Evidence for endothelial cell activation/injury in heatstroke.
OBJECTIVE
We treated the hypothesis that heatstroke is associated with endothelial cell activation/injury and examined the possibility that the markers of endothelial cell activation/injury may be associated with its severity and complications such as disseminated intravascular coagulation, lung injury, and renal dysfunction.


METHODS
Prospective analyses.


METHODS
Heatstroke Center in Makkah, Saudi Arabia.


METHODS
Twenty-two adult patients with heatstroke.


METHODS
The plasma concentration of endothelin, circulating intercellular adhesion molecule-1 (ICAM-1), and von Willebrand factor-antigen values were measured, respectively, by radioimmunoassay, enzyme-linked immunosorbent assay, and rocket electroimmunoassay, in heatstroke patients on admission (precooling) and after complete cooling (postcooling), and in ten normal control patients.


RESULTS
Precooling heatstroke patients (rectal temperature 40.9 +/- 1.1 [SD] degrees C) had increased circulating concentrations of endothelin, c-ICAM-1, and von Willebrand factor-antigen in 100%, 80%, and 77% of patients to 126.4 +/- 11.2 pmol/L, 523.1 +/- 154.4 ng/mL, and 3.85 +/- 2.3 U/mL, respectively (control values: 13.7 +/- 4.2 pmol/L [p < .001]; 247.4 +/- 68.2 ng/ml [p < .001]; and < 1.5 U/mL, respectively). There was a significant (r2 = .68, p < .01) correlation between circulating ICAM-1 and endothelin concentrations. Plasma endothelin concentration correlated negatively with temperature (r2 = .35, p < .05). Mean endothelin concentration was similar in patients with or without renal dysfunction, and mean von Willebrand factor-antigen concentration was similar in patients with or without lung injury or disseminated intravascular coagulation. There were no significant correlations between circulating ICAM-1, endothelin, or von Willebrand factor-antigen concentration and the Simplified Acute Physiology core. After cooling, mean circulating ICAM-1 and endothelin concentrations decreased significantly to 400 +/- 109 ng/mL and 93 +/- 38.5 pmol/L, respectively, whereas the mean von Willebrand factor-antigen concentration increased to 5.55 +/- 2.18 U/mL (p > .05).


CONCLUSIONS
Our findings of increased circulating concentrations of circulating ICAM-1, endothelin, and von Willebrand factor-antigen are consistent with the hypothesis that heatstroke is associated with endothelial cell activation/injury. Whether the endothelial cell activation/injury is implicated in the pathophysiology of this disorder merits further studies.
Bouchama
A
A
Department of Medicine, King Faisai Specialist Hospital and Research Centre, Rlyadh, Saudi Arabia.
Hammami
M M
MM
Haq
A
A
Jackson
J
J
al-Sedairy
S
S
D000328:Adult; D000368:Aged; D016232:Endothelins / Q000097:blood; D004730:Endothelium, Vascular / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018883:Heat Stroke / Q000097:blood / Q000473:pathology*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011863:Radioimmunoassay; D014841:von Willebrand Factor / Q000032:analysis
D016232:Endothelins; D014841:von Willebrand Factor; D018799:Intercellular Adhesion Molecule-1