Chapter 31: Common in vitro tests for allergy and immunology

Area of Science:

• Clinical immunology
• Allergy diagnostics
• In vitro testing

Background:

• Allergen-specific IgE antibody testing is a cornerstone in allergy practice.
• It aids in diagnosing hypersensitivity to foods and aeroallergens, especially when skin-prick testing is contraindicated.
• Total serum IgE and quantitative immunoglobulins (IgG, IgA, IgM) are vital for assessing atopic conditions and humoral immunodeficiency.

Purpose of the Study:

• To review the principles and applications of in vitro allergy testing.
• To highlight methods for measuring allergen-specific IgE, total IgE, and immunoglobulins.
• To discuss the role of these tests in diagnosing allergic and immunodeficiency disorders.

Main Methods:

• Radioallergosorbent test (RAST) principle for detecting allergen-specific IgE.
• Nephelometry for quantitative measurement of serum immunoglobulins (IgG, IgA, IgM).
• Flow cytometry for assessing lymphocyte subsets in cellular immunodeficiency screening.

Main Results:

• RAST detects IgE antibodies by binding antigen to a solid phase and using radiolabeled anti-human IgE.
• Total IgE levels are important for atopic conditions and guiding monoclonal anti-IgE therapy.
• Quantitative immunoglobulins and lymphocyte subset analysis are key for diagnosing humoral and cellular immunodeficiencies.

Conclusions:

• In vitro tests like RAST, total IgE, quantitative immunoglobulins, and lymphocyte subset analysis are essential diagnostic tools.
• These assays provide critical information for managing allergic diseases and primary immunodeficiencies.
• Accurate interpretation of these immunological markers guides appropriate patient care and treatment strategies.