Factor XI deficiency: phenotypic age-related considerations and clinical approach towards bleeding risk assessment.

ABSTRACT: Factor XI (FXI) deficiency is a rare bleeding disorder that presents complex challenges in patient assessment and bleeding risk management. Despite generally causing mild to moderate bleeding symptoms, clinical manifestations can vary, and bleeding tendency does not always correlate with FXI plasma levels or genotype. Our manuscript delves into the age-related nuances of FXI deficiency across an individual's lifespan. We emphasize issues faced by specific groups, including neonates and females of reproductive age experiencing abnormal uterine bleeding and postpartum hemorrhage. Older patients present unique challenges and concerns related to the management of bleeding as well as thrombotic complications. The current assortment of diagnostic laboratory assays shows limited success in predicting bleeding risk in the perisurgical setting of patients with FXI deficiency. This review explores the intricate interplay between individual bleeding profiles, surgical sites, and FXI activity levels. We also evaluate the accuracy of existing laboratory assays in predicting bleeding and discuss the potential role of investigational global assays in perioperative assessment. Furthermore, we outline our suggested diagnostic approach to refine treatment strategies and decision making. Available treatment options are presented, including antifibrinolytics, replacement products, and recombinant activated FVII. Finally, we discuss promising nonreplacement therapies for the treatment of rare bleeding disorders that can potentially address the challenges faced when managing FXI deficiency-related bleeding complications.

[PERIOPERATIVE MANAGEMENT OF AN ADOLESCENT GIRL WITH SEVERE FACTOR XI DEFICIENCY AND INHIBITORS].

INTRODUCTION: Factor XI (FXI) deficiency is an autosomal bleeding disorder characterized by injury-related hemorrhage, mostly associated with surgical procedures at sites noted for high fibrinolytic activity. Severe FXI deficiency is defined when the FXI level is lower than 15-20 IU/dL. Perioperative prophylactic treatment for high-bleeding-risk surgery in patients with severe FXI deficiency is based on fresh frozen plasma (FFP) transfusions or FXI concentrate (where available). Exposure to FFP and to FXI concentrate may lead to the development of inhibitory antibodies against FXI. This phenomenon occurs mostly in patients with very severe FXI deficiency (baseline FXI <1IU/dL) and is associated with an increased risk of substantial perioperative bleeding, unresponsive to FXI replacement. Thus, in individuals with severe FXI deficiency, routine testing for the presence of inhibitory antibodies against FXI is recommended. We present a 17-year-old adolescent patient with very severe FXI deficiency, who developed an inhibitor to FXI following FFP exposure associated with neurosurgery for medulloblastoma. Prophylactic treatment for subsequent invasive procedures consisted of single low dose (10 mcg/kg) recombinant activated factor VII (rFVIIa) and tranexamic acid (Hexakapron). The procedures were performed uneventfully, with no hemorrhagic or thrombotic complications. In patients with very severe FXI deficiency, the development of inhibitory antibodies following plasma replacement therapy comprises a rare and challenging occurrence. The formulation of a safe and effective evidence-based protocol for hemostatic support in these patients requires multi-center collaboration.

Pediatric severe factor XI deficiency: A multicenter study.

BACKGROUND: Factor XI (FXI) deficiency is a rare autosomal recessive bleeding disorder. Only scarce publications address its clinical features in children. The increased prevalence of FXI deficiency in Israel enabled data collection for this large multicenter cohort study. OBJECTIVE: Some hemostatic challenges may be unique or more common in children, such as bleeding in the neonatal period or trauma-related injury. The current study was designed to explore the potential impact of these differences in children with severe FXI deficiency. METHODS: Medical files of all children with FXI level under 15% followed at five tertiary centers were evaluated. The retrieved data comprised demographic and clinical characteristics, including bleeding episodes, surgical interventions, treatment strategies, as well as laboratory features. RESULTS: Sixty children, whose median age at diagnosis was 4.2 years and their median FXI level was 4%, were included. Three children experienced triggered intracranial hemorrhage (ICH) and two children had major bleeds. No bleeding complications occurred in surgeries in which hemostatic treatment consisting mostly of tranexamic acid or fresh frozen plasma was applied (n = 45). In contrast, excessive bleeding was noted in 25% of surgical procedures performed without hemostatic preparation (p = .002). CONCLUSION: This study's findings confirm the generally favorable outcome of this rare bleeding disorder, with no spontaneous bleeds or cases of perinatal ICH. Nonetheless, proper diagnosis and adequate hemostasis in the surgical setting are imperative. Unlike previous studies in adults, our pediatric study suggests an association between the severity of FXI deficiency and bleeding tendency.

