Rare bleeding disorders

Cellular and molecular mechanisms of skin wound healing

Wound healing is a complex process that involves the coordinated actions of many different tissues and cell lineages. It requires tight orchestration of cell migration, proliferation, matrix deposition and remodelling, alongside inflammation and angiogenesis. Whereas small skin wounds heal in days, larger injuries resulting from trauma, acute illness or major surgery can take several weeks to heal, generally leaving behind a fibrotic scar that can impact tissue function. Development of therapeutics to prevent scarring and successfully repair chronic wounds requires a fuller knowledge of the cellular and molecular mechanisms driving wound healing. In this Review, we discuss the current understanding of the different phases of wound healing, from clot formation through re-epithelialization, angiogenesis and subsequent scar deposition. We highlight the contribution of different cell types to skin repair, with emphasis on how both innate and adaptive immune cells in the wound inflammatory response influence classically studied wound cell lineages, including keratinocytes, fibroblasts and endothelial cells, but also some of the less-studied cell lineages such as adipocytes, melanocytes and cutaneous nerves. Finally, we discuss newer approaches and research directions that have the potential to further our understanding of the mechanisms underpinning tissue repair.

Comparative analysis of thrombin generation platforms for patients with coagulation factor deficiencies: A comprehensive assessment

INTRODUCTION

Thrombin generation assays (TGAs) assess the overall functionality of the hemostatic system and thereby provide a reflection of the hemostatic capacity of patients with disorders in this system. Currently, four (semi-)automated TGA platforms are available: the Calibrated Automated Thrombogram, Nijmegen Hemostasis Assay, ST Genesia and Ceveron s100. In this study, we compared their performance for detecting patients with congenital single coagulation factor deficiencies.

MATERIALS AND METHODS

Pooled patient samples, healthy control samples and normal pooled plasma were tested on all four platforms, using the available reagents that vary in tissue factor and phospholipid concentrations. The TGA parameters selected for analysis were peak height and thrombin potential. Results were normalized by using the calculated mean of healthy controls and a correction for between-run variation. Outcomes were presented as relative values, with the mean of healthy controls standardized to 100 %.

RESULTS

Across all platforms and reagents used, thrombin potentials and peak heights of samples with coagulation factor deficiencies were lower than those of healthy controls. Reagents designed for bleeding tendencies yielded the lowest values on all platforms (relative median peak height 19-32 %, relative median thrombin potential 19-45 %). Samples representing more severe coagulation factor deficiencies generally exhibited lower relative peak heights and thrombin potentials.

CONCLUSIONS

Thrombin generation assays prove effective in differentiating single coagulation factor deficient samples from healthy controls, with modest discrepancies observed between the platforms. Reagents designed for assessing bleeding tendencies, featuring the lowest tissue factor and phospholipid concentrations, emerged as the most suitable option for detecting coagulation factor deficiencies.

Heterozygosity in factor XIII genes and the manifestation of mild inherited factor XIII deficiency

BACKGROUND

The characterization of inherited mild factor XIII deficiency is more imprecise than its rare, inherited severe forms. It is known that heterozygosity at FXIII genetic loci results in mild FXIII deficiency, characterized by circulating FXIII activity levels ranging from 20% to 60%. There exists a gap in information on 1) how genetic heterozygosity renders clinical bleeding manifestations among these individuals and 2) the reversal of unexplained bleeding upon FXIII administration in mild FXIII-deficient individuals.

OBJECTIVES

To assess the prevalence and burden of mild FXIII deficiency among the apparently healthy German-Caucasian population and correlate it with genetic heterozygosity at FXIII and fibrinogen gene loci.

METHODS

Peripheral blood was collected from 752 donors selected from the general population with essentially no bleeding complications to ensure asymptomatic predisposition. These were assessed for FXIII and fibrinogen activity, and FXIII and fibrinogen genes were resequenced using next-generation sequencing. For comparison, a retrospective analysis was performed on a cohort of mild inherited FXIII deficiency patients referred to us.

RESULTS

The prevalence of mild FXIII deficiency was high (∼0.8%) among the screened German-Caucasian population compared with its rare-severe forms. Although no new heterozygous missense variants were found, certain combinations were relatively dominant/prevalent among the mild FXIII-deficient individuals.

CONCLUSION

This extensive, population-based quasi-experimental approach revealed that the burden of heterozygosity in FXIII and fibrinogen gene loci causes the clinical manifestation of inherited mild FXIII deficiency, resulting in ''unexplained bleeding'' upon provocation.

