ALEX Allergy Chip ( Allergy Explorer )

Immunology

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Description

Specific IgE tests usually contain a crude mixture of the allergen, including allergen specific and potentially cross-reactive components. ALEX allows >250 individual allergen specific components or whole allergens to be assayed simultaneously. It includes marker allergens/component groups ( eg. PR-10, LTP ) that can be used to determine the genuine cause of sensitisation. Common component groups: � PR10 proteins share similar structures to Bet v 1 which is the major allergen in birch pollen. Sensitisation to PR10 usually results in localised oral allergy syndrome symptoms and multiple positive specific IgE tests/skin prick tests. � Lipid transfer proteins ( LTPs ) are usually associated with more systemic reactions as the proteins are heat and protease labile, therefore a positive LTP result is usually due to true sensitisation rather than cross-reactivity. However some LTPs can be non-specific. � Profilins are related to Bet v 2 which is the minor birch pollen allergen ( also in grass as phl p 12 ). Generally not associated with clinical symptoms but can be the cause of multiple positive specific IgE tests/skin prick tests. � Tropomyosin is the cross reactive component associated with crustacian, mite, cockroach sensitivity. This test is particularly useful in complicated allergy cases which may be due to a single sensitising agent cross-reacting with others, or multiple sensitisations. ALEX utilises component resolved diagnostics to aid in determining the cause of sensitisation and if it is likely to be cross-reactive.

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Indications

Complex allergy cases, such as: polysensitised patients, patients not responding to satisfactorily to treatment, and in cases with inconsistent history.

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Sample Type

2mL Serum ( Gel 5mL Yellow tube ). Requests from outside Sheffield: Transport at ambient temperature via Royal Mail or Courier.

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Reference Range

See report for interpretation of results.

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Turnaround Time

Within 1 week

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Testing Frequency

Weekly

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External Notes

Please supply relevant clinical history and results of Specific IgE and skin prick test to aid interpretation of the results.

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References

Heffler E, Puggioni F, Peveri S, et al. Extended IgE profile based on an allergen macroarray: a novel tool for precision medicine in allergy diagnosis. World Allergy Organization Journal. 2018. 11:7.Buzzulini F, Da Re M, Scala E, et al. Evaluation of a new multiplex assay for allergy diagnosis. Clinica Chimica Acta: International Journal of Clinical Chemistry. 2019. 493:73-78.Sastre J. Molecular diagnosis in allergy. Clin Exp Allergy. 2010. 40( 10 ):1442-1460.

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See Also

Specific IgE, Total IgE

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.