Table 2: Overview of published clinical microparticle studies.

Performance topicReferenceType of microparticle assayTotal number of subjects in studyConcentration [MP/L]Summary statement

Accurate enumeration of microparticles (especially in the presence of platelets or other particles) Balvers et al. 2015 [51]FC20 (10 trauma patients; 10 healthy)7.5 × 103Flow cytometry does not count microparticles if bound in complexes; reported concentration is about 106 lower than reported elsewhere; sample was prepared at low temperature
Jayachandran et al. 2011 [52]FC118 (58 assayed for plasma microparticles)N/AFlow cytometry does not detect aggregates
van Ierssel et al. 2012 [53]FC13 in vitro lipid (5 coronary heart disease; 8 healthy); 5 in vivo lipid, healthy2.5 × 108 (EMP only)Flow cytometry data are affected by high circulating levels of lipids

Size of microparticles (below the detection limit of many technologies) Leong et al. 2011 [55]FC6 (acute myocardial infarction; healthy)3 × 109Platelet microparticle size is below stated detection limits of most flow cytometers. However, study confirmed that flow cytometry is capable of analyzing microparticles from plasma; approximately 2-fold for acute myocardial infarction (AMI) patient
Robert et al. 2012 [56]FC40 (30 coronary disease; 10 healthy)2.0 × 109 (1.1 × 1010 with high sensitivity FCM)Standard flow cytometry does not detect small microparticles. High-sensitivity flow cytometry allows measurement of previously undetectable microparticles; approximately 10-fold for coronary patients

Probe/marker selectionHou et al. 2011 [77]FC20 healthy donors1 × 109 (fresh) 
1.5 × 1010 (day 9)
Annexin V does not bind to membranes at low phosphatidyl-serine levels and is Ca2+ dependent; lactadherin is proposed as an alternative
Iversen et al. 2013 [58]FC49 (20 healthy; 29 systemic lupus erythematosus)9 × 109Annexin V binding is Ca2+ dependent, resulting in potential clotting of plasma; approximately 2-fold for patients with systemic lupus erythematosus (SLE)
Lanuti et al. 2012 [78]FC34 (20 diabetes; 14 healthy)1.1 × 108 (EMP only)Endothelial microparticles and circulating endothelial cells share markers such as CD144 and CD146 leading to overestimation; approximately 2-fold for patients with type 2 diabetes (Iversen et al. published endothelial microparticle concentration to be a factor 10 lower than platelet microparticles)
Bohling et al. 2012 [45]ELISA, clot-based and chromogenic and flow cytometry75 (24 healthy, 28 trauma, 23 nontrauma (patients taking warfarin, heparin, or lupus anticoagulants))4 × 1010The performance characteristics of a clot-based versus chromogenic procoagulant phospholipid assay were compared and low correlation found; neither assay was considered optimal

Standardization of methodsMarchetti et al. 2014 [61]ELISA, clot-based and thrombin generation145 (72 control, 73 essential thrombocythemia)The performance characteristics of clot-based procoagulant phospholipid assay and thrombin generation assay were compared

Method selectionStrasser et al. 2013 [62]FC, prothrombinase ELISA, clot-based ELISA31 healthy donors1.2 × 109The performance characteristics of a clot-based procoagulant phospholipid assay, prothrombinase assay, and flow cytometry were compared
Labrie et al. 2013 [20]DLS24 apheresis platelet concentrates from normal volunteers1.5 × 1012ThromboLUX microparticle assay was compared to flow cytometry and correlated highly
Xu et al. 2011 [44]DLS160 (81 platelet-rich plasma, 79 apheresis platelet concentrates)2 × 1011ThromboLUX microparticle assay was compared to flow cytometry [51]; values were calculated from reported relative content but concentrations are not published

Flow cytometry (FC) and dynamic light scattering (DLS).