Thromboelastography in acute immunologic reactions: a prospective pilot study

Background: Biomarkers of fibrinolysis are elevated during acute immunologic reactions (allergic reactions and angioedema), although it is unclear whether fibrinolysis is associated with disease severity. Objectives: We investigated a possible association between maximum lysis (ML) measured by thromboelastography and the severity of acute immunologic reactions. Methods: We recruited patients with acute immunologic reactions at a high-volume emergency department. Clinical disease severity at presentation and at the end of the emergency department stay was assessed using a 5-grade scale, ranging from local symptoms to cardiac arrest. We determined ML on admission by thromboelastography (ROTEM 's extrinsic [EXTEM], and aprotinin [APTEM] tests), expressed as ML%. Hyper fibrinolysis was de fined as an ML of >15% in EXTEM, which was reversed by adding aprotinin (APTEM). We used exact logistic regression to investigate an association between ML% and disease severity (grades 1 and 2 [mild] vs 3-5 [severe]) and between hyper fibrinolysis and disease severity. Results: We included 31 patients (71% female; median age, 52 [IQR, 35-58] years; 10 [32%] with a severe reaction). ML% was higher in patients with severe symptoms (21 [IQR, 12-100] vs 10 [IQR, 4-17]). Logistic regression found a signi ficant association between ML% and symptom severity (odds ratio, 1.07; 95% CI, 1.01-1.21; P = .003). Hyper fibrinolysis was detected in 6 patients and found to be associated with severe symptoms (odds ratio, 17.59; 95% CI, 1.52-991.09; P = .02). D-dimer, tryptase, and immunoglobulin E concentrations increased with the severity of immunologic reactions. Conclusion: ML, quanti fied by thromboelastography, is associated with the severity of acute immunologic reactions.