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 b lood, plasma, and ''eugloblin'' lysis tests. The euglobulin lysis test (ELT) is actually a modified plasma clot lysis time, which detects in creased plasminogen activation and subsequent fibrinolysis. It does no t detect the activity of antiplasmins. The purpose of this study was t o determine ELT for a group of 25 ambulatory normals. There were 10 ma les and 15 females, ranging in age from 25 to 56 years. Citrate antico agulated samples were obtained immediately after application of a tour niquet and 10 minutes after application of a sphygmomanometer inflated to midway between systolic and diastolic pressure. The citrated plasm a was precipitated with cold acetic acid. The precipitate contained fi brinogen, plasminogen, and plasminogen activators, with fibrinolytic i nhibitors theoretically removed. The precipitate was redissolved and t he euglobulin solution was clotted with thrombin. The clotted sample w as then incubated at 37-degrees-C and was observed at 10 minute interv als for clot lysis. Results: The reference range of onset of fibrinoly sis was from 1.25 to 12 hours, with a mean of 3.78 hours +/- 2.45 hour s (1 S.D.). Venostasis (use of the sphygmomanometer) resulted in an EL T that was shorter than the non-venostasis specimens in 11 of 25 speci mens. This is thought to be secondary to in vivo activation of plasmin ogen. Conclusion: The average euglobulin lysis time in 25 ambulatory n ormals 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.