Disorders of menstruation and their effect on the quality of life in women with congenital factor VII deficiency

AIMS AND OBJECTIVES: To review menstrual problems in women with congenital FVII deficiency and to study their effect on the quality of life during menstruation in women with congenital FVII deficiency. METHOD: 14 women with congenital factor VII deficiency registered with the Haemophilia Centre at the Royal Free Hospital were interviewed and their case notes reviewed. All women completed Pictorial Blood assessment Chart (PBAC) for assessment of menstrual blood loss and a quality of life questionnaire during menstruation. Similar questionnaire and PBAC was completed by an age matched healthy control group of 23 women. RESULTS: Median age of study group was 35 yrs and of control group 34 yrs. Median FVII level of the study group was 31.5 IU/dL Two women had severe FVII deficiency (FVII level < 10 IU/dL) and 12 women had mild-moderate FVII deficiency. 57% women (8/14) from study group had menorrhagia (PBAC score > 100) compared with 17% (4/23) women from the control group. Six women (43%) from the study group were diagnosed with anaemia due to heavy periods, compared to two (9%) in the control group. The quality of life scores during menstruation were significantly worse in the women with FVII deficiency, compared to controls. CONCLUSION: Women with factor VII deficiency exhibit a spectrum of bleeding symptoms, menorrhagia being one of the commonest symptoms. This has adverse effect on their quality of life.     

Postprandial coagulation activation in overweight individuals after weight loss: Acute and long-term effects of a high-monounsaturated fat diet and a low-fat diet

Diet is important in the prevention of cardiovascular disease, and it has been suggested that a high-MUFA diet is more cardioprotective than a low-fat diet. We hypothesised that the postprandial thrombotic risk profile is improved most favourably by a high-MUFA diet compared with a low-fat diet. This was tested in a parallel intervention trial on overweight individuals (aged 28.4 (SD 4.7) years) randomly assigned to a MUFA-diet (35-45% of energy as fat; > 20% as MUFA, n = 21) or a low-fat (LF) diet (20-30% of energy as fat, n = 22) for 6 months after a weight loss of ~ 10%. All foods were provided free of charge from a purpose-built supermarket. Meal tests designed after the same principles were performed before and after the dietary intervention, and blood samples were collected at 8.00 h (fasting), 12.00 h, and 18.00 h and analysed for factor VII coagulant activity (FVII:C), activated FVII, fibrinogen, prothrombin fragment 1 + 2 (F1 + 2), D-dimer, plasminogen activator inhibitor (PAI:Ag), and thrombin activatable fibrinolysis inhibitor. There were significant postprandial increases in F1 + 2 and D-dimer before and after dietary intervention, with significantly lower values after 6 months. No significant differences were observed between the postprandial changes induced by the two diets. The postprandial decrease in FVII:C and PAI:Ag did not differ before and after intervention, irrespective of the diets. Our findings suggest postprandial coagulation activation in overweight subjects with more pronounced acute than long-term effects. We observed similar effects of the MUFA diet and the LF diet on the postprandial prothrombotic risk profile.     

Tamoxifen induces resistance to activated protein C

Introduction

The estrogen antagonist tamoxifen (TAM) increases the thrombotic risk similar to estrogen containing oral contraceptives (OC). In OC users this risk is attributed to alterations of hemostasis resulting in acquired resistance to activated protein C (APC). TAM-induced APC resistance has not been reported yet.

Materials and Methods

Blood samples were collected prospectively from women with breast cancer before (n = 25) and monthly after start of adjuvant TAM treatment (n = 75). APC resistance was evaluated on basis of the effect of APC on the endogenous thrombin generation potential. To detect increased in vivo APC generation APC plasma levels were measured using a highly sensitive oligonucleotide-based enzyme capture assay. Routine hemostasis parameters were measured additionally.

Results

APC sensitivity decreased by 41% (p = 0.001) compared to baseline after one month of TAM application and remained significantly decreased during the study period. Free protein S increased (p = 0.008) while other analyzed procoagulant factors, inhibitors, and activation markers of coagulation decreased or did not change significantly. In five patients the APC concentration increased to non-physiological levels but an overall significant increase of APC was not observed.

Conclusions

This is the first study showing acquired APC resistance under TAM therapy. Acquired APC resistance might explain the increased thrombotic risk during TAM treatment. Observed changes of hemostasis parameters suggest different determinants of TAM-induced APC resistance than in OC-induced APC resistance. The presence of acquired APC resistance in TAM patients warrants further evaluation if these patients may benefit from antithrombotic prophylaxis in the presence of additional thrombotic risk factors.     