Treatment of congenital coagulopathies, from biologic to biotechnological drugs: The relevance of gene editing (CRISPR/Cas)

Congenital coagulopathies have, throughout the history of medicine, been a focus of scientific study and of great interest as they constitute an alteration of one of the most important and conserved pathways of evolution. The first therapeutic strategies developed to address them were aimed at restoring the blood components lost during hemorrhage by administering whole blood or plasma. Later on, the use of cryoprecipitates was a significant breakthrough as it made it possible to decrease the volumes of blood infused. In the 1970' and 80', clotting factor concentrates became the treatment and, from the 1990's to the present day, recombinant factors -with increasingly longer half-lives- have taken over as the treatment of choice for certain coagulopathies in a seamless yet momentous transition from biological to biotechnological drugs. The beginning of this century, however, saw the emergence of new advanced (gene and cell) treatments, which are currently transforming the therapeutic landscape. The possibility to use cells and viruses as well as specific or bispecific antibodies as medicines is likely to spark a revolution in the world of pharmacology where therapies will be individualized and have long-term effects. Specifically, attention is nowadays focused on the development of gene editing strategies, chiefly those based on CRISPR/Cas technology. Rare coagulopathies such as hemophilia A and B, or even ultra-rare ones such as factor V deficiency, could be among those deriving the greatest benefit from these new developments.

The rare case of double valve surgery in a patient with factor VII deficiency

Performing cardiac surgery on patients with bleeding diatheses poses significant challenges since these patients are at an increased risk for complications secondary to excessive bleeding. Despite its rarity, patients with factor VII (FVII) deficiency may require invasive procedures such as cardiac surgery. However, we lack guidelines on their pre-, peri-, and post-operative management. As FVII deficiency is rare, it seems unlikely to design and learn from large clinical studies. Instead, we need to base our clinical decision-making on single reported cases and registry data. Herein, we present the rare case of a patient with FVII deficiency who underwent double valve surgery. Pre-operatively, activated recombinant FVII (rFVIIa) was administered to reduce the risk of bleeding. Nevertheless, the patient experienced major bleeding. This case highlights the significance of FVII deficiency in patients undergoing cardiac surgery and emphasizes the importance of adequate and appropriate transfusion of blood products for these patients.

Treatment of Congenital Afibrinogenemia in a Neonate With Critical Pulmonary Stenosis

Fibrinogen deficiencies in neonates can lead to bleeding complications. In this report, we describe a case of congenital afibrinogenemia in a newborn with critical pulmonary stenosis who presented with bilateral cephalohematomas after an uncomplicated delivery. The initial use of cryoprecipitate was followed by administration of fibrinogen concentrate. We estimated a half-life of 24 to 48 hours with the concentrate product. This patient received fibrinogen replacement and had a subsequent successful cardiac repair. The drug's shorter half-life in this neonate contrasts with prior reports of longer half-life in older patients and is important to note in treating future neonatal patients with this diagnosis.

Pharmacokinetics, efficacy and safety of a novel fibrinogen concentrate in pediatric patients with congenital afibrinogenemia

INTRODUCTION

Congenital afibrinogenemia treatment with plasma-derived fibrinogen concentrates in pediatric patients is limited. This study investigated the pharmacokinetics, surrogate efficacy, and safety of a plasma-derived fibrinogen concentrate (FIB Grifols) in pediatric patients with congenital afibrinogenemia.

METHODS

Patients aged <18 years old diagnosed with congenital afibrinogenemia were included in this prospective, multinational, phase 1-2, single-arm study. After a single dose of a plasma-derived fibrinogen concentrate (70 mg/kg body weight), pharmacokinetic parameters were determined from plasma fibrinogen activity (Clauss method) and antigen method (ELISA), and calculated by noncompartmental and population pharmacokinetic (popPK) models. Patients were followed up over 14 days. Efficacy variables were the mean change on thromboelastographic variables (maximum clot firmness [MCF], alpha angle [ α ]) and coagulation tests (prothrombin time, activated partial thromboplastin time, and thrombin time) 1 h postinfusion. Safety parameters were assessed.

RESULTS

Eleven patients with a median (range) age 8.80 (3.7-12.7) years were treated with the plasma-derived fibrinogen concentrate. Using the popPK modeling, fibrinogen activity reached a mean (standard deviation) Cmax of 1.3 (0.225) g/l, half-life ( t1/2 ) of 60.6 (4.48) h and incremental in vivo recovery (IVR) of 1.86 (0.322) (mg/dl)/(mg/kg). Surrogate efficacy was demonstrated by significant increase in MCF (9.23 [3.94] mm; P  < 0.001; 95% confidence interval 6.58, 11.87). All coagulation times were significantly shortened after fibrinogen concentrate infusion. Adverse events were mild or moderate in severity, and unrelated to fibrinogen concentrate.

CONCLUSIONS

In pediatric patients with congenital afibrinogenemia, plasma-derived fibrinogen concentrate revealed a favorable and specific pharmacokinetic profile, demonstrated efficacy in coagulation and was safe and well tolerated.

Compound Heterozygous Mutations in the F7 Gene in 2 Unrelated Families With Congenital Factor VII Deficiency

Factor VII (FVII) deficiency is a rare bleeding disorder normally caused by homozygous and compound heterozygous mutations in the F7 gene. Whole-exome sequencing was performed to identify F7 mutations in 3 individuals from 2 unrelated families who were diagnosed with FVII deficiency. Four compound heterozygous mutations were identified and validated in these 3 probands with FVII deficiency. Among the 4 identified mutations, NM_000131.4:c.572-1_581del, NM_000131.4:c.1250A>G (p.Tyr417Cys), and NM_000131.4:c.647G>T (p.Gly216Val) were novel. All 3 novel mutations were predicted to be likely pathogenic by the American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines.

