Analysis of inter-individual variation and reference intervals of thrombin generation test indicators using different technologies

Abstract

Background. The thrombin generation test (TGT) as an integral method for analyzing the activation cascade of natural pro- and anticoagulants is of practical importance in assessing the risk of thrombotic conditions and bleeding, however its application is limited by the lack of standardization. Objective. To define reference intervals within the laboratory and assess inter-individual variation in TGT values for different technologies. Design and methods. The study included 20 donors. TGT was performed using two technologies: a calibrated automated thrombogram on a semi-automatic fluorometer (Technology 1) and automatic measurement of GT on a coagulometer (Technology 2). Obtained results were normalized to pooled normal plasma. Results. Thrombogram parameters showed a high CVG (coefficient of interindividual variation): 14–32 % for Technology 1 and 7–36 % for Technology 2. CVG did not change significantly after normalization. Significant differences in ETP (endogenous thrombin potential) were noted. The reference intervals for Technology 1 were: ETR 1478.0–2595.0 nmol/ min and peak thrombin concentration (Peak thr.) 221.6–412.0 nmol. RI for Technology 2: ETP 2451.00–3161.00 nmol/min and Peak thr. 161.60–479.30 nmol. Conclusion. Comparison of the two laboratory TGT technologies revealed high inter-individual variation. Thus, the use of a study in dynamics for each specific individual is likely to be more informative than the use of RI obtained in the general population. Dynamic monitoring of the patient must be performed using one technology.