title: Utility of plasma fibrinogen in the differential diagnosis of thyrotoxicosis.
abstract: BACKGROUND
  A study had reported that a low TSH level is associated with elevated plasma fibrinogen (FIB) levels. Our purpose was to investigate the role of FIB in the differential diagnosis of thyrotoxicosis.
  
  
  METHODS
  The data of 104 patients with primary thyrotoxicosis at the First Hospital of China Medical University from July 2010 to March 2011 were analyzed and divided into three groups: 45 cases of subacute thyroiditis, 50 cases of Graves' disease, and 9 cases of toxic multinodular goiter. The patients with subacute thyroiditis were followed up before and after the treatment. FIB levels of the three groups were compared.
  
  
  RESULTS
  There was no significant difference in serum TSH, FT3 and FT4 between the patients with three different causes of thyrotoxicosis (P > 0.05). The proportion of hyperfibrinogenemia in patients with subacute thyroiditis was 98%. The FIB levels of patients with subacute thyroiditis were significantly higher than those with Graves' disease and toxic multinodular goiter (P < 0.05). Levels of ESR show a similar tendency. The FIB levels returned to normal with the remission of subacute thyroiditis.
  
  
  CONCLUSIONS
  Elevated plasma fibrinogen is a common manifestation of the active phase of subacute thyroiditis. A FIB test can be used for the differential diagnosis of thyrotoxicosis. We can anticipate the outcome of subacute thyroiditis through the dynamic changes of FIB.
authors.affiliation: Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University Shenyang 110001, Liaoning, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University Shenyang 110001, Liaoning, P. R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University Shenyang 110001, Liaoning, P. R. China.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University Shenyang 110001, Liaoning, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Miao
authors.affiliation: Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University Shenyang 110001, Liaoning, P. R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University Shenyang 110001, Liaoning, P. R. China.
authors.forename: Yushu
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University Shenyang 110001, Liaoning, P. R. China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Guan
keywords: Fibrinogen; diagnosis; subacute thyroiditis; thyrotoxicosis