Congenital Bleeding Disorders of the Vitamin K‐Dependent Clotting Factors

Gastrointestinal Bleeding in Congenital Bleeding Disorders

Gastrointestinal bleeding (GIB) is serious, intractable, and potentially life-threatening condition. There is considerable heterogeneity in GIB phenotypes among congenital bleeding disorders (CBDs), making GIB difficult to manage. Although GIB is rarely encountered in CBDs, its severity in some patients makes the need for a comprehensive and precise assessment of underlying factors and management approaches imperative. Initial evaluation of GIB begins with assessment of hematological status; GIB should be ruled out in patients with chronic anemia, and in presentations that include hematemesis, hematochezia, or melena. High-risk patients with recurrent GIB require urgent interventions such as replacement therapy for treatment of coagulation factor deficiency (CFD). However, the best management strategy for CFD-related bleeding remains controversial. While several investigations have identified CBDs as potential risk factors for GIB, research has focused on assessing the risks for individual factor deficiencies and other CBDs. This review highlights recent findings on the prevalence, management strategies, and alternative therapies of GIB related to CFDs, and platelet disorders.

Pediatric split liver transplantation for congenital factor X deficiency: first 10-year follow-up of a case with portal vein stenting

Congenital factor X (FX) deficiency is a rare autosomal-recessive disease that induces bleeding disorder. Herein, we present the 10-year posttransplant course of a pediatric patient who underwent liver transplantation (LT) with portal vein (PV) stenting for correction of severe congenital FX deficiency, with focus on long-term maintenance of coagulation function and patency of PV stenting. A 17-month-old infant with recurrent hemorrhagic episodes due to FX deficiency underwent split LT using a left lateral section graft. The graft-recipient weight ratio was 2.2%. The graft implantation procedures were performed by following the standard pediatric split LT procedure. Nevertheless, a wall stent was inserted due to PV anastomotic stenosis on posttransplant day 1. Graft function recovered slowly because of partial parenchyma infarct, and the patient was discharged at 46 days after LT operation. The FX activity started to increase soon after LT and gradually normalized; the coagulation profiles have been maintained well for the past 10 years. The patient has been doing well for the past 10 years after LT without any episodes of abnormal bleeding. Due to the risk of vascular complications owed to PV stenting, life-long follow-up is mandatory with special attention until attainment of complete physical growth to adolescent and adulthood.

Evaluation and Management of Coagulopathies and Thrombophilias in Pediatric Patients

The diagnosis of coagulopathy or thrombophilia in pediatric patients can be challenging. Congenital coagulopathies often present in the pediatric period and require appropriate work-up for diagnosis and ongoing management. Acquired coagulopathies of childhood are frequently encountered in hospitalized children and warrant appropriate coagulation testing for goal-directed therapy. The incidence of thrombosis is increasing in pediatric patients. After identifying the presence of thrombus, acute management includes initiating therapeutic anticoagulation. Choice of anticoagulant depends on patient's clinical status, along with availability of the anticoagulant. Thrombophilia evaluation is performed when children present with spontaneous thrombosis. Thrombophilia tests are inaccurate during acute illness.

A Compound Heterozygosis of Two Novel Mutations Causes Factor X Deficiency in a Chinese Pedigree

BACKGROUND

Mutations in the F10-coding gene can cause factor X (FX) deficiency, leading to abnormal coagulation activity and severe tendency for hemorrhage. Therefore, identifying mutations in F10 is important for diagnosing congenital FX deficiency.

METHODS

We studied a 63-year-old male patient with FX deficiency and 10 of his family members. Clotting and immunological methods were used to determine activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), fibrinogen levels, FX activity, and FX antigen levels. The platelet count was determined. A mixing study was performed to eliminate the presence of coagulation factor inhibitors and lupus anticoagulant. Mutations were searched using whole-exome sequencing and certified by Sanger sequencing.

RESULTS

Genetic analysis of the proband identified two single-base substitutions: c.1085G>A (p.Ser362Asn) and c.1152C>A (p.Tyr384Ter, termination codon, caused by the DNA sequence TAA). His FX activity and antigen levels were 1.7% and 408.53 pg/mL, respectively; aPTT and PT were 52.3 and 48.0 s, respectively. One brother had the same compound heterozygous mutations, and his FX activity and antigen levels were 1.3% and 465.47 pg/mL, respectively; his aPTT and PT were 65.2 and 54.5 s, respectively. His mother, another brother, and one sister were heterozygous for c.1085G>A (p.Ser362Asn), and his daughter and grandson (6 years old) were heterozygous for c.1152C>A (p.Tyr384Ter).