Management of factor XI deficiency in oncological liver and colorectal surgery by therapeutic plasma exchange: A case report.

INTRODUCTION: Factor XI (FXI) deficiency is a rare congenital hemostatic disorder associated with increased bleeding tendency in trauma, surgery or when other hemostatic defects are present. Perioperative hemostatic management of a patient with a severe FXI deficiency undergoing major oncological liver and colorectal surgery with therapeutic plasma exchange (TPE) with fresh frozen plasma (FFP) is reported. CASE DESCRIPTION: A 54-year-old male with severe FXI deficiency was scheduled for resection of synchronous rectal cancer and multiple liver metastases. Baseline prothrombin time (PT) was 97 %, activated partial thromboplastin time (aPTT) 89 s(s) and FXI levels <1 IU/dL. The rotational thromboelastometry (ROTEM™) presented a prolonged INTEM clotting time (CT) = 443 s (RV 100-240 s) and a clot formation time (CFT) = 110 s (RV 30-100 s). TPE with FFP was carried out achieving FXI levels up to 46 IU/dL and an aPTT of 33 s, normalizing thromboelastometry parameters to an INTEM CT = 152 s and a CFT = 86 s before the procedure. After surgery, the patient received daily FFP to maintain FXI levels above 30 IU/dL until discharge on the eighth day. A total of 30 FFP units were transfused during hospital stay. No significant bleeding events neither transfusion related complications were observed during the perioperative period. CONCLUSION: Given the lack of correlation between FXI levels and bleeding risk, a multidisciplinary approach based on daily FXI levels monitoring, close clinical assessment and factor supplementation is mandatory. In conclusion, TPE with FFP is an efficacious alternative strategy to correct severe FXI deficiency in patients undergoing major surgery.

Death from Transfusion-Transmitted Anaplasmosis, New York, USA, 2017.

We report a death from transfusion-transmitted anaplasmosis in a 78-year-old man. The patient died of septic shock 2 weeks after a perioperative transfusion with erythrocytes harboring Anaplasma phagocytophilum. The patient's blood specimens were positive for A. phagocytophilum DNA beginning 7 days after transfusion; serologic testing remained negative until death.

The Evolving Dilemma of Factor XI in Pregnancy: Suggestions for Management.

A case of a patient with severe factor XI (FXI) deficiency who presented for her seventh labor and delivery is presented. The nature of FXI deficiency, its prevalence, and issues related to genetic screening are discussed. Published literature on the topic is reviewed, including criteria that were developed to assess bleeding, laboratory tools used to estimate bleeding risk, and available treatments. Within the context of this challenging clinical dilemma, specific recommendations are provided for the antepartum, intrapartum, and postpartum stages of pregnancy. These include recommendations that take into account both FXI levels and history of any abnormal bleeding. While there are effective treatments available, it is important to consider that institutional multidisciplinary protocols are needed to manage this complex disorder. More work is needed to define the best management protocols.

Acquired factor XI deficiency and therapeutic plasma exchange.

Congenital factor XI (FXI) deficiency is associated with a variable bleeding phenotype. Recent reports have documented the use of therapeutic plasma exchange to rapidly and isovolumetrically increase FXI levels before invasive procedures in patients with congenital FXI deficiency. We report a case of acquired FXI deficiency in a pregnant woman with lupus. We proved that the inhibitor was an IgG, therefore potentially capable of crossing the placenta. While immune suppression eliminated detectable circulating inhibitor, the woman's FXI remained quite low. A multi-disciplinary team was formed and therapeutic plasma exchange with 100% plasma replacement was performed when the patient went into labor, to acutely raise her FXI level and remove any potential non-neutralizing inhibitor. The mother had a controllable level of bleeding during post-TPE cesarean section; the baby had no bleeding and the baby's FXI levels were not overtly abnormal. Therapeutic plasma exchange in acquired FXI deficiency (or other acquired hemophilias) can both acutely isovolumetrically raise factor levels and remove any circulating inhibitor.