Diagnosing rare bleeding disorders

Rare bleeding disorders (RBDs) comprise the inherited deficiencies of coagulation factors such as fibrinogen, factor (F)II, FV, FV fl FVIII, FVII, FX, FXI, and FXIII, and are usually transmitted as autosomal recessive disorders. Given the low prevalence of these coagulopathies, information about their genetic, clinical and laboratory characteristics is limited. The clinical symptoms of RCDs are extremely diverse in terms of bleeding type, site, severity, age at onset, and duration. The weak association between residual coagulant activity and clinical bleeding severity, or at times inexistent, correlation between the factor's residual levels and clinical manifestations in some RBDs makes it difficult to use a single criterion to classify such conditions. Standardization and customization of coagulation assays, full genome sequencing, and global clotting assays will significantly improve diagnosis of patients with RBDs.

Pharmacokinetics, surrogate efficacy and safety evaluations of a new human plasma-derived fibrinogen concentrate (FIB Grifols) in adult patients with congenital afibrinogenemia

BACKGROUND AND AIMS

Congenital afibrinogenemia is a rare coagulation disorder resulting from a deficiency in fibrinogen. This study assessed the pharmacokinetics, surrogate efficacy and safety of FIB Grifols, a new human plasma-derived fibrinogen concentrate, to treat congenital afibrinogenemia.

METHODS

Eleven adult patients from a multinational, phase 1-2, prospective, open-label, single-arm, uncontrolled clinical study received a single infusion of FIB Grifols, 70 mg/kg bw. Fibrinogen pharmacokinetics (fibrinogen activity: Clauss method; antigen plasma concentrations: ELISA) and efficacy parameters were determined over 14 days after infusion. Efficacy endpoints were the mean change on plasma maximum clot firmness (MCF) on viscoelastic testing and coagulation tests 1-hour post-infusion, and correlation with fibrinogen levels throughout. Safety parameters were also assessed.

RESULTS

For the Clauss method, (mean [standard deviation]) baseline adjusted C_max was 1.99 (0.40) g/L, reached 1.76 (1.00) h after infusion, and half-life was 76.94 (20.21) h. Using ELISA, C_max after FIB Grifols infusion was 2.88 (0.86) mg/mL, with a t_max of 3.06 (2.24) h. Fibrinogen activity and antigen concentrations showed statistically significant correlation of 0.9120 (P < 0.001). Surrogate efficacy was demonstrated by a significant increase of 12.35 (3.85) mm in MCF. Prothrombin time, activated partial thromboplastin time and thrombin time, returned to normal ranges over time, indicating restoration of functionally active fibrinogen. There were no treatment-related adverse events, allergic reactions, serious adverse events, or discontinuations.

CONCLUSIONS

The pharmacokinetic profile of functionally active FIB Grifols was established, hemostasis was restored, and FIB Grifols was safe and well tolerated in fibrinogen-deficient patients.

Mining of mortality-related findings in rare bleeding disorders: a retrospective study from two centers

BACKGROUND

Rare bleeding disorders include inherited coagulation disorders except for von Willebrand disease and hemophilia A and B. These disorders affect both men and women worldwide and mainly have an autosomal recessive pattern of inheritance. Given the paucity of cases of rare bleeding disorders, there are limited data regarding some topics among bleeding disorders.

METHODS

This retrospective study from 2005-2019 collected demographic data and the causes of death among cases with rare bleeding disorders from 2 provinces of Iran.

RESULTS

Overall, 5 deaths were reported, including 3 cases with factor V deficiency, a case with factor XIII deficiency, and a case with combined factor V and factor VIII deficiencies. The main causes of death were bleeding in the central nervous system (2 cases; 1 with factor V deficiency and 1 with combined factor XIII deficiency). Post-partum hemorrhage was the cause of death in a woman with factor V deficiency while anaphylaxis shock was the cause of death in the case with combined factor V and factor VIII deficiencies. A woman with factor V deficiency died from an internal bleeding episode.

CONCLUSION

Gathering data on the causes of death in rare bleeding disorders through worldwide registries can be helpful for the management of this rare group of bleeding disorders.

Fibrinogen concentrate for treatment of bleeding and surgical prophylaxis in congenital fibrinogen deficiency patients

BACKGROUND

Congenital fibrinogen deficiency is an ultra-rare disorder in which patients can experience severe and/or frequent bleeding episodes (BEs). Here, we present the largest prospective study to date on the treatment of this disorder.

METHODS

Hemostatic efficacy of human fibrinogen concentrate (HFC; FIBRYGA® , Octapharma AG) for treatment of bleeding or surgical prophylaxis was assessed by investigators and adjudicated by an independent data monitoring and endpoint adjudication committee (IDMEAC) according to a four-point scale, using objective criteria. Thromboelastometry maximum clot firmness (MCF) was also determined.

