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

Expression and function of Toll-like receptor 9 in severely injured patients prone to sepsis

The purpose of this prospective study was to enumerate Toll-like receptor 9 (TLR9)(+) cells and measure their function using synthetic oligonucleotides enriched in CG dinucleotide motifs (CpG)-induced proliferation within 48 h after trauma in severely injured patients prone to sepsis. Sixteen consecutive trauma patients with an injury severity score (ISS) > 21 and 16 blood donors (controls) were included in this study. Using two-colour flow cytometry, TLR9 expression was detectable intracellularly and also on the surface of B lymphocytes. The surface expression of TLR9 of B lymphocytes from whole blood and peripheral blood mononuclear cells (PBMC) stimulated with CpG was significantly increased in B cells of severely injured patients prone to sepsis compared to controls. No significant differences could be observed between CpG-induced proliferation of PBMC of severely injured patients prone to sepsis and controls. As a measure of immunosuppression, human leucocyte antigen (HLA)-DR expression of monocytes of the trauma patients was significantly diminished compared with controls in PBMC and in whole blood. Immunosuppression in the early phase after trauma seems not to be associated with a disturbed sensing of bacterial DNA.

Endothelial oxidative stress induced by serum from patients with severe trauma hemorrhage

OBJECTIVE

Shock induces oxidative stress by ischemia-reperfusion phenomenon. Endothelial cells are involved in the inflammatory response and oxidative stress responsible for microcirculation impairment and organ failure. We examined the potential of serum from patients to induce in vitro reactive oxygen species production by cultured human umbilical vein endothelial cells (HUVECs).

PATIENTS

Three groups were compared: hemorrhagic shock trauma patients, isolated brain injured patients, and healthy volunteers.

METHODS

In the hemorrhagic shock group we sought a correlation between reactive oxygen species production and severity of shock. Serum was separated and perfused in an in vitro model of perfused HUVECs. Ex vivo reactive oxygen species production was assessed by fluorescence microscopy using dichlorodihydrofluorescein, an intracellular dye oxidized by H2O2. Results are expressed in proportional change from baseline and normalized by protidemia to control for variation related to hemodilution.

RESULTS

Reactive oxygen species production by endothelial cells exposed to serum from hemorrhagic shock patients (46.2+/-24.9%) was significantly greater than in those with brain injury (3.9+/-35.1%) and in healthy volunteers (-6.8+/-5.8%). In the hemorrhagic shock group dichlorodihydrofluorescein fluorescence was strongly correlated positively to Simplified Acute Physiology Score II and lactatemia and negatively to [HCO3-].

CONCLUSIONS

Serum from trauma patients with hemorrhagic shock induces reactive oxygen species formation in naive endothelial cells which is correlated to shock severity.

Immune monitoring of patients with septic shock by measurement of intraleukocyte cytokines

OBJECTIVE

To assess the immune competence of patients presenting with septic shock by measuring on-line the production of intracellular cytokines by circulating leukocytes.

DESIGN AND SETTING

Prospective study in a 18-bed medical intensive care unit of a university hospital.

PATIENTS AND PARTICIPANTS

21 patients with septic shock, and 11 volunteers.

INTERVENTIONS

Single-step isolation of leukocytes from whole blood obtained within the first 24 h after admission. Leukocytes were fixed immediately or after treatment with lipopolysaccharide (LPS) and/or heterologous plasma.

MEASUREMENTS AND RESULTS

Leukocytes were permeabilized, and the intracellular cytokine expression of TNF-alpha and IL-10 was quantified by immunostaining and flow cytometry. LPS treatment significantly increased monocyte intracellular cytokine TNF-alpha and IL-10 as well as lymphocyte intracellular cytokine IL-10 in normal leukocytes. Septic monocytes and granulocytes had nonstimulated intracellular cytokine TNF-alpha concentrations lower than those measured in volunteers and were severely hyporesponsive to LPS. These phenotypic changes were correlated with disease severity and could be reproduced by treatment of normal leukocytes with plasma from patients with septic shock.

CONCLUSIONS

Intracellular cytokine staining is a simple and rapid method to assess in situ and on-line the inflammatory balance and responsiveness of leukocyte subpopulations and could therefore represent a useful monitoring tool to assess the immune competence of critically ill patients. This study identifies the cellular source of cytokines in whole blood and confirms prior reports showing that septic phagocytes are characterized by a predominant anti-inflammatory phenotype, with hyporesponsiveness to LPS, depending on a plasma deactivation factor.