Use of recombinant FVIIa for intraperitoneal coagulopathic bleeding in a septic patient

Factor VIIa suppresses inflammation and barrier disruption through the release of EEVs and transfer of microRNA 10a

Coagulation protease, factor VIIa (FVIIa), binds to endothelial cell protein C receptor (EPCR) and induces anti-inflammatory and endothelial barrier protective responses via protease-activated receptor-1 (PAR1)-mediated, biased signaling. Our recent studies had shown that the FVIIa-EPCR-PAR1 axis induces the release of extracellular vesicles (EVs) from endothelial cells. In the present study, we investigated the mechanism of FVIIa release of endothelial EVs (EEVs) and the contribution of FVIIa-released EEVs to anti-inflammatory and vascular barrier protective effects, in both in vitro and in vivo models. Multiple signaling pathways regulated FVIIa release of EVs from endothelial cells, but the ROCK-dependent pathway appeared to be a major mechanism. FVIIa-released EEVs were enriched with anti-inflammatory microRNAs (miRs), mostly miR10a. FVIIa-released EEVs were taken up readily by monocytes/macrophages and endothelial cells. The uptake of FVIIa-released EEVs by monocytes conferred anti-inflammatory phenotype to monocytes, whereas EEV uptake by endothelial cells resulted in barrier protection. In additional experiments, EEV-mediated delivery of miR10a to monocytes downregulated the expression of TAK1 and activation of the NF-κB-mediated inflammatory pathway. In in vivo experiments, administration of FVIIa-released EEVs to wild-type mice attenuated LPS-induced increased inflammatory cytokines in plasma and vascular leakage into vital tissues. The incorporation of anti-miR10a into FVIIa-released EEVs diminished the ability of FVIIa-released EEVs to confer cytoprotective effects. Administration of the ROCK inhibitor Y27632, which significantly inhibits FVIIa release of EEVs into the circulation, to mice attenuated the cytoprotective effects of FVIIa. Overall, our study revealed novel insights into how FVIIa induces cytoprotective effects and communicates with various cell types.

Factor VIIa induces extracellular vesicles from the endothelium: a potential mechanism for its hemostatic effect

Recombinant factor FVIIa (rFVIIa) is used as a hemostatic agent to treat bleeding disorders in hemophilia patients with inhibitors and other groups of patients. Our recent studies showed that FVIIa binds endothelial cell protein C receptor (EPCR) and induces protease-activated receptor 1 (PAR1)-mediated biased signaling. The importance of FVIIa-EPCR-PAR1-mediated signaling in hemostasis is unknown. In the present study, we show that FVIIa induces the release of extracellular vesicles (EVs) from endothelial cells both in vitro and in vivo. Silencing of EPCR or PAR1 in endothelial cells blocked the FVIIa-induced generation of EVs. Consistent with these data, FVIIa treatment enhanced the release of EVs from murine brain endothelial cells isolated from wild-type (WT), EPCR-overexpressing, and PAR1-R46Q-mutant mice, but not EPCR-deficient or PAR1-R41Q-mutant mice. In vivo studies revealed that administration of FVIIa to WT, EPCR-overexpressing, and PAR1-R46Q-mutant mice, but not EPCR-deficient or PAR1-R41Q-mutant mice, increased the number of circulating EVs. EVs released in response to FVIIa treatment exhibit enhanced procoagulant activity. Infusion of FVIIa-generated EVs and not control EVs to platelet-depleted mice increased thrombin generation at the site of injury and reduced blood loss. Administration of FVIIa-generated EVs or generation of EVs endogenously by administering FVIIa augmented the hemostatic effect of FVIIa. Overall, our data reveal that FVIIa treatment, through FVIIa-EPCR-PAR1 signaling, releases EVs from the endothelium into the circulation, and these EVs contribute to the hemostatic effect of FVIIa.

A critical role of endothelial cell protein C receptor in the intestinal homeostasis in experimental colitis

Crohn’s disease and ulcerative colitis are the two forms of disorders of the human inflammatory bowel disease with unknown etiologies. Endothelial cell protein C receptor (EPCR) is a multifunctional and multiligand receptor, which is expressed on the endothelium and other cell types, including epithelial cells. Here, we report that EPCR is expressed in the colon epithelial cells, CD11c⁺, and CD21⁺/CD35⁺ myeloid cells surrounding the crypts in the colon mucosa. EPCR expression was markedly decreased in the colon mucosa during colitis. The loss of EPCR appeared to associate with increased disease index of the experimental colitis in mice. EPCR^−/− mice were more susceptible to dextran sulfate sodium (DSS)-induced colitis, manifested by increased weight loss, macrophage infiltration, and inflammatory cytokines in the colon tissue. DSS treatment of EPCR^−/− mice resulted in increased bleeding, bodyweight loss, anemia, fibrin deposition, and loss of colon epithelial and goblet cells. Administration of coagulant factor VIIa significantly attenuated the DSS-induced colon length shortening, rectal bleeding, bodyweight loss, and disease activity index in the wild-type mice but not EPCR^−/− mice. In summary, our data provide direct evidence that EPCR plays a crucial role in regulating the inflammation in the colon during colitis.

