Standardized method to minimize variability in a functional P2X(7) flow cytometric assay for a multi-center clinical...

Area of Science:

• Immunology
• Molecular Biology
• Biomarker Discovery

Background:

• Human P2X7 receptor (P2RX7) pore activity analysis via flow cytometry can differentiate genotypes and serve as a biomarker.
• Standardization is essential for multicenter clinical trials due to variable sample age and instrumentation.

Purpose of the Study:

• To develop and validate a standardized flow cytometric method for quantifying P2X7 receptor pore activity.
• To minimize intralaboratory and enable interlaboratory variation for P2RX7 functional genomic studies.

Main Methods:

• Utilized CD14-PE stained whole blood, YO-PRO-1, propidium iodide (PI), and a P2X7 agonist (BzATP).
• Adapted a standardized fluorescent particle-adjusted set-up method, comparing it with previous approaches.
• Evaluated systematic variability and sample age effects on P2X7 pore activity measurements.

Main Results:

• The bead-adjusted method reduced variability in YO-PRO-1 fluorescence and was less affected by compensation strategies.
• Achieved an average day-to-day coefficient of variance of 0.11 +/- 0.04 for P2X7 pore activity assessments.
• The method accommodated samples up to 4 days post-phlebotomy and showed minimal differences between analog and digital cytometers.

Conclusions:

• A standardized, quantitative flow cytometry method for P2X7 receptor phenotypes in blood monocytes was established.
• This method offers minimal intralaboratory variation and facilitates interlaboratory comparisons.
• The validated method is crucial for advancing multicenter functional genomic clinical studies.