title: Feasibility of using thrombin generation assay (TGA) for monitoring bypassing agent therapy in patients with hemophilia having inhibitors.
abstract: BACKGROUND
  Monitoring bypassing agent therapy and observing concordance with clinical hemostasis is crucial in vital hemorrhages and major surgeries in patients with hemophilia having inhibitor.
  
  
  OBJECTIVE
  We aimed to investigate the value of the thrombin generation assay (TGA) and thromboelastography (TEG) for monitoring hemostasis in patients with hemophilia having inhibitor, during supplementation therapy with bypassing agents.
  
  
  METHODS
  The study group consisted of 7 patients with hemophilia having factor VIII inhibitor. All patients were male. The median age of the participants was 10 years. Age range was 6 to 32 years. The median inhibitor level was 10 Bethesda units (BU), with a range of 5 to 32 BU. A total of 17 bleeding episodes were evaluated. Both TEG and TGA tests were assessed in addition to clinical responses. Assessments were made prior to bypass agent therapy such as recombinant factor VIIa (rFVIIa) or activated prothrombin complex concentrate (aPCC) for bleeding episodes, during the first hour and 24 hours after either intervention in patients.
  
  
  RESULTS
  No relation between clinical response and TGA or TEG parameters was found in patients. There was no difference between clinical responses after rFVIIa and aPCC treatments. However, after aPCC treatment, endogenous thrombin potential and peak thrombin levels and also TEG R, K, and alpha angle degrees were significantly higher.
  
  
  CONCLUSIONS
  In conclusion, we found that the clinical effectiveness of bypass therapy in hemophilia cannot be assessed by TGA and TEG.
authors.affiliation: Department of Hematology, Ege University Medical School, Children's Hospital, Ege Hemophilia Center, Bornova, Izmir, Turkey. dryilmazay@yahoo.com
authors.forename: Yilmaz
authors.initials: Y
authors.lastname: Ay
authors.forename: Can
authors.initials: C
authors.lastname: Balkan
authors.forename: Deniz Yilmaz
authors.initials: DY
authors.lastname: Karapinar
authors.forename: Mehmet
authors.initials: M
authors.lastname: Akin
authors.forename: Basri
authors.initials: B
authors.lastname: Bilenoglu
authors.forename: Kaan
authors.initials: K
authors.lastname: Kavakli
mesh_terms: D000293:Adolescent; D000328:Adult; D019774:Blood Coagulation Factor Inhibitors / Q000097:blood; D001779:Blood Coagulation Factors / Q000008:administration & dosage*; D001780:Blood Coagulation Tests / Q000379:methods; D016022:Case-Control Studies; D002648:Child; D005167:Factor VII / Q000008:administration & dosage*; D005169:Factor VIII / Q000037:antagonists & inhibitors*; D006467:Hemophilia A / Q000097:blood* / Q000188:drug therapy*; D006801:Humans; D008297:Male; D011994:Recombinant Proteins / Q000008:administration & dosage; D013916:Thrombelastography / Q000379:methods; D013917:Thrombin / Q000032:analysis* / Q000378:metabolism; D013918:Thrombin Time; D055815:Young Adult
chemical_list: D019774:Blood Coagulation Factor Inhibitors; D001779:Blood Coagulation Factors; D011994:Recombinant Proteins; C025667:prothrombin complex concentrates; D005167:Factor VII; D005169:Factor VIII; D013917:Thrombin