FVIIa (Factor VIIa) Induces Biased Cytoprotective Signaling in Mice Through the Cleavage of PAR (Protease-Activated Receptor)-1 at Canonical Arg41 (Arginine41) Site

OBJECTIVE

Recent studies showed that FVIIa (factor VIIa), upon binding to EPCR (endothelial cell protein C receptor), elicits endothelial barrier stabilization and anti-inflammatory effects via activation of PAR (protease-activated receptor)-1-mediated signaling. It is unknown whether FVIIa induces PAR1-dependent cytoprotective signaling through cleavage of PAR1 at the canonical site or a noncanonical site, similar to that of APC (activated protein C). Approach and Results: Mouse strains carrying homozygous R41Q (canonical site) or R46Q (noncanonical site) point mutations in PAR1 (QQ41-PAR1 and QQ46-PAR1 mice) were used to investigate in vivo mechanism of PAR1-dependent pharmacological beneficial effects of FVIIa. Administration of FVIIa reduced lipopolysaccharide-induced inflammation, barrier permeability, and VEGF (vascular endothelial cell growth factor)-induced barrier disruption in wild-type (WT) and QQ46-PAR1 mice but not in QQ41-PAR1 mice. In vitro signaling studies performed with brain endothelial cells isolated from WT, QQ41-PAR1, and QQ46-PAR1 mice showed that FVIIa activation of Akt (protein kinase B) in endothelial cells required R41 cleavage site in PAR1. Our studies showed that FVIIa cleaved endogenous PAR1 in endothelial cells, and FVIIa-cleaved PAR1 was readily internalized, unlike APC-cleaved PAR1 that remained on the cell surface. Additional studies showed that pretreatment of endothelial cells with FVIIa reduced subsequent thrombin-induced signaling. This process was dependent on β-arrestin1.

CONCLUSIONS

Our results indicate that in vivo pharmacological benefits of FVIIa in mice arise from PAR1-dependent biased signaling following the cleavage of PAR1 at the canonical R41 site. The mechanism of FVIIa-induced cytoprotective signaling is distinctly different from that of APC. Our data provide another layer of complexity of biased agonism of PAR1 and signaling diversity.

Factor VIIa induces anti-inflammatory signaling via EPCR and PAR1

Recent studies show that endothelial cell protein C receptor (EPCR) interacts with diverse ligands, in addition to its known ligands protein C and activated protein C (APC). We showed in earlier studies that procoagulant clotting factor VIIa (FVIIa) binds EPCR and downregulates EPCR-mediated anticoagulation and induces an endothelial barrier protective effect. Here, we investigated the effect of FVIIa's interaction with EPCR on endothelial cell inflammation and lipopolysaccharide (LPS)-induced inflammatory responses in vivo. Treatment of endothelial cells with FVIIa suppressed tumor necrosis factor α (TNF-α)- and LPS-induced expression of cellular adhesion molecules and adherence of monocytes to endothelial cells. Inhibition of EPCR or protease-activated receptor 1 (PAR1) by either specific antibodies or small interfering RNA abolished the FVIIa-induced suppression of TNF-α- and LPS-induced expression of cellular adhesion molecules and interleukin-6. β-Arrestin-1 silencing blocked the FVIIa-induced anti-inflammatory effect in endothelial cells. In vivo studies showed that FVIIa treatment markedly suppressed LPS-induced inflammatory cytokines and infiltration of innate immune cells into the lung in wild-type and EPCR-overexpressing mice, but not in EPCR-deficient mice. Mechanistic studies revealed that FVIIa treatment inhibited TNF-α-induced ERK1/2, p38 MAPK, JNK, NF-κB, and C-Jun activation indicating that FVIIa-mediated signaling blocks an upstream signaling event in TNFα-induced signaling cascade. FVIIa treatment impaired the recruitment of TNF-receptor-associated factor 2 into the TNF receptor 1 signaling complex. Overall, our present data provide convincing evidence that FVIIa binding to EPCR elicits anti-inflammatory signaling via a PAR1- and β-arrestin-1 dependent pathway. The present study suggests new therapeutic potentials for FVIIa, which is currently in clinical use for treating bleeding disorders.

