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.