Diagnosis & Specialist Care of Allergy & Clinical Immunology - Since 1982
What is Molecular Component Testing?
Molecular component testing, also known as component-resolved diagnosis (CRD) or molecular allergy testing, represents a significant advancement in allergy diagnostics. This cutting-edge technology allows us to delve deeper into the structure of allergens, providing more detailed and precise insights than traditional testing methods.
Understanding Allergens and Proteins
Allergens are composed of various proteins, each with different levels of stability to heat and digestion. Traditional specific IgE testing evaluates the body's sensitivity to an allergen in its entirety, such as a peanut.
While useful, this approach does not differentiate between the individual proteins within the allergen, which can be crucial in understanding the nature and severity of an allergic reaction.
How Molecular Component Testing Works
Molecular component testing goes a step further by analysing allergens on a protein-by-protein basis. By identifying which specific protein triggers an allergic reaction, doctors can gain a much clearer picture of the allergy. This level of detail allows for a more accurate assessment of the allergy’s nature and potential severity.
Benefits of Molecular Component Testing
Predicting Allergy Development
By identifying the exact proteins involved, molecular component testing can help predict how an allergy may evolve over time.
Assessing Risk of Severe Reactions
The test can estimate the likelihood of severe reactions, such as anaphylaxis, by identifying proteins that are known to be a greater risk for such responses.
Identifying Cross-Reactions
This method can uncover cross-reactions between different allergens. Cross-reactivity occurs when the body's immune system identifies the proteins in one substance (e.g., pollen) and the proteins in another (e.g., a fruit or vegetable) as being similar. Knowing whether a food allergy is triggered by pollen cross-reactivity (often less severe) or to the food itself (potentially more serious) can guide appropriate management.
Understanding Heat Stability
Some proteins are denatured by heat, meaning they lose their shape and structure when cooked. A protein which is denatured by heat is not likely to trigger an allergic reaction once the food has been cooked. Molecular component testing can indicate which protein the patient is sensitised to and therefore whether the food is likely to be tolerated when cooked, even if a reaction occurs when it is raw.
How Is the Test Performed?
Molecular component testing requires a blood sample. The analysis can focus on a specific allergen, such as peanut proteins, or it can be included in a broader test like the ALEX allergen panel, which examines a wide variety of allergens and their molecular components.