RESULTS

Twenty-five afibrinogenemia patients were treated with HFC: 24 for on-demand treatment of 89 BEs, and nine as prophylaxis for 12 surgeries. For BEs, treatment success (rating of excellent or good) evaluated by investigators was 96.6% (90% confidence interval [CI], 0.92-0.99; two missing ratings, classified as failures) and by the IDMEAC was 98.9% (90% CI, 0.95-0.999). Mean ± standard deviation (SD) increase in MCF was 5.8 ± 2.5 mm one hour after the first HFC infusion (mean ± SD dose, 61.88 ± 11.73 mg/kg). For the 12 surgeries (median [range] HFC dose/surgery, 85.80 mg/kg [34.09-225.36]), intraoperative and postoperative treatment success were both rated 100% (90% CI, 0.82-1.00) by investigators and the IDMEAC. Three adverse events were possibly treatment related, including a moderate case of thrombosis. There were no deaths, no severe allergic or hypersensitivity reactions, and no clinical evidence of neutralizing antifibrinogen antibodies.

CONCLUSIONS

Human fibrinogen concentrate was efficacious for on-demand treatment of bleeding and as surgical prophylaxis, with a favorable safety profile, in patients with congenital afibrinogenemia.

Plasma Fibrin Clot Properties as Determinants of Bleeding Time in Human Subjects: Association with Histidine-Rich Glycoprotein

Aims

Fibrin formation and histidine-rich glycoprotein (HRG) are involved in primary hemostasis and wound healing. Little is known regarding the relationship of clot characteristics, bleeding time, and wound healing.

Methods and Results

We studied 154 patients with coronary artery disease (CAD) and 154 subjects free of CAD matched for age, obesity, and current smoking. We evaluated bleeding time (BT) using standardized skin incisions on a forearm, along with plasma clot permeability (K_s), clot lysis time (CLT), and histidine-rich glycoprotein (HRG). Compared with controls, BT was 45% shorter in CAD cases. CAD patients had 32% lower K_s), clot lysis time (CLT), and histidine-rich glycoprotein (HRG). Compared with controls, BT was 45% shorter in CAD cases. CAD patients had 32% lower p < 0.001). After adjusting for potential confounders, K_s), clot lysis time (CLT), and histidine-rich glycoprotein (HRG). Compared with controls, BT was 45% shorter in CAD cases. CAD patients had 32% lower n = 79, 25.6%) was independently predicted by both short and prolonged BT in CAD cases (OR 21.87, 95% CI 7.41-64.55 and OR 10.17, 95% CI 2.88-35.97) and controls (OR 5.94, 95% CI 2.29-15.41 and OR 14.76, 95% CI 4.29-50.77, respectively).

Conclusions

The study shows that plasma fibrin clot density and HRG may influence BT and that appropriate skin wound healing is associated with medium BT. Translational Perspective. Elucidation of the complex relationships between plasma fibrin clot phenotype and wound healing might have important practical implications.

Unprovoked Pulmonary Embolism in Factor VII Deficiency

Thrombotic events in bleeding disorders such as hemophilia A or B, Von Willebrand disease, afibrinogenemia, factor VII deficiency, and factor XI deficiency are rare but have been reported. These events usually occur in the presence of prothrombotic risk factors such as recent surgery, trauma, or factor replacement therapy. We present a case of a 68-year-old Hispanic female with a history of factor VII deficiency who presented with shortness of breath, chest pain, and palpitations and was found to have pulmonary embolism. Our patient did not have any of the above-mentioned thrombotic risk factors. Our case and review of the literature show that factor VII deficiency does not provide protection against thrombosis.

A new perspective on perioperative coagulation management in a patient with congenital factor VII deficiency: A case report

RATIONALE

Congenital factor VII (FVII) deficiency is a rare coagulopathy. There are little clinical data for congenital FVII deficiency and no evidence-based medicine guidelines for treatment.

PATIENT CONCERNS

A 48-year-old woman with gallbladder stones suffered from intermittent abdominal pain for 2 months that was accompanied by an abnormally prolonged prothrombin time.

DIAGNOSES

The woman was diagnosed as having cholecystolithiasis with cholecystitis and congenital FVII deficiency.

INTERVENTION

Preoperative evaluation confirmed the necessity of recombinant activated factor VII (rFVIIa) replacement therapy. We monitored the plasma factor VII activity (FVII:C) and coagulation function, determined the half-life of rFVIIa in the patient, and administered personalized rFVIIa replacement therapy.

OUTCOMES

Laparoscopic cholecystectomy was performed successfully, and the patient recovered well without any complications.

LESSONS

The clinical manifestations and severity of bleeding in patients with congenital FVII deficiency can vary widely. The history of massive bleeding and plasma FVII:C are the decisive factors when implementing a replacement therapy. The actual half-life of rFVIIa can be determined from intensive monitoring results of plasma FVII:C at the beginning of replacement therapy, which could further guide the personalization of rFVIIa replacement therapy.

