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Medline ® Abstract for Reference 44

of 'Laboratory tests to support the clinical diagnosis of anaphylaxis'

44
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Postmortem serum tryptase levels in anaphylactic and non-anaphylactic deaths.
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McLean-Tooke A, Goulding M, Bundell C, White J, Hollingsworth P
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J Clin Pathol. 2014 Feb;67(2):134-8. Epub 2013 Aug 12.
 
BACKGROUND: The postmortem diagnosis of anaphylaxis remains difficult due to the lack of specific biomarkers. Mast cell tryptase (MCT) levels are used as a marker of mast cell degranulation in living patients and elevated levels have also been described in postmortem serum samples in anaphylaxis-associated deaths, although elevated levels may also be seen in non-anaphylaxis-associated deaths.
OBJECTIVE: To investigate the effects of cause of death, site of blood sampling, degree of sample haemolysis and the presence of opiates on postmortem MCT levels.
METHOD: We obtained sera from three collection sites from 189 non-suspicious coronial postmortems and aortic samples from 10 anaphylactic deaths to characterise postmortem MCT.
RESULTS: MCT were elevated (>11.4μg/L) in 57% of aortic samples, 58% of femoral samples and 30% of subclavian samples. In aortic samples, there were significantly higher levels of MCT in anaphylaxis-associated deaths compared with other causes of death. Aortic MCT levels>110μg/L had a sensitivity of 80% and specificity of 92.1% for anaphylaxis-associated deaths. There was a significant correlation between MCT and degree of sample haemolysis but no correlation with the presence of opiates.
CONCLUSIONS: Moderately elevated MCT levels are common in postmortem sera. Aortic values>110μg/L may support a diagnosis of anaphylaxis-associated death, although the diagnosis should not be based on this test alone. There was significant variation between sample sites and reference ranges for individual sample sites should be established.
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Department of Clinical Immunology, PathWest Laboratory Medicine WA, Queen Elizabeth II Medical Centre, , Perth, Western Australia, Australia.
PMID