In the Northwick Park Heart Study, the coagulant activity of factor VII (FVII:C) has been identified as a risk marker of ischaemic heart disease. In the fasting state, the protein concentration of FVII (FVII:Ag) might be an even better risk marker, because of the low coefficient of variation of the antigen assay. Today, most analyses are performed in plasma samples, as it is unknown whether FVII, to some extent, is consumed during coagulation. In the present study, we have investigated, whether FVII:Ag can be measured equally well in plasma and serum. FVII:Ag was measured in 88 plasma and serum samples. Results were compared by means of linear regression, where y = 0.984 x +0.770, r = 0.96. No systematic variation existed between FVII:Ag in plasma and serum. The mean difference in FVII:Ag between plasma and serum was -1.17 (SD 11.92) arbitrary units, compared with a mean difference of 0.18 (SD 8.31) arbitrary units between duplicate measurements of the same plasma dilution. Our findings indicate that there is a good agreement between FVII:Ag in plasma and serum.

Coagulation FVII (Factor VII) is a vitamin K-dependent glycoprotein synthesized in hepatocytes. It was reported previously that FVII gene (F7) expression was up-regulated by ribavirin treatment in hepatitis C virus-infected haemophilia patients; however, its precise mechanism is still unknown. In the present study, we investigated the molecular mechanism of ribavirin-induced up-regulation of F7 expression in HepG2 (human hepatoma cell line). We found that intracellular GTP depletion by ribavirin as well as other IMPDH (inosine-5'-monophosphate dehydrogenase) inhibitors, such as mycophenolic acid and 6-mercaptopurine, up-regulated F7 expression. FVII mRNA transcription was mainly enhanced by accelerated transcription elongation, which was mediated by the P-TEFb (positive-transcription elongation factor b) complex, rather than by promoter activation. Ribavirin unregulated ELL (eleven-nineteen lysine-rich leukaemia) 3 mRNA expression before F7 up-regulation. We observed that ribavirin enhanced ELL3 recruitment to F7, whereas knockdown of ELL3 diminished ribavirin-induced FVII mRNA up-regulation. Ribavirin also enhanced recruitment of CDK9 (cyclin-dependent kinase 9) and AFF4 to F7. These data suggest that ribavirin-induced intracellular GTP depletion recruits a super elongation complex containing P-TEFb, AFF4 and ELL3, to F7, and modulates FVII mRNA transcription elongation. Collectively, we have elucidated a basal mechanism for ribavirin-induced FVII mRNA up-regulation by acceleration of transcription elongation, which may be crucial in understanding its pleiotropic functions in vivo.

OBJECTIVE

The quality of some of the human plasma derived drugs such as coagulation factor VIII and coagulation factor IX which can be used for the treatment of hemophilia A and B, depends on their activity which may be affected by filtration. In this study the quality of plasma with respect to coagulation factors FVII, FVIII, FIX, FV, FXI, Fibrinogen, antithrombin III, anti-plasmin and antitrypsin activities obtained after plasma filtration with CPD (citrate-phosphate-dextrose) using integral filter was evaluated.

METHODS

Sixty units of plasma were individually separated from whole blood by centrifugation and immediately filtered by integral filter system. Specific plasma filtration was carried out between 4 and 20 hrs after blood donation. Before filtration, 60 units of non filtered fresh plasmas were kept as control. Coagulation factors were determined by one-stage clotting assay in an automated system. Antithrombin III activity was determined by immunochrom assay in an automated system. Activity of anti-plasmin was determined by Berichrom α(2)-antiplasmin and antitrypsin activity was assayed with human neutrophil elastase.

RESULTS

The activity of coagulation factors FVIII, FIX, Fibrinogen, FV, and FXI, were not affected by filtration, in all experiments. Filtration only caused negligible change in FVII activity. Antithrombin III, anti-plasmin and antitrypsin activities were not influenced by filtration. Nonfiltrated and filtrated plasma values were not significantly different (P> 0.05).

