The determination of euglobulin clot lysis time reference intervals in Beckton Dickinson and Kima 3.2% sodium citrate coagulation tubes

Enhanced fibrinolysis or hyperfibrinolysis may lead to life-threatening blood loss, while reduced activity may contribute to thrombosis. Euglobulin clot lysis time (ECLT) is a manual method that measures plasma fibrinolytic activity and is considered the gold standard. However, the data on reference interval is scarce and outdated. We have employed one-sided reference interval (>3 h) since the implementation of ECLT in our laboratory; therefore, we aimed to establish reliable ECLT reference interval and to explore the possible preanalytical influence of different blood collection tubes on the established ECLT reference interval. Establishing a reference interval for fibrinolysis was performed according to CLSI EP28-A3c guidelines by employing a posteriori direct sampling technique. The predefined exclusion criteria included a history of malignant or hepatobiliary disease, a history of deep vein thrombosis/pulmonary embolism (DVT/PE), an acute inflammatory state at the time of the venipuncture. We collected vein blood samples in Vacutest plastic coagulation tubes (Kima, Italy) and Vacutainer glass coagulation tubes (Beckton Dickinson, USA) containing 0.109 mol/l buffered trisodium citrate as an anticoagulant at a blood-to-anticoagulant ratio 9 : 1. We calculated two-sided reference interval and presented as 2.5th and 97.5th percentiles. ECLT values did not differ between sexes or the types of tubes enrolled in the study ( P = 0.8979). The established reference interval ranged from 130 to 297 min for the KIMA Vacutest tube and from 120 to 292 min for the BD Vacutainer tube. The established ECLT reference interval differed significantly from the currently used cut-off value in our laboratory, thus enabling the assessment of hyperfibrinolysis by employing double-sided reference interval.