Atherosclerosis is an inflammatory process in which adhesion molecules play an intimate role in both the initiation and progression of lesions. It is postulated that they also play a role in the presentation of acute coronary syndromes and that plasma levels thereafter may be of potential prognostic significance. The stability of sample levels under different laboratory conditions is unknown.
Stability of plasma levels was assessed in six healthy subjects under four different laboratory conditions. The time course of levels was studied in 57 patients with acute chest pain, 21 of non-cardiac aetiology, 23 unstable angina and 13 acute myocardial infarction, at mean times of 2.3, 8.2 and 17.3 h after the onset of pain. Samples were assayed for intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, E-selectin and C-reactive protein (CRP).
ICAM-1, VCAM-1, P-selectin and E-selectin levels did not differ under different laboratory conditions. Levels were similar at presentation in patients with acute chest pain of non-cardiac aetiology, unstable angina or acute myocardial infarction (median levels ICAM-1 269 μg/l, VCAM-1 379 μg/l, P-selectin 167 μg/l and E-selectin 53 μg/l). Levels did not change in the 24 h following the onset of pain. CRP levels did not differ at presentation between groups (median level 2.1 mg/l), but rose more than 12 h after the onset of pain in the group with acute myocardial infarction (P < 0.05).
Adhesion molecule levels are stable under normal laboratory sample handling conditions. Levels do not change in the 24 h following the onset of chest pain of non-cardiac or acute ischaemic aetiology.