Ex Vivo Prediction of Comprehensive Coagulation Potential Using Simulated Blood Concentrations of Emicizumab in Patients with Acquired Hemophilia A

2021 ◽  
Author(s):  
Masahiro Takeyama ◽  
Shoko Furukawa ◽  
Koji Yada ◽  
Kenichi Ogiwara ◽  
Naruto Shimonishi ◽  
...  
Keyword(s):  
Hemophilia A ◽  
Clinical Course ◽  
Ex Vivo ◽  
Plasma Concentrations ◽  
Waveform Analysis ◽  
Severe Bleeding ◽  
Maximum Plasma ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Blood Concentrations

Abstract Introduction Emicizumab prophylaxis improves coagulation function in congenital hemophilia A, regardless of inhibitor presence. We recently reported that emicizumab enhanced the coagulant potentials, ex vivo, in plasmas from patients with acquired hemophilia A (PwAHAs) at diagnosis. However, coagulant effects of emicizumab in PwAHAs during the clinical course remain unclear. Aim To assess ex vivo coagulant effects of emicizumab in PwAHAs during the clinical course. Methods/Results Blood samples were obtained from 14 PwAHAs on (median) days 0 and 6 during a severe-bleeding phase, and days 27 and 59 during a reduced-bleeding phase with elevated endogenous factor VIII (FVIII) and decreased inhibitor titers. If administered a single dose of 3 or 6 mg/kg, or two doses at 6 mg/kg followed by 3 mg/kg, estimated plasma emicizumab concentrations (10/5/2.5, 20/10/5, and 30/15/7.5 µg/mL on days 0–7/30/60, respectively) could be used to represent potential changes, based on the half-life (T 1/2: ∼30 days). Emicizumab concentrations that covered maximum plasma concentrations of each dosage were used for spiking on day 0. Ex vivo addition of estimated emicizumab to PwAHA's plasma containing endogenous FVIII and/or inhibitor, without and with recombinant (r)FVIIa administration during immunosuppressive therapy, increased the calculated Ad|min1| values, assessed by clot waveform analysis, and their coagulant potentials were below normal levels. Rotational thromboelastometry revealed that ex vivo emicizumab addition resulted in the further improvement of coagulant potentials in whole bloods when combined with rFVIIa administration. Conclusion Based on ex vivo and in vitro data, emicizumab has the potential to be effective in clinical situations for PwAHAs.

Emicizumab for the treatment of acquired hemophilia A

Blood ◽  
2020 ◽  
Author(s):  
Paul Knoebl ◽  
Johannes Thaler ◽  
Petra Jilma ◽  
Peter Quehenberger ◽  
Karoline Veronika Gleixner ◽  
...  
Keyword(s):  
Hemophilia A ◽  
Coagulation Factor ◽  
Standard Of Care ◽  
Early Discharge ◽  
Severe Bleeding ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Breakthrough Bleeding ◽  
Hemostatic Efficacy ◽  
Bypassing Agents

Acquired hemophilia A (AHA) is a severe bleeding disorder caused by inhibiting autoantibodies to coagulation factor VIII (FVIII). For hemostatic treatment, bypassing agents, human or porcine FVIII are currently standard of care. Emicizumab is a bispecific, FVIII-mimetic therapeutic antibody, that reduced the annualized bleeding rates in congenital hemophiliacs. Here we report on 12 patients with AHA, 6 male, 6 female, age 74 yrs (64/80) (all data medians and IQR), treated with emicizumab. Initial FVIII was <1%, inhibitor 22.3BU/mL (range 3-2000). Eight patients had severe bleeding. Emicizumab was started with 3mg/kg sc. weekly for 2-3 doses, followed by 1.5mg/kg every 3 weeks to keep the lowest effective FVIII levels. For FVIII monitoring, chromogenic assays with human and bovine reagents were used. All patients received immunosuppression with steroids and/or rituximab. After the first dose of emicizumab, APTT normalized in 1-3 days, FVIII (human reagents) exceeded 10% after 11 (7.5/12) days. Hemostatic efficacy was obtained and bypassing therapy stopped after 1.5 (1/4) days. FVIII (bovine reagents) exceeded 50%, indicating complete remission, after 115 (67/185), and emicizumab was stopped after 31 days (15/79), in median 5 injections (range 3-9) were given. No patient died from bleeding or thromboembolism, and no breakthrough bleeding was observed after the first dose of emicizumab. In conclusion, emicizumab seems to be an effective hemostatic therapy for AHA, with the advantages of sc. therapy (every 1-3 weeks), good hemostatic efficacy, early discharge, reduction of immunosuppression and adverse events.

Rituximab in the Treatment of Acquired Hemophilia a (AHA): A Novel Eradicating Therapy?

