Clinical manifestations in 28 Italian and Iranian patients with severe factor VII deficiency

Inherited factor VII deficiency and surgery: clinical data are the best criteria to predict the risk of bleeding

Inherited factor VII (FVII) deficiency is a rare autosomal disorder characterized by a weak relationship between FVII activity (FVII:C) and operative bleeding risk. We report a retrospective study of 17 patients with a FVII:C below 0.1 IU/ml, in whom surgery was performed without any replacement therapy. Clinical and biological data were analysed to establish predictive criteria for bleeding tendency. We found that systematic preoperative replacement therapy may not be necessary for 'minor' surgical procedures, for patients suffering from inherited FVII deficiency, unless the clinical history includes severe haemorrhagic symptoms such as haemarthrosis, severe haematomas (even of soft tissue) or abundant epistaxis.

Autosomal recessive deficiencies of coagulation factors

Deficiencies of coagulation factors that cause a bleeding disorder, other than factor VIII and factor IX, are inherited as autosomal recessive traits and are generally rare, with prevalence in the general population varying between 1 in 500 000 and 1 in 2 000 000. In the last few years, the number of patients with recessively transmitted coagulation deficiencies has increased in European countries with a high rate of immigration of Islamic populations where consanguineous marriages are frequent. As a consequence of the relative rarity of these deficiencies, the type and severity of bleeding symptoms, the underlying molecular defects and the actual management of bleeding episodes are not as well established as for hemophilia A and B. This article reviews these disorders, in terms of clinical manifestations and characterization of the molecular defects. The general principles of management are also discussed.

Anti- and procoagulant activities in factor VII-deficient subjects

The clinical feature in patients with congenital factor VII deficiency is in part dependent on the underlying genetic defect, but the mechanisms influencing the genotype-phenotype correlation remain to be fully elucidated. In addition, thromboembolic events have been reported. Compensatory mechanisms involving vitamin K-dependent factors have been suggested. We have measured anticoagulant activities in 25 factor VII-deficient subjects (factor VII activity < or =36%) and 23 age-matched controls and correlated these to the vitamin K-dependent procoagulant activities. Two of the patients had a history of thromboembolism. The factor VII-deficient patients were found to have a significantly lower protein C activity than the controls [0.84 U/ml (95% CI 0.78; 0.89) vs. 0.98 U/ml (95% CI 0.91; 1.05), P=.004]. In addition, the protein C activity was correlated to that of factor VII (r=.36; P=.014), factor IX (r=.45; P=.002) and factor X (r=.50; P=.0006), respectively. The level of prothrombin fragment 1+2 was correlated to the protein C (r=.40; P=.012) and to the factor VII activity (r=.42; P=.011). No differences between patients and controls were seen regarding total and free protein S, antithrombin, plasminogen activator inhibitor-1 (PAI-1) and tissue factor pathway inhibitor (TFPI). Seven of the patients were found to have the Factor V Leiden mutation, but none of them had experienced any thromboembolic event. The present data support the notion that compensatory hemostatic mechanisms might exist in that the protein C activity was found to be decreased in the factor VII-deficient subjects. Whether this could influence the clinical feature, including the risk of thromboembolic events in association with replacement therapy, remains to be evaluated.

Analysis of the genotypes and phenotypes of 37 unrelated patients with inherited factor VII deficiency

Severe inherited factor VII (FVII) deficiency is a rare autosomal recessive disorder with a poor relationship between FVII coagulant activity and bleeding tendency. Both clinical expression and mutational spectrum are highly variable. We have screened for mutations the FVII gene of 37 unrelated patients with a FVII coagulant activity less than 5% of normal pooled plasmas. The nine exons with boundaries and the 5' flanking region of the FVII gene were explored using a combination of denaturing gradient gel electrophoresis and direct DNA sequencing. This strategy allowed us to characterise 68 out of the 74 predicted FVII mutated alleles. They corresponded to a large panel of 40 different mutations. Among these, 18 were not already reported. Genotypes of the severely affected patients comprised, on both alleles, deleterious mutations which appeared to be related to a total absence of activated FVII. We suggest that this absence of functional FVII can explain the severe clinical expression. Whether a small release of FVII is sufficient to initiate the coagulation cascade and to prevent the expression of a severe phenotype, requires further investigations.

