[Autoimmune coagulation factor V/5 deficiency during chronic disseminated intravascular coagulation].

Aortic regurgitation, a thoracoabdominal aortic aneurysm, chronic myeloid leukemia, and chronic kidney disease were all being treated at two hospitals for an 83-year-old man. He was admitted to the Department of Orthopedics at our hospital with a lumbar compression fracture. Later, he experienced melena, for which the Department of Internal Medicine was consulted. Due to the aberrant results of PT-INR (7.1) and a PTT > 200 seconds on a coagulation test, we suspected the presence of an autoimmune coagulation factor deficiency, and prednisolone immunosuppressive therapy medication was started right away. Due to a sharp decline in FV/5 activity, the presence of FV/5 inhibitors, and the presence of anti-FV/5 autoantibodies, a final diagnosis of autoimmune coagulation factor V (FV/5) deficiency was made. After the start of immunosuppressive therapy, the FV/5 inhibitor and anti-FV/5 autoantibodies disappeared, and the FV/5 activity progressively returned to normal. Disseminated intravascular coagulation-which may have been caused by a known aortic aneurysm-worsened while tapering off prednisolone. Due to the patient's advanced age and other problems, the aneurysm was extensive and inappropriate for surgical repair. The coagulation test findings improved gradually upon initiation of warfarin therapy. Herein, the patient had autoimmune FV/5 deficiency, a rare disorder that made diagnosis and therapy difficult because of the patient's several coexisting conditions.

Congenital coagulation factor V deficiency with intracranial hemorrhage.

BACKGROUND: Congenital coagulation factor V (FV) deficiency is a very rare hemorrhagic disease with an incidence of approximately one in a million. The common clinical manifestations of FV deficiency include ecchymosis and mucosal bleeding. Life-threatening intracranial bleeding is rare. It has been reported in several cases. However, the molecular basis has been established in only a few cases. METHODS: We reported a 2-month-old girl with congenital FV deficiency and intracranial hemorrhage. Coagulation screening combined with clinical manifestations was performed to diagnose congenital FV deficiency. Genetic testing was performed to identify the pathogenic genes. A literature review was included to emphasize the clinical manifestation, diagnosis, and treatment for congenital FV deficiency with intracranial bleeding. RESULTS: The coagulation tests revealed a significantly prolonged prothrombin time (PT) of 51 s and an activated partial thromboplastin time (APTT) of 73.7 s. The patient had a plasma FV activity of 0.9%. Genetic testing showed compound heterozygous mutations of the patient's FV gene. A literature review showed that patients with homozygous or compound heterozygous variants of the FV gene were often associated with a severe bleeding phenotype. CONCLUSION: Our study provides a direction for the rapid and accurate diagnosis and treatment for FV deficiency to avoid life-threatening bleeding. Infants with spontaneous cranial hematoma and intracranial hemorrhage should be investigated for underlying hemostatic defects. Congenital coagulation factor deficiency should be considered. Once congenital FV deficiency is diagnosed, fresh frozen plasma (FFP) should be given on a regular basis. Liver transplantation may be performed in severe cases.

[Successful management of acquired factor V deficiency developing shortly after induction of hemodialysis].

Autoimmune factor V deficiency (AiF5D) is caused by autoantibodies to coagulation factor V (FV); its clinical manifestations range from asymptomatic to fatal hemorrhage. Herein, we report the case of a 68-year-old man who was diagnosed with end-stage renal disease at the time of a femoral fracture and developed AiF5D after initiating hemodialysis. A wound infection that occurred after joint replacement was treated with antibiotics; however, it was poorly controlled. One month after the procedure, his coagulation time prolonged. The infection was improved by debridement and antibiotics; however, the coagulation time was not decreased and poor hemostasis at the shunt was still persistent. Because ELISA detected anti-FV-binding IgG with FV activity of <2.8% and FV inhibitor levels were 11.8 BU/ml, AiF5D was diagnosed. Oral prednisolone (PSL) was started. Dialysis was initially performed without anticoagulants, but blood clots were not found in the circuit. Anticoagulants were resumed when the coagulation time decreased. After achieving complete remission, PSL dose was tapered and finally discontinued. Few reports have described the management of AiF5D via dialysis. We consider that our report would be useful for the management of patients with similar manifestations.

Understanding the Impact of Aberrant Splicing in Coagulation Factor V Deficiency.