CONCLUSIONS

Plasma filtration dose not result in a measurable impairment of coagulation factors and inhibitors. Although a little changes in FVII activity was observed after filtration, but these filtration-dependent changes apparently have no impact on the therapeutic quality of whole blood- filtered fresh plasma for transfusion.

To facilitate studies of the in vivo role of the extrinsic pathway of coagulation in experimental hemostasis and thrombosis, a full-length cDNA-encoding rabbit factor VII was isolated using polymerase chain reaction-mediated DNA amplification from plaque-purified lambda gt11 phage. Repeated DNA sequencing of both full-length rabbit factor VII cDNA and shorter cDNA fragments verified four changes in the previously reported amino acid sequence of mature rabbit factor VII, now predicted to be 405 amino acids in length. Rabbit factor VII cDNA was transfected into human embryonic kidney 293 cells and a cell line that permanently expressed rabbit recombinant factor VII was established. Rabbit recombinant factor VII was purified from tissue culture media using a combination of barium citrate precipitation, DEAE-sepharose FF chromatography, benzamidine agarose, and affinity chromatography using a sheep antirabbit factor VII polyclonal antibody. The purity and authenticity of rabbit recombinant factor VII was confirmed by polyacrylamide gel electrophoresis and Western blot analysis. Homogeneous rabbit recombinant factor VII was fully active biologically as determined by prothrombin time assay in factor FVII-depleted plasmas, of both human and rabbit origin, using either human or rabbit thromboplastin. Rabbit recombinant factor VII should prove useful for future in vivo investigations of experimental coagulopathies.

BACKGROUND

Coagulation factor VII (FVII) levels in plasma are usually related to ischemic heart disease (IHD) and cerebral infarction shares many of the risk factors related to IHD. Is there any relationship between factor VII and cerebral infarction? We investigated the relationship between FVII and acute cerebral infarction and reported genotype frequencies and allelic frequencies of FVII gene polymorphisms in the Chinese Han population.

METHODS

We recruited 62 patients with acute cerebral infarction confirmed by magnetic resonance imaging (MRI) from Ruijin Hospital, and 149 age-matched patients clinically free of vascular disease to act as controls. All of them were unrelated, and were from the Chinese Han population. FVII coagulant activity (FVIIc) was determined using an clotting assay, activated FVII (FVIIa) and FVII Ag were assayed using enzyme immunoassay kits. The FVII gene polymorphisms to be detected included-401G/T, -402G/A, 5'F7A1/A2, IVS7 and R353Q. 5'F7 and IVS7 were revealed by means of a PCR and direct agarose gel electrophoresis. The rest were examined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The results showed that FVIIc, FVIIAg and FVIIa were higher in the acute cerebral infarction group than in the control group (P < 0.01, P < 0.05, P < 0.05, respectively). There were no significant differences in the genotype frequencies of FVII gene polymorphisms between the two groups. The allelic frequencies in the Chinese Han population were as follows: -401G/T (96.64/3.36), -402G/A (52.01/47.99), 5'F7A1/A2 (96.64/3.36), IVS7 H5/H6/H7/H8 (0.34/52.35/46.98/0.34) and R353Q (95.64/4.36). There were significant differences (P < 0.01, P < 0.001, P < 0.001, P < 0.001, P < 0.001, respectively) in these allelic frequencies between the Chinese Han and European populations.

CONCLUSIONS

The results indicate that increased plasma FVII levels may contribute to thrombosis in cerebral infarction. And there was no significant difference in genotype frequencies of these five FVII gene polymorphisms between the acute cerebral infarction and control groups. Moreover, these results showed that the frequencies of protective allele, including -401T, 5'F7 A2 and 353Q were lower, but that -402A, which was previously found to be associated with increased plasma FVII levels, is higher in Chinese Han population.

