title: Inhibition of streptokinase-induced, antibody-mediated platelet aggregation with tirofiban after exposure to streptokinase or streptococcal infection.
abstract: OBJECTIVE
  To evaluate the effect of tirofiban (a glycoprotein IIb-IIIa inhibitor) in preventing streptokinase-induced, antibody-mediated platelet aggregation after administration of streptokinase or development of a streptococcal infection.
  
  
  METHODS
  Prospective analysis.
  
  
  METHODS
  Research center of a Canadian hospital.
  
  
  METHODS
  Forty-five healthy volunteers, 45 patients who had received streptokinase within the past 3 years, and 13 patients who had a severe streptococcal infection also within the past 3 years.
  
  
  METHODS
  Blood samples were drawn to measure the extent of inhibition of streptokinase-induced, antibody-mediated platelet activation and aggregation by tirofiban.
  
  
  RESULTS
  Platelet aggregation was measured by using a turbidimetric method. The extent of inhibition by tirofiban was measured by incubating tirofiban for 2 minutes before adding streptokinase 5000 U/ml. Also, tirofiban was added 2 minutes before adding adenosine 5'-diphosphate (ADP) 2 microM/L into the last tube as a comparison. Strepto-kinase-induced, antibody-mediated platelet aggregation was observed in 10 (22%) of the 45 patients treated with streptokinase, in 3 (23%) of the 13 patients with streptococcal infection, and in none of the 45 healthy volunteers. Tirofiban inhibited streptokinase-induced, antibody-mediated platelet aggregation by 89 +/- 14% (p<0.001). Similarly, ADP-induced platelet aggregation was inhibited by 92 +/- 6% (p<0.001) with tirofiban.
  
  
  CONCLUSIONS
  Streptokinase-induced, antibody-mediated platelet aggregation occurred in 13 (22%) of 58 patients who received streptokinase or were exposed to a streptococcal infection in the past 3 years. Such patients may not benefit from streptokinase therapy. In these patients, tirofiban significantly decreased the extent of antistreptokinase antibody-mediated platelet aggregation. Hence, patients undergoing streptokinase therapy may benefit from tirofiban as adjunctive therapy.
authors.affiliation: Research Center, Hôpital du Sacré-Coeur de Montréal, 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; D000917:Antibody Formation / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011446:Prospective Studies; D013290:Streptococcal Infections / Q000188:drug therapy / Q000276:immunology; D013300:Streptokinase / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000627:therapeutic use; D000077466:Tirofiban; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D010975:Platelet Aggregation Inhibitors; D014443:Tyrosine; D013300:Streptokinase; D000077466:Tirofiban