title: Smallpox vaccination does not elevate systemic levels of prothrombotic proteins associated with ischemic cardiac events.
abstract: BACKGROUND
  During the recent smallpox vaccination campaigns, ischemic cardiac complications were observed after vaccination. To examine a possible association between the smallpox vaccine and postvaccination ischemic events, we investigated alterations in levels of prothrombotic proteins (plasminogen activator inhibitor type 1 [PAI-1] and soluble CD40 ligand [sCD40L]) in recently vaccinated individuals.
  
  
  METHODS
  Vaccinia-naive (cohort N; aged 18-32 years) and vaccinia-experienced (cohort E; aged 33-49 years) healthy adults were vaccinated with a 1 : 5 dilution of the Aventis Pasteur smallpox vaccine. Plasma levels of PAI-1 and sCD40L were measured in 30 subjects (cohort N, n=15; cohort E, n=15) at baseline and twice after vaccination (between days 7 and 9 and between days 26 and 30).
  
  
  RESULTS
  Baseline mean PAI-1 levels significantly differed between cohorts N and E (P=.04). Within each exposure cohort, mean PAI-1 levels did not significantly change after vaccination. Baseline sCD40L levels did not differ between cohorts N and E. In cohort N, sCD40L levels significantly decreased after vaccination but returned to baseline levels within 1 month. Vaccination did not significantly alter levels of sCD40L in cohort E.
  
  
  CONCLUSIONS
  Levels of PAI-1 and sCD40L did not significantly increase after smallpox vaccination. Vaccine-induced alterations in levels of these prothrombotic proteins do not appear to play a role in ischemic events observed after smallpox vaccination.
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Julia F
authors.initials: JF
authors.lastname: Shaklee
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Talbot
authors.forename: James A S
authors.initials: JA
authors.lastname: Muldowney
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Vaughan
authors.forename: Javed
authors.initials: J
authors.lastname: Butler
authors.forename: Frances
authors.initials: F
authors.lastname: House
authors.forename: James E
authors.initials: JE
authors.lastname: Crowe
authors.forename: L Harris
authors.initials: LH
authors.lastname: Smith
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
mesh_terms: D000293:Adolescent; D000328:Adult; D023201:CD40 Ligand / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000139:chemically induced*; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D012900:Smallpox Vaccine / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D012900:Smallpox Vaccine; D023201:CD40 Ligand