The diagnostic value of soluble CD163 in patients presenting with chest pain

CD163 is a scavenger receptor for the uptake of haptoglobin–hemoglobin (Hpt–Hb) complexes. The Hpt–Hb complexes are being formed in the plaque in response to intraplaque hemorrhage, a hallmark of atherosclerotic plaque instability. We therefore investigated whether soluble CD163 (sCD163) was elevated in patients with an acute coronary syndrome. All subjects presenting with chest pain suggestive of myocardial ischemia referred to either the emergency department or the coronary care unit were included in a prospective follow-up study. Plasma was collected and frozen at − 80 °C until assayed. sCD163 was measured using a commercially available Elisa assay. Of 526 included chest pain patients, the final diagnosis was non-cardiac chest pain in 244 (46%) patients, non-STEMI in 67 (13%), and STEMI in 215 (41%). The non-STEMI patients were older, used more medication, had undergone more often coronary interventions, but did not differ with respect to risk factors, except for a higher incidence in dyslipidemia. Unexpectedly, sCD163 did not differentiate between patients with non-STEMI or STEMI and the non-cardiac chest pain patients (2.09 ± 0.76 versus 2.24 ± 0.86). Although ACS is characterized by intraplaque hemorrhage, the amount of intraplaque Hb release seems not to be substantial enough to result in a measurable difference in sCD163.