Recombinant Activated Factor VII in Patients at High Risk of Bleeding

Currently, recombinant activated factor VII (rFVIIa) (NovoSeven) is indicated for the treatment of spontaneous and surgical bleeding in congenital haemophilia A and B patients with inhibitors to factors VIII (FVIII) and IX (FIX) >5 Bethesda units (BU) worldwide, and in patients with acquired haemophilia, congenital FVII deficiency and Glanzmann's thrombasthenia in Europe. Until April 2003, almost three-quarters of a milion doses of rFVIIa have been administered proving its efficacy and excellent safety record. According to results from initial clinical trials and a large number of case reports, the rFVIIa may be effective not only in treating haemophilia patients but also in treatment of bleeding in patients on oral anticoagulation or heparin, patients with liver diseases, von Willebrand disease (vWD), thrombocytopenia, various platelet defects, congenital or acquired deficiency of FVII, and in subjects without any pre-existing coagulopathy with diffuse life-threatening bleeding triggered by surgery or trauma. This review will briefly summarize rFVIIa mode of action in haemostasis, the current clinical experience with rFVIIa and focus on the alternative use of rFVIIa in patients at the high risk of bleeding in both spontaneous cases and clinical trials reports.

Use of recombinant factor VIIa in the treatment of massive retroperitoneal bleeding due to severe necrotizing pancreatitis

Background. Recently, a growing number of case reports and case series have suggested that the use of recombinant activated factor VII (rFVIIa) may be effective in treatment of patients with non-hemophilic acquired coagulopathy not responding to conventional treatment such as major surgery, major trauma, sepsis, necrotizing pancreatitis and bleeding due to cerebral arteriovenous malformations. Case report. We presented a septic patient with massive, lifethreatening bleeding caused by retroperitoneal necrosis, due to severe acute necrotizing pancreatitis. As conservative treatment (blood, plasma, cryoprecipitates and platelet transfusions) failed to induce cessation of bleeding, the patient was urgently operated on. In spite of usual procedures of surgical hemostasis (ligation, suture, thermocauterisation, fibrin glue, temporary tamponade), hemorrhage could not be stopped. The patient manifested the signs of hypothermia and metabolic acidosis and, therefore, the decision was made to use recombinant activated factor VII (Novo Seven?). The application of rFVIIa resulted in significant discontinuation of hemorrhage, restoration to normal blood count as well as other relevant coagulation parameters. Conclusion. Although application of rFVIIa is still in the initial clinical phase, and the experience is based mainly on uncontrolled series as well as on individual observations, it seems that this drug can be promising, potent and attractive adjunctive prohemostatic agent. This drug may play a beneficial role in the treatment of serious and unresponsive, 'nonsurgical', life-threatening bleeding due to severe acute necrotizing pancreatitis.

Recombinant activated factor VIIa for the treatment of bleeding in major abdominal surgery including vascular and urological surgery: a review and meta-analysis of published data

Background

The purpose of this study was to determine the role of recombinant activated factor VII (rFVIIa) in abdominal, vascular, and urological surgery.

Methods

We conducted meta-analyses of case series and placebo-controlled studies reporting on the treatment or prophylaxis of bleeding with rFVIIa regarding 'reduction or cessation of bleeding', 'mortality', and 'thromboembolism'.

Results

All case reports (n = 15 case reports and 17 patients) documented an effect of rFVIIa in the treatment of bleeding. A meta-analysis of 10 case series revealed a reduction or cessation of bleeding in 39 out of 50 patients after administration of rFVIIa (estimated mean effect 73.2%, 95% confidence interval [CI] 51.0% to 95.4%) and a mean probability of survival of 53.0% (95% CI 26.4% to 79.7%). Among the rFVIIa responders, 19 out of 29 patients (66%) survived versus 1 out of 10 rFVIIa nonresponders (P = 0.003). Six out of 36 patients from the case series had a thromboembolic complication (estimated mean probability 16.5%, 95% CI 1.2% to 31.8%). Compared with a meta-analysis of eight placebo-controlled studies, no increased risk of thromboembolism was seen after administration of rFVIIa.

Conclusion

The meta-analysis of case series showed that, in a mean of 73% patients, rFVIIa achieved at least a reduction of bleeding and that the probability of survival is increased in patients responding to rFVIIa. rFVIIa was not associated with an increased risk of thromboembolism compared with placebo.

