T helper subsets during the acute post-traumatic period in children

Abstract

Severe mechanical injury is among the main reasons of disability and mortality in pediatric patients. The imbalance between the states of inflammation and immune suppression during the critical period of post-traumatic injury bears an elevated risk for infectious complications and/or multiple organ failure. The present study aimed to determine the informative immunological criteria in order to evaluate severity and prognosis for clinical outcomes in children from the severe injury group (SInj, ISS 16, n = 87); mild/moderate injury group (MInj, ISS 16, n = 34), as based on assessment of helper T cells (Th) ratios, i.e., Th17/Treg, T127hi/ Treg, and Th17/T127hi. The patients with severe injuries were classified by their outcomes (favorable, n = 47; unfavorable, n = 40), presence of infectious complications (IC, n = 16) and the development of multiple organ failure (MOF, n = 11). Th ratios were studied on the 1st, 3rd, 5th, 7th, 14th day after injury. For the Sinj group, a pronounced increase of Th17/Treg ratio in the acute post-traumatic period with a decrease by 14 days was revealed. The indices of T127hi/Treg ratio on the first day for the patients from Minj group corresponded to the values of control group and significantly differed from patients with SInj in the 3rd to 5th day. There are different kinetics of Th subset ratio in peripheral blood of children with severe injuries over time in different groups, as well as with/without MOF, in presence, or absence of infectious complications and different clinical outcomes. Significant differences in T127hi/Treg ratio level were found in group with IC from 1st to 3rd day and from 7th to 14th day. Significant differences in Th17/Treg ratio level were found in IC group (7th day), in MOF group on 14th day post-injury. The patients with MOF had lower median concentrations of Th17/Treg and T127hi/Treg than patients without MOF. The results of the study indicate that the levels of Th17/Treg and T127hi/Treg ratio in children may be used to predict outcome of the traumatic disease and assess the risk of infectious complications and multiple organ dysfunction syndrome.