Continuous infusion of recombinant activated factor VII during caesarean section delivery in a patient with congenital factor VII deficiency

Recombinant activated factor VII (rFVIIa) can be used as an alternative therapy in patients with FVII deficiency. However, as the drug has a very short half-life, continuous infusion could be a meaningful administration modality. We report the case of a 30-year-old woman with moderate FVII deficiency and human immunodeficiency virus infection who underwent a caesarean section delivery. She was treated with a continuous infusion of rFVIIa and did not suffer any bleeding complication. The continuous infusion of rFVIIa was a safe and effective therapeutic approach for our patient, maintaining her levels of FVII:C and avoiding bleeding during caesarean section and afterwards.

A novel polymorphism in intron 1a of the human factor VII gene (G73A): study of a healthy Italian population and of 190 young survivors of myocardial infarction

We have identified a novel polymorphism located in intron 1a of the human factor VII gene, caused by the nucleotide change G to A at position + 73. In a population of 128 healthy individuals from northern Italy, the variant A73 allele had a frequency of 0.21, whereas the frequency of the previously reported 10 bp insertion allele located at -323 in the promoter region was 0.17 and that of the Q353 allele in the catalytic region of the factor VII gene was 0. 20. In 75% of the healthy individuals, the A73 allele was present together with the 10 bp insertion and the Q353 alleles, indicating a strong linkage disequilibrium. The concomitant presence of A73 with both the 10 bp and the Q353 alleles was associated with the lowest factor VII levels, measured as coagulant activity, activated factor VII and factor VII antigen. The G73A polymorphism was also evaluated in 190 survivors of myocardial infarction who had experienced the event before the age of 45 years and in 179 individuals with a negative exercise test matched with patients for sex, age and geographical origin. Patients carrying the A73 allele associated with lower factor VII levels tended to have a lower risk of myocardial infarction (adjusted odds ratio 0.54; 95% confidence intervals 0.29-0.99). In conclusion, we found a novel variant allele in intron 1a of the human factor VII gene that is often associated in healthy individuals with the 10 bp and Q353 alleles in the promoter and catalytic region of the same gene. This intronic mutation, alone or in association with other factor VII gene polymorphisms, might confer protection against myocardial infarction in the young.

Clinical efficacy and recovery levels of recombinant FVIIa (NovoSeven) in the treatment of intracranial haemorrhage in severe neonatal FVII deficiency

The use of replacement FVII is critical to the successful treatment of life-threatening bleeds in newborns and infants with severe FVII deficiency (<1%). However, the clinical efficacy, optimum dosage and pharmacologic recovery of rFVIIa in such children has not been studied systematically. This report is a case of an infant with severe FVII deficiency (FVII:C at 0%) and massive intracranial haemorrhage in which successful use of rFVIIa (NovoSeven) was carefully monitored. The drug was administered by intravenous bolus through a central line every 4 h at each of three dose levels: 15 microg kg-1, 22 microg kg-1 and 30 microg kg-1. FVII:C was >100% between 30 and 180 min after each infusion with mean trough levels above 25% for all three dose levels. There was no evidence of hyper-coagulation as indicated by measurements of the platelet count, D-dimer, plasma protamine paracoagulant and fibrinogen levels in spite of high FVII:C concentration. In this infant, rFVIIa was well-tolerated, maintained effective haemostasis with good clinical outcome, and produced consistent therapeutic mean trough levels above 25% FVII:C even at 15 microg kg-1 every 4 h.

Characterization of Two Naturally Occurring Mutations in the Second Epidermal Growth Factor-Like Domain of Factor VII

We investigated the mechanisms responsible for severe factor VII (FVII) deficiency in homozygous Italian patients with either Gly97Cys or Gln100Arg mutations in the second epidermal growth factor domain of FVII. Transient expression of complementary DNA coding for the mutations in COS-1 cells showed impaired secretion of the mutant molecules. Using stably transfected Chinese hamster ovary (CHO) cells, we performed pulse-chase labeling studies, immunohistochemistry, and experiments with inhibitors of protein degradation, showing that FVII-Cys97 did not accumulate intracellularly but was degraded in a pre-Golgi, nonlysosomal compartment by a cysteine protease. In stably transfected CHO cells expressing FVII-Arg100, the level of intracellular FVII was not increased by several inhibitors of protein degradation, but FVII-Arg100 was retained in the endoplasmic reticulum for a longer period of time than wild-type FVII. FVII-Arg100 had a lower apparent molecular weight than did wild-type FVII under nondenaturing conditions, which is attributable to misfolding due to abnormal disulfide bond formation.