Potential role of recombinant activated factor VII for the treatment of severe bleeding associated with disseminated intravascular coagulation: a systematic review

Recombinant activated factor VII (rFVIIa) is a novel hemostatic agent, originally developed for the treatment of hemorrhage in hemophiliacs with inhibitors, which has been successfully used recently in an increasing number of nonhemophilic bleeding conditions. In the present systematic review we report the existing literature data on the use of this hemostatic agent in severe bleeding, unresponsive to standard treatment, associated with disseminated intravascular coagulation. A total of 99 disseminated intravascular coagulation-associated bleeding episodes treated with rFVIIa were collected from 27 published articles: in the majority of the cases, the underlying disorder complicated by disseminated intravascular coagulation was a postpartum hemorrhage, while in the remaining cases it was a cancer, trauma, sepsis or liver failure. Although limited, the data available suggest that rFVIIa could have a potential role in this clinical setting. Large randomized trials are needed, however, to confirm the preliminary results and to assess the safety and dosing regimens of this agent in refractory bleeding associated with disseminated intravascular coagulation.

Pro/con debate: does recombinant factor VIIa have a role to play in the treatment of patients with acute nontraumatic hemorrhage?

Perhaps it is not surprising that in the critical care environment, where lives are frequently on the line, off-label use of certain drugs is relatively common. In general, there are two camps of opinion on this type of utilization. One camp would suggest that potentially life saving products cannot ethically be withheld from patients who may benefit. The other camp would counter that it is inappropriate to administer products if the risk/benefit ratio has not been clearly defined in clinical trials. Off-label use of factor VII is debated in this issue of Critical Care for a patient with uncontrolled nontraumatic hemorrhage. Perhaps this product promotes additional discussion given that its ability to control bleeding can be dramatic, yet its costs and potential for complications high.

Recombinant activated factor VII in an unselected series of cases with upper gastrointestinal bleeding

INTRODUCTION

The mortality rate associated with UGI bleeding remains high at 7-14%. Pharmacologic and endoscopic interventions are the current standard treatment, but there are few alternative options should these fail. This study aimed to assess the efficacy and safety of recombinant activated factor VII (rFVIIa) in the rescue treatment of severe upper gastrointestinal (UGI) bleeding.

METHOD

Eleven patients (age: 8-64 years) were treated with rFVIIa at 15.0-90 microg/kg to control UGI bleeds. All three pediatric/adolescent cases and four of the eight adults had UGI hemorrhage associated with liver disease; the origins of the bleeds for remaining adults were trauma (n=1), peptic duodenal ulcer (n=1), hemorrhagic gastritis with sepsis (n=1) and pancreatitis (n=1).

RESULTS

Bleeding stopped in seven patients and was markedly reduced in two patients, while there was no change in two patients. Coagulation parameters displayed a tendency to improve, and transfusion requirements were reduced in most patients. In total, five patients died within 2 weeks of rFVIIa treatment. In each case, fatality was judged unrelated to rFVIIa treatment. No thromboembolic events occurred.

CONCLUSIONS

These results suggest that, even if our data are optimistic, the use of rFVIIa in the treatment of severe UGI bleeding warrants further investigation in prospective, randomized trials.

Recombinant activated factor VIIa and hemostasis in critical care: a focus on trauma

In this article we describe the current use of recombinant activated factor VII (rFVIIa; NovoSeven) in trauma patients. Emphasis is placed on current uses as defined by key studies, efficacy data, and safety data. Most published studies in trauma patients are retrospective case studies and reports, although an international, double-blind, randomized, controlled, phase II study has been conducted that reported on the efficacy of rFVIIa in reducing the amount of blood products transfused in blunt trauma patients. That study demonstrated the efficacy and safety profile of this hemostatic agent as compared with placebo as adjunctive therapy in the management of severe bleeding associated with trauma. Further prospective, randomized, and placebo-controlled clinical trials will yield more information on the role of rFVIIa in the management of traumatic bleeding.

Uses of recombinant factor VIIa in trauma

PURPOSE OF REVIEW

Despite advances in the care of the injured, the morbidity and mortality of traumatic hemorrhage remain a significant problem. Traumatologists continue to look for ways to treat bleeding and prevent the sequelae of hemorrhagic shock. Recombinant factor VIIa, developed for the treatment of patients with hemophilia, has been used with some success in acute bleeding associated with injuries.

