Lack of association of soluble CD40 ligand with the presence of acute myocardial infarction or ischemic stroke in the emergency department.

BACKGROUND Soluble CD40 ligand (sCD40L) has been proposed as a new risk marker for cardiovascular diseases; however, its possible role as a diagnostic marker in the emergency department (ED) has not yet been investigated. METHODS We investigated sCD40L for the diagnosis of acute myocardial infarction or ischemic stroke in 1089 consecutive patients (525 males, 564 females; age, 17-98 years; median, 56 years) in an ED treating mainly adults with medical or neurologic emergencies. We used a research assay from Roche Diagnostics to measure sCD40L in heparinized plasma prepared from routinely drawn blood samples. RESULTS Intraassay and interassay CVs in our laboratory ranged from 1.6%-4.2% and from 4.4%-4.9%, respectively. A multiple linear regression analysis revealed sCD40L concentration to be significantly associated with C-reactive protein concentration (P = 0.012) and platelet count (P < 0.001). In addition, a subgroup analysis revealed a significant association between smoking and sCD40L concentration (P = 0.006). All other tested variables, including discharge diagnosis, age, sex, and other laboratory variables, showed no significant associations. CONCLUSIONS In adults presenting to the ED, sCD40L is not useful as a diagnostic marker for acute cardiac, cerebrovascular ischemic, or thromboembolic events.