Pharmacokinetics, clot strength and safety of a new fibrinogen concentrate: randomized comparison with active control in congenital fibrinogen deficiency

Essentials Congenital afibrinogenemia causes a potentially life-threatening bleeding and clotting tendency. Two human fibrinogen concentrates (HFCs) were compared in a randomized pharmacokinetic study. Bioequivalence was not shown for AUCnorm , which was significantly larger for the new HFC. Increases in clot strength were comparable, and no thromboses or deaths occurred in the study.

SUMMARY

Background Human fibrinogen concentrate (HFC) corrects fibrinogen deficiency in congenital a-/hypofibrinogenemia. Objectives To assess pharmacokinetics (PK), effects on thromboelastometry maximum clot firmness (MCF), and safety of a new double virus-inactivated/eliminated, highly purified HFC vs. active control. Patients/Methods In this multinational, randomized, phase II, open-label, crossover study in 22 congenital afibrinogenemia patients aged ≥ 12 years, 70 mg kg-1 of new HFC (FIBRYGA, Octapharma AG) or control (Haemocomplettan® P/RiaSTAP™, CSL Behring GmbH) were administered, followed by crossover to the other concentrate. Fibrinogen activity, PK and MCF in plasma were assessed. Results The concentrates were not bioequivalent for the primary endpoint, AUCnorm (mean ratio, 1.196; 90% confidence interval [CI], 1.117, 1.281). Remaining PK parameters (Cmaxnorm , IVR, t1/2 , MRT) reflected bioequivalence between concentrates, except for clearance (mean ratio, 0.836; 90% CI, 0.781, 0.895) and Vss (mean ratio, 0.886; 90% CI, 0.791, 0.994). Mean AUCnorm was significantly larger for the new HFC (1.62 ± 0.45 vs. 1.38 ± 0.47 h kg g L-1  mg-1 , P = 0.0001) and mean clearance was significantly slower (0.665 ± 0.197 vs. 0.804 ± 0.255 mL h-1  kg-1 , P = 0.0002). Mean MCF increased from 0 mm to 9.68 mm (new HFC) and 10.00 mm (control) 1-hour post-infusion (mean difference, -0.32 mm; 95% CI, -1.70, 1.07, n.s.). No deaths, thromboses, viral seroconversions or serious related adverse events occurred. Conclusions Bioequivalence was not demonstrated for AUCnorm , clearance and Vss . Larger AUCnorm and slower clearance were observed for the new HFC. Remaining pharmacokinetic parameters reflected bioequivalence to control. Safety profiles and increases in clot strength were comparable between concentrates.

High proportion of patients with bleeding of unknown cause in persons with a mild-to-moderate bleeding tendency: Results from the Vienna Bleeding Biobank (VIBB)

INTRODUCTION

Data on clinical characteristics and the prevalence of underlying coagulopathies in patients with mild-to-moderate bleeding disorders (MBDs) are scarce.

AIM

We established the Vienna Bleeding Biobank (VIBB) to characterize and thoroughly investigate Austrian patients with MBDs.

RESULTS

Four hundred eighteen patients (female = 345, 82.5%) were included. A platelet function defect (PFD) was diagnosed in 26 (6.2%) and a possible PFD in 30 (7.2%) patients. Eight patients (1.9%) were diagnosed with von Willebrand disease (VWD) (type 1 n = 6; type 2 n = 2), and 29 patients had low VWF (30-50 IU/dL). Deficiencies in factor VIII, IX, XI or XIII were found in 11 (2.6%), 3 (0.7%), 3 (0.7%) and 1 patient(s), 2 patients had dysfibrinogenaemia, and further 2 had possible PFD and FXI deficiency. Probable causal mutations were detected in 8 of 11 patients with FVIII deficiency, 2 of 3 patients with FIX deficiency and 2 of 8 patients with VWD. Three hundred three patients (72.5%) had normal results in the coagulation assays and were categorized as patients with bleeding of unknown cause (BUC). The bleeding score did not differ between patients with and without established diagnosis. A diagnosis of a bleeding disorder was more frequently made in men than in women (49.3% vs 22.9%). Male sex (OR 3.55, 95% CI: 2.02-6.22; P < .001) and blood group 0 (OR 1.86, 95% CI: 1.17-2.94; P = .008) were independently associated with diagnosis of a bleeding disorder.

CONCLUSION

The high rate of patients with BUC despite in-depth haemostatic assessment underlines the incompleteness of available routine laboratory tests. Males with MBDs were more likely to be diagnosed with an established bleeding disorder than females.

Anticoagulation beyond direct thrombin and factor Xa inhibitors: indications for targeting the intrinsic pathway?