In vitro evaluation of residual procoagulants in human intravenous immunoglobulins from 11 Chinese blood fractionation companies

Introduction

Residual procoagulants has been suggested to play an important role in the occurrence of thromboembolic events with intravenous immunoglobulin.

Objective

This study investigated the predominant plasma proteases in 81 intravenous immunoglobulin lots from 11 Chinese manufacturers to examine the procoagulants of these human therapeutic intravenous immunoglobulin products.

Methods

In one-stage clotting assays, the procoagulant activities of factors II, VII, IX, X, XI, and XII were quantified. Non-activated partial thromboplastin time and a modified thrombin generation test served as global and activated coagulation factor XI specific clotting assays, respectively.

Results

The coagulation factor clotting activities of the 78 intravenous immunoglobulin lots were below the detection limit of the assays. The time to peak of thrombin generation using a thrombin generation test was longer than 35 min. The relevant amount of activated coagulation factor XI was below 0.37 nM. Non-activated partial thromboplastin time was greater than 203 s, except for the three pilot samples of manufacturer B in which we observed 0.48 to 0.09 IU/mL factor XI lever, 20 to 26 min for the time to peak of thrombin generation, 0.54 to 37.99 nM activated coagulation factor XI, and 155 to 182 s for non-activated partial thromboplastin time.

Conclusions

The three intravenous immunoglobulin lots from manufacturer B showed significant procoagulant potential. Further study is required to determine whether a program for activated coagulation factor XI determination in intravenous immunoglobulin products should be launched in China.     

The P303T mutation in the human factor VII (FVII) gene alters the conformational state of the enzyme and causes a severe functional deficiency

We report the results of in vitro expression and biochemical characterization of the naturally occurring type II mutation Pro303Thr (P303T) in the factor VII (FVII) gene. Recombinant activated mutated FVII (FVIIa303T), compared with the activated wild-type FVII (FVIIaWT), showed reduced amidase activity toward synthetic substrates, especially when the observed reduced binding affinity for human soluble tissue factor (TF) (K(d) from 4.4 nmol/l for FVIIaWT to 17.3 nmol/l for FVIIa303T) was overcome by a fully saturating TF concentration. Likewise, factor X (FX) hydrolysis by FVIIa303T showed a reduced activity in the absence (and more severely in the presence) of TF (k(cat)/K(m) from 2.3 x 10(7)/mol/l s for FVIIaWT to 8.7 x 10(5)/mol/l s for FVIIa303T). These results showed that the mutant FVIIa is more shifted toward a zymogen-like form compared to FVIIaWT, suggesting that P303 facilitates the conformational transitions that stabilize the active form of FVIIa. The alteration of these allosteric equilibria is especially evident in the presence of TF, which was unable to shift the equilibrium toward a fully active FVIIa form. Additional experiments showed that both TF-catalysed FVII303T autoactivation and FVII303T activation by activated FX in the presence of TF were severely impaired, mainly because of an increase of the K(m) value. Altogether, these defects may explain the severe bleeding symptoms in a patient carrying the FVIIP303T mutation.     

Heparin lowers plasma levels of activated factor VII

Based on heparin's antithrombin and anti-FXa activity and its in vitro inhibition of activated factor VII (FVIIa) activity, we hypothesized that unfractionated heparin (UFH) may decrease plasma levels of FVIIa in humans. Therefore, 10 healthy young male volunteers received an intravenous UFH infusion over 24 h. Heparin decreased FVIIa levels by 30% (95% CI 14-47%) at 12 h, which was sustained until 24 h. In contrast, neither the substrate pool (i.e. total factor VII) as measured by FVII antigen nor FVII activity were affected by UFH. These results may improve our understanding of the regulation of FVIIa levels and heparin's mode of action.     

A multicenter pharmacokinetic study of the B-domain deleted recombinant factor VIII concentrate using different assays and standards