RECENT FINDINGS

The mechanism of action is via a tissue factor-dependent effect and/or platelet activation. Coagulation occurs at the site of tissue injury, where tissue factor is exposed. Case series have described the beneficial effects of recombinant factor VIIa in the treatment of acute hemorrhage, early treatment of traumatic brain injury, and reversal of premorbid anticoagulation. In addition, there have been numerous reports of recombinant factor VIIa use in acute bleeds secondary to other causes as well as some evidence that recombinant factor VIIa may be efficacious when used prophylactically in high-risk patients and for high-risk procedures. Typical doses range from 50 to 100 microg/kg as a single bolus. Although there has been concern over the risk of inappropriate thrombosis with recombinant factor VIIa administration, this complication has seldom been described in published series.

SUMMARY

Although case experience is encouraging, no level 1 evidence has been published that demonstrates clinical or economic benefit of the use of recombinant factor VIIa in trauma patients. Many questions remain to be answered, ideally through randomized, prospective clinical trials. In particular, the issues of patient selection, ideal dosing, and factors associated with futile administration need to be elucidated.

Treatment of intra-abdominal bleeding with recombinant activated factor VII in a patient with disseminated intravascular coagulation secondary to septic shock

Although mainly indicated for treatment of bleeding in haemophilia patients with inhibitors, recombinant activated factor VII (rFVIIa) has also been successfully used in other situations. However, no data are available on its use in the treatment of disseminated intravascular coagulation (DIC) secondary to septic shock. We report a man with DIC and septic shock due to retrocaecal appendicitis and severe intra-abdominal bleeding after surgery. Despite conventional treatment, the bleeding persisted, and treatment with rFVIIa controlled the haemorrhage. No side-effects related to rFVIIa were noted. This case suggests a potential role of rFVIIa in the treatment of severe bleeding associated with DIC.

Use of recombinant activated factor VII for bleeding in pancreatitis: a case series

OBJECTIVES

To describe the effects of recombinant activated factor VII (rFVIIa) in the treatment of bleeding in a series of patients with acute or chronic pancreatitis.

METHODS

Twelve patients (age, 2.5-65 years) with pancreatitis and bleeding were treated with 18.5 to 120 microg/kg of rFVIIa. Eight patients also had sepsis/infection and/or disseminated intravascular coagulation (DIC). The effects of rFVIIa on bleeding, coagulation status, and transfusion requirements were noted.

RESULTS

Bleeding stopped in 4 patients, was markedly reduced in 4 patients, was reduced in 3 patients, and was remained unchanged in 1 patient. For most patients with pre- and post-rFVIIa data, coagulation parameters improved and transfusion requirements reduced. No thrombotic adverse events occurred. Seven patients died for reasons considered to be unrelated to rFVIIa treatment.

CONCLUSIONS

This case series indicates that rFVIIa may be an effective hemostatic treatment of patients with pancreatitis suffering from massive bleeding. There were no thromboembolic events in any patient, including those with sepsis or DIC.

RECOMBINANT FACTOR VIIa INCREASES THE PRESSURE AT WHICH REBLEEDING OCCURS IN PORCINE UNCONTROLLED AORTIC HEMORRHAGE MODEL

In trauma patients, resuscitation to endpoints below normal blood pressure (BP) levels may reduce further blood loss due to the rebleeding often caused by more aggressive resuscitation. However, patients whose BP is maintained at lower levels for extended periods are at increased risk for organ failure. The purpose of this study was to determine whether recombinant activated factor VII (rFVIIa) raises the BP level at which rebleeding occurs in a prospective, randomized, blinded study using a porcine model of uncontrolled hemorrhage and resuscitation. Thirty anesthetized 40-kg pigs were assigned to three groups (n = 10/group): control, low-dose rFVIIa (180 microg/kg), or high-dose (720 microg/kg). Vehicle or drug was infused 5 min before creating a 2.0-mm infrarenal aortotomy. Ten minutes later, resuscitation with lactated Ringer's (LR) solution at 100 mL/min was begun. Hemorrhage and LR volumes and BP were recorded continuously. We found that pretreatment with rFVIIa increased the mean arterial pressure at which rebleeding occurred during resuscitation (45 +/- 3, 69 +/- 5, and 66 +/- 6 mmHg in the control, low-dose, and high-dose groups, respectively, P = 0.003). Rebleed hemorrhage volume was reduced with rFVIIa (39 +/- 9, 22 +/- 7, and 26 +/- 5 mL/kg for control, and low and high dose, respectively; P = 0.055). This is the first study to show that rFVIIa increases the BP at which rebleeding occurs during resuscitation in an injury to a major artery, suggesting the formation of a tight, stronger fibrin plug in the presence of high concentrations of rFVIIa.