HLA-DR (cellular and soluble) and inflammatory serum markers in patients after trauma: Can they predict outcome?

Background: Infectious complications remain a serious problem in patients after trauma. HLA-DR molecules have a central role in the activation of specific immune response to infection, and inflammatory mediators has been implicated in the pathogenesis of organ dysfunction. To asses whether HLA-DR and inflammatory markers predict the development of sepsis after trauma, a prospective study was performed in 95 injuried patients. Methods: The patients were categorized into three groups: with minor injury (Injury Severity Score: ISS<16) (group 1, n=17), severely injured patients (ISS>16) without sepsis (group 2, n=53), and severely injured patients (ISS>16) with sepsis (group 3, n=25). We monitored cellular and soluble HLA-DR plasma levels, interleukin-1β (IL-1β), interleukin 6 (Il-6), C-reactive Protein (CRP) and neutrophil elastase in the patients immediately after trauma and serially during the subsequent days. Results: The septic patients had significantly lower soluble HLA-DR plasma levels and lower cellular HLA-DR. A statistically significant increase of plasma elastase was recorded in patients with sepsis. IL-1β, IL-6 and CRP serum levels were significantly higher in group 3 and 2 if compared to group 1 on day 3, but there was not a significant difference between patients with sepsis and without sepsis. Conclusions: After a severe injury, low levels of cellular and soluble HLA-DR was associated with development of sepsis. Elastase concentration increases in patients with sepsis. The concentrations of IL-1β, IL-6 and CRP increase in proportion to trauma, but not allows to distinguish infection from inflammation.