title: IL-37 increased in patients with acute coronary syndrome and associated with a worse clinical outcome after ST-segment elevation acute myocardial infarction.
abstract: BACKGROUND
  IL-37 emerges as a natural suppressor of inflammatory responses. The potential role of IL-37 in the pathology of atherosclerosis is unclear. The purpose of this study was to assess IL-37 profile in acute coronary syndrome (ACS) and the prognostic role of this cytokine in patients with ST-segment elevation acute myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).
  
  
  METHODS
  In a case-control study, we prospectively enrolled 216 patients undergoing the first coronary angiography, which consisted of 5 groups: normal (n=57), stable angina (SAP, n=36), unstable angina (UAP, n=42), non-STEMI (n=36), STEMI (n=45). Plasma IL-37, IL-6 and serum amyloid A (SAA) were measured using a commercially ELISA kit. Besides, in a prospective cohort study, 125 patients with STEMI of onset <12h undergoing PPCI were enrolled and divided into 2 groups according to the concentrations of IL-37 (<341.1pg/ml or ≥341.1pg/ml). In-hospital major adverse cardiac event (MACE) including nonfatal myocardial infarction (MI), target lesion revascularization, acute heart failure, and cardiac death were estimated for prognosis.
  
  
  RESULTS
  IL-37 was gradually increased in accordance with the severity of coronary artery disease. The circulating concentration of IL-37 was remarkably higher in the ACS patients than in either of the normal or SAP patients (p<0.05), and especially higher in the AMI patients including STEMI and non-STEMI than in the angina pectoris subjects no matter SAP or UAP (p<0.05). There was no statistical difference of IL-37 between normal and SAP patients, STEMI and non-STEMI patients (p>0.05). The trend of the change of IL-37 was consistent with that of SAA or IL-6. A higher circulating concentration of IL-37 before PPCI was accompanied with the decreased LVEF and the increased NT-proBNP concentrations, and independently predictive of in-hospital MACE rate in patients with STEMI undergoing PPCI (OR=3.652, 95% CI=1.113-11.983, p<0.05).
  
  
  CONCLUSIONS
  We demonstrated the IL-37 profile in patients with acute coronary syndrome and the increased IL-37 concentration was associated with a worse clinical in-hospital outcome in STEMI patients undergoing PPCI.
authors.affiliation: Heart Center of Beijing Chao-Yang Hospital Affiliated Capital Medical University, 8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing 100020, China; Department of Cardiology, Peking University Shougang Hospital, Shijingshan District, Beijing 100144, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Cardiology, Peking University Shougang Hospital, Shijingshan District, Beijing 100144, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Tang
authors.affiliation: Department of Cardiology, Peking University Shougang Hospital, Shijingshan District, Beijing 100144, China.
authors.forename: Xinyuan
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Heart Center of Beijing Chao-Yang Hospital Affiliated Capital Medical University, 8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing 100020, China. Electronic address: yangxinchun2016@163.com.
authors.forename: Xinchun
authors.initials: X
authors.lastname: Yang
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications*; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention; D011379:Prognosis; D000072657:ST Elevation Myocardial Infarction / Q000097:blood* / Q000150:complications* / Q000175:diagnosis / Q000628:therapy
chemical_list: C508587:IL37 protein, human; D007375:Interleukin-1
keywords: Acute coronary syndrome; IL-37; Inflammation; Prognosis