Isolated acquired factor VII deficiency: review of the literature

OBJECTIVES

Isolated acquired factor VII (FVII) deficiency is a rare haemorrhagic disorder. We report what is currently known about the pathogenesis, clinical features, diagnosis, treatment and prognosis of acquired FVII deficiency.

METHODS

We performed a literature search and included all articles published between 1980 and August 2015.

RESULTS AND CONCLUSIONS

Acquired FVII deficiency has been reported in 42 patients. There are well-established clinical diseases associated with acquired FVII deficiency, most notably infections, malignancy and haematological stem cell transplantation. The exact pathogenesis of the diseases is still unknown, but different pathophysiological hypotheses have been suggested. The clinical manifestation of acquired FVII deficiency varies greatly in severity; asymptomatic course as well as severe life-threatening bleeding diathesis and fatal bleedings have been described.

Recurrent intracranial haemorrhages in a patient with factor seven deficiency: a case report

Inherited factor VII (FVII) deficiency is a rare autosomal recessive hemorrhagic disorder. Clinical bleeding can vary widely and does not always correlate with the level of FVII coagulant activity measured in plasma. Most severe cases of factor VII (FVII) deficiency are diagnosed during childhood, often during the first 6 months of life. In infancy, the most common sites of bleeding occur in the gastrointestinal tract or CNS, accounting for 60-70% of bleeds in this age group. Recombinant factor VIIa (rFVIIa) is one such agent, which has been shown to prevent hematoma expansion and improve outcome in acute intracranial haemorrhages. The purpose of this case report is to share our experience regarding the usefulness of rFVIIa in the management of acute intracranial haemorrhage.

[The influence of factor VII deficiency on cardiac operations with extracorporeal circulation]

During preoperative blood coagulation testing the factor VII (FVII) deficiency was found in two patients. No liver disease or cardiac insufficiency was found. No history of bleeding episodes existed. The latent (mild) deficiency of the FVII was diagnosed. The treatment with vitamin K (Vitacon) was administered in order to exclude vitamin K deficiency. The treatment showed no impact on the level of the FVII. Mixing study corrected the deficit (normal PT was found). Both patients underwent cardiac surgery with extracorporeal circulation. The epsilon-aminocapronic acid and fresh frozen plasma were used to prevent bleeding. The postoperative bleeding was compared to average of the year. No difference was found. The patients with mild FVII deficiency may safely undergo cardiac surgery with extracorporeal circulation.

Congenital factor VII deficiency: therapy with recombinant activated factor VII - a critical appraisal

Congenital factor VII (FVII) deficiency is a rare bleeding disorder with high phenotypic variability, and optimal management has yet to be determined. Treatment has traditionally involved FVII replacement therapy using fresh frozen plasma, prothrombin complex concentrates or plasma-derived FVII concentrates. Recombinant activated FVII (rFVIIa, NovoSeven(R)), the first recombinant treatment option, has recently been approved in the European Union for use in congenital FVII deficiency, but has been available on an emergency and compassionate use basis since 1988. In FVII deficiency, rFVIIa serves as substitution therapy as it provides the physiological ligand (FVIIa) for tissue factor, its receptor exposed at the site of vascular injury. This paper provides an overview of published and unpublished experience with rFVIIa in patients with congenital FVII deficiency from the NovoSeven compassionate and emergency use programmes (1988-99) and of independent reports in the literature. Recombinant FVIIa has been reported to provide effective haemostasis in patients of all ages and in a range of bleeding situations, including acute central nervous system/life-threatening bleeding episodes (15 episodes in 12 patients), non-life-threatening bleeding episodes (>32 episodes in 17 patients), surgery (>40 interventions in 25 patients) and childbirth (three women). Preliminary reports suggest that it may also be effective prophylactically. The risk of thrombosis in FVII-deficient patients treated with rFVIIa is unknown, as is the occurrence of inhibiting antibodies. A postlicensure pharmacovigilance registry (Seven Treatment Evaluation Registry) has been set up to continue to monitor the efficacy and safety (including alloantibody development) of rFVIIa in patients with FVII deficiency.

