{"title":"Evaluation of a laboratory reflex testing protocol to detect hypopituitarism in primary care presenting as hypothyroxinaemia.","authors":"Colleen Flannery, Ana Rakovac, Gerard Boran","doi":"10.1177/00045632241298891","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Thyroid function tests (TFTs) are routinely requested by general practitioners (GPs) in the clinical biochemistry laboratory. Hypothyroxinaemia (low fT4) accompanied by TSH within the reference interval (RI) is a discordant pattern which is seen commonly in non-thyroidal illness and also as result of medications. Hypopituitarism is a lot rarer, but a serious condition the laboratory does not want to miss.</p><p><strong>Methods: </strong>All thyroid hormone samples from primary care meeting the discordant case definition under investigation [fT4<10 pmol/L and TSH within RI (0.3-4.2 mU/L)] had partial anterior pituitary profiles [PAPP (cortisol, oestradiol/testosterone, prolactin, gonadotrophins)] added as reflex tests and results interpreted by a chemical pathologist. From January to June 2023, we conducted structured interviews with the requesting GPs, and, where indicated, requested repeat samples for full anterior pituitary profile [FAPP (PAPP, growth hormone (GH) and insulin-like growth factor 1 (IGF-1)]. We also reviewed the laboratory records of patients with previously known hypopituitarism to determine their fT4 and TSH values at diagnosis.</p><p><strong>Results: </strong>Over the 6 months 41,487 GP TFTs were requested; 54 (0.13%) fitted the discordant case definition and had PAPP reflexed. 13 FAPPs were requested. We identified 3 cases of hypopituitarism. The number of additional tests required to diagnose 1 case of hypopituitarism was 129. In 74% of reflex-tested cases, there was a plausible explanation for the TFT pattern (medications, known thyroid dysfunction, non-thyroidal illness, pregnancy).</p><p><strong>Conclusion: </strong>This study highlights the importance of medical liaison and early intervention in a biochemistry laboratory in identifying cases of unsuspected hypopituitarism.</p>","PeriodicalId":8005,"journal":{"name":"Annals of Clinical Biochemistry","volume":" ","pages":"45632241298891"},"PeriodicalIF":2.1000,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Annals of Clinical Biochemistry","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1177/00045632241298891","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MEDICAL LABORATORY TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Thyroid function tests (TFTs) are routinely requested by general practitioners (GPs) in the clinical biochemistry laboratory. Hypothyroxinaemia (low fT4) accompanied by TSH within the reference interval (RI) is a discordant pattern which is seen commonly in non-thyroidal illness and also as result of medications. Hypopituitarism is a lot rarer, but a serious condition the laboratory does not want to miss.
Methods: All thyroid hormone samples from primary care meeting the discordant case definition under investigation [fT4<10 pmol/L and TSH within RI (0.3-4.2 mU/L)] had partial anterior pituitary profiles [PAPP (cortisol, oestradiol/testosterone, prolactin, gonadotrophins)] added as reflex tests and results interpreted by a chemical pathologist. From January to June 2023, we conducted structured interviews with the requesting GPs, and, where indicated, requested repeat samples for full anterior pituitary profile [FAPP (PAPP, growth hormone (GH) and insulin-like growth factor 1 (IGF-1)]. We also reviewed the laboratory records of patients with previously known hypopituitarism to determine their fT4 and TSH values at diagnosis.
Results: Over the 6 months 41,487 GP TFTs were requested; 54 (0.13%) fitted the discordant case definition and had PAPP reflexed. 13 FAPPs were requested. We identified 3 cases of hypopituitarism. The number of additional tests required to diagnose 1 case of hypopituitarism was 129. In 74% of reflex-tested cases, there was a plausible explanation for the TFT pattern (medications, known thyroid dysfunction, non-thyroidal illness, pregnancy).
Conclusion: This study highlights the importance of medical liaison and early intervention in a biochemistry laboratory in identifying cases of unsuspected hypopituitarism.
期刊介绍:
Annals of Clinical Biochemistry is the fully peer reviewed international journal of the Association for Clinical Biochemistry and Laboratory Medicine.
Annals of Clinical Biochemistry accepts papers that contribute to knowledge in all fields of laboratory medicine, especially those pertaining to the understanding, diagnosis and treatment of human disease. It publishes papers on clinical biochemistry, clinical audit, metabolic medicine, immunology, genetics, biotechnology, haematology, microbiology, computing and management where they have both biochemical and clinical relevance. Papers describing evaluation or implementation of commercial reagent kits or the performance of new analysers require substantial original information. Unless of exceptional interest and novelty, studies dealing with the redox status in various diseases are not generally considered within the journal''s scope. Studies documenting the association of single nucleotide polymorphisms (SNPs) with particular phenotypes will not normally be considered, given the greater strength of genome wide association studies (GWAS). Research undertaken in non-human animals will not be considered for publication in the Annals.
Annals of Clinical Biochemistry is also the official journal of NVKC (de Nederlandse Vereniging voor Klinische Chemie) and JSCC (Japan Society of Clinical Chemistry).