Rational Use of Recombinant Factor VIIa in Clinical Practice

Perioperative Management of a Frail Patient With Bernard-Soulier Syndrome

Bernard-Soulier syndrome (BSS) is an autosomal recessive inherited bleeding disorder characterized by prolonged bleeding time, thrombocytopenia, and giant platelets. Patients with BSS are at an increased risk of bleeding, especially during traumatic injury and surgical procedures. The literature on the anesthetic management of patients with BSS is limited. In this report, we detail the successful management of a frail patient with BSS who underwent a major surgical procedure. Despite comprehensive clinical monitoring and an extended pharmacological strategy, a hemorrhagic complication occurred in the later postoperative phase, emphasizing the necessity for continued support and vigilant clinical monitoring due to the ongoing bleeding risk associated with these patients. In this case, a combined strategy involving antifibrinolytics, recombinant factor VII, and platelet transfusions proved effective.

Site-directed mutagenesis of tissue factor pathway inhibitor-binding exosite D60A on factor VII results in a new factor VII variant with lower coagulant activity

Background

Recombinant factor (F)VIIa (rFVIIa) has been approved by the US Food and Drug Administration for the treatment of hemophilia A and B with inhibitors and congenital FVII deficiency. Moreover, the investigational uses of rFVIIa are becoming of interest since it can be used to treat various clinical bleeding conditions. However, there is evidence showing that rFVIIa is a potent procoagulant agent that potentially leads to an increased risk of thrombotic complications.

Objectives

To design a new rFVII with lower coagulant activity that could potentially be used as an alternative hemostatic agent aiming to minimize the risk of thrombogenicity.

Methods

D60A was introduced into the F7 sequence by polymerase chain reaction-based mutagenesis. Wild type (WT) and D60A were generated in human embryonic kidney 293T cells by stable transfection. FVII coagulant activities were determined by amidolytic cleavage of the FVIIa-specific substrate, 2-step FXa generation, thrombin generation (TG), and clot-based assays.

Results

WT and D60A demonstrated similar FVIIa amidolytic activity. However, D60A showed approximately 50% activity on FX activation and significantly longer lag time in the TG assay than that shown by WT. The clotting time produced by D60A spiked in FVII-deficient plasma was significantly prolonged than that of WT. Additionally, the ex vivo plasma half-lives of WT and D60A were comparable.

Conclusion

D60A demonstrated lower coagulant activities, most likely due to the weakening of FX binding, leading to impaired FX activation and delayed TG and fibrin formation. Considering that a plasma FVII level of 15% to 25% is adequate for normal hemostasis, D60A is a molecule of interest for future development of an rFVII with a lesser extent of thrombogenicity.

Emergency cesarean section in glanzmann thrombasthenia: Anaesthetic management without recombinant factor VIIa

Glanzmann thrombasthenia (GT) is a congenital disorder inherited autosomal recessively, caused by deficiency of platelet membrane glycoprotein IIb-IIIa complex leading to defective platelet aggregation, and manifesting as mucocutaneous bleeding. Parturients with GT requiring emergency cesarean section are at high risk for perioperative bleeding complications. The anesthetist should be prepared with the necessary measures to control bleeding. This paper presents the successful management of a 23-year-old primigravida with GT undergoing cesarean section in a resource-limited setup where thromboelastography and recombinant factor VIIa (rFVIIa) are not available.

Biomaterials as Haemostatic Agents in Cardiovascular Surgery: Review of Current Situation and Future Trends

Intraoperative haemostasis is of paramount importance in the practice of cardiovascular surgery. Over the past 70 years, topical haemostatic methods have advanced significantly and today we deal with various haemostatic agents with different properties and different mechanisms of action. The particularity of coagulation mechanisms after extracorporeal circulation, has encouraged the introduction of new types of topic agents to achieve haemostasis, where conventional methods prove their limits. These products have an important role in cardiac, as well as in vascular, surgery, mainly in major vascular procedures, like aortic dissections and aortic aneurysms. This article presents those agents used for topical application and the mechanism of haemostasis and offers general recommendations for their use in the operating room.

