title: Diagnostic methods of TSH in thyroid screening tests.
abstract: BACKGROUND
  Reliable and quick thyreologic diagnostics, as well as verification of the effectiveness of the therapy undertaken, is of great importance for the state of health of society. The measurement of plasma TSH is the commonly accepted and most sensitive screening test for primary thyroid disorders, which are the most frequent diseases related to the endocrine glands. At present, the available methods for the determination of TSH are characterized by high sensitivity ≤0.01 µIU/ml and lack of cross-reactivity. However, many drugs and substances, as well as pathological conditions, may affect the TSH level.
  
  
  OBJECTIVE
  evaluation of contemporary laboratory methods for the determination of TSH and the principles of interpretation of screening tests.
  
  
  BACKGROUND
  In many countries, the TSH test is the only test performed in the diagnostics of thyroid function; nevertheless, it seems that for genuine and objective assessment of thyroid status the TSH level, together with FT4 level, should be absolutely determined, which allows the differentiation and assessment of the intensity of thyroid function disorders and foresee its consequences. The interpretation of TSH results in screening tests is different in such population groups as: children aged under 14, pregnant women, the elderly, and patients with non-thyroidal illnesses.
  
  
  CONCLUSIONS
  From among currently used laboratory methods for determination of TSH levels, third generation non-isotopic methods are most frequently recommended, especially the method of immunochemiluminescence.
authors.affiliation: Department of Endocrinology, Medical University, Lublin, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Matyjaszek-Matuszek
authors.affiliation: Department of Endocrinology, Medical University, Lublin, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Pyzik
authors.affiliation: Department of Endocrinology, Medical University, Lublin, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Nowakowski
authors.affiliation: Department of Health Informatics and Statistics, Institute of Rural Health, Lublin, Poland; Faculty of Pedagogy and Psychology, University of Economics and Innovation, Lublin, Poland.
authors.forename: Mirosław J
authors.initials: MJ
authors.lastname: Jarosz
mesh_terms: D006801:Humans; D013959:Thyroid Diseases / Q000097:blood / Q000175:diagnosis*; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood
chemical_list: D013972:Thyrotropin; D013974:Thyroxine