Antithrombotic drugs like vitamin K antagonists and heparin have been the gold standard for the treatment and prevention of thromboembolic disease for many years. Unfortunately, there are several disadvantages of these antithrombotic drugs: they are accompanied by serious bleeding problems, it is necessary to monitor the therapeutic window, and there are various interactions with food and other drugs. This has led to the development of new oral anticoagulants, specifically inhibiting either thrombin or factor Xa. In terms of effectiveness, these drugs are comparable to the currently available anticoagulants; however, they are still associated with issues such as bleeding, reversal of the drug and complicated laboratory monitoring. Vitamin K antagonists, heparin, direct thrombin and factor Xa inhibitors have in common that they target key proteins of the haemostatic system. In an attempt to overcome these difficulties we investigated whether the intrinsic coagulation factors (VIII, IX, XI, XII, prekallikrein and high-molecular-weight kininogen) are superior targets for anticoagulation. We analysed epidemiological data concerning thrombosis and bleeding in patients deficient in one of the intrinsic pathway proteins. Furthermore, we discuss several thrombotic models in intrinsic coagulation factor-deficient animals. The combined results suggest that intrinsic coagulation factors could be suitable targets for anticoagulant drugs.

Bone Density Status in Bleeding Disorders: Where Are We and What Needs to Be Done?

Bleeding disorders, including hemophilia, can be seen in every ethnic population in the world. Among various bleeding disorders, reduced bone density has been addressed in hemophilia A. In recent years, there has been an increasing interest in addressing osteopenia and osteoporosis in hemophilia A. There is little or no study about the possible susceptibility of other individuals with bleeding disorders to reduced bone density. Questions have been raised about the role of blood coagulation factors in bone mineralization. This review provides new insight and ideas for further survey in the field of bleeding disorders and reduced bone density.

Factor VII Deficiency: Clinical Phenotype, Genotype and Therapy

Factor VII deficiency is the most common among rare inherited autosomal recessive bleeding disorders, and is a chameleon disease due to the lack of a direct correlation between plasma levels of coagulation Factor VII and bleeding manifestations. Clinical phenotypes range from asymptomatic condition—even in homozygous subjects—to severe life-threatening bleedings (central nervous system, gastrointestinal bleeding). Prediction of bleeding risk is thus based on multiple parameters that challenge disease management. Spontaneous or surgical bleedings require accurate treatment schedules, and patients at high risk of severe hemorrhages may need prophylaxis from childhood onwards. The aim of the current review is to depict an updated summary of clinical phenotype, laboratory diagnosis, and treatment of inherited Factor VII deficiency.

Anticoagulation Therapy Considerations in Factor VII Deficiency

Factor VII (FVII) deficiency is the most prevalent rare bleeding disorder in the USA and affects approximately 1 out of every 500,000 people. Warfarin inhibits the synthesis of FVII, in addition to other clotting factors. Warfarin is contraindicated in patients with bleeding tendencies or blood dyscrasias; therefore, the literature regarding the use of warfarin in FVII deficiency is very limited. We report a successful re-challenge of warfarin therapy in a patient with FVII deficiency. A 70-year-old woman with FVII deficiency experienced a significant decrease in FVII activity and subsequent vaginal bleeding roughly 5 weeks after starting warfarin for atrial fibrillation. The patient was switched to aspirin therapy. Nearly 4 years later, warfarin therapy was re-attempted by a different haematologist. After 9 months, FVII activity remained in an acceptable range and no bleeding events had occurred. In addition, once the maintenance dose was established, the international normalized ratio remained within the goal range (1.5-2.0) for the majority of assessments. Regarding future considerations, we hypothesize that anticoagulants that do not directly affect FVII, such as the direct oral anticoagulants, would carry less risk of bleeding complications and therefore may be safer alternatives to warfarin to reduce the risk of thromboembolic stroke in patients with atrial fibrillation and FVII deficiency.

Pharmacogenomics and pharmacogenetics for the intensive care unit: a narrative review

PURPOSE

Knowledge of how alterations in pharmacogenomics and pharmacogenetics may affect drug therapy in the intensive care unit (ICU) has received little study. We review the clinically relevant application of pharmacogenetics and pharmacogenomics to drugs and conditions encountered in the ICU.

SOURCE

We selected relevant literature to illustrate the important concepts contained within.

PRINCIPAL FINDINGS

Two main approaches have been used to identify genetic abnormalities - the candidate gene approach and the genome-wide approach. Genetic variability in response to drugs may occur as a result of alterations of drug-metabolizing (cytochrome P [CYP]) enzymes, receptors, and transport proteins leading to enhancement or delay in the therapeutic response. Of relevance to the ICU, genetic variation in CYP-450 isoenzymes results in altered effects of midazolam, fentanyl, morphine, codeine, phenytoin, clopidogrel, warfarin, carvedilol, metoprolol, HMG-CoA reductase inhibitors, calcineurin inhibitors, non-steroidal anti-inflammatory agents, proton pump inhibitors, and ondansetron. Changes in cholinesterase enzyme function may affect the disposition of succinylcholine, benzylisoquinoline muscle relaxants, remifentanil, and hydralazine. Genetic variation in transport proteins leads to differences in the response to opioids and clopidogrel. Polymorphisms in drug receptors result in altered effects of β-blockers, catecholamines, antipsychotic agents, and opioids. Genetic variation also contributes to the diversity and incidence of diseases and conditions such as sepsis, malignant hyperthermia, drug-induced hypersensitivity reactions, cardiac channelopathies, thromboembolic disease, and congestive heart failure.

