Stability and utility of flow cytometric platelet activation tests: A modality to bridge the gap between diagnostic demand and supply

Abstract

Light transmission aggregometry (LTA) is the gold standard for the diagnosis of platelet function disorders (PFDs). The requirement of customized aggregometer, large blood volume, normal platelet count and processing within 4 hours of venipuncture for LTA makes platelet function testing inaccessible to wider population. Flow cytometric platelet activation test (PACT) may overcome these limitations. This study compares the performance of PACT with LTA, characterizes diagnostic patterns of PFDs on PACT and assesses the stability of PACT beyond 4 hours of venipuncture in controls (n = 5) at different temperature conditions. LTA and PACT were performed in 121 healthy controls and 66 patients with suspected PFD. PACT had excellent agreement (kappa = 0.93) with LTA and 94.1% sensitivity, 98.5% specificity. PACT had distinct patterns in Bernard Soulier Syndrome (n = 10), Glanzmann Thrombasthenia (n = 24), δ-granule disorder (n = 7), and other PFDs (n = 12). PACT could assess platelet function in patients (14%) with thrombocytopenia/lipemia wherein LTA was inconclusive. PACT was stable up to 24 hours in samples stored/transported at 2–8◦C. The results of utility and stability are only valid for the specific markers, agonist concentrations, and conditions investigated in this paper. PACT is a useful modality for the diagnosis of PFD, especially in children, thrombocytopenia cases or in the setup where an aggregometer is not readily available.

Keywords:

• Blood platelet disorders
• flow cytometry
• platelet activation
• platelet aggregation
• platelet function tests

Disclosure statement

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

Data sharing and data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Author contributions

R. G. Dave and S. C. Nair designed the study. R. G. Dave, T. Geevar, R. Vijayan and A. Samuel performed the experiments. R. G. Dave, G. K. Chellaiya and M. Gowri analyzed the data. R. G. Dave wrote the manuscript. S. C. Nair and J.J. Mammen reviewed the manuscript, provided guidance and critical revision. J. J. Mammen and S.C. Nair provided administrative support.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website

Additional information

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. This study was funded by the Department of Transfusion Medicine and Immunohematology, Christian Medical College, Vellore, India