Atypical complication in an adult patient with dengue and autoimmune hemolytic anemia: a case report

Severe dengue infection is associated with life-threatening complications, including severe bleeding. The bleeding tendency is typically associated with the shock phase of infection, for which blood replacement may be needed. However, repetitive blood transfusion can lead to volume overload. Administration of recombinant activated factor VII (rFVIIa) might be used to counteract bleeding without inducing volume overload. We describe the case of a patient with severe dengue infection who presented with intractable bleeding; he was initially treated with massive blood transfusions, which resulted in volume overload. He was then treated with rFVIIa to reverse the bleeding. During the second week of his hospitalization, his hematocrit dropped precipitously, and autoimmune hemolytic anemia was diagnosed. Supportive treatment was provided until recovery. Autoimmune hemolytic anemia is a rare complication in adult patients with dengue. Supportive care was effective for this atypical complication.

Atypical complication in an adult patient with dengue and autoimmune hemolytic anemia: a case report

Severe dengue infection is associated with life-threatening complications, including severe bleeding. The bleeding tendency is typically associated with the shock phase of infection, for which blood replacement may be needed. However, repetitive blood transfusion can lead to volume overload. Administration of recombinant activated factor VII (rFVIIa) might be used to counteract bleeding without inducing volume overload. We describe the case of a patient with severe dengue infection who presented with intractable bleeding; he was initially treated with massive blood transfusions, which resulted in volume overload. He was then treated with rFVIIa to reverse the bleeding. During the second week of his hospitalization, his hematocrit dropped precipitously, and autoimmune hemolytic anemia was diagnosed. Supportive treatment was provided until recovery. Autoimmune hemolytic anemia is a rare complication in adult patients with dengue. Supportive care was effective for this atypical complication.

Spontaneous hemorrhage after external ventricular drain placement in the setting of low factor VII secondary to liver cirrhosis

BACKGROUND

Alterations in normal coagulation and hemostasis are critical issues that require special attention in the neurosurgical patient. These disorders pose unique challenges in the management of these patients who often have concurrent acute ischemic and hemorrhagic injuries. Although neurosurgical intervention in such cases may be unavoidable and potentially life-saving, these patients should be closely observed after instrumentation.

CASE DESCRIPTION

A 57-year-old male with liver cirrhosis secondary to amyloid light-chain amyloidosis was admitted to the intensive care unit for the management of delayed hydrocephalus. An external ventricular drain (EVD) was placed for the treatment and monitoring of hydrocephalus. Five days after EVD placement, a head computed tomography scan revealed a tract hemorrhage. However, on repeated imaging, the size of the hemorrhage continued to increase despite aggressive blood pressure control and several doses of phytonadione. Extensive coagulopathy workup was remarkable for low factor VII levels. In that setting, recombinant activated factor VII was administered to normalize factor VII levels, and the tract hemorrhage stabilized.

CONCLUSION

To the best of our knowledge, this is the first case of spontaneous hemorrhage after EVD placement in the setting of liver cirrhosis-associated factor VII deficiency. Our case highlights the importance of identifying coagulation disorders in neurosurgical patients at high risk for coagulopathy and closely monitoring them postoperatively.

Cost-utility analysis of emicizumab prophylaxis in haemophilia A patients with factor VIII inhibitors in Korea

AIMS

Haemophilia A patients with factor VIII inhibitors (HAPI) experience frequent spontaneous bleeding, approximately once a week, and require expensive bypassing agent (BPA) treatments to control bleeding over their lifetime. According to the HAVEN 1 trial, weekly emicizumab (Hemlibra®) prophylaxis injection reduces annualized bleeding rates (ABR) by 87% compared with BPA on-demand treatment (BPA-OD) administered at the time of bleeding. Our study aimed to assess the cost-effectiveness of emicizumab prophylaxis in HAPI in Korea.

METHODS

Using a lifetime Markov model with health states of 'alive with bleeds' and 'dead', we simulated the experience of HAPI receiving emicizumab prophylaxis (treatment arm) or BPA-OD (control arm) and estimated expected clinical and economic outcomes under each treatment arm. Model parameters included comparative effectiveness, clinical and epidemiologic characteristics of Korean HAPI, costs of drug treatment and medical events and utility for 'alive with bleeds' state under each treatment. We utilized local data, including National Health Insurance claims data, national statistics, literature and expert surveys with haematologists.