CONCLUSION

Application of pharmacogenetics and pharmacogenomics has seen improvements in drug therapy. Ongoing study and incorporation of these concepts into clinical decision making in the ICU has the potential to affect patient outcomes.

Quality of Life in Children and Adolescents With Rare Bleeding Disorders in Southern Iran

The aim of this study is to evaluate quality of life (QOL) in patients with rare bleeding disorders (RBDs). In this cross-sectional study, 52 consecutive children aged between 4 and 18 years old with RBDs registered at the Haemophila Center of Fars province in Southern Iran were investigated from January to April 2015. Quality of life was evaluated using Haemo-QOL questionnaire. Final score is defined between 0 and 100, and higher score of QOL shows worse condition. P value less than .05 was considered statistically significant. Mean age of the patients was 13.96 ± 4.50 and ranged from 4 to 18 years old including 28 males and 24 females. Family and friends were the 2 most impaired domains of Haemo-QOL in these patients. In univariate analysis, bleeding severity based on bleeding score, health status, and being bothered by the disease showed statistically significant correlations with QOL of the patients ( P < .05). In multiple linear regression models, only degree of being bothered by the disease was determined as an independent influencing factor on QOL. Taking together, Haemo-QOL of children with RBDs was better than what was reported in patients with hemophilia in our region, but it was worse than that reported in patients with hemophilia in other developing and developed countries. Due to chronic feature of bleeding disorders, more attention to different aspects of the disease, especially in 2 dimensions of family and friends through considering educational and psychological program for the patients and their family, are recommended to improve QOL of the patients with RBDs.

Eptacog alfa activated: a recombinant product to treat rare congenital bleeding disorders

Glanzmann's thrombasthenia (GT) and congenital factor VII deficiency (FVII CD) are rare autosomal recessive bleeding disorders: GT is the most frequent congenital platelet function disorder, and FVII CD is the most common factor-deficiency disease after haemophilia. The frequency of these disorders in the general population ranges from 1:500,000 to 1:2,000,000. Because GT and FVII CD are both rare, registries are the only approach possible to allow the collection and analysis of sufficient observational data. Recombinant activated factor VII (rFVIIa, eptacog alfa activated) is indicated for the treatment of acute bleeding episodes and for surgery coverage in patients with GT who are refractory to platelets and have antiplatelet or anti-human leukocyte antigen (HLA) antibodies, and for the prevention and treatment of bleeding in patients with FVII CD. This article summarises published data on the mechanism of action and use of rFVIIa in these disorders from two international, prospective, observational registries: the Glanzmann's Thrombasthenia Registry (GTR) for GT; and the Seven Treatment Evaluation Registry (STER) for FVII CD. Haemostatic effectiveness rates with rFVIIa were high across all patients with GT and those with FVII CD, and treatment with rFVIIa in the GTR and STER registries was well tolerated. The GTR and the STER are the largest collections of data in GT and FVII CD, respectively, and have expanded our knowledge of the management of these two rare bleeding disorders.

[Hereditary afibrinogenemia: A literature review and clinical observations]

Afibrinogenemia is a rare congenital coagulopathy that leads to life-threatening bleeding. In afibrinogenemia, plasma fibrinogen levels are less than 0.1 g/L. The clinical manifestations of the disease can be both bleeding and thromboses of different localizations, which is determined by the multifunctional role of fibrinogen in hemostasis. The described cases demonstrate different clinical phenotypes of the disease. In both cases the diagnosis was confirmed by genetic examinations that revealed homozygous mutations in the fibrinogen A genes. The nature of the mutations assumes consanguineous marriages, as confirmed by the results of a genealogical analysis. Fibrinogen preparations are promising in treating afibrinogenemia in Russia.

How do we encounter rare factor deficiencies in children? Single-centre results from Turkey

BACKGROUND

Rare factor deficiencies (RFDs) are autosomal recessively inherited coagulation factor deficiencies encountered at a frequency of between one in 500, 000 and one in two million.

MATERIALS AND METHODS

One hundred and ninety-two patients, diagnosed as having RFD, followed and treated in our clinic between 1990 and 2013 were retrospectively evaluated in this study.

RESULTS

From the 192 patients, 142 had FVII, 15 had FX, 14 had FXI, 10 had fibrinogen, six had FV, two had FXIII, two had FV + FVIII and one had FII deficiency. One hundred and thirty of the cases were boys and 62 were girls. The age range was 2 weeks to 24 years and the ages at the admission were between 2 weeks and 16 years. The rate of consanguinity was 49.4%. Eighty-eight of our patients were asymptomatic (45.8%) and 104 were symptomatic (54.2%). Asymptomatic patients were diagnosed by family histories (39.8%), preoperative laboratory studies (54.6%) and operational bleeding (5.6%). Sixty-eight of our symptomatic patients displayed grade II (65.4%) and 36 displayed grade III bleeding symptoms (34.6%). First bleeding regions were skin (33%), nose (28%), central nervous system (CNS) (15.5%), oral cavity (10.5%), soft tissue (6%), joint (3%), urinary system (2%) and gastrointestinal system (GIS) (2%), respectively. The bleeding prevalence rates of our symptomatic patients are listed as epistaxis 62.5%, skin bleedings 53%, oral cavity bleeding 28.8%, haematomas 18.3%, CNS bleedings 17.3%, haemarthrosis 14.4%, GIS bleedings 3.8%, menorrhagia 2.9%, haematuria 1.9%, bleeding because of operations 1.9% and iliopsoas bleedings 1.9%. CNS bleedings (41%) take the first place among the serious bleedings of our cases, followed by haemarthrosis (36.4%), GIS bleedings (18.1%) and iliopsoas bleedings (4.5%). Prophylaxy was applied to nine patients (five patients with FVII, two patients with fibrinogen and one each with FV and FX deficiency).