CONCLUSION

The heterozygous variants p.Ser362Asn or p.Tyr384Ter indicate mild FX deficiency, but the compound heterozygous mutation of the two causes severe congenital FX deficiency and bleeding. Genetic analysis of these two mutations may help characterize the bleeding tendency and confirm congenital FX deficiency.

Vitamin K-Dependent Coagulation Factors That May be Responsible for Both Bleeding and Thrombosis (FII, FVII, and FIX)

Vitamin K-dependent clotting factors are commonly divided into prohemorrhagic (FII, FVII, FIX, and FX) and antithrombotic (protein C and protein S). Furthermore, another protein (protein Z) does not seem strictly correlated with blood clotting. As a consequence of this assumption, vitamin K-dependent defects were considered as hemorrhagic or thrombotic disorders. Recent clinical observations, and especially, recent advances in molecular biology investigations, have demonstrated that this was incorrect. In 2009, it was demonstrated that the mutation Arg338Leu in exon 8 of FIX was associated with the appearance of a thrombophilic state and venous thrombosis. The defect was characterized by a 10-fold increased activity in FIX activity, while FIX antigen was only slightly increased (FIX Padua). On the other hand, it was noted on clinical grounds that the thrombosis, mainly venous, was present in about 2% to 3% of patients with FVII deficiency. It was subsequently demonstrated that 2 mutations in FVII, namely, Arg304Gln and Ala294Val, were particularly affected. Both these mutations are type 2 defects, namely, they show low activity but normal or near-normal FVII antigen. More recently, in 2011-2012, it was noted that prothrombin defects due to mutations of Arg596 to Leu, Gln, or Trp in exon 15 cause the appearance of a dysprothrombinemia that shows no bleeding tendency but instead a prothrombotic state with venous thrombosis. On the contrary, no abnormality of protein C or protein S has been shown to be associated with bleeding rather than with thrombosis. These studies have considerably widened the spectrum and significance of blood coagulation studies.

Factor X Friuli Coagulation Disorder: Almost 50 Years Later

The story of factor X (FX) Friuli. Factor X Friuli was discovered in 1969 to 1970. However, the story of that disease was an international event since patients with this defect were studied in France and in Italy, and different diagnoses were reached-FVII; FX; combined prothrombin complex; and combined FII, FVII, and FX deficiencies. The diagnostic difficulties were due to the peculiar clotting pattern presented by these patients, namely, prolonged partial thromboplastin time, prolonged prothrombin time but normal Russell viper venom clotting time. Only suitable anti-FX antisera clarified the pattern. Altogether 12 homozygotes and 102 heterozygotes have been followed during 4 decades. Six homozygotes died, 2 of them due to HIV infection and 1 due to hepatitis B liver cirrhosis. The other 3 died of nontransfusion-related morbidity. Bleeding tendency has been moderate in agreement with the extrinsic or intrinsic system assay results-FX level of 4% to 5% is considered normal. Heterozygotes may present occasional bleeding manifestations usually during surgery or delivery. Molecular analysis have shown that the mutation responsible for the defect is a Pro343Ser substitution in exon 8. Chimeric FX Friuli mice have been useful in studying the effect of FX levels on embryonic or natal mortality of these animals. No new homozygote but several heterozygotes have been recently seen. The study of FX Friuli has revolutionized the diagnostic approach to FX deficiencies. The FX should be assayed by all assay systems. The FX Friuli has never been described in any other country, and all patients studied come from the Friuli Meduna River Valley.

Thrombotic and Hemorrhagic Conditions Due to a Gain of Function of Coagulation Proteins: A Special Type of Clotting Disorders

Coagulation disorders can be classified into 2 types, namely, type I and type II. In the former, there is a concomitant decrease in factor activity and antigen (activity-antigen ratio is 1), whereas in the latter, there is a discrepancy between factor activity which is always low and antigen which is normal or near normal (activity-antigen ratio is <1, eg, 0.5). Recently, several gain-of-function disorders have been described. These are characterized by an increased activity with respect to the antigen level. The condition involves polymorphisms of factor V and factor II, factor IX, von Willebrand disease, thrombomodulin, tissue factor pathway inhibitor, and thrombin activatable fibrinolysis inhibitor. The conditions could be subdivided into prothrombotic and prohemorrhagic. They should also be distinguished as cases of true gain of function (intrinsic increase activity without concomitant increase in protein level) and of "pseudo" gain of function (increase in both activity and protein level). This is a new concept of coagulation defects that has considerably enhanced our knowledge of blood coagulation and that should be familiar to all those interested in the mechanism of blood clotting and its disorders.

