[Changes in human leukocyte antigen-DR expression on monocytes and its value of prediction on infection complication in trauma patients].

Objective: To observe the changes of human leukocyte antigen DR (HLA-DR) expression in monocytes of trauma patients and its value of prediction on infection complications.

Methods: Fifty-four trauma patients were divided into three groups according to severity of injury: severe trauma group injury severity score (ISS) >or=25, moderate trauma group (16or=16) were divided into three groups according to infection or not: no infection group, localized infection group and systemic infection group. Blood samples were collected immediately after admission and serially at 8:30 to 9:00 a.m. on days 1, 2, 4, 6, 8, 14 after admission, and monocyte HLA-DR expression was determined with monoclonal staining and flow cytometry.

Results: The HLA-DR expression in monocytes was reduced in the trauma patients. The lowest levels of HLA-DR were recorded on day 2 after trauma. Subsequently HLA-DR expression in monocytes increased gradually. During the whole observation, the HLA-DR expression was significantly decreased in both severe trauma group and moderate trauma group versus control group, but no significant differences were found between severe trauma group and moderate trauma group, mild trauma group and control group, Immediately after trauma, HLA-DR expression in monocytes was significantly lower in the localized infection group than that in the patients without infection, and lasted until day 4 after trauma. The mean fluorescence intensity of HLA-DR expression in monocytes on the day 2 to 14 after trauma, the percentage of HLA-DR monocytes on the day 1 to 14 after trauma were significantly lower in the systemic infection group than those in the localized infection group. The level of HLA-DR expression in monocyte in the 2 died trauma patients was lowered till died.

Conclusion: In severe trauma patients, the HLA-DR expression in monocytes is significantly decreased, and decreased levels of HLA-DR expression in monocytes might be the early indicators of an immune deviation associated with the development of infection complications and prognosis.