The utility of flow cytometric platelet forward scatter as an alternative to mean platelet volume

Abstract

The use of mean platelet diameter (MPD) to classify inherited thrombocytopenia (IT) has been demonstrated in several studies. Alternatively, the mean platelet volume (MPV) may be used, but in macrothrombocytopenia this may not be available. We hypothesized that platelet forward scatter (FSC) measurements using flow cytometry may be used for the size-based classification of IT. The study aimed to assess the ability of platelet FSC to measure platelet size and whether it could be used as an alternative to the MPD or MPV.

Blood samples were obtained from individuals undergoing investigation for inherited platelet function disorders (IPFD, n = 40) or platelet number disorders (IPND, n = 46). A hematology analyzer was used to obtain MPV and platelet counts, flow cytometry to measure platelet FSC and ImageJ software to measure MPD from stained blood smears. The International Society of Thrombosis and Hemostasis (ISTH) Bleeding Assessment Tool (BAT) was used to calculate bleeding scores.

Twenty-nine(63%) of IPND patients had an MPV that could not be reported. A significant correlation to platelet FSC was found to the MPD (p < .0001) and MPV (p < .0001) and an inverse correlation with platelet count (p < .0001). No significant correlation was found between FSC and bleeding history. In conclusion, platelet FSC is an alternative to MPV and may be used in macrothrombocytopenia where the MPV is not recorded

Keywords:

• Flow cytometry
• forward scatter
• inherited platelet function disorder
• inherited platelet number disorder
• mean platelet diameter
• platelets

Acknowledgements

The authors acknowledge all patients and their referring physicians, as well as Ying Zhu (Kolling Institute of Medical Research) for the development of NGS analysis pipelines, and Laurence Ricafort, Unni Krisnan Leela Sukumaran and Simon Lee (Prince of Wales Hospital) for performing some of the platelet testing as part of the project.

The study data were collected and managed using REDCap electronic data capture tools hosted at St Vincent’s Hospital, Sydney.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the St Vincent’s Clinic Foundation Annual Research Grant, St Vincent’s Centre for Applied Medical Research Translational Research Grant, the Thrombosis and Hemostasis Society of Australia and New Zealand (THANZ) Educational Grant-In-Aid, the Hemophilia Foundation of Australia Research Grant and Pathology North (NSW Health Pathology) NGS support grant.