Steps Towards an Effective Treatment Strategy in Congenital Factor VII Deficiency

Congenital factor VII (FVII) deficiency is a consequence of a genetic polymorphism that can produce a wide spectrum of disease severity. Mildly affected patients may experience increased bleeding after surgery, trauma or mucosal bleeding, while spontaneous and life-threatening bleeding occurs in patients who are severely affected. Replacement therapy is the mainstay of treatment for patients with FVII deficiency. This has traditionally been achieved using fresh frozen plasma (FFP), prothrombin complex concentrates (PCCs), or plasma-derived FVII concentrates. However, recombinant activated FVII is now widely used for therapy in these patients. As cases of FVII deficiency tend to be encountered infrequently in most centers, no consolidated evidence-based therapeutic regimens have evolved and the side effects of the available treatments have not been comprehensively evaluated. Consequently, an online registry, the Seven Treatment Evaluation Registry (STER) has been set up. This is a prospective study that aims to evaluate the efficacy and safety of the different therapeutic options with which FVII-deficient patients may be treated. Recruitment of patients into the study is currently underway.

The emerging role of recombinant activated Factor VII (rFVIIa) in the treatment of blunt traumatic haemorrhage

Recombinant activated Factor VII (rFVIIa; eptacog alpha [activated], NovoSeven) is currently used for the management of a subgroup of haemophilia patients with inhibitors to Factors VIII or IX, and is under investigation as an adjuvant therapy for critical bleeding from other causes, including trauma. rFVIIa has a mode of action founded on physiological coagulation processes, and causes localised haemostasis at injury sites, both spontaneous and traumatic, with the capacity to correct the systemic coagulopathy associated with massive blood loss and its management. This review charts the development of rFVIIa as a new and potent adjuvant therapy for severe bleeding and coagulopathy caused by blunt trauma, where it is reported to produce rapid and significant haemostasis, reducing transfusion requirements and improving clinical outcome.

Total hip arthroplasty in severe congenital factor VII deficiency: successful use of recombinant activated factor VII for hemostasis

Congenital factor VII (FVII) deficiency is a rare hemorrhagic disorder, and, in affected patients, surgery is likely to cause excessive bleeding. In this article, we report the first case of total hip arthroplasty in a patient with severe congenital FVII deficiency in which recombinant activated factor VII (rFVIIa, NovoSeven) was successfully used to manage bleeds. The patient was a 68-year-old woman with severe congenital FVII deficiency, who suffered from a hemorrhagic arthrosis of her left hip joint. We administered rFVIIa as intermittent bolus infusions both perioperatively and postoperatively; dosing was based on the results of a preoperative rFVIIa challenge test. During surgery and the 3-day postoperative treatment period, we observed normal hemostasis with no excessive bleeding or complications.

Lack of bleeding in patients with severe factor VII deficiency

Factor VII deficiency, although rare, is now recognized as the most common autosomal recessive inherited factor deficiency. It is usually considered to be associated with bleeding only in the severely affected subject and heterozygotes (>10%) are not considered at risk. The general recommendation for surgery is to achieve a FVII level in excess of 15% (0.15 1U/mL). We present three cases of severe factor VII deficiency, each of whom appeared hemostatically competent based on clinical history. Subject 1 is a 33 year-old African-American female with a baseline FVII of <1%, who had a fractured tibia requiring open reduction with internal fixation without any FVII replacement and subsequently underwent successful laparoscopic knee surgery with a factor VII level measured at 6%. Subject 2 is a 58 year-old African-American female with a factor VII level of 9% who underwent an elective left total hip replacement without any factor replacement and had no excessive bleeding, but who sustained a pulmonary embolism postoperatively. Subject 3 is a 19-year-old African-American male with a baseline FVII of 1% with a history of active participation in football without noticeable injury and who underwent an emergent appendectomy without bleeding. These three cases represent individuals with the severe form of FVII deficiency who did not exhibit excessive bleeding when challenged with surgical procedures. The clinical history would appear the most valuable tool in predicting the likelihood of bleeding in these patients, and we suggest that the presumption that all patients with severe FVII deficiency should receive replacement therapy before surgical procedures may not be valid in all cases.

