Abstract Text: Eileen Donahue, Tomoko Kakegawa-Peech, Claudia Bispo, Michelle Graham AbbVie, Inc. 1000 Gateway Blvd. South San Francisco
Introduction: Immunophenotyping human blood in clinical trials often requires real-time assessment and/or isolation of mononuclear cells from large blood volumes, limiting the ability to evaluate cellular biomarkers of development stage candidate therapeutics. Coupling spectral flow cytometry with convenient methods to bank human whole blood enables evaluation of broad ranges of cellular biomarkers.
Objective: To overcome operational challenges such as blood volume limitations, batching errors, and sample stability, we evaluated a high-parameter spectral cytometry panel using Proteomic™ stabilized human whole blood samples, stored at -80deg.
Methods: A 33-color Cytek Aurora full spectrum cytometry panel characterized common and rare immune cell populations from 1mL of heparinized Proteomic Stabilizer (Smart Tube Inc) preserved human whole blood over 9 months. Banked samples were thawed, stained, and analyzed in triplicate monthly. Immune cell percentages were monitored for precision and stability and a minimum cell event determination was evaluated using down-sampling in FCS express on 100K CD45+CD15- cell events.
Results: Common immune cell populations were stable ( < 25% CV) up to 9 months. A minimum of 25,000 CD45+CD15- collected cellular events demonstrated precision ( < 25% CV) for rare populations with minimal change associated with storage at 9 months.
Conclusion: Broad immunophenotyping using Proteomic stabilized samples reduces blood volume needs and increases the number of conveniently evaluable cellular biomarkers with a high degree of precision and stability. Used in combination these tools enable broad coverage cellular biomarker monitoring in the clinical setting.