Rare inherited coagulation disorders (RICDs) are congenital deficiencies of the plasma proteins that are involved in blood coagulation, which generally lead to lifelong bleeding manifestations. These diseases are generally qualitative and/or quantitative defects that are associated with monoallelic or biallelic mutations in the relevant gene. Among RICDs, factor V (FV) deficiency is one of the least characterized at the molecular level. Here, we investigated four unrelated patients with reduced plasma FV levels (three severe, one mild), which were associated with a moderately severe bleeding tendency. Sequence analysis of the FV gene identified seven different variants, five hitherto unknown (p.D1669G, c.5789-11C>A, c.5789-12C>A, c.5789-5T>G, and c.6528G>C), and two previously reported (c.158+1G>A and c.5789G>A). The possible pathogenic role of the newly identified missense variant was studied by in silico approaches. The remaining six genetic defects (all putative splicing mutations) were investigated for their possible effects on pre-mRNA splicing by transient transfection experiments in HeLa cells with plasmids expressing appropriate hybrid minigenes. The preparation of minigene constructs was instrumental to demonstrate that the two adjacent variants c.5789-11C>A and c.5789-12C>A are indeed present in cis in the analyzed FV-deficient patient (thus leading to the c.5789-11_12CC>AA mutation). Ex vivo experiments demonstrated that each variant causes either a skipping of the relevant exon or the activation of cryptic splice sites (exonic or intronic), eventually leading to the introduction of a premature termination codon.

[Recurrence of acquired factor V inhibitor after four years of remission].

Acquired factor V inhibitor (AFV-I) is a rare bleeding disorder wherein autoantibodies are developed against coagulation factor V (FV). The clinical symptoms are variable, from laboratory abnormalities without bleeding to life-threatening hemorrhage. We report herein the case of a patient with AFV-I with two relapses 4 years after the first remission. A 66-year-old male was diagnosed with AFV-I in March 20XX-4. He was treated with prednisolone (PSL) at 50 mg/day and achieved remission within 1 month. PSL dose was tapered to oral administration of 2.5 mg every other day, and long-term remission was maintained. He had been treated with dual antiplatelet therapy (DAPT) for old myocardial infarction. FV activity was markedly reduced to 3.4%, and FV inhibitor was detected (1.0 BU/ml) in May 20XX. We followed the patient without increasing the treatment dose for 2 months, but no spontaneous improvement was seen. Because DAPT was ongoing, we judged that the bleeding risk was high, although only minor bleeding symptoms appeared. PSL was therefore increased to 40 mg/day in June. FV inhibitor rapidly disappeared. When PSL dose was gradually decreased, FV activity decreased, and subcutaneous bleeding occurred in February 20XX＋1. PSL dose was increased again for the second relapse, and the patient achieved remission. Few reports have described recurrent AFV-I, and no cases of two relapses have been reported. We believe that this case report is useful for examining the long-term management of AFV-I.

Factor V Leiden Heterozygous: Complicated by Recurrent Venous Thromboembolism and Bilateral Pulmonary Embolism.

Factor V Leiden (FVL) is a hypercoagulable disorder that puts patients at increased risk of initial venous thromboembolism (VTE). However, those with heterozygote status are not usually susceptible to recurrent VTE. This is a case of a 35-year-old Caucasian male who presented to the emergency department with shortness of breath and chest pain. He had a past medical history of superficial thrombophlebitis and deep vein thrombosis (DVT) and was known to be FVL heterozygous. His home medications did not include anticoagulation medications at the time of presentation to the emergency department. The patient was diagnosed with bilateral pulmonary embolisms (PEs) secondary to a recurrent DVT. Initial treatment included a pulmonary thrombectomy and a lower extremity thrombectomy. Despite the patient being placed on heparin, there was a recurrence of the PE three days later, requiring a repeat pulmonary thrombectomy. This case of recurrent VTE in a heterozygous FVL patient is unusual and should lead to new considerations on the approach to lifelong anticoagulation in these patients.

Homozygous Carriers of F2 c.20210G>A Variant: A Report of Two Cases and Literature Review.

