Platelet surface marker analysis by mass cytometry

Mass cytometry is a next generation flow cytometry technology which analyzes cells one at a time (up to 1000/sec) using mass spectrometry to detect probes labeled with rare-earth metals. Rare-earth metals detected by mass spectrometry have extremely low backgrounds and can be identified with high resolution enabling the routine simultaneous detection of more than 45 probes on each cell without the need for complex compensation matrices. Here we describe a panel of 14 platelet-specific metal-conjugated antibodies (targeting cluster of differentiation [CD] 9, CD29, CD31, CD36, CD41, CD42a, CD42b, CD61, CD62P, CD63, CD107a, CD154, glycoprotein [GP] VI and activated integrin αIIbβ3) and methods for staining and analysis of platelets by mass cytometry. High dimensional clustering algorithms, which take into account the levels of all 14 markers detected by mass cytometry on each cell, allow identification of platelet subpopulations not previously appreciated. We previously reported that platelet heterogeneity identified by mass cytometry appears similar across healthy donors and consistent over time. High dimensional analysis revealed the presence of a platelet subpopulation with significantly higher levels of surface expression of activated GPIIb-IIIa and P-selectin suggesting this subpopulation may play a greater role in thrombus formation than other platelet subpopulations. Thus, analysis by mass cytometry of platelet heterogeneity and subpopulations may suggest distinct biological roles for different platelet subpopulations and may be useful in evaluating inherited or acquired platelet disorders and platelet function in health and disease.