fibrin and Hyperthyroidism

Available data on fibrin clot properties and fibrinolysis in hyperthyroidism and hypothyroidism are inconsistent. Our objective was to assess the impact of effective treatment of hyper- and hypothyroidism on fibrin clot characteristics.. In a case-control study, ex vivo plasma fibrin clot permeability (Ks) and efficiency of fibrinolysis were assessed in 35 consecutive hyperthyroid and 35 hypothyroid subjects versus 30 controls. All measurements were performed before and after 3months of thyroid function normalizing therapy.. At baseline, hyperthyroid, but not hypothyroid, patients had lower Ks than controls (p<0.0001). Hyperthyroid and hypothyroid groups compared with controls had prolonged clot lysis time (CLT), and lower rate of D-dimer release from clots (D-Drate) (all p<0.05). The regression analysis adjusted for fibrinogen showed that in hyperthyroid patients, pre-treatment thyroid stimulating hormone (TSH) independently predicted Ks, while thrombin activatable fibrinolysis inhibitor (TAFI) antigen predicted CLT. In hypothyroid individuals a similar regression model showed that TSH independently predicts CLT. After 3months of thyroid function normalizing therapy, 32 (91.4%) hyperthyroid and 30 (85.7%) hypothyroid subjects achieved euthyroidism and had improved fibrin clot properties (all p<0.05), with normalization of Ks in hyperthyroid and lysability in hypothyroid patients.. Both hyper- and mild-to-moderate hypothyroidism are associated with prothrombotic plasma fibrin clot phenotype and restoration of euthyroidism improves clot phenotype. Abnormal fibrin clot phenotype might contribute to thromboembolic risk in thyroid disease.

Topics: Adult; Case-Control Studies; Female; Fibrin; Fibrin Clot Lysis Time; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Humans; Hyperthyroidism; Hypothyroidism; Male; Middle Aged; Thrombosis

Hyperthyroidism is associated with increased thrombosis risk, and fibrin clot structure determines susceptibility to vascular thrombotic events.. Our objective was to investigate clot formation and lysis in hyperthyroidism using observational and interventional studies.. Ex vivo fibrin clot structure/fibrinolysis and plasma levels of thrombotic/inflammatory markers were investigated in hyperthyroid individuals (n = 24) and matched controls (n = 19), using turbidimetric assays, ELISA, and confocal and electron microscopy. The effects of normalizing thyroid function were analyzed (n = 19) and the role of short-term exogenous hyperthyroidism in healthy volunteers studied (n = 16).. Hyperthyroid subjects displayed higher clot maximum absorbance compared with controls (0.41 ± 0.03 and 0.27 ± 0.01 arbitrary units, respectively; P < 0.01), and longer clot lysis time (518 ± 23 and 461 ± 18 sec, respectively; P < 0.05), which correlated with free T(4) levels. Plasma levels of fibrinogen and plasminogen activator inhibitor-1 were significantly higher in patients compared with controls. Normalizing thyroid function in 19 subjects was associated with lower maximum absorbance and shorter lysis time, accompanied by reduction in fibrinogen, plasminogen activator inhibitor-1, and D-dimer levels. Complement C3, but not C-reactive protein, levels were higher in hyperthyroid subjects compared with controls (0.92 ± 0.05 and 0.64 ± 0.03 g/liter, respectively; P < 0.01), correlated with clot structure parameters, and decreased after intervention. Confocal and electron microscopy confirmed more compact clots and impaired fibrinolysis during hyperthyroidism. Exogenous hyperthyroidism in healthy volunteers had no effect on any of the clot structure parameters.. Endogenous hyperthyroidism is associated with more compact clots and resistance to fibrinolysis ex vivo, related to the degree of hyperthyroidism and C3 plasma levels, and these changes are modulated by achieving euthyroidism. Altered clot structure/lysis may be one mechanism for increased thrombotic risk in hyperthyroidism.

Topics: Adult; Blood Coagulation; Cross-Sectional Studies; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Hyperthyroidism; Male; Plasminogen Activator Inhibitor 1; Risk; Thrombosis; Thyroid Function Tests; Thyroid Gland

A rapid slide test for the detection of degradation products of fibrinogen/fibrin (FDP) using a new antibody-coated latex particle is described. The latex particle has been specifically coated with antibody to fragments D and E. The latex agglutination test (Thrombo-Wellcotest) has been compared with the tanned red cell haemagglutination inhibition immunoassay (TRCHII) in 143 patients with a variety of clinical conditions. There is a high degree of agreement between the methods with a coefficient of correlation of 0.83. The method provides a rapid, simple screening test for fibrin degradation products.

Topics: Antibodies; Fibrin; Fibrinogen; Hemagglutination Inhibition Tests; Humans; Hyperthyroidism; Kidney Diseases; Latex; Liver Diseases; Methods; Microspheres; Neoplasms; Pulmonary Embolism

Topics: Aged; Arteriosclerosis; Fibrin; Fibrinolysis; Humans; Hyperthyroidism; Middle Aged; Myxedema; Thrombelastography

Topics: Blood Chemical Analysis; Caseins; Coagulants; Deoxyribonuclease I; Fibrin; Fibrinogen; Fibrinolysin; Hemostatics; Humans; Hyperthyroidism; Plasma; Plasminogen; Streptodornase and Streptokinase; Streptokinase; Thrombin; Trypsin