Acquired isolated factor VII deficiency associated with severe bleeding and successful treatment with recombinant FVIIa (NovoSeven)

Acquired isolated FVII deficiency not due to vitamin K deficiency or liver disease is rare and often associated with severe bleeding. We present a case of transient acquired factor VII deficiency associated with major bleeding, successfully treated with twice daily intermittent intravenous recombinant activated factor VII (rFVIIa) (NovoSeven; Novo Nordisk). The severe transient reduction in factor VII coagulant activity (FVII:C) levels, unresponsive to fresh frozen plasma and vitamin K administration, raise the possibility of an acquired inhibitor to factor VII. However, no inhibitor to factor VII could be demonstrated using protein G sepharose adsorption, or a Bethesda assay using IgG purified from patient plasma. There are few reports of the use of rFVIIa in this setting and this case suggests that rFVIIa is effective therapy, and should be considered early when acquired factor VII deficiency is associated with severe bleeding.

Congenital factor VII deficiency: a case report

Factor VII deficiency is a rare congenital blood disorder. Its clinical features are rather variable and ranges from epistaxis to massive intracranial haemorrhage. Treatment involves replacement therapy, which constitutes use of fresh frozen plasma, prothrombin complex concentrates or recombinant activated factor VII. Although it is a rare entity, one still needs to consider it as a probable diagnosis in a newborn with coagulopathy. We report here a case of Factor VII deficiency in a newborn who presented with subdural haemorrhage at day 4 of life.

Prophylactic effect of recombinant factor VIIa in factor VII deficient patients

Inherited factor VII (FVII) deficiency is a rare autosomal recessive disorder associated with a bleeding tendency. We describe three patients with congenital FVII deficiency who have been treated with activated recombinant factor VII (rVIIa). Two patients had novel mutations and were treated prophylactically with 1.2 mg rVIIa two to three times a week. Patients 1 and 2 had a severe bleeding tendency. The frequency and severity of bleeding decreased by treatment with rVIIa compared with similar treatment with plasma-derived FVII. The third patient with a moderate bleeding phenotype was treated on demand and showed no change in the frequency of bleeding upon treatment with rVIIa or plasma products. The beneficial effect of rVIIa cannot be explained by the rVIIa half-lives. Pharmacokinetical analysis showed rVIIa activity half-lives of 35, 50 and 54 min for patients 1, 2 and 3, respectively. In conclusion, prophylactic treatment of FVII deficient patients with rVIIa appears to be applicable, safe and successful, although the mechanism of action remains to be elucidated.

Palliative open heart surgery in an infant with factor VII deficiency

An infant with factor VII deficiency underwent palliative open heart surgery for pulmonary atresia with an intact ventricular septum. No references had been found on the management of this rare coagulation disorder in infantile cardiac surgery. We describe the peri- and postoperative management with a replacement therapy including a recombinant factor VIIa concentrate. We conclude that an appropriate replacement therapy is needed to control bleeding during open heart surgery with factor VII deficiency.

Outcome of intracranial hemorrhage in infants with congenital factor VII deficiency

The outcome of 8 episodes of intracranial hemorrhage in 7 patients (4 males, 3 females) with congenital factor VII deficiency was evaluated. Their levels of factor VII clotting activity (FVII:C) were less than 1 per cent (n = 3) and ranged from 1.7 to 2.3 per cent (n = 4). The onset varied from the first week (n = 2), first month (n = 3), and at the ages of 6, 11 and 12 months (n = 3). The replacement therapy of 10 ml/kg of fresh frozen plasma (FFP) every 6-12 hours for 5-7 days was given to 6 patients. Only one craniotomy for the removal of hematoma was performed. The seventh patient experienced two episodes of bleeding. First, she received 20 microg/kg of recombinant factor VIIa (rFVIIa) every 6 hours for 4 days (1,200 microg) followed by FFP in one episode. Second, a craniotomy for the removal of a 7 cm diameter hematoma was performed by giving 20 microg/kg of rFVIIa every 6 hours for 12 days (9,600 microg) followed by FFP in another episode. As a result of these treatments, 2 died and 5 survived with sequelae, except for one who received rFVIIa. The sequelae included seizure disorder (n = 1) and hydrocephalus (n = 3). Subsequently, the surviving patients received 15 ml/kg of lyophilized fresh plasma every 3-5 days as prophylactic treatment. In conclusion, rFVIIa in the dose of 20 microg/kg every 6 hours has been shown to be effective in controlling intracranial hemorrhage in patients with congenital factor VII deficiency.