Thromboembolism is known to be a multifactorial event that is impacted by various genetic and environmental factors. The genetics society's recommended name for this variant is c.*97G>A (this is the nomenclature we need to use in the patient report). However, people have been using legacy names c.20210G>A or G20210A (so these are common names). One of the most common genetic variants associated with inherited thrombophilias, F2 c.20210G>A is acknowledged to be a weak but significant risk factor for thromboembolism. However, its clinical presentation has been described as phenotypically heterogeneous. We present two rare cases with homozygous F2 c.20210G>A variant, one of which also carries a heterozygous variant in coagulation factor V gene F5, c.1601G>A (p.Arg534Gln; commonly known as factor V Leiden). We described the clinical courses of these two cases and discussed F2 c.20210G>A and factor V Leiden as genetic risk factors in thromboembolism, the role of provoking factors, such as surgery and malignancy, and the management of such patients.

Case Report: Novel Mutation of F5 With Maternal Uniparental Disomy Causes Severe Congenital Factor V Deficiency.

We summarized two cases of congenital factor V deficiency (FVD) associated with a novel F5 mutation, and analyzed the relationship of the clinical features and genetic characteristics in congenital FVD. Case 1 was a female newborn infant with remarkable bleeding who died of severe intracranial hemorrhage on day 42 after birth. She had significant prolongation of prothrombin time (PT) and activated partial thromboplastin time (APTT). The percentage activity of FV (PFV) was lower than 3% in case 1. The mother of case 1 showed no tendency to bleed. She had mild prolongation of PT and APTT. The PFV was only 43%. Both cases were found to have the same novel mutation in F5, which was c.5419G>A (p.Ala1807Thr) in exon 16. The variant in case 1 was inherited from the mother of case 1. Whole-exome sequencing (WES) also found a splice site mutation: a 103 Mb maternal uniparental disomy (UPD) of 1q21.1-qter in case 1, in which the F5 gene is located in this segment. So case 1 was homozygote and the mother of case 1 was heterozygote. The novel mutation of F5 was predicted to be harmful by bioinformatics software including Sorting Intolerant From Tolerant (SIFT), Polyphen2, LRT, and Mutation Taster. In summary, c.5419G>A (p.Ala1807Thr) in exon 16 of F5 is a pathogenic mutation, which causes severe congenital FVD in homozygote patients.

FVIII inhibitors display FV-neutralizing activity in the prothrombin time assay.

BACKGROUND: The coagulation factors (F)V and VIII are homologous proteins that support hemostasis through their regulation of FX activity. Hemophilia A (HA) patients have reduced FVIII activity and a prolonged bleeding time that is corrected through the administration of exogenous FVIII. Around one-third of severe HA patients develop FVIII neutralizing antibodies, known as "inhibitors," which neutralize FVIII activity and preclude them from further FVIII therapy. OBJECTIVES: We hypothesized that, based on the degree of homology between FV and FVIII (~40%), FVIII-neutralizing antibodies could cross react with FV. To test this hypothesis, a panel of recombinant, patient-derived, FVIII-neutralizing antibodies were screened for cross-reactivity against FV. METHODS: Factor V and FVIII activity was measured using one-stage clotting assays; structural analysis was carried out using a structural approach. RESULTS: We detected FV neutralizing activity with the anti-FVIII A2 domain antibody NB11B2. Because this antibody was derived from an HA inhibitor patient, FV-neutralizing activity was then evaluated in a number of HA inhibitor patient plasma samples; nine alloimmune samples had FV-neutralizing activity whereas no FV neutralizing activity was found in the two autoimmune samples available. We next examined the degree of surface homology between FV and FVIII and found that structural similarity could explain the cross reactivity of the anti-A2 antibody and likely accounts for the cross reactivity we observed in patient samples. CONCLUSIONS: Although this novel observation is of interest, further work will be needed to determine whether FV neutralization in HA patient samples contributes to their bleeding diathesis.

Comprehensive N- and O-glycosylation mapping of human coagulation factor V.

BACKGROUND/OBJECTIVE: Coagulation factor V (FV), a multidomain glycoprotein, is an essential cofactor in the blood clotting cascade. FV deficiency is a rare bleeding disorder that results in poor clotting after an injury or surgery. The only treatment for the disease is infusions of fresh frozen plasma and blood platelets. Glycosylation affects the biological activity, pharmacokinetics, immunogenicity, and in vivo clearance rate of proteins in the plasma. The glycan profile of FV, as well as how it affects the activity, stability, and immunogenicity, remains unknown. METHODS: In this study, we comprehensively mapped the glycosylation patterns of human plasma-derived FV by combining multienzyme digestion, hydrophilic interaction chromatography enrichment of glycopeptides, and alternated fragmentation mass spectrometry analysis. RESULTS/CONCLUSION: A total of 57 unique N-glycopeptides and 51 O-glycopeptides were identified, which were categorized into 40 N-glycan and 17 O-glycan compositions. Such glycosylation details are fundamental for future functional studies and therapeutics development. In addition, the established methodology can be readily applied to analyze glycosylation patterns of proteins with more than 2000 amino acids.