Characterization of Two Naturally Occurring Mutations in the Second Epidermal Growth Factor-Like Domain of Factor VII

We investigated the mechanisms responsible for severe factor VII (FVII) deficiency in homozygous Italian patients with either Gly97Cys or Gln100Arg mutations in the second epidermal growth factor domain of FVII. Transient expression of complementary DNA coding for the mutations in COS-1 cells showed impaired secretion of the mutant molecules. Using stably transfected Chinese hamster ovary (CHO) cells, we performed pulse-chase labeling studies, immunohistochemistry, and experiments with inhibitors of protein degradation, showing that FVII-Cys97 did not accumulate intracellularly but was degraded in a pre-Golgi, nonlysosomal compartment by a cysteine protease. In stably transfected CHO cells expressing FVII-Arg100, the level of intracellular FVII was not increased by several inhibitors of protein degradation, but FVII-Arg100 was retained in the endoplasmic reticulum for a longer period of time than wild-type FVII. FVII-Arg100 had a lower apparent molecular weight than did wild-type FVII under nondenaturing conditions, which is attributable to misfolding due to abnormal disulfide bond formation.

Symptoms of inherited factor V deficiency in 35 Iranian patients

The type of bleeding symptom has been evaluated in 35 Iranian patients with an inherited deficiency of factor V, with plasma levels between 1% and 10%. The most frequent symptoms included epistaxis and excessive bleeding after surgery. Haemarthroses and muscle haematomas were less common, even in severely deficient patients. More severe symptoms such as gastrointestinal and central nervous system bleeding were rare. The severity of bleeding symptoms was only partially related to the degree of factor V deficiency in plasma. On the whole, human factor V deficiency is characterized by a moderately severe bleeding phenotype.

Clinical picture and treatment strategies in factor VII deficiency

Factor VII is a trace protein required for normal haemostasis. Deficiency of factor VII comprises a highly heterogeneous disease group. Factor VII deficiency can cause bleeding, in particular if factor VII is extremely low, but a few cases lacking factor VII function entirely or subtotally may not present with a history of bleeding. Bleeding problems are not often reported in patients having a factor VII:C level at 10-15% of normal or more. Bleeding is frequently of mucocutaneous type, but the whole array of haemophilic bleeding may also occur. To control bleeding, during surgery in particular, substitution is required in the severe case of factor VII deficiency, but clinical studies documenting which correctional levels of factor VII:C to aim are lacking. It appears that a critical low level (trough) value at 10-15% may be anticipated, but clear documentation does not exist. Substitution programmes may include plasma or plasma derived factor IX concentrates of lower degrees of purity, so-called prothrombin complex concentrates that also are relatively impure, and pure factor VII concentrates. An alternative is a recombinant factor VIIa molecule. However, this concentrate has not received license in a number of countries. Thrombotic manifestations appear to occur more often than expected in the factor VII deficient patients, some have been linked to the use of impure concentrates, others to preexisting thrombophilic risk factors, but some are unexplained and may bear a relationship to the deficiency state of factor VII itself. Controlled clinical trials are highly warranted in this rare bleeding condition.

Congenital factor X deficiency: spectrum of bleeding symptoms in 32 Iranian patients

The spectrum of the clinical manifestations of congenital factor X deficiency was studied in 32 Iranian patients. The most frequent symptom was epistaxis, which occurred in 72% of patients, with all degrees of deficiency. Other mucosal haemorrhages (e.g. haematuria, gastrointestinal bleeding) were less frequent and occurred mainly in patients with unmeasurable factor X. Menorrhagia occurred in half of the women of reproductive age. Soft tissue bleeding occurred in two-thirds of the patients; spontaneous haematomas and haemarthroses led to severe arthropathy in five patients. Bleeding from the umbilical stump was an unexpected finding in nine patients. This study demonstrated that the bleeding tendency of factor X deficiency is severe and correlates with factor levels.

Bleeding symptoms in 27 Iranian patients with the combined deficiency of factor V and factor VIII

Inherited deficiency of factors V and VIII is the most frequent combined coagulation defect. The cases reported so fair are mostly single cases or small series from different centres, making it difficult to evaluate the overall pattern of clinical manifestations of the combined defect. We examined at a single institution 27 Iranian patients. Mucocutaneous and post-surgical bleeding were the most frequent clinical manifestations. The presence of two defects did not make the severity of bleeding greater than that expected in patients with single coagulation defects of similar degrees.