Acquired Isolated FVII Deficiency

Objective:

To investigate all cases of isolated factor VII (FVII) deficiency as gathered from personal files or by a PubMed search.

Patients and Methods:

Personal files dealing with patients studied in Padua during the years 1970 to 2010 were reevaluated. The PubMed search was time unlimited and was carried on 2 occasions during 2014. Cross-checking of the references, listed in every article, was also carried out to avoid omissions. Inclusion criteria were isolated FVII defect of less than 40% of normal, negative coagulation pattern in the family, normal level of other vitamin K-dependent clotting factors, and normalization of the clotting factor after the therapeutic procedures, unless the patient died.

Results:

Twenty-nine patients met the inclusion criteria (18 male and 9 female, in 2 cases gender was unreported). This number included 1 personal case. Mean age was 37.9 (range 3-80). Underlying diseases were the following: neoplasia, infections, polytrauma, penicillin administration, nephrotic syndrome Wiskott Aldrich syndrome, and left heart failure (1 case, each); 2 patients had no underlying disease. Bleeding was variable but usually mild. There were 11 fatalities.

Conclusions:

Isolated FVII deficiency is a rare defect, which appears to be a finding associated with several morbid conditions, especially sepsis and tumors. This indicates the need for a careful investigation of even a mild prolongation of prothrombin time, especially when fibrinogen and partial thromboplastin time are normal.

A family with factor X deficiency from Argentina: a compound heterozygosis because of the combination of a new mutation (Gln138Arg) with an already known one (Glu350Lys)

The objective was to investigate a family from Argentina. The proposita was a 51-year-old woman who had a moderate bleeding tendency. Some of her children showed a mild bleeding tendency. Her mother and the husband were asymptomatic. Clotting, immunological and molecular biology techniques were used. Partial thromboplastin, prothrombin, Russell Viper venom-clotting times were moderately prolonged in the proposita, whereas they were slightly prolonged in the children and in her mother. Factor X (FX) activity was about 2-3% of normal in all assay systems. FX antigen was less than 5%. Other clotting factors and platelet were normal. Genetic analysis showed a compound heterozygosis: combination of a 'new' mutation (Gln138Arg) with an already known mutation (Glu350Lys). The children had intermediate FX levels (35-63% of normal) and were carriers of one of the two mutations present in the proposita. This is the first observation of a FX deficiency in Argentina.

Rare and Unusual Bleeding Manifestations in Congenital Bleeding Disorders

Epistaxis, superficial and deep hematomas, hemarthrosis, gastrointestinal bleeding, hematuria represent the most frequent hemorrhagic events in congenital coagulation disorders. Occasionally, bleeding manifestations occur in unusual sites or are peculiar. A clotting defect may alter the clinical aspect of skin conditions or infections (hemorrhagic scabies or varicella). Hemobilia may occur as a complication of transjugular liver biopsy in hemophilia or Bernard-Soulier syndrome. Hemarthrosis of small joints of feet and hands occur in patients with hemophilia treated with protease inhibitors. Intramedullary hematomas of long bones have been described in α2-plasmin inhibitor or fibrinogen deficiencies. Spleen fracture with consequent hemoperitoneum has been reported in patients with fibrinogen deficiency. Rectus muscle sheath hematoma may occur in patients with factor VII (FVII)or FX deficiency. Acute or subacute intestinal obstruction may be caused by intramural wall hematomas in hemophilia and von Willebrand (vW)-disease. Physicians should always keep in mind that a congenital hemorrhagic disorder may cause bleeding in any tissue of the body and therefore alter the normal clinical features of a given disease.

Comparative incidence of thrombosis in reported cases of deficiencies of factors of the contact phase of blood coagulation

Thrombotic manifestations occurring in patients with coagulation defects have drawn considerable attention during the last decade. It concerned mainly patients with hemophilia, vW disease or FVII deficiency. Occasional reports involved also the deficiencies of the contact phase of blood coagulation, mainly FXII deficiency. The purpose of the present study was to evaluate the comparative incidence of thrombosis in all reported patients with FXII, Prekallikrein and Kininogens deficiencies. Out of the reported 341 cases with these conditions that could be tracked there were 43 cases with thrombosis. More specifically, there were 32 patients with FXII deficiency who also had a thrombotic event (16 arterial and 16 venous). As far as Prekallikrein deficiency is concerned, there were nine cases with thrombosis (five arterial and four venous). Finally, two patients with Total or High molecular weight Kininogen deficiencies had also a thrombotic manifestation (one arterial and one venous). The thrombotic manifestations were M.I. 11 cases; ischemic stroke 9 cases; peripheral arteries 3 cases; deep vein thrombosis with or without pulmonary embolism 17 cases; thrombosis in other veins 3 cases. Congenital or acquired associated prothrombotic risk factors were present in 33 out of 36 cases. In three cases the existence of associated risk factors was excluded whereas in the remaining seven patients no mention is made in this regard. This study clearly indicates that the severe in vitro coagulation defect seen in these conditions does not protect from thrombosis.

