title: Increased thrombin-activatable fibrinolysis inhibitor and decreased tissue factor pathway inhibitor and thrombomodulin levels in children with hypothyroidism.
abstract: OBJECTIVE
  We determined the profile of coagulation/fibrinolytic and vascular endothelial cell function parameters including plasminogen activator inhibitor (PAI) and thrombin-activatable fibrinolysis inhibitor (TAFI), tissue factor pathway inhibitor (TFPI), thrombomodulin (TM), and tissue plasminogen activator (tPA) levels in children with hypothyroidism.
  
  
  METHODS
  Forty children with hypothyroidism aged 0-16 months who presented for the first time to our hospital and 29 age-and sex-matched healthy controls were enrolled in the study. All coagulation tests were performed with ELISA method. One year after Na-L-thyroxine treatment, the study parameters were re-evaluated in 25 euthyroid children out of the 40 patients diagnosed with hypothyroidism.
  
  
  RESULTS
  Although no significant effect was detected regarding PAI antigen (Ag) and tPA Ag, the levels of TAFI, TM, and TFPI were consistent with subclinical hypercoagulability and hypofibrinolysis. There was a significant increase in TAFI Ag levels and a significant decrease in TFPI Ag and TM Ag levels in hypothyroid patients compared to healthy controls. As a result of correlation tests, the largest impact of hypothyroidism on coagulation system was on TFPI. In accordance with these findings, TAFI Ag levels decreased and TFPI Ag and TM Ag levels increased with hormonal replacement therapy.
  
  
  CONCLUSIONS
  Increased TAFI and decreased TFPI and TM in patients with hypothyroidism may indicate a potential hypercoagulable and hypofibrinolytic state as well as possible endothelial dysfunction, which may increase the risk of atherosclerotic and atherothrombotic complications. Thyroid hormone levels should also be checked in patients with a predisposition to coagulation, and thyroid replacement therapy should be initiated.
authors.affiliation: The Ministry of Health of Turkey, Ankara Training and Research Hospital, Department of Pediatric Hematology, Director of the Hematology Laboratories, Ankara, Turkey. alioglub@gmail.com
authors.forename: Bülent
authors.initials: B
authors.lastname: Alioğlu
authors.forename: Nevin
authors.initials: N
authors.lastname: Kılıç
authors.forename: Enver
authors.initials: E
authors.lastname: Şimşek
authors.forename: Yıldız
authors.initials: Y
authors.lastname: Dallar
mesh_terms: D000293:Adolescent; D000347:Afibrinogenemia / Q000209:etiology; D025901:Carboxypeptidase B2 / Q000097:blood*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D007223:Infant; D007455:Iodine / Q000172:deficiency; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D015849:Plasminogen Inactivators / Q000097:blood; D018180:Thrombomodulin / Q000097:blood*; D019851:Thrombophilia / Q000209:etiology; D013974:Thyroxine / Q000627:therapeutic use
chemical_list: D008074:Lipoproteins; D015849:Plasminogen Inactivators; C546931:THBD protein, human; D018180:Thrombomodulin; C051928:lipoprotein-associated coagulation inhibitor; D007455:Iodine; D025901:Carboxypeptidase B2; D013974:Thyroxine