01-12-2003 | Experimental
Human leukocyte antigen-DR expression in peripheral blood mononuclear cells from healthy donors influenced by the sera of injured patients prone to severe sepsis
Published in: Intensive Care Medicine | Issue 12/2003
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Objective
To study the influence of sera from severely injured patients on the human leukocyte antigen (HLA)-DR expression of normal peripheral blood mononuclear cells (PBMC).
Design
In vitro study.
Setting
University hospital.
Patients and participants
Sera from 34 patients were obtained within 8 h after trauma. Seventeen of these patients developed posttraumatic sepsis (sepsis group) and 17 recovered without infectious complications. Sera from ten healthy individuals served as controls. Phytohemagglutinin (PHA)-activated PBMC from 44 healthy donors were used to study the effects of a patient's serum.
Measurements and results
Medium containing 5% of serum from the sepsis group significantly (p<0.05) reduced the HLA-DR expression (channels, mean ± standard error of the mean) on monocytes (patients 883±22, controls 962±15), B (patients 922±14, controls 972±7) and T cells (patients 932±13, controls 968±5) of PHA-activated PBMC. Significantly increased accumulation of TNFα on (1.8±0.4% of PBMC) and within T cells (0.98±0.26% of PBMC) was observed by flow cytometry after incubation with medium containing sera of the sepsis group compared with controls (on 0.5±0.1%, within 0.27±0.05% of PBMC). A significant negative correlation between relative cell counts of intracellular TNFα-positive T cells with HLA-DR expression was observed for monocytes (r= −0.61), B cells (r= −0.57) and proliferation (r= −0.68) as estimated by 3H-thymidine uptake [patients 139,971±12,844 counts per minute (cpm), controls 198,973±19,347 cpm, p<0.05] in the presence of sera from the sepsis group.
Conclusions
Reduced cellular immunity and, therefore, immunodeficiency after trauma appears to be caused by soluble factors influencing T cell function in particular.