Myeloid-related protein 8/14 complex is released by monocytes and granulocytes at the site of coronary occlusion: a novel, early, and sensitive marker of acute coronary syndromes.
OBJECTIVE
We investigated whether myeloid-related protein 8/14 complex (MRP8/14) expressed by infiltrating monocytes and granulocytes may represent a mediator and early biomarker of acute coronary syndromes (ACS).


RESULTS
Immunohistochemistry of coronary thrombi was done in 41 ACS patients. Subsequently, levels of MRP8/14 were assessed systemically in 75 patients with ACS and culprit lesions, with stable coronary artery disease (CAD), or with normal coronary arteries. In a subset of patients, MRP8/14 was measured systemically and at the site of coronary occlusion. Macrophages and granulocytes, but not platelets stained positive for MRP8/14 in 76% of 41 thrombi patients. In ACS, local MRP8/14 levels [22.0 (16.2-41.5) mg/L] were increased when compared with systemic levels [13.4 (8.1-14.7) mg/L, P = 0.03]. Systemic levels of MRP8/14 were markedly elevated [15.1 (12.1-21.8) mg/L, P = 0.001] in ACS when compared with stable CAD [4.6 (3.5-7.1) mg/L] or normals [4.8 (4.0-6.3) mg/L]. Using a cut-off level of 8 mg/L, MRP8/14 but not myoglobin or troponin, identified ACS presenting within 3 h from symptom onset.


CONCLUSIONS
In ACS, MRP8/14 is markedly expressed at the site of coronary occlusion by invading phagocytes. The occurrence of elevated MRP8/14 in the systemic circulation prior to markers of myocardial necrosis makes it a prime candidate for the detection of unstable plaques and management of ACS.
Altwegg
Lukas A
LA
Cardiovascular Center, Cardiology, University Hospital Zürich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
Neidhart
Michel
M
Hersberger
Martin
M
Müller
Simone
S
Eberli
Franz R
FR
Corti
Roberto
R
Roffi
Marco
M
Sütsch
Gabor
G
Gay
Steffen
S
von Eckardstein
Arnold
A
Wischnewsky
Manfred B
MB
Lüscher
Thomas F
TF
Maier
Willibald
W
D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D040501:Calgranulin A / Q000378:metabolism*; D040502:Calgranulin B / Q000378:metabolism*; D003324:Coronary Artery Disease / Q000175:diagnosis*; D003328:Coronary Thrombosis / Q000175:diagnosis*; D005260:Female; D006098:Granulocytes / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D039841:Leukocyte L1 Antigen Complex / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D012307:Risk Factors; D013577:Syndrome
D015415:Biomarkers; D040501:Calgranulin A; D040502:Calgranulin B; D039841:Leukocyte L1 Antigen Complex