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4533-4533 ◽  
Author(s):  
Karla O. Mota ◽  
Silvia Nakanishi Bastos
Keyword(s):  
B Cell ◽  
Soft Tissues ◽  
Hemophilia A ◽  
Clinical Findings ◽  
High Rate ◽  
Severe Bleeding ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Fviii Inhibitor

Abstract Background: Acquired inhibitors against factor VIII (FVIII), also termed Acquired Hemophilia A (AHA), occur rarely in the nonhemophilic population. Its incidence is approximately 1 to 4 per million/year. The incidence of AHA increases with age and a major peak is seeing in patients aged 68 to 80 years. These autoantibodies are associated with high rate of morbidity (90% of severe bleeding in affected patients) and mortality (8–22% of the cases). The diagnosis of AHA is based on the demonstration of an isolated prolongation of the activated partial thromboplastin time (APTT), not corrected by incubating the patient’s plasma with equal volumes of normal plasma (mixing study), associated with FVIII reduced levels and formal evidence of a FVIII inhibitor in a patient with no previous personal or family history of bleeding. In approximately half of affected patients there is no identification of relevant concomitant diseases. The bleeding pattern in AHA is characterized by hemorrhages into the skin, muscles or soft tissues, and mucous membranes. Rituximab (Mabthera®; Roche; Switzerland) is a chimeric monoclonal antibody against the pan B-cell antigen CD20 that induces a rapid in vivo depletion of normal B lymphocytes. Primarily developed to treat B-cell non Hodgkin Lymphomas, more recently, Rituximab has demonstrated effectiveness in a number of autoantibody-mediated diseases including AHA. Case Report: We treated a 69-year-old diabetic and hypertensive patient with AHA. In March 2007, the diagnosis was made by a prolonged APTT (ratio 2.74 sec), not corrected by the mixing study, and FVIII inhibitor 320 Bethesda units. The patient had no evidence of malignancy, autoimmune disease or use of drugs. His bleeding manifestations were large ecchymosis of upper and lower extremities for almost a year, and at admission to the hospital, a hematoma of left calf and gengival bleeding. First line therapy consisted of steroids and cyclophosphamide (CFM). The steroids had to be withdraw after one week of use, because of very difficult glycemic control. The CFM were use in the dose of 50mg/day adding an total accumulative dose of 3g. This protocol were used considering the incapacity of the patient to tolerate higher dose of CFM due to leukopenia. After treatment, the patient was evaluated and neither normalization of APTT nor improvement of clinical findings happened. Therefore, considering all the above, it was decided to use Rituximab 375mg/m2, weekly, for four weeks. In June 2007, the patient received and tolereted very well all the infusions. In August 2007, he had no bleeding symptoms and his APTT was normal. At his laterest visit to the clinic in July 2008, an year after finishing his treatment, he was still very well and his bleeding tests were normal. Conclusion: Rituximab should be considered a treatment option for AHA.

Anti-FVIII Autoantibodies Share Similar Characteristics In Acquired Hemophilia A Patients With and Without An Associated Disease

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1110-1110
Author(s):  
Joerg Kahle ◽  
Christoph Königs ◽  
Anja Naumann ◽  
Thomas Klingebiel ◽  
John F Healey ◽  
...  
Keyword(s):  
Autoimmune Disease ◽  
Hemophilia A ◽  
Conflicts Of Interest ◽  
Underlying Disease ◽  
Severe Bleeding ◽  
Bleeding Tendency ◽  
C2 Domain ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Fviii Inhibitor

Abstract Introduction Acquired hemophilia A (AHA) is an autoimmune disease caused by the development of inhibitory autoantibodies against factor VIII (FVIII) resulting in severe hemorrhages. Associated pathologies, such as autoimmune disease, malignancy and pregnancy are observed in approximately 50% of patients. Aim To elucidate the relationship between an underlying disease, the bleeding tendency and patients immunological profile the characteristics of anti-FVIII autoantibodies in AHA patients with (n=6) and without an underlying disease (n=9) were determined. Patients and Methods The median age of this cohort (n=15) was 71 years with two-thirds older than 70 years. Treatment parameters were analysed and patients were classified according to there bleeding tendency into a mild, moderate and severe phenotype. FVIII domain specificity of anti-FVIII autoantibodies was analysed in ELISA by binding to (i) FVIII fragments (heavy (HC) and light chain (LC), A2 and C2 domain) and (ii) single human domain hybrid human/porcine FVIII proteins. The amount of FVIII-specific IgGs was measured by ELISA and their relative contribution to the total amount of anti-FVIII IgG was calculated from standard curves for FVIII-specific IgG1, IgG2, IgG3, and IgG4. Results All but one patient were treated with bypassing agents including activated FVII, activated prothrombin complex concentrate or porcine FVIII. All patients received immunosuppressive treatments. 14/15 achieved initial complete remission with 6 patients experiencing another episode of inhibitors. Characteristics of anti-FVIII autoantibodies in AHA patients with or without an underlying disease were similar: FVIII-specific autoantibodies targeted primarily the FVIII LC with a dominance of epitopes located C2 domain compared to the C1 domain. FVIII-specific antibodies belonged to the subclasses IgG1, IgG2, and IgG4. The individual IgG subclass levels did not correlate with the total amount of anti-FVIII antibodies or inhibitory anti-FVIII antibodies in Bethesda units. IgG1 and 2 vs IgG4 levels did not correlate with bleeding tendency. Patients with a mild bleeding phenotype only recognized the C2 domain, whereas other patients had antibodies against C2 and or other domains. Although lower levels of FVIII activity (FVIII:C) were observed in disease-associated AHA patients with a median FVIII:C of 0.5% (range, 0-6%) compared to 1.5% (range, 0-10%) in idiopathic AHA patients, this difference was not statistically significant. FVIII:C levels and FVIII inhibitor titers at clinical presentation did not correlate to the severity of bleeds: the median FVIII:C level in patients who had strong bleeds was 0.5% (range, 0-10%), moderate bleeds 3.6% (range, 0-6%), and mild bleeds 1.2% (range, 1-6%). The FVIII inhibitor titer at presentation was similar in patients who had mild, moderate and severe bleeding tendency with a median of 35 BU/mL (range, 29-55 BU/mL), 49.5 BU/mL (range, 9-156 BU/mL), and 17.3 BU/mL (range, 2.2-614 BU/mL), respectively. Conclusion The presented data challenges the view from other small cohorts that differential immunological profiles exist between disease-associated and idiopathic AHA patients. Data on the influence of epitopes and IgG subclasses on outcome in AHA patients remains conflicting and needs further study. Disclosures: No relevant conflicts of interest to declare.