RESULTS

Base-case analysis results showed that compared with BPA-OD, lifetime emicizumab prophylaxis prevented 807 bleedings, extended 3.04 quality-adjusted life-years and reduced costs by 2.6 million US dollars. Thus, emicizumab prophylaxis is a dominant treatment option with better effectiveness and lower costs than BPA-OD. A series of one-way sensitivity analyses consistently showed dominant results, confirming that lifetime emicizumab prophylaxis is a cost-saving intervention for HAPI.

CONCLUSION

Emicizumab prophylaxis is an excellent treatment choice reducing ABR, improving quality of life and reducing costs.

Life-Threatening Pulmonary Hemorrhage Responds to Recombinant Factor VIIa: A Case Series in South Florida Hospitals

Intravenous recombinant activated Factor VIIa (rFVIIa) is approved as a hemostatic agent for only a few bleeding disorders. Since the first reported case of off-label use for rFVIIa in 1999, off-label use far exceeds the use for approved conditions. The endobronchial administration of rFVIIa to control alveolar hemorrhage has been published in only a few case reports. Herein we report a case series of endobronchial rFVIIa use for life-threatening pulmonary hemorrhage at two institutions in south Florida. 

Use of low dose of rFVIIa (recombinant Factor VII activated) to control late bleeding after percutaneous dilational tracheostomy

In our case, the use of a low intravenous bolus dose of rFVIIa (recombinant factor VII activated; 15-20 mcg/kg) was effective and uneventful in controlling late postprocedural PDT bleeding associated with thrombocytopenia that cannot be corrected and after all other treatments failed.

Hemostatic Agents in Critically Ill Patients

How to cite this article: Das SK, Reddy MM, Ray S. Hemostatic Agents in Critically Ill Patients. Indian J Crit Care Med 2019;23(Suppl 3):S226–S229.

Successful synthesis of active human coagulation factor VII by co-expression of mammalian gamma-glutamyl carboxylase and modification of vit.K cycle in Drosophila Schneider S2 cells

Mammalian gamma-glutamyl carboxylase and reduced vitamin K are indispensable for synthesis of mature mammalian vitamin K dependent proteins including some of blood coagulation factors (factors II, VII, IX, and X). It was well known that Drosophila melanogaster expressed gamma-glutamyl carboxylase and possessed a vit.K cycle although native substrates for them have not been identified yet. Despite the potential capability of gamma carboxylation in D. melanogaster derived cells such as S2 cells, Drosophila gamma-glutamyl carboxylase failed to gamma carboxylate a peptide fused to the human coagulation factor IX propeptide. Thus, it had been believed that the Drosophila system was not adequate to synthesize mammalian vit.K dependent proteins. Indeed, we previously attempted to synthesize biologically active factor VII in S2 cells although we were not able to obtain it. However, recently, a successful transient expression of biologically active human factor IX from S2 cells was reported. In the present study, several expression vectors which enable expressing mammalian GGCX, VKORC1, and/or PDIA2 along with F7 were developed. S2 cells transfected with pMKA85, pMAK86, and pMAK219 successfully synthesized active FVII. Thus, mammalian GGCX was indispensable to synthesize active FVII while mammalian VKORC1 and PDIA2 were not critical but supportive factors for S2 cells.

Rapid rFVIIa enhanced on-demand dosing in haemophilia inhibitor patients

Recombinant factor VII activated (rFVIIa) is a bypassing agent widely used in haemophilia A and B patients with antibodies against coagulation factors VIII or IX. When used according to the correct doses, rFVIIa may control bleeding, subclinical bleeding and rebleeding, avoiding the effect of neutralising inhibitors. Because of the fast action of the rFVIIa, haemostasis occurs promptly and enables a fast bleeding control with on-demand treatment in home or in surgical setting. Rapidity is also a distinguishing feature in preparation and injection of rFVIIa to cope the restraining times of busy patients and parents. The effective haemostatic activity of rFVIIa enables a sustained bleeding control, which is implemented with every other day (eod) administration and suited for enhanced on-demand therapy and short-term repeated infusions use of rFVIIa to prevent microhaemorrhages or rebleeding. Comprehensive appreciation of these pharmacological and pharmacodynamic' characteristics will likely be a further stimulus to the wider enhanced on-demand use of rFVIIa.