EUGLOBULIN LYSIS TIMES - AN UPDATE

There are several clot lysis tests available to assess the presence of increased fibrinolysis in a clinical situation. These include whole blood, plasma, and ''eugloblin'' lysis tests. The euglobulin lysis test (ELT) is actually a modified plasma clot lysis time, which detects increased plasminogen activation and subsequent fibrinolysis. It does not detect the activity of antiplasmins. The purpose of this study was to determine ELT for a group of 25 ambulatory normals. There were 10 males and 15 females, ranging in age from 25 to 56 years. Citrate anticoagulated samples were obtained immediately after application of a tourniquet and 10 minutes after application of a sphygmomanometer inflated to midway between systolic and diastolic pressure. The citrated plasma was precipitated with cold acetic acid. The precipitate contained fibrinogen, plasminogen, and plasminogen activators, with fibrinolytic inhibitors theoretically removed. The precipitate was redissolved and the euglobulin solution was clotted with thrombin. The clotted sample was then incubated at 37-degrees-C and was observed at 10 minute intervals for clot lysis. Results: The reference range of onset of fibrinolysis was from 1.25 to 12 hours, with a mean of 3.78 hours +/- 2.45 hours (1 S.D.). Venostasis (use of the sphygmomanometer) resulted in an ELT that was shorter than the non-venostasis specimens in 11 of 25 specimens. This is thought to be secondary to in vivo activation of plasminogen. Conclusion: The average euglobulin lysis time in 25 ambulatory normals is approximately 3.5 hours. The ELTs vary over a broad range (1.25 to 12.0 hours) in normal ambulatory volunteers. Interpretation of shortened ELTs must be made cautiously in the clinical situation.