The potential pattern of circulating lymphocytes TH1/TH2 is not altered after multiple injuries

Area of Science:

• Immunology
• Trauma Research
• Cellular Biology

Background:

• Impaired immune responses after severe trauma are a significant concern.
• A shift in helper T cells type 1 (T(H)1) toward type 2 (T(H)2) has been hypothesized to underlie post-traumatic immune dysfunction.
• Understanding T(H)1/T(H)2 cell patterns is crucial for trauma patient outcomes.

Purpose of the Study:

• To investigate alterations in the T(H)1/T(H)2 cell balance following major trauma (polytrauma).
• To determine if changes in T(H)1/T(H)2 cell ratios contribute to post-traumatic immune suppression.
• To explore potential pathomechanisms of T-cell dysfunction in trauma patients.

Main Methods:

• Prospective study of 35 polytraumatized patients admitted to a level I trauma center.
• Serial measurements of intracellular interleukin-2 (IL-2) and IL-4 in CD3(+) T cells via flow cytometry.
• Analysis of T-cell activation marker CD69, cytokine release from peripheral blood mononuclear cells, and plasma IL-4 levels.
• Comparison with age- and sex-matched healthy donors, correlating data with Injury Severity Scores and outcomes.

Main Results:

• No significant alterations in the ratio of circulating T(H)1/T(H)2 cells were observed in polytraumatized patients.
• Intracellular cytokine staining for IL-2 and IL-4 showed no significant posttraumatic changes, except a minor early decrease in IL-2(+) cells.
• While systemic IL-4 levels and CD69 expression remained similar to controls, patients showed increased IL-2 and IL-4 release from stimulated PBMCs.

Conclusions:

• Polytrauma patients do not exhibit significant alterations in their circulating T(H)1/T(H)2 cell ratio.
• The study suggests that post-traumatic T-cell suppression involves pathomechanisms distinct from shifts in the T(H)1/T(H)2 balance.
• Further research is needed to elucidate the specific mechanisms of T-cell dysfunction after severe injury.