Acquired hemophilia A manifesting as plasma transfusion-uncontrolled severe bleeding 2 weeks after chorioamnionitis-induced abortion

2017 ◽  
Vol 43 (4) ◽  
pp. 763-767 ◽  
Author(s):  
Ayumi Matsuoka ◽  
Hiromasa Sasaki ◽  
Chiharu Sugimori ◽  
Shinya Hirabuki ◽  
Tsutomu Hoshiba ◽  
...  
Keyword(s):  
Hemophilia A ◽  
Induced Abortion ◽  
Severe Bleeding ◽  
Plasma Transfusion ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia

scholarly journals Recombinant porcine FVIII for bleed treatment in acquired hemophilia A: findings from a single-center, 18-patient cohort

2020 ◽  
Vol 4 (24) ◽  
pp. 6240-6249
Author(s):  
Patrick Ellsworth ◽  
Sheh-Li Chen ◽  
Raj S. Kasthuri ◽  
Nigel S. Key ◽  
Micah J. Mooberry ◽  
...  
Keyword(s):  
Hemophilia A ◽  
Rescue Therapy ◽  
Severe Bleeding ◽  
Activity Levels ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Fviii Activity ◽  
Hemostatic Efficacy ◽  
Bypassing Agents ◽  
Activated Prothrombin Complex Concentrates

Abstract Acquired hemophilia A (AHA) is a rare bleeding disorder in which acquired autoantibodies to endogenous factor VIII (FVIII) decrease FVIII activity and lead to a bleeding phenotype. A substantial majority of individuals who develop AHA present with severe bleeding. Effective treatment requires both immunosuppressive therapy and prompt hemostatic treatment. Bleeding is commonly treated with bypassing agents (BPAs) such as recombinant activated FVII (rFVIIa) or activated prothrombin complex concentrates Disadvantages to BPAs include the inability to monitor response with standard laboratory assays, inconsistent hemostatic efficacy, and thrombosis. Recombinant porcine FVIII (rpFVIII: Obizur, Baxter, Deerfield, IL) was approved by the US Food and Drug Administration (FDA) for bleed treatment in AHA in 2014, and has the advantage of laboratory monitoring of FVIII activity levels and known hemostatic efficacy in the presence of anti-human FVIII inhibitors and after failure of BPAs. Using an algorithm-based approach, rpFVIII has been used to successfully treat 18 patients with AHA at our center with substantially lower doses than the current FDA-recommended dosing. Additionally, data from our cohort show that the preexposure anti-porcine Bethesda titer does not reliably predict the clinical response to rpFVIII treatment and is not correlated with the anti-human Bethesda titer. We also present data showing lower total rpFVIII use for initial bleed resolution when rpVIII is used upfront, as compared with use as rescue therapy. We validated our dosing algorithm, which uses much lower than FDA-recommended doses with 14 more patients than in our previously reported patient series.

scholarly journals An anti‐factor IXa/factor X bispecific antibody, emicizumab, improves ex vivo coagulant potentials in plasma from patients with acquired hemophilia A

2020 ◽  
Vol 18 (4) ◽  
pp. 825-833 ◽  
Author(s):  
Masahiro Takeyama ◽  
Keiji Nogami ◽  
Tomoko Matsumoto ◽  
Mariko Noguchi‐Sasaki ◽  
Takehisa Kitazawa ◽  
...  
Keyword(s):  
Bispecific Antibody ◽  
Hemophilia A ◽  
Ex Vivo ◽  
Factor X ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Factor Ixa
Sign in / Sign up

Export Citation Format

Share Document