title: Enhanced expression of the S100A8/A9 complex in acute myocardial infarction patients.
abstract: BACKGROUND
  S100A8/A9 complex (S100A8/A9) is expressed in activated human neutrophils and macrophages. Enhanced expression of S100A8/A9 in atherosclerotic plaque of patients with unstable angina pectoris (UAP) has been demonstrated, but its profile in acute myocardial infarction (AMI) has not been clarified.
  
  
  RESULTS
  Serum S100A8/A9 levels were serially measured in patients with AMI (n=55) and UAP (n=16) during the acute period. The expression of S100A8/A9 was examined immunohistochemically in the infarcted myocardium of 7 autopsied patients with AMI. Serum S100A8/A9 levels on the 1st day were 1,118+/-115 (SE) ng/ml in AMI patients as compared with 787+/-147 ng/ml in UAP patients. On days 3-5, serum S100A8/A9 levels in AMI patients reached a peak value and were significantly higher than the values in UAP patients (1,690+/-144 ng/ml vs 844+/-100 ng/ml; P<0.0001). In AMI patients, peak S100A8/A9 levels positively correlated with peak white blood cell and neutrophil counts, and peak creatine kinase-MB and peak C-reactive protein levels. Double immunostaining revealed that S100A8/A9 was specifically expressed in neutrophils and macrophages infiltrating the infarcted myocardium.
  
  
  CONCLUSIONS
  S100A8/A9 is implicated in the pathophysiology of AMI and may be an additional biomarker of the local inflammatory response following AMI.
authors.affiliation: Department of Internal Medicine III, Osaka Medical College, Takatsuki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Katashima
authors.forename: Takahiko
authors.initials: T
authors.lastname: Naruko
authors.forename: Fumio
authors.initials: F
authors.lastname: Terasaki
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Fujita
authors.forename: Kaoru
authors.initials: K
authors.lastname: Otsuka
authors.forename: Shougo
authors.initials: S
authors.lastname: Murakami
authors.forename: Akira
authors.initials: A
authors.lastname: Sato
authors.forename: Michiaki
authors.initials: M
authors.lastname: Hiroe
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ikura
authors.forename: Makiko
authors.initials: M
authors.lastname: Ueda
authors.forename: Masaki
authors.initials: M
authors.lastname: Ikemoto
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kitaura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000789:Angina, Unstable / Q000097:blood; D001344:Autopsy; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D040501:Calgranulin A / Q000097:blood*; D040502:Calgranulin B / Q000097:blood*; D052279:Creatine Kinase, MB Form / Q000097:blood; D005260:Female; D006801:Humans; D007962:Leukocytes; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000473:pathology; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D009504:Neutrophils / Q000473:pathology
chemical_list: D015415:Biomarkers; D040501:Calgranulin A; D040502:Calgranulin B; D002097:C-Reactive Protein; D052279:Creatine Kinase, MB Form