Adrenal and thyroid disorders

• What are the symptoms or Hyperthyroidism

  • Sweating
  • Weight loss
  • Tachycardia
• What are the symptoms of Graves' Disease

  • Hyperthyroidism symptoms
  • Staring eyes.
  • Thyroid is large and soft (goitre)
• What is a Thyroid Adenoma

  Benign follicular tumour forms a single lump in the thyroid glands.
• Define an active thyroid follicle

  Endocytosis of the colloid, which contains thyroglobulin. Proteolysis of thyroglobulin produces thyroxine and triiodothyronine.
• What is meant by free T4.

  This is T4, which is not bound to a protein for transport.
• Is free T4 active or inactive

  Active
• What is total T4

  The number of bound and free T4.
• What test is used for TSH levels


  2 site ELISA
• What tests are used for T4 or T3 levels


  2 step competitive ELISA
• What test is used for Anti-TSH receptor antibodies


  Cell assay
• What test is used for anti-thyroid peroxidase antibodies

  ELISA
• Describe the test for TSH levels

  • Bind TSH antibodies to the well [Beta subunit]
  • Add serum
  • Add enzyme-linked antibody [Alpha subunit] [HRP]
  • Add chromogenic substrate [TMB]
  • Colour change
  • Spectroscopy
• What enzyme is used in Adrenal or thyroid ELISAs

  Horse Radish Proxidase
• What is the chromogenic substrate for a Thyroid or Adrenal ELISA

  TMB
• What does a low absorbance in a 2-site ELISA for TSH indicate.

  • Little enzyme bound to convert substrate
  • Little TSH in serum
• Describe the 2 step competitive ELISA for FT4


  • Bind FT4 antibody to well
  • Add Serum
  • Add enzyme-linked FT4 [HRP]
  • Add chromogenic substrate [TMB]
  • Colour change
  • Spectroscopy
• What is the colour change for a 2 site ELISA for TSH levles

  Blue changes to yellow when HCl is added.
• What does a high Absorbance indicate in the 2 step competitive ELISA for FT4


  • Lots of TMB is converted by HRP
  • Lots of HRP linked FT4 bound to antibodies
  • Little FT4 in serum
• Describe the 2 step competitive ELISA for TT4


  • Bind T4 Antibody to well
  • Add serum.
  • Add enzyme labelled T4 [HRP]
  • Add chromogenic substance [TMB]
  • Colour change
  • Spectroscopy
• What does a weak abosbance in the 2 step competitive ELISA for TT4 mean


  • Little TMB is converted
  • Little HRP labelled T4 bound
  • Lots of T4 in sample
• Which site does the FT4 antibody bind to

  The site which binds to the transport protein.
• What are the two thyroid tests for autoantibodies

  Cell assay and ELISA.
• What are the two thyroid tests for hormone levels

  2 site ELISA. 2 step competitive ELISA.
• Describe the positive result for the cell assay for anti-TSH receptors autoantibodies


  Cells are modified to express the TSH receptor, luciferase gene and promotor. Patient's serum is added to cells. Autoantibodies bind to TSH receptors. cAMP is the second messenger and so intracellular concentrations rise. This acitivates the luciferase gene to produce luciferase. The cells are then exposed to luciferin which is converted to visible light by luciferase.
• What activates the luciferase gene

  cAMP
• What does the activated luciferase gene produce

  luciferase
• What is converted to visible light in the Anti-TSH receptor assay

  luciferin using luciferase.
• Briefly describe the negative result for the anti-TSh receptor assay. 


  Cells are modified to express TSH receptors, luciferase genes and promotors. Patient's serum added. No Anti-TSH receptor antibodies bind to the receptor. No cAMP is activated. No luciferin is converted to visible light using luciferase.
• What is a TPO-ELISA


  Anti-Thyroid peroxidase antibody ELISA.
• Describe the TPO-ELISA


  • Bind TPO antigens to well
  • Add serum
  • Add enzyme-labelled antihuman antibodies [HRP]
  • Add chromogenic substrate [TMB]
  • Colour change
  • Spectroscopy
• What does a high absorbance in an Anti-TPO ELISA mean 


  • Lots of TMB converted by HRP
  • Lots of HRP anti-human antibodies bound
  • Anti-TPO antibodies in patients' sample
• What is hyperthyroidism


  Overactive thyroid.
• What is the pathology of hyperthyroidism. 


  Increased T3 and T4 production reduces TSH due to negative feedback.
• Why does hyperthyroidism cause weight loss


  Results in an increased metabolism.
• What is goitre

  Large and soft Thyroid.
• What is the pathology of Grave's disease 


  Thyroid hyperplasia causes an increase in FT3 and FT4.
• What is thyroid hyperplasia 


  Increased division of follicle cells.
• What is thyrotoxic hyperplasia


  
  

  Hyperplasia resulting in increased production of T4 and T3.
• What are the substances identified in graves' disease


  • Increased FT4 and FT3 levels
  • Decreased TSH levles
  • Anti-TSH receptor antibodies
• How do Anti-TSH receptor antibodies contribute to graves' disease

  Increases follicle cell division leading to hyperplasia.