[CROATIAN GUIDELINES FOR IN VITRO DIAGNOSIS OF IgE MEDIATED HYPERSENSITIVITY]

Area of Science:

• Allergy diagnostics
• Immunology
• In vitro testing

Background:

• In vitro diagnostic procedures in allergology are essential for diagnosing allergic conditions.
• These tests include measuring total and allergen-specific IgE and IgG antibodies, plasma tryptase, eosinophil cationic protein (ECP), and basophil activation tests (BAT).
• In vitro tests should complement clinical history, physical examination, and in vivo allergy testing methods.

Purpose of the Study:

• To outline the role and clinical relevance of various in vitro diagnostic tests in allergology.
• To highlight the utility of specific biomarkers and assays in diagnosing and managing allergic diseases.
• To provide guidance on the appropriate application of in vitro allergy testing based on patient presentation and clinical context.

Main Methods:

• Measurement of serum total and allergen-specific IgE and IgG antibodies.
• Assays for plasma tryptase and eosinophil cationic protein (ECP).
• Basophil activation test (BAT) using flow cytometry to detect CD63 and CD203 antigens.
• ImmunoCAP fluoroimmunoassay for IgE quantification.
• Molecular allergy diagnosis for complex cases.

Main Results:

• Elevated allergen-specific IgE, with a positive medical history, indicates clinically relevant allergy.
• Serum allergen-specific IgG has limited diagnostic value in food allergy but can monitor venom immunotherapy.
• Plasma tryptase and ECP levels indicate mast cell activation and eosinophilic inflammation, respectively.
• BAT is useful for diagnosing venom, food, and drug allergies, and assessing tolerance.
• Molecular allergy diagnosis is crucial for cross-reactivity, immunotherapy decisions, and complex anaphylaxis.

Conclusions:

• In vitro allergy testing provides valuable diagnostic information when integrated with clinical assessment.
• Allergen-specific IgE is a primary diagnostic marker, while other tests support specific clinical scenarios.
• The judicious use of various in vitro tests, including advanced molecular diagnostics, optimizes allergy management.