization to age-specific reference values. A comparison group included 34 children with mild or moderate trauma (ISS<16), and the control group consisted of 60 age- and sex-matched healthy children.The findings revealed a significant and sustained reduction in CD3⁺, CD19⁺, and NK lymphocyte counts in children with severe trauma as early as day 1, with partial recovery by days 5–7. In children with mild trauma, these changes were less pronounced. Persistent lymphopenia—particularly in CD3⁺ and NK cells—was significantly associated with MODS, PSC, and poor outcomes. These results highlight the prognostic relevance of dynamic monitoring of lymphocyte subpopulations as sensitive markers of immune dysfunction in the context of severe trauma. Incorporating cellular immune parameters into risk stratification protocols may enhance the early identification of children at high risk for adverse outcomes and guide targeted therapeutic interventions.