Combined deficiency of factors II, VII, IX, and X (Borgschulte-Grigsby deficiency) in pregnancy

BACKGROUND

Combined deficiency of vitamin K-dependent coagulation factors (II, VII, IX, X) is an uncommon challenge for the expectant gravida.

CASE

A 34-year-old primigravida had congenital combined deficiency of factors II, VII, IX, and X that were incompletely sensitive to vitamin K. She had an altered form of vitamin K-dependent factors that retained immunologic activity but lacked coagulant activity and the normal complement of gamma-carboxyglutamic acid residues. She required vitamin K supplementation throughout her life. After an uneventful pregnancy she had postpartum hemorrhage resulting from an episiotomy. Fresh frozen plasma was administered to achieve hemostasis. The remainder of her postpartum course was normal.

CONCLUSION

Combined congenital deficiency of factors II, VII, IX, and X can be managed in pregnancy with the use of vitamin K and fresh frozen plasma.

[Inherited factor VII deficiency and pregnancy. Apropos of 1 case]

Hereditary factor VII deficiency is a rare autosomal recessive condition. Factor VII's level elevates during pregnancy in normal patients, as well in deficient individuals for some authors. Various treatments (fresh frozen plasma, prothrombin complex or factor VII concentrate) have been used to lessen the peri-partum hemorrhage in those factor VII-deficient pregnant women. We report the case of a pregnant woman presenting a factor VII deficiency (level 4%), without variation of level during her pregnancy. The single infusion of factor VII concentrate, prior to delivery, has elevated factor VII's level at 17% and has likely permitted minimal post-partum bleeding. The peripartum management of factor VII deficiency is discussed.

Repair of abdominal aortic aneurysm in severe Factor VII deficiency

Congenital Factor VII deficiency is a rare disorder associated with reduced levels of Factor VII activity. Replacement therapy is necessary to control hemorrhaging or if surgery is needed. We report operative treatment of one case of chronic abdominal aortic aneurysm in a patient affected by a severe form of congenital Factor VII deficiency (endogenous FVII level <1%). The operation was carried out after the administration of Factor VII concentrate raised the Factor VII concentration to hemostatic levels. The patient continued to receive the concentrate every 6 hrs during the first three postoperative days. Dosage was assessed to obtain Factor VII levels not lower than 25%. No postoperative bleeding or thrombotic events were observed. The patient was discharged in excellent condition.

[New possibilities in the management of hemorrhagic diathesis caused by factor deficiency and thrombocytopenia: recombinant active factor VII concentrate]

Recombinant Factor VIIa, a new therapeutic tool to treat severe bleeding caused by inhibitory haemophilia cases, some cases of thrombocytopenia and thrombocytopathy (e.g. severe type III von Willebrand disease) receives growing attention in clinical practice. Exogeneous FVIIa-in a supraphysiological concentration (clearly over 6 U/ml) seems to be able to generate quickly and safely (without thrombotic side effects) thrombin--the final enzyme of clotting--in physiological, or pathological conditions. A concise review about the possible mechanisms of action, indications, monitoring and clinical experience gained sofar with FVIIa is given in this report.

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 VII deficiency in a patient with an abdominal aortic aneurysm

A patient with congenital factor VII deficiency underwent surgery for an inflammatory abdominal aortic aneurysm. No references in the literature have been found on the management of this coagulation defect in patients who require vascular surgery. We present one such case, with special reference to the perioperative management of factor VII replacement therapy.

Hereditary factor VII deficiency in pregnancy: peripartum treatment with factor VII concentrate

This report describes pregnant sisters with severe factor VII deficiency and peripartum management with factor VII concentrate. In this family, two affected members had previously developed severe postpartum hemorrhage when managed with fresh frozen plasma. Therapy-related complications owing to plasma infusion included viral disease transmission and pulmonary edema. Therefore, to lessen the risks of complications, specific factor therapy was initiated shortly before parturition in both patients. Factor VII concentrate was administered prior to delivery and every 6 hr for the next 72 hr to keep trough levels at approximately 10%. Based on peak and trough levels, the mean factor VII half-lives were determined to be 3.6 and 5.7 hr. Use of the concentrate was associated with uncomplicated delivery and minimal postpartum bleeding.

