Summary
The platelet transcriptome has been extensively characterised using distinct genetic
profiling platforms, with evolving evidence for differential expression patterns between
healthy individuals and subject cohorts with various haematologic and cardiovascular
disorders. Traditional technological platforms for platelet genetic biomarker quantification
have limited applicability for clinical molecular diagnostics due to inherent complexities
related to RNA isolation and analysis. We have previously established the feasibility
of fluorescent microspheres as a simple and reproducible strategy for simultaneous
quantification of platelet mRNAs from small volume of blood using intact platelets.
We now extend these observations by formally comparing in a 50-member normal cohort
the cross-platform behaviour of fluorescent microspheres to the currently accepted
Q-PCR standard, using a clinically relevant 15-biomarker gene subset able to discriminate
among normal and thrombocytosis cohorts. When compared to Q-PCR, genetic biomarker
quantification using fluorescent microspheres demonstrated lower coefficients of variation
for low-abundant transcripts, better linearity in serially diluted samples, and good
overall between-platform consistency via the geometric mean regression. Neither platform
demonstrated age or gender effects for any of the 15 biomarkers studied. Binding site
saturation for highly abundant transcripts using fluorescent microspheres can be readily
eliminated using an optimal platelet number corresponding to 0.3 ml of peripheral
blood, additionally applicable to thrombocytopenic cohorts. These data provide a detailed
cross-platform analysis using a relevant biomarker subset, further highlighting the
applicability of fluorescent microspheres as potentially superior to Q-PCR for platelet
mRNA diagnostics.
Keywords
Platelets - transcript profiling - fluorescent microspheres - mRNA - QuantiGene Plex
2.0 technology