Summary. When the one‐stage clotting assay is used in comparison with the chromogenic and immunological assays, plasma levels of factor (F)VIII are underestimated by 40–50% after infusion of B‐domain deleted recombinant FVIII (BDD‐rFVIII) in patients with hemophilia. A possible way to counteract the underestimation of FVIII levels by the one‐stage assay is the adoption of a recombinant FVIII reference standard instead of a plasma standard. To evaluate the usefulness of such a standard [ReFacto^® Laboratory Standard (RLS)], the pharmacokinetic parameters of a single dose of BDD‐rFVIII (25 U kg^?1) were evaluated in a multicenter study carried out in 18 patients with severe hemophilia A. The very low in vivo recovery, obtained with the combination of the one‐stage assay and plasma reference standard, was increased up to the values obtained by the chromogenic assay when the results were expressed in terms of RLS. When the plasma standard was used, the one‐stage/chromogenic ratio was 0.82 ± 0.12 for FVIII levels above 25 U dL^?1 and 1.42 ± 0.99 for FVIII levels below 25 U dL^?1. Using the RLS, the one‐stage/chromogenic ratio increased to 1.01 ± 0.19 at FVIII levels above 25 U dL^?1, as a consequence of a complete overlap of the two decays; however, at FVIII levels below 25 U dL^?1, the one‐stage/chromogenic ratio was still 1.6 ± 0.85. After the twelfth hour, FVIII concentrations obtained by chromogenic assay were always lower than those resulting from the one‐stage clotting assay, independently of the standard used. Results obtained by chromogenic assay were not affected by the type of standard used. Compared with those obtained by the one‐stage assay, higher values of clearance, lower volume of distribution area and shorter plasma half‐life or mean residence time were obtained by chromogenic assay because of a shape change of the decay curve due to a shift to higher values in the first part (time interval 0–12 h) and to lower values in the second part of the decay curve (time interval 12–48 h). As a consequence, the slope of the decay curve obtained by means of chromogenic assay was steeper. In conclusion, the more homogeneous results of in vivo recovery and pharmacokinetic analysis, due to the decrease of discrepancy between the two methods when RLS was used, make the cheaper and more widely used one‐stage assay preferable to the more expensive chromogenic assay, on condition that the ReFacto specific standard has used.     

Seminal factor VII and factor VIIa: supporting evidence for the presence of an active tissue factor-dependent coagulation pathway in human semen

Human semen spontaneously coagulates into a semisolid mass and then wholly liquefies in a process that may have some similarity to that of normal blood. This well described phenomenon is referred to as coagulation and liquefaction of semen. Besides other active components of the haemostatic system, semen contains a significant amount of functional tissue factor (TF). However, TF needs factor (F)VII in order to exert it actions. In this study, we assessed human semen for the presence of FVII and FVIIa, and related their levels to conventional fertility parameters. Using a functional, one stage, clotting assay based upon the prolongation of the prothrombin clotting time, using the ACL 300R analyser and an Imubind FVIIa ELISA assay, FVII and FVIIa levels were measured in 97 semen specimens obtained from sub-fertile (sperm counts <20 x 10(6)/mL), normally fertile (sperm counts >or=20 x 10(6) but <60 x 10(6)/mL), fertile sperm donors (sperm counts >or=60 x 10(6)/mL), vasectomized subjects and in a pooled normal semen parameters group (categorization into groups was based on the World Health Organization guidelines on fertility criteria). In addition, conventional semen parameters were analysed on all semen samples. Both FVII and FVIIa were quantifiable in human semen. The mean levels of FVII and FVIIa were 4.4 IU/dL and 12 ng/mL respectively. Despite the observed variations of FVIIa levels in the studied groups they did not meet statistical significance when the groups were tested against each other. However, seminal FVIIa levels showed a significant positive association with semen liquefaction time, sperm motility and semen volume. The anti-sperm antibodies and sperm-agglutination groups were also associated with raised seminal FVIIa levels. We observed no significant relationship between FVIIa levels and total sperm concentration, sperm count per mL (sperm density), sperm progression and days of sexual abstinence. This study demonstrates that human semen contains appreciable amounts of FVII and FVIIa. It is possible to quantify these using commercially available assays. There also appears to be a direct correlation between the levels of these factors and certain seminal parameters. This finding reinforces the concept of an active clotting system in human semen, by establishing the missing link in the activation of a TF-dependent pathway.     

Congenital factor VII deficiency and subarachnoidal haemorrhage due to intracranial aneurysm: a case report

The management of subarachnoid haemorrhage by aneurysm rupture is well codified. Some rare cases can be problematical. We report a case of a patient suffering from factor VII (FVII) deficiency who presented a subarachnoid haemorrhage by sylvian aneurysm rupture. The bleeding risk was prevented by plasmatic factor VII substitution and aneurysm coiling. Anticoagulation in order to prevent from thromboembolic risk after embolisation was started for 36 hours, associated with plasmatic FVII substitution (with an objective of plasmatic FVII rate of 30%). After this stage at high thromboembolic risk, there has been no shift to platelet antiaggregants and FVII substitution was stopped. The outcome at 1 month was propitious without any bleeding nor arterial thrombosis.