Factor IXa-factor VIIIa-cell surface complex does not contribute to the basal activation of the coagulation mechanism in vivo

We have infused recombinant factor VIIa into patients with hereditary factor VII deficiency with marked reductions in plasma concentrations of factor IX activation peptide (FIXP), factor X activation peptide (FXP), and prothrombin activation fragment F1+2. These investigations show substantial elevations in these markers of coagulation activation and thereby demonstrate that the factor VII-tissue factor pathway is largely responsible for the activation of factor IX as well as factor X in the basal state (ie, the absence of thrombosis or provocative stimuli). We have administered a monoclonal antibody purified factor IX concentrate to individuals with hemophilia B. These studies show an increase in the plasma levels of FIXP that were initially greatly decreased, but no change in FXP or F1+2. We have also infused highly purified factor VIII concentrate into patients with hemophilia A. The data demonstrate no significant changes in the plasma concentrations of FXP and F1+2. The above observations indicate that factor IXa generated by the factor VII-tissue factor pathway is unable to activate factor X under basal conditions. Based upon the above findings, we outline a model of blood coagulation system function under basal conditions, and suggest a process by which the generation of factor Xa and thrombin might be accelerated during normal hemostasis and in the setting of thrombotic disorders.

Acquired factor VII deficiency associated with aplastic anaemia: correction with bone marrow transplantation

We report a patient with severe aplastic anaemia found to have a prolonged prothrombin time due to acquired factor VII deficiency. No evidence for a factor VII inhibitor or inactivator was demonstrable. Laboratory studies identified deficiency both of factor VII activity and factor VII antigen. The factor VII deficiency persisted from clinical presentation until approximately 50 d after allogeneic marrow transplantation when restoration of factor VII activity and antigen was noted. The patient's serum could be depleted of factor VII activity by in vitro incubation with Protein A bound to Sepharose, suggesting the presence of an IgG or IgG containing complex able to bind factor VII, but not neutralize its procoagulant activity. A dual specificity solid phase immunoassay identified a factor VII binding immunoglobulin which was detectable throughout the course of factor VII deficiency. The concordant appearance of this factor VII reactive immunoglobulin and the factor VII deficiency suggested the pathologic role of this immunoglobulin in the aetiology of the factor VII deficiency. This factor VII binding immunoglobulin may have induced rapid plasma clearance of the factor VII molecule or, alternatively, may have modified factor VII synthesis. The immunosuppressive therapy and subsequent lymphohaematopoietic engraftment following allogeneic marrow transplant was accompanied by complete resolution of the factor VII deficiency.

Factor VII deficiency and pregnancy

Hereditary factor VII deficiency is very rare in pregnancy (one in 500,000). However, obstetricians should consider this diagnosis whenever the prothrombin time is prolonged while the activated partial thromboplastin time is normal. The factor VII level increases in normal pregnancy, but the effect of pregnancy upon the factor VII level in deficient individuals is unknown. We report two cases of factor VII deficiency in pregnancy. In both, factor VII levels were 15% or less in the third trimester and were lower postpartum, suggesting that pregnancy does elevate factor VII in deficient individuals as well. Fresh frozen plasma is the treatment of choice. If the level is very low, fresh frozen plasma can be given prophylactically; otherwise, it should be given if blood loss becomes excessive.

