Background Fluorogenic thrombin generation (TG) assays are commonly used to determine global coagulation phenotype in plasma. Whole blood (WB)‐TG assays reach one step closer to physiology by involving the intrinsic blood cells, but erythrocytes cause variable quenching of the fluorescence signals, hampering its routine application. Objective To develop a new assay for continuous WB‐TG measurement. Methods In the new WB‐TG assay, the erythrocyte‐caused distortion of signal was solved by continuously mixing the sample during the measurement. The assay was validated by evaluating the reproducibility and comparing with the paper‐based WB‐TG assay. Reconstituted human blood and WB from 119 healthy donors was tested to explore the influences of hematocrit and platelet count on TG. Results This novel WB‐TG assay showed good reproducibility while being less affected by contact activation compared with the previous paper‐based assay. Reconstitution experiments showed that the lag time of TG was shortened by the addition of platelets but not erythrocytes. Increasing hematocrit strongly augmented the peak thrombin, even in the presence of high platelet counts. The lag time and peak of WB‐TG of 119 healthy donors were positively related to erythrocyte count after adjusting for age, sex, and oral contraceptive use with multiple linear regression analyses. The reference range and interindividual variation of WB‐TG were determined in the healthy cohort. Conclusions A novel WB‐TG assay was developed, which is a straightforward tool to measure the involvement of platelets and erythrocytes in TG and may assist the research of blood cell‐associated coagulation disorders.

Background and Aims Patients with cirrhosis have a rebalanced hemostasis, often with normal or elevated thrombin‐generating (TG) capacity in plasma. Whole blood (WB) TG allows faster determination and, importantly, includes the influence of all circulating blood cells. We aimed to study the TG profile of patients with cirrhosis in WB and in platelet poor plasma. Methods Thrombin‐generating capacity in WB and plasma were assessed with a near‐patient WB‐TG assay and the calibrated automated thrombinography assay, respectively. TG assays were tested in presence and absence of thrombomodulin. Conventional coagulation tests were also performed. Results Thirty‐four patients with cirrhosis and twenty‐two controls were analyzed. Compared with controls, patients had substantially deranged results in conventional coagulation tests. Comparable WB‐TG capacity (endogenous thrombin potential until peak, ETPp) but significantly lower peak thrombin were found in patients, and these results persisted when thrombomodulin was present. TG of the patients was more resistant to thrombomodulin than controls in both WB and plasma, although the inhibitory effect of thrombomodulin was drastically weaker in WB than in plasma. The peak of WB‐TG in patients correlated moderately with their hematocrit and platelet count. Significant correlations were found between TG results in WB and plasma. Conclusions The WB‐TG assay shows a normal to hypocoagulable state in patients with cirrhosis with a decreased anticoagulant activity of TM compared to plasma‐TG. The clinical value of this assay needs further validation.

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