CONTRIBUTION OF THE G1691A ALLELE CARRYING OF THE COAGULATION FACTOR V GENE TO THE DEVELOPMENT OF THROMBOSES IN RADIATION-EXPOSED PATIENTS WITH REACTIVE CHANGES IN PERIPHERAL BLOOD. / VNESOK NOSIISTVA ALEL'NOGO VARIANTA G1691A GENA V FAKTORU KOAGULIaTsIÏ V ROZVYTOK TROMBOTYChNYKh USKLADNEN' V OSIB Z REAKTYVNYMY ZMINAMY U PERYFERIINII KROVI, ShchO ZAZNALY RADIATsIINOGO OPROMINENNIa.

Thrombosis triggers, in addition to «classic¼ risk factors (RFs) of cardiovascular events, includes the reactive changesof peripheral blood (RCPB), markers of the hereditary thrombophilia and radiation anamnesis. However, results ofmost studies suggest the «classic¼ RFs are able to neutralize the prothrombogenic potential of the hereditary thrombophilia and other, less powerful predictors of thrombosis. OBJECTIVE: to determine the influence of the G1691A allele of the proaccelerin gene carrying to the thrombosis development, taking into account the vascular type of their occurrence, the presence of RFs in individuals with RCPB (reactive leukocytosis and thrombocytosis, and secondary erythrocytosis), as well as with and without radiation anamnesis. MATERIAL AND METHODS: In general, it was analyzed the results of clinical and molecular-genetic data of 152 patientswith RCPB, 19 patients had radiation anamnesis, 133 - did not have. The thrombotic complications were detected in5 (26.31 %) of radiation-exposer patients and 25 (18.79 %) patients without radiation anamneses. The carrying ofthe G1691A allele proaccelerin gene (APG) (Leiden mutation (LM)) was detected using the allele-specific polymerasechain reaction. RESULTS: The LM was found in 5.9 % (9 carriers) of the general cohort (GC) of RPBC patients. There were no differencein the LM frequency between the groups of patients with and without radiation anamnesis (р = 0.312). In the groupof radiation-exposer patients (р = 0.017), as well as in the group without its (р = 0.031), venous thromboses only weremore frequently in the LM carriers. In the presence of a radiation anamnesis, G1691A APG carriers with RFs have thehigher frequency (р = 0.008) and the probability of the occurrence (relative risk [RR] = 25.00; CI 95 %: 1.56-399.68)of venous thrombosis. In the group without radiation anamnesis, the frequency of venues thrombosis in the LMcarriers is higher in the younger age subgroup (р = 0.001), without RFs (p = 0.044) and without RFs under 60 years(р = 0.023). The risk of venous thrombosis in the G1691A APG carriers of the group without radiation anamnesis is5.78 (95 % CI: 1.58-21.13). In LM carriers without radiation anamnesis and RFs, as well as under the 60 years of age,the probability of venous thrombosis was 6.85 (95 % CI: 1.86-25.22) and 19.40 (95 % CI: 4.64-81.09), respectively,and in the absence of both criteria - 9.57 (95 % CI: 2.49-36.73). CONCLUSIONS: In patients with and without radiation anamnesis, the risk of venues thrombosis are observed moreoften in carriers of LM. The carrying of the G1691A APG in patients with RPBC and without RA increased the risk ofvenues thrombosis development in subjects without FRs and below 60 years of age. In the radiation-exposure group,the frequency and the risk of venues thrombosis in the G1691A APG carriers was higher in the subgroup with RFs. It isprobably due to the peculiarity of the samples, or prothrombogenic interaction between LM and radiation-associated endothelial damage.

Blood coagulation factor Va's key interactive residues and regions for prothrombinase assembly and prothrombin binding.

