Agreement between blood draw techniques for assessing platelet activation by flow cytometry

Area of Science:

• Hematology
• Clinical Pathology

Background:

• Preanalytical variables, particularly blood collection methods, are believed to influence platelet activation assays.
• Accurate assessment of platelet function is crucial for diagnosing and managing various hemostatic and thrombotic disorders.

Purpose of the Study:

• To evaluate the impact of blood collection methods (vacuum tubes vs. manual syringes) on platelet activation.
• To determine the necessity of a discard tube in platelet function testing.

Main Methods:

• Whole blood flow cytometry was used to measure platelet P-selectin expression and platelet-monocyte complexes.
• Blood samples were collected using vacuum tubes and manually aspirated syringes.
• The effect of a discard tube versus a second draw was assessed under basal and stimulated conditions (ADP).

Main Results:

• Bland-Altman analysis showed agreement between vacuum tube and syringe-aspirated samples within a 5% limit.
• No significant difference in platelet activation markers was found between discard tube and second draw samples for both collection methods.

Conclusions:

• Manual syringe aspiration is a viable alternative to vacuum tubes for platelet activation assays.
• The use of a discard tube is not necessary for accurate assessment of platelet activation by flow cytometry.