Therapeutic plasma exchange for perioperative management of patients with congenital factor XI deficiency.

BACKGROUND: Factor XI (FXI) deficiency (hemophilia C [HEM-C]) is a bleeding disorder with unpredictable severity that correlates poorly with FXI coagulation activity (FXI:C). It poses a perioperative hemostatic management challenge. For US patients with severe disease, fresh frozen plasma (FFP) or, in current use, thawed plasma is the most readily available option but comes with risk of volume overload. We report our experience of using therapeutic plasma exchange (TPE) as an alternative perioperative management strategy. METHODS: A retrospective review of all HEM-C patients who underwent surgical procedures. Data were collected, including demographics, bleeding history, surgical site, perioperative hemostatic intervention, and outcome. RESULTS: Between July 1997 and September 2014, 28 HEM-C patients (12 men) were identified, 4 with severe disease (FXI:C <2% or excessive bleeding). Nineteen patients underwent 91 invasive procedures. For nearly 60% of the procedures, no periprocedural hemostatic intervention was provided; before 4 procedures (3 patients), 1 plasma volume TPE preoperatively with FFP was administered. Patient 1, a 28-year-old woman (FXI:C, 35%) with a history of excessive surgical bleeding, underwent 2 TPE procedures before laparoscopic pelvic biopsy and subsequent abdominal hysterectomy with salpingo-oophorectomy that increased her FXI:C to 48%. Patient 2, a 79-year-old man (FXI:C, <2%), had TPE before total hip arthroplasty, increasing his FXI:C to 24%. Patient 3, a 59-year-old man (FXI:C, <2%), had TPE before prostate laser enucleation, increasing his FXI:C to 46%. Patients 1 and 3 had mild reactions during TPE; no patient had evidence of volume overload. All patients had adequate intraoperative surgical hemostatic outcomes. CONCLUSION: TPE is an effective alternative presurgical hemostatic intervention in HEM-C with potentially lower risk of circulatory volume overload.

Preoperative management of factor XI deficiency with therapeutic plasma exchange: A case report and literature review.

Patients with factor XI deficiency may have bleeding complications during surgery. Because bleeding severity and factor levels correlate poorly, factor replacement needs to be personalized based on bleeding history and type of procedure. We report a 65-year-old male with factor XI deficiency (7 IU dL-1 ) who presented before scheduled hip arthroplasty. He had a history of total hip arthroplasty complicated by bleeding, delayed healing and prosthesis removal, despite receiving prophylactic treatment with plasma infusion. For the current surgery a factor XI ≥50 IU dL-1 level was targeted. The calculated plasma infusion needed to achieve this goal was 3100 mL (14 U). Because of concerns about circulatory overload and inability to achieve target by simple infusion, prophylactic treatment with therapeutic plasma exchange (TPE) was requested. TPE was performed the morning before the surgery, using 100% plasma as replacement fluid (3912 mL of plasma), and a positive fluid balance of 631 mL. Factor XI activity level was 51 IU dL-1 immediately post TPE. The patient received daily infusions of 3 U (∼ 660 mL) of plasma to maintain a factor XI level of 30 IU dL-1 until post-operative day 7. Aminocaproic acid was given during the surgery and until post-operative day 10. There were no bleeding or thrombotic complications. CONCLUSION: TPE was effective in increasing factor XI levels; it was well tolerated and did not result in circulatory overload. TPE can be considered when therapeutic factor levels cannot be achieved by simple plasma infusion, or when circulatory overload is a concern. J. Clin. Apheresis 31:579-583, 2016. © 2015 Wiley Periodicals, Inc.

Rare bleeding disorders - bleeding assessment tools, laboratory aspects and phenotype and therapy of FXI deficiency.

