Human leukocyte antigen-DR expression in peripheral blood mononuclear cells from healthy donors influenced by the sera of injured patients prone to severe sepsis.

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 TNFalpha 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 TNFalpha-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 (3)H-thymidine uptake [patients 139971+/-12844 counts per minute (cpm), controls 198973+/-19347 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.