Akinci Baris, Comlekci Abdurrahman, Ali Ozcan Mehmet, Demir Tevfik, Yener Serkan, Demirkan Fatih, Yuksel Faize, Yesil Sena
Dokuz Eylul University Medical School, Department of Internal Medicine, Division of Endocrinology and Metabolism, Izmir, Turkey.
Endocr J. 2007 Feb;54(1):45-52. doi: 10.1507/endocrj.k06-062. Epub 2006 Nov 8.
The influence of hypothyroidism on haemostasis is an active research area. Not only bleeding tendency but also hypercoagulable states have been reported in hypothyroid patients. Decreased and increased fibrinolytic activity in hypothyroid patients has been shown in several studies. Thrombin activatable fibrinolysis inhibitor (TAFI) is an inhibitor of fibrinolysis, which has been recently isolated from human plasma. The aim of our study was to determine plasma TAFI antigen levels in overt and subclinical hypothyroidism, and to investigate the effect of levothyroxine treatment on TAFI levels. The study was performed in age- and sex-matched 30 overt hypothyroid, 30 subclinical hypothyroid patients, and 30 healthy controls. Blood samples were obtained from patients with overt and subclinical hypothyroidism before levothyroxine replacement, and one month after achieving a euthyroid state with levothyroxine. TAFI antigen levels were measured using Enzyme-Linked ImmunoSorbent Assay kits (Affinity Biologicals; Ontario, Canada). In baseline evaluation both the overt and subclinical hypothyroid groups had higher TAFI antigen levels than control group (p<0.05). High levels of TAFI antigen were correlated with the degree of thyroid failure. After achieving euthyroid state with levothyroxine replacement, TAFI antigen levels decreased significantly in patients with overt and subclinical hypothyroidism (p<0.05). Our data suggest that there are elevated plasma levels of TAFI antigen both in overt and subclinical hypothyroidism, which may be associated with hypofibrinolysis and elevated risk of thrombosis. Normalization of thyroid state by levothyroxine replacement seems to be effective in lowering of TAFI antigen levels in hypothyroidism.
甲状腺功能减退对止血的影响是一个活跃的研究领域。甲状腺功能减退患者不仅有出血倾向，还存在高凝状态。多项研究表明，甲状腺功能减退患者的纤溶活性降低和升高。凝血酶激活的纤溶抑制物（TAFI）是一种纤溶抑制物，最近已从人血浆中分离出来。我们研究的目的是测定显性和亚临床甲状腺功能减退患者的血浆TAFI抗原水平，并研究左甲状腺素治疗对TAFI水平的影响。该研究纳入了年龄和性别匹配的30例显性甲状腺功能减退患者、30例亚临床甲状腺功能减退患者和30例健康对照者。在左甲状腺素替代治疗前以及左甲状腺素治疗使甲状腺功能恢复正常状态1个月后，采集显性和亚临床甲状腺功能减退患者的血样。使用酶联免疫吸附测定试剂盒（Affinity Biologicals；加拿大安大略省）测定TAFI抗原水平。在基线评估中，显性和亚临床甲状腺功能减退组的TAFI抗原水平均高于对照组（p<0.05）。TAFI抗原水平升高与甲状腺功能减退程度相关。左甲状腺素替代治疗使甲状腺功能恢复正常状态后，显性和亚临床甲状腺功能减退患者的TAFI抗原水平显著降低（p<0.05）。我们的数据表明，显性和亚临床甲状腺功能减退患者的血浆TAFI抗原水平均升高，这可能与纤溶功能减退和血栓形成风险增加有关。左甲状腺素替代治疗使甲状腺状态恢复正常似乎对降低甲状腺功能减退患者的TAFI抗原水平有效。
