Technical Validation and Utility of an HLA Class II Tetramer Assay for Type 1 Diabetes: A Multicenter Study

Area of Science:

• Immunology
• Diabetes Research
• T-cell Biology

Background:

• Validated assays for autoantigen-specific T-cell measurement are crucial for type 1 diabetes (T1D) management.
• Assessing T-cell frequency and phenotype aids in risk stratification, disease monitoring, and therapy evaluation.

Purpose of the Study:

• To technically validate a tetramer assay for HLA-DRB1*04:01, a key allele in T1D susceptibility.
• To enumerate and phenotype T cells specific for T1D autoantigens and a reference influenza epitope.

Main Methods:

• Tetramer assay validation using single and multicenter testing with spiked samples and T1D patient replicates.
• Assay applied to a cross-sectional T1D cohort to evaluate clinical utility.
• Target coefficient of variation (CV) < 30% for reproducibility.

Main Results:

• Reproducible measurements achieved for both influenza- and islet-specific T cells, with CVs generally within the target range.
• Exploratory study revealed correlations between T-cell frequencies, phenotypes, and clinical factors like disease duration and sex.
• A significant proportion of islet-specific T cells displayed a naive phenotype.

Conclusions:

• The validated tetramer assay is reproducible and effective for characterizing islet-specific T cells.
• The assay facilitates the identification of correlations between T-cell metrics and clinical characteristics in T1D.
• This tool supports personalized antigen-based therapies and improved T1D management.