Is monocyte HLA-DR expression predictive for clinical outcome in sepsis?

Excerpt

During the past 20 years many investigators have focused on the immunological changes in the sepsis disease, and great attention has been paid to the development of a practicable means of immunomonitoring. Especially monocytes have been intensively studied for this purpose since they play a central role in both specific and nonspecific immunity against bacterial, viral, and fungal infection. Monocytes are characterized by a large number of cell surface receptors which are correlated with functional properties of these cells. The very well characterized cell surface antigen in the septic disease is the human leukocyte antigen (HLA) with its cluster HLA-DR. HLA-DR is part of the major histocompatibility class (MHC) II antigen complex which is located on chromosome 6. The function of MHC class II molecules is to present short polypeptide sequences generated in the intracellular vesicles to CD4⁺ T cells, which then control the cells containing the foreign protein. In vivo HLA-DR is strongly regulated by cytokines as well as by a variety of other substances such as catecholamines and amino acids that affect its expression. …