[Practical approaches for surgical procedures in congenital factor VII deficiency]

A 33 year old female with a congenital deficit in factor VII underwent four operations, all without any haemorrhage. One of then was carried out using substitutive therapy. She had a non-A non-B hepatitis one month after this treatment. Substitutive therapy depends on the assessment of the risk of haemorrhage, which can be estimated by the concentration of factor VII, the severity of spontaneous haemorrhage, the surgical history, and the planned operation. Since the risk of transmitting viruses with freeze-dried blood products would appear to be virtually nil, since 1985, fresh frozen plasma should be avoided for this type of indication. The doses of concentrated factor VII to be used lie between 20 IU.kg-1 every 4 h and 40 IU.kg-1 every 8 h. Such a dose should be administered in either one or several injections, according to whether the risk of haemorrhage is important or not. Substitutive therapy should be continued as long as the risk persists. Using a test dose of factor VII and, afterwards, measuring its biological activity can help to determine the best time for starting the treatment in order to obtain a level of factor VII greater than the minimum required for surgical haemostasis (10%).

Selection of replacement therapy for patients with severe factor VII deficiency

The risk of significant bleeding in patients with severe Factor VII (FVII) deficiency is well documented. However, controversy regarding management exists not only for the choice of FVII replacement product, but also for the desired hemostatic level of FVII. Two case reports are presented where fresh frozen plasma (FFP) and several Factor IX (FIX) complex concentrates were used to achieve hemostasis. Significantly higher FVII levels were achieved with Proplex (FIX Complex, Hyland Therapeutics) than with other products. Although this and other reports indicate that minor bleeding can be controlled with levels of FVII under 15%, life-threatening hemorrhages require higher FVII levels that can be attained only by using a product with a significant FVII content. It is important to know the FVII content of FIX concentrates in order to plan appropriate therapy for patients with FVII deficiency.

Hereditary factor VII deficiency: report of a case of intracranial hemorrhage

A case of factor VII deficiency in a 52-year-old woman who developed central nervous system hemorrhage is here reported. Screening coagulation tests were all normal except for prothrombin time, normotest and thrombotest. Specific assays of vitamin K-dependent factors revealed that factor VII activity was reduced (11 U/dl). The studies of the family demonstrated that 2 sisters out of 4 were heterozygous for the defect. The activity of factor VII in the offspring, classified as obligatory carriers, ranged between 62 and 78 U/dl, the antigen between 55 and 75 U/dl. The wide variability of factor VII in normal people and the possible compensative effect of normal alleles in carriers do not allow to define the variant, namely if the patient is a CRMR homozygote or a CRMR/CRM-double heterozygote.

A factor VII concentrate for therapeutic use

A concentrate of factor VII suitable for therapeutic use has been prepared from human plasma by a method forming part of a comprehensive scheme of large-scale plasma fractionation. Factor VIII was separated as cryoprecipitate and factors II, IX and X were adsorbed on DEAE-cellulose. Most of the factor VII remained in the supernatant. By batch adsorption on DEAE-Sepharose, followed by elution on a chromatographic column, factor VII was concentrated about 25-fold, and purified about 50-fold compared with original plasma, without the need for further dialysis or concentration steps. Data are presented from 10 batches, each from 80-120 kg plasma. Following doses of factor VII to six congenitally deficient patients, the mean rise in plasma factor VII was 95-100% of theoretical; the half-disappearance time was about 4 h. The treatment of four patients with acquired deficiency of factor VII is also described. No untoward side effects were observed.

Treatment of congenital factor VII deficiency with a new concentrate

A new factor VII concentrate, made from ACD plasma by a process involving successive absorptions of cryoprecipitate supernatant on DEAE Sephadex and of the resulting supernatant on A1(OH)3, was administered to 10 patients with severe factor VII deficiency. 5 patients received only one dose for treatment of a single bleeding episode, the remaining 5 were given multiple infusions (47) for spontaneous hemorrhages or for the prevention of surgical bleeding. In vivo factor VII recovery ranged from 43 to 126% (average 88%) of the assayed in vitro activity of the concentrate. A dose of 0.5 u/kg was found to produce a 1% rise of the plasma factor VII levels. The mean half-life on injected factor VII as assessed in 7 kinetic studies was 205 min (range 168--234). Spontaneous bleeding was easily controlled by the concentrate and major surgical procedures (two tonsillectomies) could be performed without complications. 1 patient developed HBSAg positive hepatitis, but otherwise no serious side effects were observed. Factor VII concentrate reduced the risk of precipitating circulatory overload associated with the use of plasma and avoids the unnecessary rise of factor II, IX and X which follows prothrombin complex concentrates.