Monitoring dendritic cells in clinical practice using a new whole blood single-platform TruCOUNT assay

Area of Science:

• Immunology
• Flow Cytometry
• Cell Biology

Background:

• Dendritic cells (DCs) are crucial for immune responses.
• Accurate quantification of distinct DC subsets has been challenging.
• Existing methods for DC counting have limitations in precision and reproducibility.

Purpose of the Study:

• To develop a precise, single-platform flow cytometric assay for quantifying blood dendritic cell (DC) subsets.
• To establish a reliable method for DC counting suitable for clinical and research applications.
• To investigate the impact of age and disease on absolute blood DC counts.

Main Methods:

• Development of a novel flow cytometry assay using TruCOUNT beads and a "Lyse/No-Wash" whole blood protocol.
• Precise enumeration of specific CD14(-) blood DC subsets: CD11c(+)CD16(-), CD11c(+)CD16(+), CD123(hi), CD1c(+), and BDCA-3(+).
• Validation of the assay's reproducibility, sample volume requirement, and compatibility with EDTA samples and different blood sources.

Main Results:

• The assay provides highly reproducible DC counts with low intra- and inter-assay variation (<3% and <11%).
• Absolute blood DC counts were found to decrease with age in healthy individuals.
• Preliminary findings show altered DC subset counts in breast carcinoma and multiple myeloma patients compared to controls.

Conclusions:

• The developed TruCOUNT assay offers a precise and reliable method for quantifying blood dendritic cell subsets.
• This assay overcomes limitations of previous methods, enabling accurate DC enumeration without hematology analyzers.
• The findings suggest potential for standardized DC counting in clinical settings for disease monitoring and diagnosis.