BACKGROUND

The association between myocardial infarction (MI) and the R353Q polymorphism of the Factor VII (FVII) gene, which reportedly influences FVII concentrations, activated Factor VII (FVIIa), or FVII antigen (FVIIag), remains controversial.

RESULTS

The present case - control study in 127 Japanese men with their first MI at or before 45 years of age and 150 matched healthy controls was designed to clarify this association in premature MI. R353Q polymorphism was determined by polymerase chain reaction, and plasma concentrations of FVIIa and FVIIag were assayed. The distribution of the RR, RQ, and QQ genotypes with respect to R353Q polymorphism was 117, 10, and 0 in the patients, and 131, 17, and 2 in the controls. The Q allele was negatively associated with premature MI (odds ratio =0.41, p=0.038). The plasma concentration of FVIIa was slightly higher in patients (55.1+/-40.9 U/L) than in controls (44.8+/-20.2 U/L), but not significantly (p=0.078); the plasma concentration of FVIIag did not differ between patients (88.7+/-15.7%) and controls (87.0+/-9.0%) (p=0.557). Plasma FVIIa concentrations were influenced by R353Q polymorphism (p<0.001).

CONCLUSIONS

The Q allele may be protective against premature MI.

OBJECTIVE

To determine whether polymorphisms in the genes for coagulation factor II, V, VII could predispose an individual to increase risk for coronary artery disease (CAD) and/or myocardial infarction (MI) in Chinese.

METHODS

We screened coagulation factor II(G20210A),V(G1691A),VII (R353Q and HVR4) genotype in 374 patients undergoing coronary angiography by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) assay.

RESULTS

The R353Q and HVR4 genotype of the factor VII distribution was in accordance with Hardy-Weinberg equilibrium. The frequencies of FVII genotype or allele did not show statistically significant differences between CAD group and controls or between male and female. The frequencies of the Q allele and (RQ + QQ) genotype were significantly higher among the CAD patients without myocardial infarction (MI) history than among those with MI history (P < 0.05). However, HVR4 polymorphism was not significantly different within groups. We only find one normal control of factor II (G20210A) mutation. No coagulation factor V(G1691A) mutation was found in the CAD patients and controls.

CONCLUSIONS

The factor II(G20210A) ,V(G1691A) mutation is absent and may not be a major genetic factor for CAD and/or MI; the Q allele of the R353Q polymorphism of the factor VII gene may be a protective genetic factor against myocardial infarction in Chinese.

OBJECTIVE

Steroid hormones, especially estrogens, are known to affect hemostatic risk factors for thromboembolism, cardiovascular disease, and stroke. We examined these risk factors during depression of the serum estradiol concentration by a GnRH analogue.

METHODS

Patients were treated with a GnRH analogue, goserelin (Zoladex), 3.6 mg/inj monthly, for a period of 6 months. Blood samples were collected during and after treatment and in a control group. In ten patients a blood sample was also drawn before treatment. Measurements were made of serum estradiol, and the plasma concentrations of tissue-type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor (PAI-1) antigen, antithrombin III (AT III) and protein C activity, factor VII (FVII) antigen, and fibrinogen.

METHODS

Outpatient clinics at the Departments of Obstetrics and Gynecology at two university hospitals in southern Sweden.

METHODS

Twenty-seven women with endometriosis were consecutively included. A control group comprised 20 women with normal menstrual cycles.

METHODS

The concentrations of the hemostatic components during depression of the serum estradiol concentrations, as compared to those during normal ovulatory cycles.

RESULTS

Serum estradiol concentrations during treatment were comparable to those of postmenopausal women (mean, 23.2 pmol/L), and both AT III and protein C activity were significantly increased (P < .005 and P < .02, respectively). As compared to controls, plasma concentrations of PAI-1 and t-PA of patients were significantly higher both during and after treatment. In the subgroup also studied prior to treatment, there were no differences in hemostatic components, when comparing pretreatment and posttreatment values.

