ComponentResolved

Component-resolved diagnostics (CRD), sometimes referred to as componentresolved, is an approach in allergy testing that identifies patient-specific IgE reactivity to individual allergen components rather than to whole allergen extracts. This allows for more precise interpretation of sensitization patterns and can help distinguish clinically relevant allergies from cross-reactive responses.

CRD uses purified natural or recombinant allergen molecules. Testing can be performed as singleplex assays or multiplex platforms, such as allergen microarrays. Examples include major allergen components with diagnostic value and cross-reactive pan-allergens. The pattern of reactivity helps distinguish true sensitization to clinically relevant proteins from cross-reactivity due to related proteins in different foods or pollens.

Applications include assessment of food allergy, pollen-induced rhinitis, and venom allergy. In food allergy, CRD can help predict the likelihood of systemic reactions and reduce false positives due to cross-reactivity. In pollen-food syndrome, CRD can explain why sensitization to a pollen protein causes a subset of foods to trigger symptoms. In venom allergy, component profiles aid risk assessment and treatment decisions.

Advantages include improved diagnostic specificity, better risk stratification, and more targeted management, such as avoidance recommendations and selection of immunotherapy. Limitations include incomplete component catalogs for all foods and pollens, variable test availability and cost, and the need for clinical context to interpret results. Results are typically integrated with patient history and other tests.

CRD emerged with advances in molecular allergology in the late 20th and early 21st centuries, driven by recombinant allergen production and high-throughput platforms. It has become an adjunct to traditional extract-based testing and is used in research and routine allergology in many centers.