title: Combined role of the Lewis antigenic system, Chlamydia pneumoniae, and C-reactive protein in unstable angina.
abstract: OBJECTIVE
  The goal of this study was to assess the prognostic role of the Lewis antigenic system, Chlamydia pneumoniae (CP) seropositivity (CP+), and C-reactive protein (CRP) levels in unstable angina (UA).
  
  
  BACKGROUND
  The role of CP infection in acute coronary syndromes is contradictory. The Lewis antigenic system, a genetically determined blood group system associated with infections and several disorders, including ischemic heart disease, might influence the susceptibility to CP infection, inflammatory response, and risk of cardiac ischemic events.
  
  
  METHODS
  The CRP levels, Lewis antigens, and CP+ were measured in 54 patients with Braunwald's class IIIB UA. All patients were followed up for one year, and the occurrence of new coronary events (coronary death, myocardial infarction, and recurrence of instability) were recorded.
  
  
  RESULTS
  Twenty-five coronary events occurred during follow-up. At univariate analysis CRP >3 mg/l (CRP+) (p = 0.0056), Lewis antigen b (Leb+) (p = 0.028), and the combination of Leb+ and CP+ (p = 0.006) and of CRP+ and Leb+ (p = 0.003) were associated with new coronary events, while CP+ alone was not. At multivariate analysis, CRP+ (p = 0.008) and combined Leb+CP+ (p = 0.03) were independent predictors of worse outcome. The event rate was 64% in CRP+ patients, 67% in Leb+CP+ patients, and 86% in CRP+Leb+CP+ patients. Combined Leb+CP+, but not Leb+ and CP+ alone, was related to CRP levels (p = 0.03). Among CP+ patients, CRP levels were higher in Leb+ than Leb- (p = 0.028).
  
  
  CONCLUSIONS
  Our data demonstrate that in UA the Lewis antigenic system plays an important role, probably determining individual susceptibility to the detrimental effects of CP infection and by determining an enhanced inflammatory response.
authors.affiliation: Institute of Cardiology, Catholic University of the Sacred Heart, Largo A. Gemelli 8, 00168 Rome, Italy.
authors.forename: Dominick J
authors.initials: DJ
authors.lastname: Angiolillo
authors.forename: Giovanna
authors.initials: G
authors.lastname: Liuzzo
authors.forename: Simona
authors.initials: S
authors.lastname: Pelliccioni
authors.forename: Erica
authors.initials: E
authors.lastname: De Candia
authors.forename: Raffaele
authors.initials: R
authors.lastname: Landolfi
authors.forename: Filippo
authors.initials: F
authors.lastname: Crea
authors.forename: Attilio
authors.initials: A
authors.lastname: Maseri
authors.forename: Luigi M
authors.initials: LM
authors.lastname: Biasucci
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000097:blood* / Q000150:complications / Q000382:microbiology*; D002097:C-Reactive Protein / Q000032:analysis*; D023521:Chlamydophila Infections / Q000097:blood* / Q000150:complications / Q000382:microbiology*; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000209:etiology / Q000382:microbiology*; D011237:Predictive Value of Tests; D011379:Prognosis
chemical_list: D007983:Lewis Blood Group Antigens; D002097:C-Reactive Protein