CONCLUSIONS

Treatment with this type of GnRH analogue for 6 months is safe with regard to its effect on hemostatic risk factors. The similar responses of t-PA and its inhibitor, PAI-1, to alterations in estrogen levels as well as inflammatory reactivity presumably constitute a balance mechanism preserving fibrinolytic defenses.

We have studied a family with homozygous lethal, blood coagulation factor VII (FVII) deficiency. To identify the mutation responsible for the deficiency, exons 2 to 8 and the intron-exon junctions of their FVII genes were amplified from peripheral white blood cell DNA by polymerase chain reaction and screened by single-strand conformational polymorphism analysis. The fragment showing aberrant mobility was cloned and sequenced. We detected a single point mutation, a homozygous G to A substitution at nucleotide position 6070, in the invariant GT dinucleotide at the 5' splice site of intron 4. Homozygosity was confirmed by loss of a site for the restriction endonuclease Mlu I. Analysis of the splicing pattern of ectopic transcripts in lymphocytes in the parents revealed that this mutation is associated with skipping of exon 4, which produces an mRNA encoding FVII with an in-frame deletion of the first epidermal growth factor-like domain (EGF 1). Transient transfection of COS-7 cells with an expression vector containing the triangle upEGF 1 FVII cDNA shows that this mutant protein is not expressed. The identification of the molecular basis of the FVII deficiency in this family allowed mutation-specific prenatal diagnosis to be performed in a subsequent pregnancy. In this family complete FVII deficiency is associated with a severe bleeding diathesis but no developmental abnormalities, lending weight to the hypothesis that fetal FVII is not required for the putative angiogenic functions of tissue factor in humans.

Factor VII (FVII) deficiency, the most frequent defect among the rare bleeding disorders, is commonly divided into type I and type II. In the former, there is a concomitant decrease in FVII activity and antigen. In the latter, there is a clear discrepancy between activity which is low and antigen which is normal or nearly normal. FVII Padua (Arg304Gln) is characterized by different reactivity towards different tissue thromboplastins. FVII levels were assayed by the use of different tissue thromboplastins, namely rabbit brain, human placenta, human recombinant and ox brain thromboplastin, in 6 homozygous patients. Cases reported in the literature were also evaluated. Ox brain thromboplastins yielded normal values, whereas human tissue or recombinant human thromboplastins yielded only slightly higher levels of activity than those obtained with rabbit brain reagents. The ox brain versus rabbit brain ratio was about 22, whereas the ratio for human placenta or human recombinant versus rabbit brain thromboplastin was only about 5. The FVII antigen versus rabbit brain, human tissue and ox brain activity ratios were 24.8, 4.3 and 1.1, respectively. These results indicate that the ox brain versus the rabbit brain thromboplastin ratio supplies a wider difference than the one between human tissue and rabbit brain. The antigen/ox brain activity ratio of 1.1 fully confirms this assertion.

Recombinant factor VIIa is indicated for treatment of bleeding episodes in patients with haemophilia A or B with inhibitors; in FVII deficiency and in Glanzmann's thrombasthenia. The aim of the study reported here was to compare the pharmacokinetic profiles between two formulations of rFVIIa that are produced in two different cell lines and media: Chinese hamster ovary cells cultured in a serum-free medium (CHO-rFVIIa) and baby hamster kidney cells cultured in a non-human serum-based medium (BHK-rFVIIa). Two clinical trials were performed; one in healthy subjects and the other in patients with congenital haemophilia A or B, with or without inhibitors. Subjects were recruited into a two-way crossover trial and were randomized to receive a dose of CHO-rFVIIa and BHK-rFVIIa. Healthy subjects received one dose of 90 μg CHO-rFVIIa kg(-1) bodyweight (bw) in the newly developed room-temperature stable rFVIIa formulation and one dose of 90 μg BHK-rFVIIa kg(-1) bw, in the original rFVIIa formulation. Patients with haemophilia received one dose of 270 μg CHO-rFVIIa kg(-1) and one dose of 270 μg BHK-rFVIIa kg(-1), both in the room-temperature stable formulation. The trials showed higher FVII activity levels [higher area under the plasma concentration-time curve (AUC)] following administration of CHO-rFVIIa than after BHK-rFVIIa. Therefore, bioequivalence could not be established. The difference in FVII activity levels is believed to be a result of different glycosylation patterns between the two products. Neither the use of CHO-rFVIIa nor the use of one single dose of 270 μg kg(-1) of the newly developed room-temperature stable rFVIIa raised any safety concerns.

