title: Platelet activity and antibody titers after exposure to streptokinase or streptococcal infection.
abstract: BACKGROUND
  Streptokinase use, in acute myocardial infarction, is hindered by failure to reperfuse (60%) and early reocclusion (16%). This phenomenon may, among other causes, be due to systemic inactivation of streptokinase, as well as streptokinase-induced platelet aggregation and clot propagation from antibodies to streptokinase produced after streptokinase administration or streptococcal infections. The purpose of this study was to determine the incidence of streptokinase-induced, antibody-mediated, platelet activation and aggregation after administration of SK or development of a streptococcal infection.
  
  
  METHODS
  We included 45 normal volunteers (Control group), as well as 45 patients who had received streptokinase (Streptokinase group) and 13 who had suffered a severe streptococcal infection (Streptococcal infection group) within the past 3 years. Extent of streptokinase-induced, antibody-mediated, platelet activation and aggregation, as well as anti-streptokinase antibody and streptokinase resistance titers (lowest streptokinase concentration to cause clot lysis within 10 min) were measured.
  
  
  RESULTS
  Whereas streptokinase-induced, antibody-mediated, platelet activation was observed in 49% of streptokinase patients and in only 17% and 15% of streptococcal infection patients and normal volunteers (p<0.05 Streptokinase vs. Control and Streptokinase vs. Streptococcal infection), streptokinase-induced platelet aggregation was observed in 23% of streptokinase patients and streptococcal infection patients, and in none of the control patients (p<0.05).
  
  
  CONCLUSIONS
  Streptokinase-induced, antibody-mediated, platelet activation and aggregation occur in patients with high titers of anti-streptokinase antibody and may play a role in failure of streptokinase therapy. Streptococcal infection patients behave like streptokinase patients in terms of the reactivity of their platelets to subsequent streptokinase dose in vitro.
authors.affiliation: Research Center, Hôpital du Sacré-Coeur de Montréal and Faculty of Pharmacy, Université de Montréal, Montreal, Quebec, Canada.
authors.forename: Maryse
authors.initials: M
authors.lastname: Courval
authors.forename: Donald A
authors.initials: DA
authors.lastname: Palisaitis
authors.forename: Jean G
authors.initials: JG
authors.lastname: Diodati
authors.forename: Bernard
authors.initials: B
authors.lastname: Lesperance
authors.forename: Chantal
authors.initials: C
authors.lastname: Pharand
mesh_terms: D000328:Adult; D000906:Antibodies / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D015539:Platelet Activation / Q000187:drug effects* / Q000276:immunology; D013290:Streptococcal Infections / Q000097:blood* / Q000201:enzymology* / Q000276:immunology; D013300:Streptokinase / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood* / Q000276:immunology
chemical_list: D000906:Antibodies; D013300:Streptokinase