title: Acute prognostic factors for post-thrombotic syndrome in children with limb DVT: a bi-institutional cohort study.
abstract: BACKGROUND
  Early identification of children with deep venous thrombosis (DVT) of the limb who are at heightened risk for post-thrombotic syndrome (PTS) is important in order to evaluate therapeutic interventions aimed at decreasing the risk and severity of PTS.
  
  
  OBJECTIVE
  We sought to evaluate acute prognostic factors for PTS in children following DVT of the limbs.
  
  
  METHODS
  In this bi-institutional mixed cohort study with prospective ascertainment of PTS using a validated pediatric instrument, we collected data on patient/thrombus characteristics, thrombophilia testing results, and outcomes in children (<21years at event) diagnosed with acute limb DVT at Rady Children's Hospital of San Diego and Children's Hospital Colorado.
  
  
  RESULTS
  Median age at presentation was 13years (range, 0-18years). Cumulative incidence (i.e. risk) of PTS was 23%, at a median follow-up duration of 33months (range, 13.2-65months). The presence of a lupus anticoagulant by dilute Russell Viper venom time (dRVVT) testing within two weeks of DVT diagnosis was associated with markedly increased odds of developing clinically-significant PTS (OR: 16.8, 95%CI 1.60-176.2; P=0.02). The presence of an infectious or inflammatory condition at DVT presentation was neither associated with PTS risk nor dRVVT positivity.
  
  
  CONCLUSIONS
  An acutely positive dRVVT following diagnosis of limb DVT appears to be a significant prognostic factor for development of clinically significant PTS in children. Larger collaborative cohort studies are required to substantiate these findings, evaluate other prognostic factors, and determine whether the present association is modulated by persistent dRVVT positivity or beta-2-glycoprotein-I dependence.
authors.affiliation: Department of Pediatrics, Division of Hematology/Oncology, University of California San Diego and Rady Children's Hospital, San Diego, CA, USA. clyle@billingsclinic.org
authors.forename: Courtney A
authors.initials: CA
authors.lastname: Lyle
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Gibson
authors.forename: Amy E
authors.initials: AE
authors.lastname: Lovejoy
authors.forename: Neil A
authors.initials: NA
authors.lastname: Goldenberg
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D002140:California / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003120:Colorado / Q000453:epidemiology; D005121:Extremities / Q000098:blood supply*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D016682:Lupus Coagulation Inhibitor / Q000097:blood; D015999:Multivariate Analysis; D016017:Odds Ratio; D054070:Postthrombotic Syndrome / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011517:Prothrombin Time; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D020246:Venous Thrombosis / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D016682:Lupus Coagulation Inhibitor