Interindividual Variability and Normal Ranges of Whole Blood and Plasma Thrombin Generation

Abstract

Background Assays measuring thrombin generation (TG) in plasma increasingly gained attention in the field of thrombosis and hemostasis. Adaptation of the method enabled the measurement of TG in whole blood (WB). Despite their potential, TG assays did not reach the stage of universal clinical application, partly because of the absence of normal ranges. Our study aimed to accurately determine normal ranges and interindividual variability of TG and correlate results with coagulation factor levels, sex, and oral contraceptive usage. Methods The study protocol was evaluated by the local medical ethical board. In total, 129 healthy volunteers gave full informed consent. Normal ranges of TG in platelet-poor plasma (PPP), platelet-rich plasma (PRP), and WB were determined according to CLSI guidelines. Results Our study is the first to measure normal ranges of TG in PPP, PRP, and WB in a large healthy cohort. Significant correlations were found between TG in plasma and WB. Interindividual variability of TG in WB was comparable to that of plasma. Oral contraceptive use increased TG in PPP, PRP, and WB. The inhibitory effect of thrombomodulin on TG was significantly lower in females than in males. This effect was more pronounced upon oral contraceptive use. Primary clotting factor determinants for TG parameters depended on the tissue factor concentration, but were similar in WB and plasma. Conclusions Establishing normal ranges for TG brings us 1 step closer to clinical use. Good correlations between plasma and WB (including clotting factor determinants for TG) suggest that WB TG can be reliably used in clinic.

High prevalence of reduced thrombin generation and/or decreased platelet response in women with unexplained heavy menstrual bleeding

“…In a recent study, we have shown that, in our laboratory, there is no significant difference in TG parameters between men and women who are not using oral contraceptives . Similarly, we did not observe correlations between TG parameters and age within our cohort .…”

“…31 Similarly, we did not observe correlations between TG parameters and age within our cohort. 31 This is not necessary a problem, because both platelet function and coagulation are not affected by age or gender. 30 Another study showed that there are no discordant effects of age on the relation between platelet function and HMB.…”

Effects of Repeated Bouts of Exercise on the Hemostatic System

“…To characterize changes in their hemostatic profile, we measured VWF (total antigen, 126 VWF propeptide, 62 and active VWF) levels, FVIII, 126,127 thrombin generation, 128 fibrinogen levels, 127 platelet activation, 129 and clot lysis time 127 (methods according to references). Peripheral blood cell counts in citrated whole blood were determined using a COULTER counter analyzer (Beckman Coulter, Woerden, the Netherlands).…”

Thrombin Generation Assay: Are We Ready for Prime Time?

“…In this issue of The Journal of Applied Laboratory Medicine, Bloemen et al (12) describe development of reference intervals for TGA in whole blood, platelet-rich plasma, and platelet-poor plasma. As evidence of the lack of standardization for this assay, the authors report 9 different reference intervals that would need further separation based on sex and oral contraceptive use.…”

“…For example, it was recently reported that predicting risk of bleeding in patients with factor XI deficiency required that a TGA be performed with platelet-rich plasma and corn trypsin inhibitor (12). This set of conditions proved superior to either PTT-based factor-XI-activity assays, notorious for not predicting bleeding in these patients, or standard plasma-based TGAs.…”