Abstract Number: PB0327
Meeting: ISTH 2020 Congress
Background: Emicizumab entered the market for the prophylaxis in patients with haemophilia A (HA) and inhibitor. Global tests, such as thromboelastography (TEG), seem to be more suitable than “classical” clotting ones for the monitoring of emicizumab. Recently, efficacy of emicizumab has been shown in patients without inhibitor. Here, we report TEG and clotting tests assessment in a patient with severe HA without inhibitor.
Aims: To determine the impact of emicizumab on TEG parameters.
Methods: The patient is a 14-years-old boy with a diagnosis of severe HA (factor VIII < 1%) without inhibitor. Annualised bleeding rate (ABR) was 3. When he was 3-years-old, he started factor VIII replacement prophylaxis (octocog alfa 2000 IU 3 times per week). At the beginning of December 2019, the patient switched to emicizumab and received a subcutaneously prophylaxis dose of 3 mg/kg body weight of emicizumab per week for 4 weeks followed by a current maintenance regimen of 1.5 mg/kg weekly. Factor VIII determinations were performed by means of one-stage clotting and chromogenic (bovine reagent) assays. TEG was performed on a TEG® 5000 Thrombelastograph® Hemostasis Analyzer (Haemonetics).
Results: Main laboratory findings obtained before starting emicizumab are summarised in table 1. The aPTT resulted to be prolonged and TEG assay showed reduction of enzymatic clotting (prolonged “R”) and a hypocoagulable state (high “K” and low “angle” and “MA”). As expected, aPTT was shortened 30 min after the first administration of emicizumab. At the same time we observed changes in TEG parameters towards a normal profile. All tests confirmed this trend at 2-months of treatment (table 1).
Conclusions: TEG reflects trends toward normalization of haemostasis induced by emicizumab in a patient with HA without inhibitor. Present data could be helpful to measure globally the haemostatic effects during treatment with emicizumab. However, further data are warranted.
| aPTT ratio (0.8-1.2) | R (min) (2-8) | K (min) (1-3) | angle (degrees) (55-78) | MA (mm) (51-69) | |
| 1st infusion_Pre | 2.50 | 16.40 | 5.50 | 34.20 | 49.00 |
| 1st infusion_Post (30 min) | 1.70 | 13.20 | 4.20 | 44.10 | 53.80 |
| 2-months of prophylaxis | 0.78 | 12.70 | 2.50 | 57.50 | 63.10 |
[Table 1 Laboratory Findings]
To cite this abstract in AMA style:
Tiscia GL, Cappucci F, De Laurenzo A, Colaizzo D, Favuzzi G, Vaira P, Ostuni A, Margaglione M, Grandone E. Use of Thromboelastography to Monitor Emicizumab in a Patient with Severe Haemophilia A without Inhibitor [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/use-of-thromboelastography-to-monitor-emicizumab-in-a-patient-with-severe-haemophilia-a-without-inhibitor/. Accessed September 22, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/use-of-thromboelastography-to-monitor-emicizumab-in-a-patient-with-severe-haemophilia-a-without-inhibitor/