Thromboelastography in acute immunologic reactions: a prospective pilot study

Abstract

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%. Hyperfibrinolysis was defined 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 hyperfibrinolysis 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 significant association between ML% and symptom severity (odds ratio, 1.07; 95% CI, 1.01-1.21; P = .003). Hyperfibrinolysis 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, quantified by thromboelastography, is associated with the severity of acute immunologic reactions.

Keywords: blood coagulation; fibrinolysis; immunological models; thromboelastography; tissue plasminogen activator.

Figure 1

Medians and IQRs for maximum lysis (%) in thromboelastography and serum tryptase levels (μg/L) on admission to the emergency department in mild and severe immunologic reactions

Figure 2

Medians and IQRs for maximum lysis (%) in thromboelastography (EXTEM test) and serum tryptase levels (μg/L) on admission to the emergency department in relation to the severity grades of immunologic reactions. Numbers in parentheses indicate the number of patients in each group.

Supplementary Figure S1

Maximum lysis (ML) before (EXTEM) and after (APTEM) inhibition of fibrinolysis using aprotinin.

Supplementary Figure S2

Clinical disease courses of individual patients from admission to the emergency department to follow-up using a simplified World Allergy Organization (WAO) grading system.