Commercial insulin immunoassays fail to detect commonly prescribed insulin analogues

2.50
Hdl Handle:
http://hdl.handle.net/11287/594009
Title:
Commercial insulin immunoassays fail to detect commonly prescribed insulin analogues
Authors:
Parfitt, Ceri; Church, D.; Armston, A.; Couchman, L.; Evans, C.; Wark, G.; McDonald, Timothy J. ( 0000-0003-3559-6660 )
Abstract:
OBJECTIVES: Blood insulin and C-peptide are key investigations in the differential diagnosis of hypoglycaemia. Analogues of insulin have modified primary-sequences compared to native human insulin, as such may not cross react with insulin assays. This has important implications in detecting surreptitious or malicious insulin administration. The aim of this study is to assess the cross-reactivity of all insulins currently listed in the British National Formulary (BNF65, 2013) in clinical insulin assays currently used in UK clinical laboratories. DESIGN AND METHODS: Sample sets were prepared for all 15 exogenous insulin classes listed in the BNF, at concentrations of 1000pmol/L and 300pmol/L, using pooled human serum. Samples were sent blinded to 5 participating analytical laboratories to cover analysis on the 10 major clinical insulin assays used in the UK. RESULTS: The ability of insulin assays to detect exogenous insulin preparations was highly variable and ranged from 0% to >140% for a single exogenous insulin. Four assays were highly specific for the human insulin sequence and had no cross-reactivity with any synthetic analogue insulin. Two detected all insulin types (human sequence, animal and synthetic analogue), with the remaining having variable cross-reactivity. CONCLUSION: The cross-reactivity of the 15 exogenous insulin preparations is highly variable in the assays used in clinical laboratories around the UK. It is important that laboratories and clinicians are aware of the limitations of their local assays to avoid missing the important diagnosis of hypoglycaemia secondary to excessive exogenous insulin. Where necessary, samples should be referred to specialist centres for insulin analysis and ideally by a validated and fully-quantitative mass spectrometry-based method.
Citation:
Clin Biochem. 2015 Dec;48(18):1354-7
Publisher:
Elsevier
Journal:
Clinical biochemistry
Issue Date:
11-Jul-2015
URI:
http://hdl.handle.net/11287/594009
DOI:
10.1016/j.clinbiochem.2015.07.017
PubMed ID:
26171976
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0009912015002787
Type:
Journal Article
Language:
Eng
ISSN:
1873-2933
Appears in Collections:
2015 RD&E publications; Exeter Clinical Laboratory International (Blood Sciences, Genetics, Cellular Pathology & Microbiology)

Full metadata record

DC FieldValue Language
dc.contributor.authorParfitt, Cerien
dc.contributor.authorChurch, D.en
dc.contributor.authorArmston, A.en
dc.contributor.authorCouchman, L.en
dc.contributor.authorEvans, C.en
dc.contributor.authorWark, G.en
dc.contributor.authorMcDonald, Timothy J.en
dc.date.accessioned2016-01-19T12:38:32Zen
dc.date.available2016-01-19T12:38:32Zen
dc.date.issued2015-07-11en
dc.identifier.citationClin Biochem. 2015 Dec;48(18):1354-7en
dc.identifier.issn1873-2933en
dc.identifier.pmid26171976en
dc.identifier.doi10.1016/j.clinbiochem.2015.07.017en
dc.identifier.urihttp://hdl.handle.net/11287/594009en
dc.description.abstractOBJECTIVES: Blood insulin and C-peptide are key investigations in the differential diagnosis of hypoglycaemia. Analogues of insulin have modified primary-sequences compared to native human insulin, as such may not cross react with insulin assays. This has important implications in detecting surreptitious or malicious insulin administration. The aim of this study is to assess the cross-reactivity of all insulins currently listed in the British National Formulary (BNF65, 2013) in clinical insulin assays currently used in UK clinical laboratories. DESIGN AND METHODS: Sample sets were prepared for all 15 exogenous insulin classes listed in the BNF, at concentrations of 1000pmol/L and 300pmol/L, using pooled human serum. Samples were sent blinded to 5 participating analytical laboratories to cover analysis on the 10 major clinical insulin assays used in the UK. RESULTS: The ability of insulin assays to detect exogenous insulin preparations was highly variable and ranged from 0% to >140% for a single exogenous insulin. Four assays were highly specific for the human insulin sequence and had no cross-reactivity with any synthetic analogue insulin. Two detected all insulin types (human sequence, animal and synthetic analogue), with the remaining having variable cross-reactivity. CONCLUSION: The cross-reactivity of the 15 exogenous insulin preparations is highly variable in the assays used in clinical laboratories around the UK. It is important that laboratories and clinicians are aware of the limitations of their local assays to avoid missing the important diagnosis of hypoglycaemia secondary to excessive exogenous insulin. Where necessary, samples should be referred to specialist centres for insulin analysis and ideally by a validated and fully-quantitative mass spectrometry-based method.en
dc.language.isoEngen
dc.publisherElsevieren
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0009912015002787en
dc.titleCommercial insulin immunoassays fail to detect commonly prescribed insulin analoguesen
dc.typeJournal Articleen
dc.identifier.journalClinical biochemistryen

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