CONCLUSIONS

The characteristics of clinical presentations, first bleeding attacks, bleeding prevalence and severe bleedings as well as prophylactic approaches are discussed in this article.

Spatial aspects of blood coagulation: two decades of research on the self-sustained traveling wave of thrombin

In a number of experimental studies, it has been demonstrated that the forefront of blood coagulation can propagate in the manner of a signal relay. These data strongly support the concept that the formation of a blood clot is governed by a self-sustained traveling wave of thrombin. The present review critically appraises the experimental data obtained in recent decades concerning the self-sustained spatial propagation of thrombin. Open questions regarding the experimental detection of the self-sustained propagation of thrombin are discussed.

Dispelling myths about coagulation abnormalities in internal medicine

The clotting screen is an 'integral' part of the routine blood tests in most medical wards. It is likely that only with the increasing requests for prothrombin time and activated partial thromboplastin time are abnormal results noted. Interpretation of these results requires good understanding of the coagulation system and problems with the laboratory analysis. Due to variable understanding of this complex system, many misconceptions have arisen in relation to the clinical effects expected from abnormal clotting screens. Some of these are discussed with considerations of appropriate management in those situations.

Restoring hemostasis: fibrinogen concentrate versus cryoprecipitate

Fibrinogen plays a key role in the coagulation process, and therefore maintaining adequate quantities of fibrinogen is an essential step in achieving satisfactory hemostasis in patients with acquired hypofibrinogenemia. Potential options for treating acquired hypofibrinogenemia in patients with uncontrolled bleeding include the use of cryoprecipitate or fibrinogen replacement therapy. This review provides a brief overview of the hemostatic process and the methods for assessing coagulopathy and discusses the efficacy and safety of cryoprecipitate and fibrinogen concentrate in restoring fibrinogen levels, achieving hemostasis and reducing transfusion requirements in different patient populations requiring rapid hemostasis. Other issues relevant to the clinical use of these agents in restoring hemostasis, including variations in product composition, preparation time and cost, are also examined.

Inherited abnormalities of coagulation: hemophilia, von Willebrand disease, and beyond

Bleeding disorders are broadly classified into primary and secondary hemostatic defects. Primary hemostatic disorders (disorders of platelets and von Willebrand factor) mainly result in mucocutaneous bleeding symptoms such as epistaxis, menorrhagia, petechiae, easy bruising, and bleeding after dental and surgical interventions. Secondary hemostatic disorders (congenital or acquired deficiencies of coagulation factors) typically manifest with delayed, deep bleeding into muscles and joints. This article provides a generalized overview of the pathophysiology, clinical manifestations, laboratory abnormalities, and molecular basis of inherited abnormalities of coagulation with a focus on hemophilia, von Willebrand disease, and rare inherited coagulation disorders.

Rare bleeding disorders in children: identification and primary care management

Bleeding symptoms are common in healthy children but occasionally may indicate an underlying congenital or acquired bleeding diathesis. The rare bleeding disorders (RBDs) comprise inherited deficiencies of coagulation factors I (congenital fibrinogen deficiencies), II, V, VII, X, XI, and XIII and combined factor deficiencies, most notably of factors V and VIII and of vitamin K-dependent factors. These disorders often manifest during childhood and may present with recurrent or even serious or life-threatening bleeding episodes, particularly during the neonatal period. Accordingly, primary care and other nonhematologist pediatric providers should be familiar with the clinical presentation and initial evaluation of these rare disorders. Bleeding manifestations generally vary within the same RBD and may be indistinguishable from 1 RBD to another or from other more common bleeding disorders. Serious bleeding events such as intracranial hemorrhage may be heralded by less serious bleeding symptoms. The results of initial coagulation studies, especially prothrombin time and activated partial thromboplastin time, are often helpful in narrowing down the potential factor deficiency, with factor XIII deficiency being an exception. Consultation with a hematologist is advised to facilitate accurate diagnosis and to ensure proper management and follow-up. The approach to bleeding episodes and invasive procedures is individualized and depends on the severity, frequency, and, in the case of procedures, likelihood of bleeding. Prophylaxis may be appropriate in children with recurrent serious bleeding and specifically after life-threatening bleeding episodes. When available, specific purified plasma-derived or recombinant factor concentrates, rather than fresh frozen plasma or cryoprecipitate, are the treatment of choice.