Expression and secretion of IL-2 receptor in trauma patients.
The high-affinity cell-surface receptor for interleukin-2 (IL-2R) consists of the 75-kilodalton (kd) chain and a 55-kd glycoprotein known as Tac. This report examines the cellular expression of IL-2R and secretion of the soluble form of Tac in immunosuppressed blunt trauma (n = 20, injury severity score -20) and thermally injured (n = 20, Total body surface area greater than 35%) patients. The percentage of IL-2R-expressing peripheral blood mononuclear cells (PBMC) in mitogen-stimulated cultures from patients and age-matched normal donors was determined by direct immunofluorescence with a monoclonal anti-Tac followed by flow cytometry analysis. Levels of soluble Tac in patient sera were measured by a monoclonal antibody-based enzyme-linked immunosorbent assay. Expression of Tac antigen by mitogen-activated PBMC cultures from blunt trauma patients was transiently reduced (by as much as 40%) in 4 of 14 patients examined. Levels of serum Tac were significantly elevated (p less than 0.05) in 15 of 20 blunt trauma patients ranging from 750 to 3000 U/mL compared with 180 to 420 U/mL in control subjects. All burn patients studied 10 to 50 days after the injury demonstrated a significant reduction (by 50% to more than 90%) in the percentage of IL-2 receptor-bearing cells. Similarly serum levels of IL-2R increased significantly (p less than 0.001 to 0.05) in all burn patients studied, reaching concentrations as high as 5500 U/mL. These results suggest that major trauma, whether mechanical or thermal, induces alterations in the T-lymphocyte activation process. However the degree and duration of such changes may vary based on the nature of the injury.
Teodorczyk-Injeyan
J A
JA
Department of Surgery, University of Toronto, Toronto General Hospital, Canada.
McRitchie
D I
DI
Peters
W J
WJ
Lalani
S
S
Girotti
M J
MJ
D000293:Adolescent; D000328:Adult; D002056:Burns / Q000276:immunology / Q000378:metabolism; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D008875:Middle Aged; D015375:Receptors, Interleukin-2 / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D014949:Wounds, Nonpenetrating / Q000276:immunology / Q000378:metabolism*
D015375:Receptors, Interleukin-2