Recombinant activated factor VII (rFVIIa) is approved for prevention and treatment of bleeding in hemophilia patients with inhibitors to FVIII (hemophilia A) or IX (hemophilia B), patients with congenital and acquired hemophilia and in patients with FVII deficiency or Glantzmann thrombasthenia (last indication is approved only in Europe). Off-labeled, the drug has been prescribed for prevention, or treatment of bleeding in severe hepatic disease, neonatal coagulopathies, high-risk surgical procedures, trauma, thrombocytopenia and platelet function disorders, as well as for urgent reversal of oral anticoagulation. Here we report a case of a 53-year-old female patient with delayed graft function after kidney transplantation, who had kidney biopsy complicated with prolonged bleeding. After unsuccessful treatment with desmopressin, the patient was treated with rFVIIa and the bleeding stopped immediately. Only few anecdotal reports of use of rFVIIa for treatment of bleeding in uremic patients have been published thus far. To our knowledge, this is the first case that describes use of rFVIIa for management of bleeding as a complication of renal biopsy in a uremic patient in the early kidney posttransplantation period.

BACKGROUND

Factor V deficiency (FVD) is a rare bleeding disorder (RBD) mostly present in regions with a high rate of consanguinity. FVD after FXIII deficiency is the next more prevalent RBD in Sistan and Baluchistan (S&B) in southeastern Iran. The aim of this study was to evaluate the clinical manifestations and severity of bleeding diathesis in patients with FVD.

METHODS

This descriptive study was conducted on 23 patients with FVD in S&B province. FVD was diagnosed by clinical findings and routine laboratory tests. Bleeding diatheses were classified into three grades (I-III) depending on the severity of symptoms. The severity of bleeding episodes in our patients was compared with other RBDs.

RESULTS

Based on residual plasma FV activity, 6 (26%), 16 (69.5%) and 1 (4.5%) patients had mild, moderate and severe factor deficiency, respectively. 24% of the patients had grade III life-threatening bleeding episodes which in comparison with FVII deficiency (17.4%) and FI deficiency (21%) had a higher incidence, and in comparison with FX deficiency (41.7%) and FXIII deficiency (63.1) had a lower incidence. Grade II and grade I bleeding diathesis were observed in 56.2 and 16.7% of the patients, respectively.

CONCLUSIONS

FVD is the second most common type of RBD in S&B province and grade II bleeding episodes were the major bleeding presentation and observed in more than half of the patients.

Pregnancies and deliveries represent important hemostatic challenges for congenital coagulation disorders. The same is true for the assumption of oral contraceptives. Available information mainly deals with von Willebrand's disease, factor XI (FXI) deficiency and carriers of hemophilia A. Data concerning patients with congenital prothrombin complex factor deficiencies are very scanty. In the present study, data of a total of 27 women are presented, 11 patients with homozygous or double heterozygous deficiencies of FII, FVII and FX, together with 16 cases of hemophilia B carriers. The patients with FII, FVII or FX defects had a total of 14 pregnancies and often needed transfusion therapy. Proper management resulted in a decrease in postpartum bleeding and satisfactory fetal outcome. Elective cesarean delivery seems indicated only in recent years. Carriers of hemophilia B had a total of 19 pregnancies but showed no bleeding and needed no substitutive therapy. Searching the literature, we discovered only 9 additional patients with prothrombin deficiency or FX deficiency, having a total of 16 pregnancies. On the contrary, there were at least 17 additional patients with FVII deficiency, with a total of 21 pregnancies. The management of the diseases has been variable, but in substantial agreement with the personal observations. Oral contraceptive therapy was administered in some of our patients and in a few additional cases described in the literature. Medication was always well tolerated and patients who took it for a long period of time showed a decrease in menometrorrhagia and an improvement in hematocrit levels. This led to a decrease in transfusional needs and to improved general conditions.

