PATHCHAT Edition
Published: 2024
Please contact your local Ampath pathologist for more information.
The Facts on Allergy Component Testing
✅ What is the ALEX2 Test?
- A multiplex IgE immunoassay that detects both whole allergen extracts and molecular allergen components.
- Provides a cost-effective way to examine IgE sensitisation patterns.
- Particularly useful for patients with:
- Complex allergy symptoms.
- Poly-sensitisation.
- High levels of total serum IgE.
✅ How Allergy Component Testing Works
- Also referred to as:
- Component-resolved diagnostics.
- Molecular-based diagnostics.
- Precision allergy molecular diagnostics.
- Detects IgE directed against:
- Primary allergens.
- Cross-binding allergens.
- Pan allergens.
📌 Precision allergy molecular diagnostics improve the personalised management of allergic diseases.
Why Allergy Component Testing Matters
✅ Traditional IgE Testing vs. Component Testing
- Traditional IgE testing only identifies sensitisation.
- Component testing distinguishes between:
- True allergy sensitisation.
- Cross-reactivity.
- Cross-sensitisation.
✅ How ALEX2 Improves Allergy Diagnosis
- Detects clinically relevant IgE sensitisation while reducing diagnostic uncertainty.
- Helps identify cross-reactive markers between homologous proteins.
- Provides a detailed molecular profile of allergy components.
📌 Laboratory tests indicate sensitisation, but a clinical diagnosis requires both symptoms and sensitisation.
About ALEX2
✅ Key Features
- Includes ~300 whole allergen extracts and molecular components.
- Requires only 0.5 mL of blood.
- Results available within ~7 working days.
✅ Advantages of ALEX2 Testing
- Comprehensive IgE-based allergy test.
- User-friendly interpretive report.
- Increases diagnostic accuracy.
- Improves allergy management.
📌 ALEX2 simplifies complex allergy diagnostics, enhancing precision in treatment planning.
How Allergy Component Testing Helps
✅ Distinguishing True Allergy vs. Cross-Reactivity
- True allergy sensitisation is indicated by specific allergen markers.
- Cross-reactivity occurs when allergens share structural similarities.
- Cross-sensitisation leads to IgE positivity without clinical symptoms.
✅ Examples of Cross-Reactivity in Allergy
✔ Cow’s Milk & Meat Allergy:
- Bos d 8: A heat-stable milk protein that causes severe, persistent allergy.
- Bos d 6: A serum albumin found in both cow’s milk and beef, explaining allergic reactions to meat in milk-allergic patients.
✔ Pollen-Food Syndrome:
- Patients with primary pollen allergy may react to fruits and peanuts due to shared allergens.
📌 Component testing differentiates between true allergy, cross-reactivity, and clinically irrelevant sensitisation.
Advantages of ALEX2 Allergy Component Testing
✅ Provides In-Depth Allergy Profiles
- Explains IgE poly-sensitisation against pollen and plant-based foods.
- Detects cross-reactive syndromes (e.g., pollen-food, latex-fruit, cat-pork, bird-egg).
- Identifies risk allergens to predict the severity of allergic reactions.
✅ Improves Allergy Management
- Helps predict whether children will outgrow food allergies (e.g., cow’s milk).
- Optimises selection for immunotherapy (e.g., honeybee venom desensitisation).
- Guides dietary recommendations (e.g., milk tolerance in baked goods).
- Prevents unnecessary food avoidance.
✅ Enhances Diagnosis of Anaphylaxis & Pet Selection
- Identifies allergens responsible for unexplained anaphylaxis.
- Helps guide pet selection based on allergenic profiles (e.g., dog gender differences).
📌 Molecular sensitisation profiling may also serve as a biomarker for disease progression, such as predicting asthma development in children.
Contact Information
✅ For more details or to arrange ALEX2 testing, contact:
- Ampath Allergy Experts: 012 678 0613/4
📌 ALEX2 provides an advanced, molecular-based approach to allergy diagnostics, improving patient care and personalised allergy management.