Haematologica (Jun 2019)

High-throughput elucidation of thrombus formation reveals sources of platelet function variability

  • Johanna P. van Geffen,
  • Sanne L.N. Brouns,
  • Joana Batista,
  • Harriet McKinney,
  • Carly Kempster,
  • Magdolna Nagy,
  • Suthesh Sivapalaratnam,
  • Constance C.F.M.J. Baaten,
  • Nikki Bourry,
  • Mattia Frontini,
  • Kerstin Jurk,
  • Manuela Krause,
  • Daniele Pillitteri,
  • Frauke Swieringa,
  • Remco Verdoold,
  • Rachel Cavill,
  • Marijke J. E. Kuijpers,
  • Willem H. Ouwehand,
  • Kate Downes,
  • Johan W.M. Heemskerk

DOI
https://doi.org/10.3324/haematol.2018.198853
Journal volume & issue
Vol. 104, no. 6

Abstract

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In combination with microspotting, whole-blood microfluidics can provide high-throughput information on multiple platelet functions in thrombus formation. Based on assessment of the inter- and intra-subject variability in parameters of microspot-based thrombus formation, we aimed to determine the platelet factors contributing to this variation. Blood samples from 94 genotyped healthy subjects were analyzed for conventional platelet phenotyping: i.e. hematologic parameters, platelet glycoprotein (GP) expression levels and activation markers (24 parameters). Furthermore, platelets were activated by ADP, CRP-XL or TRAP. Parallel samples were investigated for whole-blood thrombus formation (6 microspots, providing 48 parameters of adhesion, aggregation and activation). Microspots triggered platelet activation through GP Ib-V-IX, GPVI, CLEC-2 and integrins. For most thrombus parameters, inter-subject variation was 2-4 times higher than the intra-subject variation. Principal component analyses indicated coherence between the majority of parameters for the GPVI-dependent microspots, partly linked to hematologic parameters, and glycoprotein expression levels. Prediction models identified parameters per microspot that were linked to variation in agonist-induced αIIbβ3 activation and secretion. Common sequence variation of GP6 and FCER1G, associated with GPVI-induced αIIbβ3 activation and secretion, affected parameters of GPVI-and CLEC-2-dependent thrombus formation. Subsequent analysis of blood samples from patients with Glanzmann thrombasthenia or storage pool disease revealed thrombus signatures of aggregation-dependent parameters that were subject-dependent, but not linked to GPVI activity. Taken together, this high-throughput elucidation of thrombus formation revealed patterns of inter-subject differences in platelet function, which were partly related to GPVI-induced activation and common genetic variance linked to GPVI, but also included a distinct platelet aggregation component.