Rare bleeding disorders (RBDs) are inherited deficiencies of coagulation factors such as fibrinogen, factor (F) II, FV, FVII, combined FV+FVIII, FX, FXI and FXIII. These disorders usually have a low prevalence in the general population and constitute approximately 3-5% of all coagulation disorders. However, in some countries they may have the same prevalence as haemophilia B due to the practice of consanguineous marriage. The clinical picture of RBDs is highly variable and can vary markedly from mild to severe, making both diagnosis and optimal treatment quite challenging. This review focuses on: (i) the efforts to establish a bleeding assessment tool adequate to RBDs, (ii) the optimal management of patients affected with FXI deficiency and (iii) the correlation between clinical severity and laboratory diagnosis when determining the minimum coagulant activity required to prevent bleeding in each RBD.

Perioperative management of factor XI deficiency in a patient undergoing hip arthroplasty.

Factor XI deficiency, or hemophilia C, is a rare autosomal recessive bleeding disorder often diagnosed by inappropriate bleeding associated with trauma or a surgical procedure, and reports of anesthetic management of this disorder are rare. We experienced an 85-year-old man with femoral neck fracture who was diagnosed preoperatively with factor XI deficiency based on abnormally long activated partial thromboplastin time (APTT). He was scheduled for bipolar hip arthroplasty and was prepared for surgery by transfusion of fresh frozen plasma (FFP), instead of factor XI concentrates, which are not commercially available in Japan. Five units of FFP were transfused 6 days before surgery, and 10 units of FFP with 2 units of red concentrated cells (RCC) were used on the day of surgery. Transfusion of FFP shortened the APTT to a level sufficient to allow hemostasis, although not to within the normal range. Although the patient required transfusion of 2 units of RCC postoperatively, no bleeding complications occurred. For bipolar hip arthroplasty, transfusion of FFP produced sufficient hemostasis without the use of tranexamic acid, factor VII preparations, or desmopressin.

Congenital factor XI deficiency: an update.

Severe factor XI (FXI) deficiency is an injury-related bleeding disorder, common in Ashkenazi Jews (with two mutations prevailing), but rare worldwide (with heterogeneous mutations). In the past two decades, more than 220 mutations in the FXI gene have been reported in patients with FXI deficiency, of which 7 showed a founder effect. Inhibitors to FXI were described in patients with null-allele mutations, following exposure to plasma, FXI concentrates, or anti-RhD immunoglobulin. Treatment of patients with severe FXI deficiency remains challenging because factors influencing bleeding risks are still unknown. The use of lower doses of recombinant activated factor VII in comparison with the doses commonly applied in hemophilia A or B seems promising also when assessed in vitro by thrombin generation test. Recently, FXI has been shown to have a separate role in hemostasis and in thrombosis. In animal models, targeting FXI by knocking out the gene or by using FXI-neutralizing antibodies, antisense oligonucleotides, and peptidomimetic inhibitors, prevents arterial and vein thrombosis. The homology between human and murine FXI and the significant antithrombotic effect of FXI deficiency in animal models resulted in the development of a novel approach of targeting FXI for prevention of thrombosis without impairing hemostasis in high-risk patients. The acceptance of FXI as a risk factor for thrombosis is a new concept, and patients with severe FXI deficiency might gain profit during life course.

Factor XI Deficiency.

Factor XI (FXI) deficiency (hemophilia C or Rosenthal disease) was first described in the 1950s in a multigenerational family experiencing bleeding related to surgery and dental procedures. Managing patients with FXI deficiency presents several challenges, including a lack of correlation of bleeding symptoms with FXI activity levels, the large volume of fresh frozen plasma required to achieve hemostatic FXI levels, lack of availability of FXI concentrate in certain regions of the world, and the inherent thrombotic risk associated with replacement therapy. This article summarizes presentation, diagnosis, and management of patients with FXI deficiency in a variety of clinical settings.

How to manage bleeding disorders in aging patients needing surgery.

