Evaluation of T and B lymphocyte function in clinical practice using a flow cytometry based proliferation assay

Area of Science:

• Immunology
• Cellular Immunology
• Clinical Immunology

Background:

• The gold standard for assessing immunodeficiencies involves [(3)H]-thymidine incorporation, a radioactive method.
• Emerging whole blood proliferation assays offer non-radioactive alternatives with parallel lymphocyte lineage analysis.
• Evaluating novel functional assays is crucial for accurate immunodeficiency diagnosis.

Purpose of the Study:

• To evaluate the Flow-cytometric Assay for Specific Cell-mediated Immune-response in Activated whole blood (FASCIA) as a non-radioactive functional assay.
• To compare FASCIA with the established [(3)H]-thymidine incorporation method.
• To establish reference values and determine optimal conditions for FASCIA.

Main Methods:

• FASCIA was compared against [(3)H]-thymidine incorporation in four severe combined immunodeficiency patients.
• Lymphocyte thresholds for reliable FASCIA responses were determined.
• Reference values were established from 100 healthy donors using mitogenic and antigen-specific stimuli.
• Responses to PWM and SEA+SEB were assessed with immunomodulatory compounds.

Main Results:

• FASCIA demonstrated a reliable assessment of lymphocyte reactivity.
• The assay requires a minimal number of lymphocytes for accurate results.
• Reference values were established for various stimuli in healthy individuals.
• FASCIA showed sensitivity in detecting responses to mitogens and antigens.

Conclusions:

• FASCIA is a rapid, stable, and sensitive functional whole blood assay.
• The assay requires minimal blood volume, making it practical for clinical use.
• FASCIA provides a reliable method for assessing lymphocyte reactivity in patients with immunodeficiencies.