Novel method for quantitative ANA measurement using near-infrared imaging

Area of Science:

• Immunology
• Autoimmunity Research
• Diagnostic Assay Development

Background:

• Antinuclear antibodies (ANA) are key biomarkers for systemic rheumatic diseases and autoimmunity.
• Current gold standard, indirect immunofluorescence (IIF) on HEp-2 cells, lacks standardization, objectivity, and quantification.
• Existing alternative methods have not replaced IIF for ANA screening.

Purpose of the Study:

• To develop and validate a simple, quantitative method for ANA detection.
• To improve the objectivity, sensitivity, and reproducibility of ANA titer determination.
• To provide a standardized assay for ANA measurement in human and animal samples.

Main Methods:

• Combined indirect immunofluorescence (IIF) on HEp-2 cells with near-infrared imaging (NII) analysis.
• Utilized NII for quantitative ANA titer determination in human patient and mouse serum samples.
• Compared NII-derived titers with traditional IIF results.

Main Results:

• NII determined ANA titers within 2 dilutions of IIF for 86.5% of human samples.
• Combining microscopy screening with NII titration achieved 97.3% agreement (within 2 dilutions) with IIF.
• The NII method demonstrated speed, simplicity, objectivity, sensitivity, and reproducibility.

Conclusions:

• Near-infrared imaging offers a promising quantitative approach for ANA detection.
• This NII-based method addresses limitations of traditional IIF assays.
• The assay is suitable for standardization and application in both clinical and research settings for autoimmunity.