With improvements in medical care, the life expectancy of patients with bleeding disorders is approaching that of the general population. A growing population of older adult patients with bleeding disorders is at risk of age-related comorbidities and in need of various elective and emergent age-related procedures. The increased risk of thrombosis and volume overload in older adults complicates perioperative hemostatic management. Furthermore, antithrombotic treatment such as antiplatelet or anticoagulant therapy, which is frequently required for various cardiovascular interventions, requires a meticulous individualized approach. Evidence-based guidelines for the management of aging patients with bleeding disorders are lacking, largely due to the underrepresentation of older adult patients in clinical trials as well as the rarity of many such bleeding disorders. We discuss the current guidelines and recommendations in the perioperative hemostatic management of older adult patients with hemophilia and von Willebrand disease as well as other rare bleeding disorders. The optimal management of these patients is often complex and requires a thorough multidisciplinary and individualized approach involving hematologists, surgeons, anesthesiologists, and the specialists treating the underlying disorder.

Factor XI Deficiency in a Patient with Cervical Spondylotic Myelopathy.

STUDY DESIGN: Case report. OBJECTIVE: To summarize the clinical manifestations and treatment of Factor XI deficiency in a patient with cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: Factor XI deficiency is a rare genetic bleeding disorder caused by reduced levels and insufficient activity of a coagulation factor XI. It is claimed to be associated with prominent bleeding in case of trauma and surgery irrelevant to the FXI level. This is the first ever case of a patient with factor XI deficiency with cervical spondylotic myelopathy. METHODS: A case was investigated retrospectively and the relevant literature was reviewed. RESULTS: A 66-year-old man with a 2-months history of lack of finger dexterity and gait disturbance was referred to our department. He did not have a history of bleeding or coagulation disorder nor did his family. Magnetic resonance imaging (MRI) of the cervical spine revealed spinal canal stenosis at C3/4 to C5/6 and intramedullary hyperintensity at C3/4 on the :T2 weighted image (T2WI). Preoperative examination revealed no abnormal findings but a severe prolonged activated partial-thromboplastin time (APTT) of 139.8 seconds. Coagulation factor activity assay revealed severe deficiency of factor XI (<0.1%). In accordance with hematologist's recommendation, four units of fresh frozen plasma (FFP) were transfused on the day before surgery and APTT assayed early morning on the day of surgery was 70.5 seconds. An additional four units of FFP were transfused during the surgery and APTT was 60 seconds. The postoperative course was uneventful and the patient was discharged on the postoperative day 14. CONCLUSION: Factor XI deficiency patients may develop excessive bleeding after trauma or surgery. Preoperative examination with prolonged APTT should be pursued until a diagnosis of is made. Under diagnosis of Factor XI deficiency, meticulous attentions are required for perioperative bleeding management including postoperative hematoma in spinal surgery.Level of Evidence: 5.

The clinical management of factor XI deficiency in pregnant women.

INTRODUCTION: Factor XI (FXI) deficiency is associated with highly variable bleeding, including excessive gynecologic and obstetrical bleeding. Since approximately 20% of FXI-deficient women will experience pregnancy-related bleeding, careful planning and knowledge of appropriate hemostatic management is pivotal for their care. AREAS COVERED: In this manuscript, authors present our current understanding of the role of FXI in hemostasis, the nature of the bleeding phenotype caused by its deficiency, and the impact of deficiency on obstetrical care. The authors searched PubMed with the terms, 'factor XI', 'factor XI deficiency', 'women', 'pregnancy', and 'obstetrics' to identify literature on these topics. Expectations of pregnancy-related complications in women with FXI deficiency, including antepartum, abortion-related, and postpartum bleeding, as well as bleeding associated with regional anesthesia are discussed. Recommendations for the care of these women are considered, including guidance for management of prophylactic care and acute bleeding. EXPERT COMMENTARY: FXI deficiency results in a bleeding diathesis in some, but not all, patients, making treatment decisions and clinical management challenging. Currently available laboratory assays are not particularly useful for distinguishing patients with FXI deficiency who are prone to bleeding from those who are not. There is a need for alternative testing strategies to address this limitation.

The obstetric experience of women with factor XI deficiency.