Blood coagulation factor Va serves an indispensable role in hemostasis as cofactor for the serine protease factor Xa. In the presence of an anionic phospholipid membrane and calcium ions, factors Va and Xa assemble into the prothrombinase complex. Following formation of the ternary complex with the macromolecular zymogen substrate prothrombin, the latter is rapidly converted into thrombin, the key regulatory enzyme of coagulation. Over the years, multiple binding sites have been identified in factor Va that play a role in the interaction of the cofactor with factor Xa, prothrombin, or the anionic phospholipid membrane surface. In this review, an overview of the currently available information on these interactive sites in factor Va is provided, and data from biochemical approaches and 3D structural protein complex models are discussed. The structural models have been generated in recent years and provide novel insights into the molecular requirements for assembly of both the prothrombinase and the ternary prothrombinase-prothrombin complexes. Integrated knowledge of functionally important regions in factor Va will allow for a better understanding of factor Va cofactor activity.

Protein S K196E mutation reduces its cofactor activity for APC but not for TFPI.

BACKGROUND: Protein S (PS) is an anticoagulant molecule that functions as a cofactor for activated protein C (APC) in the inactivation of activated coagulation factors Va (FVa) and VIIIa. It also serves as a cofactor for tissue factor pathway inhibitor (TFPI) in the efficient inhibition of factor Xa (FXa). The Lys196-to-Glu (K196E, Tokushima) mutation in the EGF-2 domain of PS is a genetic risk factor for venous thromboembolism (VTE) in the Japanese population. OBJECTIVES: To investigate the molecular basis of the thrombophilic phenotype of Japanese patients carrying the PS K196E mutation. METHODS: We expressed recombinant human PS wild-type (PS-K) and K196E-mutant (PS-E) in CHO cells, and purified them by Ni2+-affinity and anion exchange column chromatography. We investigated the anticoagulant functions of PS-K and PS-E by measuring APC cofactor activity, TFPI cofactor activity, affinity for the ß chain of complement component C4b-binding protein (C4BP), and cleavage by thrombin. RESULTS: PS-E had approximately 40% APC cofactor activity compared with PS-K in a clotting-based assay and a FVa inactivation assay. The TFPI cofactor activity of PS-E in the FXa inactivation assay was equivalent to that of PS-K in the absence and presence of coagulation factor V. The strengths of PS-E and PS-K binding to the ß chain of C4BP were comparable, and both were equally cleaved by thrombin. CONCLUSIONS: The PS K196E mutation increases the risk of VTE because of reduced APC cofactor activity but does not alter various other properties, including the TFPI cofactor activity.

Three novel variants in the coagulation factor V gene associated with deep venous thrombosis in Chilean patients with Amerindian ethnic background.

BACKGROUND: The activated protein C (APC) resistance is the most common prothrombotic defect in thrombosis patients, mainly related with alterations in the F5 gene. In this work, we evaluated the presence of variants in the FV gene in Amerindian patients with deep venous thrombosis and APC resistance. METHODS: A total of 87 patients with deep venous thrombosis (DVT) confirmed by Doppler ultrasonography, and Amerindian genetic background, were included in this study. APC resistance was assayed by clotting methods and polymorphism F51691G>A was genotyped by molecular methods. In Amerindian patients with APC resistance, the promoter region, exon 7 and exon 10 of the F5 gene were screened by PCR-SSCP and DNA sequencing. The prediction of functional effect of novel mutations was analyzed using Polyphen-2 software. RESULTS: In DVT patients, 14.9% showed functional APC resistance in the absence of F51691G>A polymorphism. Interestingly, three novel missense mutations in exon 10 of F5 gene (M443L, E461Q and G493E) were identified. These genetic variants were absent in 100 healthy subjects. According to in silico analysis, the sequence variants G493E and E461Q are potentially deleterious. CONCLUSIONS: Our data shows that the APC resistance phenotype is not associated with the presence of the F51691G>A variant. We described, for the first time, the presence of three novel variants in F5 gene in Chilean patients with APC resistance. Further studies are required to investigate the real contribution of these novel mutations to the APC resistance phenotype.

Acquired factor v inhibitor developing after treatment with dabigatran etexilate methanesulfonate: a case report and review of the literature.

A 90-year-old man presented with subcutaneous ecchymoses. He had been under treatment with dabigatran etexilate methanesulfonate (DEM). Prolonged APTT and decreased PT was developed 2 months after the start of DEM, more prolonged 6 months later. DEM was discontinued, the coagulopathy did not improve. Factor V activity was decreased, along with appearance of coagulation factor V inhibitor (FVI). He did not have antiphospholipid syndrome or malignancy. He was diagnosed as having acquired FVI caused by DEM. Steroid pulse therapy was effective. There have been 74 reported cases of AFVI induced by drug treatment, but none after treatment with DEM.