Relationship between acquired deficiency of vitamin K-dependent clotting factors and hemorrhage

This study examined the changes of activities of vitamin K-dependent clotting factors (VKDCF) under various pathological conditions and explored the relationship between acquired deficiency of VKDCFs and hemorrhage. Clinical data of 35 patients who were diagnosed as having acquired deficiency of VKDCF were retrospectively analyzed. Coagulation factors involved in the intrinsic and extrinsic pathways were detected in these patients and 41 control subjects. The results showed that the average activities of VKDCFs were decreased in the patients in comparison to the control subjects and significantly increased after treatment of these patients with vitamin K and blood products. Multivariate regression analysis indicated that decreased activity of VKDCF was not an independent risk factor for bleeding disorders owing to deficiency or metabolic disturbance of vitamin K. It was concluded that acquired deficiency of VKDCF occurs under a variety of pathologic conditions and is closely associated with hemorrhagic events. Administration of vitamin K and transfusion of blood products containing high concentrations of VKDCFs helps alleviate the hemorrhagic diseases.

Prothrombin Complex Concentrate Such as Therapy and Prophylaxis in Factor X-Deficient Patient (Friuli Variant)

Background: Factor X (FX) deficiency is a serious, rare bleeding disorder, with 1 in 500 000 affected people. Hemorrhages, hematuria, epistaxis, and other bleeding complications are frequent. Case Report: Now, we report a case of a well-known 77-year-old FX-deficient patient (Friuli variant, level <1%, mutation Pro343→Ser, exon VIII) with hypertension, chronic obstructive pulmonary disease (COPD), and chronic gastritis, admitted many times to hospital due to surgical complications after aortic abdominal aneurysm (AAA) repair. Use of prothrombin complex concentrate (PCC) such as hemostatic therapy during surgeries and prophylaxis after discharge is shown in this article. Three consecutive surgeries were considered. First, endoleak postendoprosthesis; second, AAA breakage; and third, planned surgery, a new endovascular prosthesis positioning and femur-femoral bypass. No adverse events due to PCC were found by local physicians. Discussion: We discuss the methods commonly used in the treatment and prophylaxis of patients with FX deficiency to reduce hemorrhagic risk and to improve their quality of life. Conclusion: Waiting for specific therapeutic options for FX deficiency, currently, the best treatment is represented by PCC. Its correct use permits an improvement in life quality and a reduction in bleeding frequency in FX-deficient patients.

Third trimester fetal intracranial hemorrhage owing to vitamin K deficiency associated with hyperemesis gravidarum

In rare cases, severe fetal vitamin K deficiency bleeding may occur in utero as a result of insufficient vitamin K placental transfer. We present a case of a 32-week-preterm infant born with severe intracranial hemorrhage to a pregnant woman who suffered from hyperemesis gravidarum. Neonatal hematologic status was compatible with vitamin K deficiency whereas the maternal coagulation function was normal. This case emphasizes the potential risk of fetal bleeding owing to vitamin K deficiency in pregnancies complicated with hyperemesis gravidarum. These women should be closely monitored and vitamin K prophylaxis might be considered.

Unexplained Discrepancies in the Activity—Antigen Ratio in Congenital FX Deficiencies With Defects in the Catalytic Domain

Studies on molecular biology have considerably enhanced our understanding of congenital coagulation disorders but have failed so far to supply tools for an adequate classification of defects. In fact, mutations in the same domain may give rise to different phenotypes. Conversely, mutations in different domains, controlled by different exons, may cause similar patterns. The 37 kindreds with congenital factor X (FX) deficiency, known to have a defect in the catalytic domain, have been evaluated in an attempt to investigate the genotype—phenotype relation. Discrepant results were obtained because about half kindreds showed a type I pattern, namely a concomitant decrease in FX activity and antigen. The other half showed a type II pattern, namely a decrease in FX activity with a normal or near normal FX antigen. In a few instances, the allocation of the kindred either to type I or to type II defect could not be reached, due to the lack of information about the antigen.

The comparison of the kindreds in which the same mutation has been discovered by different investigations is not always possible also for lack of information.

The study analyzes the need to have a multipronged approach to the study of congenital FX deficiency. The indication of a mutation in a given domain does not provide clear information about the phenotype.