OBJECTIVES. To assess the obstetric outcome in women with factor XI (FXI) deficiency. DESIGN. Retrospective review of medical records. SETTING. Tertiary referral university hospital. POPULATION. Women with FXI deficiency. METHOD. Review of pregnancies over a 10-year period (1997-2006). Main outcome measures. Pregnancy outcome, mode of delivery, changes in FXI levels during pregnancy, use of prophylaxis during labor and delivery, antepartum hemorrhage, and postpartum hemorrhage (PPH). RESULTS. There were 61 pregnancies among 30 women with FXI deficiency (two severe, FXI level <15-20 IU/dL, and 28 partial, FXI level 20-70 IU/dL) resulting in 49 live births (two sets of twins), eight miscarriages, and six terminations of pregnancy. The modes of delivery included 38 spontaneous vaginal deliveries, three instrumental deliveries, and six cesarean sections (two emergency and four elective). No significant change in FXI levels was observed during pregnancy. Intrapartum prophylaxis with FXI concentrate or tranexamic acid was given in 19 deliveries where the mother had a positive bleeding history. Four women had excessive bleeding related to pregnancy loss and three experienced antepartum bleeding. All these women had a positive bleeding history. There were five (11%) primary and five (11%) secondary PPHs among seven women including four with a positive bleeding history. CONCLUSION. Women with FXI deficiency, particularly those with a positive bleeding history, are at risk of bleeding complications related to miscarriage or childbirth. The unpredictable nature of their bleeding tendency demands careful planning and close collaborations between obstetricians and hematologists.

Peri- and Postpartum Management of Patients With Factor XI Deficiency.

Factor XI (FXI) deficiency is an uncommon autosomal disorder with variable bleeding phenotype, making peripartum management challenging. We describe our experience in pregnant women with FXI deficiency and identify strategies to minimize the use of hemostatic agents and increase utilization of neuraxial anesthesia. Electronic records of 28 pregnant women with FXI deficiency seen by a hematology service in an academic medical center from January 2006 to August 2018 were reviewed. Data on bleeding, obstetric history, peripartum management, and FXI activity were collected. Partial FXI deficiency was defined as >20 IU/dL and severe <20 IU/dL. Median FXI activity was 42 IU/dL (range <1-73 IU/dL), and median activated partial thromboplastin time was 32.2 seconds (range: 27.8-75 seconds). There were 64 pregnancies: 53 (83%) live births and 11 (17%) pregnancy losses. Postpartum hemorrhage occurred in 9 (17%) pregnancies. Antifibrinolytic agents and fresh frozen plasma were used only in women with severe deficiency (42% with bleeding and 17% with no bleeding phenotype, respectively). Neuraxial anesthesia was successfully administered in 32 (59%) deliveries. Most women with FXI deficiency have uncomplicated pregnancies and deliveries with minimal hemostatic support. Neuraxial anesthesia can be safely administered in most women.

Single Low Dose of rFVIIa Combined with Antifibrinolytic Agent is a Simple and Safe Treatment for Factor XI-Deficient Patients undergoing Surgery.

BACKGROUND: Factor XI (FXI) deficiency is a rare autosomal bleeding disorder. The rarity of spontaneous bleeding and absence of optimal tools to predict the bleeding risk in FXI-deficient patients hamper the standardization of prophylactic treatment enabling them to undergo major surgeries without blood products. OBJECTIVES: We explored the effectiveness of a single and very low dose of recombinant factor VIIa (rFVIIa) along with tranexamic acid (TXA) as prophylactic treatment for FXI-deficient patients undergoing various types of surgery at various sites of injury. We studied the potential use of thrombin generation (TG) as a surrogate tool for predicting thrombogenicity. PATIENTS AND METHODS: Our cohort consisted of 10 patients with severe FXI deficiency undergoing 12 interventions. Patients received a single dose of 10 to 15 µg/kg rFVIIa at the end of surgery in addition to TXA initiated 2 hours before surgery at the dose of 4 g/day for 3 to 5 days. TG was tested before and 30 minutes after rFVIIa administration. RESULTS: All operations were uneventful and none of the patients bled excessively or required blood products. No thrombotic event was reported, and the postoperative hospitalization duration was comparable to that of patients without bleeding disorders. TG performed at the peak of rFVIIa was below the curve of healthy controls, thus confirming that the administered dose was not thrombogenic. CONCLUSION: A single very low dose of rFVIIa along with TXA is a simple and safe treatment to control hemostasis in severe FXI-deficient patients undergoing diverse type of surgical procedure at various sites.