Thrombotic diseases increase in incidence with advancing years and this might be partly due to an increased propensity for fibrin formation in older individuals. Accordingly we decided to investigate whether the time taken to generate 50% thrombin activity in vitro varied with the age of the plasma donor. Coagulation was initiated in defibrinated, diluted plasma by contact activation and thrombin activity measured using the chromogenic substrate, S2238. The rate of thrombin generation was assessed by measuring the time taken to reach 50% maximal activity (T50/s). There was a highly significant negative correlation between T50 and age, T50 declining from 93 s at 19 years to 71 s at 65 years (r = -0.637, p less than 0.0001). A strong negative correlation was demonstrated between T50 and FVII level (r = -0.415, p = 0.0007) and FVIII:C level (r = -0.465, p = 0.0001). Although FVII concentration correlated with age (r = 0.307, p = 0.014) no relationship was seen between age and FVIII:C. These data suggest that coagulation rates in plasma accelerate with age.

Prenatal diagnosis is sought after for those genetic disorders, whose management is not satisfactory either because of the outcome or owing to extreme cost involved in the management of the patients affected by a specific disorder. Severe hemophilia and homozygous thalassemia are the 2 disorders for which there is an increasing demand for prenatal diagnosis in India. Rare severe deficiencies of coagulation factor X (FX) and factor VII (FVII) may present with severe bleeding manifestations. Because of their rarity the laboratory offering prenatal diagnosis for severe hemophilia and thalassemia may not be in a position to provide genetic diagnosis in the fetus. In this communication, we describe 2 families, 1 with an index patient of severe FVII deficiency and the other with severe FX deficiency where successful prenatal diagnosis was given after cordocentesis between 17 and 19 weeks using a battery of coagulation factor assays. Follow-up studies were performed 3 to 4 months after delivery and the diagnoses were reconfirmed on these babies by a repeat factor assay for FX and FVII deficiency, respectively.

Congenital factor VII (FVII) deficiency is a rare bleeding disorder caused by mutations in F7 gene with autosomal recessive inheritance. A clinical heterogeneity with poor correlation with FVII:C levels has been described. It was the objective of this study to identify genetic defects and to evaluate their relationships with phenotype in a large cohort of patients with FVII:C<50 %. One hundred twenty-three probands were genotyped for F7 mutations and three polymorphic variants and classified according to recently published clinical scores. Forty out of 123 patients (33 %) were symptomatic (43 bleedings). A severe bleeding tendency was observed only in patients with FVII:C<0.10 %. Epistaxis (11 %) and menorrhagia (32 % of females in fertile age) were the most frequent bleedings. Molecular analysis detected 48 mutations, 20 not reported in the F7 international databases. Most mutations (62 %) were missense, large deletions were 6.2 %. Compound heterozygotes/homozygotes for mutations presented lower FVII:C levels compared to the other classes (Chi2=43.709, p<0,001). The polymorphisms distribution was significantly different among the three F7 genotypic groups (Chi2=72.289, p<0,001). The presence of truncating mutations was associated with lowest FVII:C levels (Chi2=21.351, p=0.002). This study confirms the clinical and molecular variability of the disease and the type of symptoms. It shows a good correlation between the type of F7 mutation and/or polymorphisms and FVII:C levels, without a direct link between FVII:C and bleeding tendency. The results suggest that large deletions are underestimated and that they represent a common mechanism of F7 gene inactivation which should always be investigated in the diagnostic testing for FVII deficiency.

