Background: A traumatic insult initiates an inflammatory cascade, which is a contributor to cell damage and could be a marker of injury severity.
Objective: To compare the initial and 4-h post-injury lymphocyte subsets and cytokine levels between patients with minor and major injury.
Methods: Prospective, cross-sectional study of trauma patients in an urban level I trauma center.
Inclusion criteria: Adult patients with significant mechanism of injury requiring admission.
Variables: cell counts (B-cells, Natural Killer cells, monocytes; and CD4 and CD8 T lymphocytes) and cytokines (IL-1, IL-5, IL-6, IL-10, and TNFalpha). We divided subjects into two groups (major and minor injury). We defined major injury as an injury severity score > or =15, or drop in hematocrit > or =10 points or blood transfusion requirement.
Statistical analysis: Univariate analysis was performed using each inflammatory marker, and multivariate logistic regression analysis was performed to identify the inflammatory markers associated with major injury.
Results: 79 patients were studied (mean age: 35+/-17, age range: 13-88, 84% male, 38% penetrating trauma, 96% African-American). 25% of patients (n=20) experienced major injury. Larger base deficit (-3.6+/-6.2 vs. -0.9+/-4.2) levels were observed in major trauma patients. We found that major injury is associated with a drop in absolute CD4 cell count (but not in the CD8 cells), a rise in absolute B-cell count (but not in the NK-cells or monocytes), and a rise in IL-6 (but not in the IL-1, IL-5, IL-10, TNF-a).
Conclusion: We found evidence of a measurable early inflammatory response to trauma, using cytokine levels and lymphocyte subset counts.