title: Elevated plasma factor VIII and D-dimer levels as predictors of poor outcomes of thrombosis in children.
abstract: BACKGROUND
  Elevated levels of plasma factor VIII and D-dimer predict recurrent venous thromboembolism in adults. We sought to determine whether an elevation of factor VIII, D-dimer, or both at diagnosis and persistence of the laboratory abnormality after three to six months of anticoagulant therapy correlate with poor outcomes of thrombosis in children.
  
  
  METHODS
  We evaluated levels of factor VIII and D-dimer and additional components of an extensive laboratory thrombophilia (i.e., hypercoagulability) panel at the time of diagnosis in 144 children with a radiologically confirmed acute thrombotic event. All patients were treated initially with heparin and then with either warfarin or low-molecular-weight heparin for at least three to six months, according to the current standard of care. Patients were examined at follow-up visits 3, 6, and 12 months after diagnosis and then annually, at which times testing was repeated in children with previously abnormal factor VIII and D-dimer test results and a uniform evaluation for the post-thrombotic syndrome was performed.
  
  
  RESULTS
  Among 82 children for whom complete data were available regarding laboratory test results at diagnosis and thrombotic outcomes during follow-up, 67 percent had factor VIII levels above the cutoff value of 150 IU per deciliter, D-dimer levels above 500 ng per milliliter, or both at diagnosis, and at least one of the two laboratory values was persistently elevated in 43 percent of the 75 patients in whom testing was performed after three to six months of anticoagulant therapy. Fifty-one percent of the 82 patients had a poor outcome (i.e., a lack of thrombus resolution, recurrent thrombosis, or the post-thrombotic syndrome) during a median follow-up of 12 months (range, 3 months to 5 years). Elevated levels of factor VIII, D-dimer, or both at diagnosis were highly predictive of a poor outcome (odds ratio, 6.1; P=0.008), as was the persistence of at least one laboratory abnormality at three to six months (odds ratio, 4.7; P=0.002). The combination of a factor VIII level above 150 IU per deciliter and a D-dimer level above 500 ng per milliliter at diagnosis was 91 percent specific for a poor outcome, and after three to six months of standard anticoagulation, the combination was 88 percent specific.
  
  
  CONCLUSIONS
  Elevated levels of plasma factor VIII, D-dimer, or both at diagnosis and a persistent elevation of at least one of these factors after standard-duration anticoagulant therapy predict a poor outcome in children with thrombosis.
authors.affiliation: Department of Pediatrics, Section of Hematology, Oncology, and Bone Marrow Transplantation, University of Colorado Health Sciences Center and the Children's Hospital, 1056 E. 19th Ave., B-115, Denver, CO 80218, USA. neil.goldenberg@uchsc.edu
authors.forename: Neil A
authors.initials: NA
authors.lastname: Goldenberg
authors.forename: R
authors.initials: R
authors.lastname: Knapp-Clevenger
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Manco-Johnson
mesh_terms: D000293:Adolescent; D000328:Adult; D000925:Anticoagulants / Q000627:therapeutic use; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005169:Factor VIII / Q000032:analysis*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D011379:Prognosis; D012008:Recurrence; D012307:Risk Factors; D019851:Thrombophilia / Q000097:blood / Q000188:drug therapy; D013927:Thrombosis / Q000097:blood* / Q000188:drug therapy; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D005169:Factor VIII