Congenital factor VII (FVII) deficiency is an autosomal recessive bleeding disorder with variable phenotypic correlation between FVII activity and bleeding risk. We report a novel mutation of the FVII gene that creates the amino acid change Ser 103 to Gly, which resulted in severe FVII deficiency with reduced FVII antigen. This mutation in the heterozygous form was also present in a mildly affected, unrelated patient. We also report on the natural history of an FVII inhibitor in the patient with severe FVII deficiency.

OBJECTIVE

To present a rare case with factor VII deficiency (FVIID) that first diagnosed during pregnancy, and to disccuss the ante-, peri- and postpartum management.

METHODS

A case report and review of the literature.

RESULTS

FVIID was diagnosed for the first time in a 23-year-old pregnant woman at the 24th week of gestation due to complaint of intermittent epistaxis. She was successfully treated by ante-, peripartum and postpartum replacement of recombinant FVII (rFVII). She was uneventfully discharged on the 3rd postoperative day and referred to hematology department for further follow-up.

CONCLUSIONS

FVIID, a rare cause of ante- and postpartum hemorrhages that may differently present by other hemorrhages (i.e.: epistaxis), can be optimally managed with replacement of rFVII.

Acquired haemophilia (AH) is a rare, often severe bleeding disorder characterised by autoantibodies to coagulation factor VIII (FVIII). Observational studies offer crucial insight into the disease and its treatment. Recombinant activated factor VII (rFVIIa, eptacog alfa activated) was available on an emergency and compassionate use basis from 1988 to 1999 at sites in Europe and North America. In 1996, rFVIIa was approved in Europe for the treatment of AH; it was licensed for this indication in the United States in 2006. Recombinant activated FVII is approved for first-line treatment of bleeding episodes and prevention of bleeding in surgical/invasive procedures in patients with AH. This review provides an up-to-date summary of the haemostatic efficacy of rFVIIa in patients with AH, from the first emergency and compassionate use programmes, to patient registries and a post-marketing surveillance study. In acute bleeding episodes, rFVIIa provided high and consistent rates of control, and available data showed that acute bleed control rates were higher for first-line rFVIIa versus salvage rFVIIa. In surgical procedures, rFVIIa also provided high rates of control. In patients with AH, rFVIIa has a high rate of haemostatic efficacy in acute and surgical bleeding episodes.

Congenital factor VII (FVII) deficiency is characterized by genotypic variability and phenotypic heterogeneity. Traditional screening and factor assays are unable to reliably predict clinical bleeding phenotype and guide haemorrhage prevention strategy. Global assays of coagulation and fibrinolysis may better characterize overall haemostatic balance and aid in haemorrhagic risk assessment. We evaluated the ability of novel global assays to better understand clinical bleeding severity in congenital FVII deficiency. Subjects underwent central determination of factor VII activity (FVII:C) as well as clot formation and lysis (CloFAL) and simultaneous thrombin and plasmin generation (STP) global assay analysis. A bleeding score was assigned to each subject through medical chart review. Global assay parameters were analysed with respect to bleeding score and FVII:C. Subgroup analyses were performed on paediatric subjects and subjects with FVII ≥ 1 IU dL(-1). CloFAL fibrinolytic index (FI2 ) inversely correlated with FVII:C while CloFAL maximum amplitude (MA) and STP maximum velocity of thrombin generation (VT max) varied directly with FVII:C. CloFAL FI2 directly correlated with bleeding score among subjects in both the total cohort and paediatric subcohort, but not among subjects with FVII ≥ 1 IU dL(-1) . Among subjects with FVII ≥ 1 IU dL(-1), STP time to maximum velocity of thrombin generation and time to maximum velocity of plasmin generation inversely correlated with bleeding score. These preliminary findings suggest a novel potential link between a hyperfibrinolytic state in bleeding severity and congenital FVII deficiency, an observation that should be further explored.

BACKGROUND

Use of liquid plasma (LP) has been reported as early as the mid 1930s. Unlike fresh-frozen plasma (FFP), LP is maintained at 1 to 6°C for up to 40 days after collection and processing. Despite its approved use by the US Food and Drug Administration, the coagulation profile of LP is incompletely described. In this study we evaluate the coagulation profile of LP stored up to 30 days.

METHODS

LP was prepared by removing plasma from nonleukoreduced whole blood within 24 hours of collection. Three LP units from each ABO group were collected and stored at 1 to 6°C. Plasma aliquots were obtained at Postcollection Days 1 to 5, 10, 15, 20, 25, and 30 and then stored at -70°C. Each aliquot was tested for prothrombin time, activated partial thromboplastin time, and other coagulation and fibrinolytic factors.

RESULTS

There was a significant decrease in Factor (F)V, FVII, FVIII, von Willebrand factor (VWF), protein S (PS) activity, and endogenous thrombin potential on Day 15 compared with Day 1. No significant difference was observed for PS antigen, D-dimer, or thrombin-antithrombin complex. At least 50% activity of all measured factors was noted on Day 15, compared to Day 1. Considerable heterogeneity was observed between the different blood groups for FVII, FVIII, and VWF.

CONCLUSIONS

These data demonstrate that LP maintains at least 50% of factor activity and thrombin-generating capacity up to 15 days of refrigerated storage. It may be more appropriate to limit LP storage and supplement with FFP when used for management of massively bleeding patients.

We report a factor VII (FVII) variant, FVIIShinjo, characterized by normal FVII antigen levels and variable procoagulant activity using tissue thromboplastin from different sources. Normal FVII activity is obtained using human placenta thromboplastin but low activity using rabbit or bovine brain thromboplastin. Exons 2-8 and the intron-exon junctions of the FVII genes of the propositus were amplified by PCR from DNA extracted from peripheral white blood cells, and screened by single-strand conformational polymorphism (SSCP) analysis. DNA fragments showing aberrant mobility were cloned and sequenced. We detected a single-point mutation, a homozygous G to A transition at nucleotide position 6,055 in exon 4, which results in the substitution of Arg 79 by Gln in the first EGF-like domain. This mutation results in a loss of a site for the restriction endonuclease MspI. The Msp I digestion pattern of the PCR-amplified exon 3+4 fragments from each member of the family was determined. The Msp I haplotypes were consistent with this G to A transition being associated with reduced FVII activity as detected using thromboplastins from various species. We conclude that the Arg 79 to Gln substitution in the first EGF-like domain of FVII identified in the propositus is responsible for the inherited FVII abnormality in this Japanese family. We postulate that one of the sites of interaction between FVII and tissue thromboplastin includes Arg 79 in the first EGF-like domain of factor VII.

FVII(tTA/-) mice are heterozygous for the FVII- null allele and a gene-targeted allele expressing very low levels of FVII. Approximately half the FVII(tTA/-) in a mixed C57Bl/6:129x1/SVJ background survive much longer than mice in a C57Bl/6 background, suggesting that genetic background affects the survival of mice expressing very low levels of FVII. A lineage of long-term surviving FVII(tTA/-) mice in a predominantly C57Bl/6 background was generated by selecting 16 weeks or older FVII(tTA/-) males and breeding them with C57Bl/6 FVII+/- females. It is postulated that these mice maintain 129x1/SVJ alleles at putative hemostatic modifier loci necessary for the survival of mice expressing very low levels of FVII. A SNP genomic scan was performed on DNA from long-term surviving FVII(tTA/-) mice. The scan identified 8 regions enriched for 129x1/SVJ sequences that might contain putative hemostatic modifier genes.