Pregnancy-associated acquired haemophilia A: results from the European Acquired Haemophilia (EACH2) registry.

OBJECTIVE: The European Acquired Haemophilia registry (EACH2) collected data on the demographics, diagnosis, underlying disorders, bleeding characteristics, treatment, and outcome of women with acquired haemophilia A (AHA), a rare and often severe bleeding disorder caused by autoantibodies directed against coagulation factor VIII. DESIGN: Prospective, multi-centre, large-scale, pan-European registry. SETTING: A total of 117 haemophilia centres in 13 European countries. POPULATION: Pregnancy-associated AHA. METHODS: Data were reported using a web-based electronic case report form. Diagnosis was based on the presence of a prolonged activated partial thromboplastin time, reduced coagulation Factor VIII level and positive inhibitor assay. MAIN OUTCOME MEASURES: Presenting characteristics, time to diagnosis, haemostatic treatment and outcome, immunosuppressive treatment and outcome. RESULTS: The EACH2 registry (n = 501) documented 42 (8.4%) cases of AHA associated with the peripartum period, a median Factor VIII level at diagnosis of 2.5 (range 0-25) IU/dl and inhibitor titre of 7.8 (range 0.7-348) BU/ml. Antepartum inhibitors were evident in eight women. Time to diagnosis of AHA after delivery was 89 (range 21-120) days. First-line haemostatic treatment was successful in 20/23 (87%) women treated. Bleeding episodes resolved in 17/18 (94%) women treated with a bypassing agent and 29/39 (74%) women achieved complete remission with first-line immunosuppressive treatment. Two babies experienced postnatal bleeding, suggesting transplacental transfer of the antibody. All women were alive at last follow-up. CONCLUSIONS: Although rare, pregnancy-associated AHA may cause severe bleeding-related morbidity. Once diagnosed, women respond well to haemostatic treatment with bypassing agents and immunosuppression. Awareness of peripartum AHA requires improvement to facilitate rapid and appropriate management.

Demographic and clinical data in acquired hemophilia A: results from the European Acquired Haemophilia Registry (EACH2).

BACKGROUND: Acquired hemophilia A (AHA) is a rare autoimmune disease caused by autoantibodies against coagulation factor VIII and characterized by spontaneous hemorrhage in patients with no previous family or personal history of bleeding. Although data on several AHA cohorts have been collected, limited information is available on the optimal management of AHA. OBJECTIVES: The European Acquired Hemophilia Registry (EACH2) was established to generate a prospective, large-scale, pan-European database on demographics, diagnosis, underlying disorders, bleeding characteristics, treatment and outcome of AHA patients. RESULTS: Five hundred and one (266 male, 235 female) patients from 117 centers and 13 European countries were included in the registry between 2003 and 2008. In 467 cases, hemostasis investigations and AHA diagnosis were triggered by a bleeding event. At diagnosis, patients were a median of 73.9 years. AHA was idiopathic in 51.9%; malignancy or autoimmune diseases were associated with 11.8% and 11.6% of cases. Fifty-seven per cent of the non-pregnancy-related cases were male. Four hundred and seventy-four bleeding episodes were reported at presentation, and hemostatic therapy initiated in 70.5% of patients. Delayed diagnosis significantly impacted treatment initiation in 33.5%. Four hundred and seventy-seven patients underwent immunosuppression, and 72.6% achieved complete remission. CONCLUSIONS: Representing the largest collection of consecutive AHA cases to date, EACH2 facilitates the analysis of a variety of open questions in AHA.

Costs of on-demand and prophylactic treatment for severe haemophilia in Norway and Sweden.

The expected annual cost (in the year 2000 prices) for a 30-year-old patient with average individual and treatment characteristics for on-demand EUR 51,832 (95% CI: 44,324-59,341) and for prophylaxis EUR 146,118 (95% CI: 129,965-162,271), was obtained from panel-data analysis of an 11-year retrospective panel of 156 patients with severe haemophilia in Norway and Sweden. Costs included haemophilia-related treatment costs within the health-care sector (factor concentrate, doctors' visits, diagnostic procedures, hospitalisation, invasive procedures, etc.) and cost for haemophilia-related resource use in other sectors (lost production, use of special equipment, adaptation of workplace and domicile, etc). Although costs of lost production, reconstructive surgery and hospitalisation were higher for on-demand, they did not balance out the higher costs of factor-concentrate consumption in prophylaxis. The cut-off risk of premature death, where on-demand and prophylaxis would have been equally costly, was 3.7 percentage units higher for on-demand than for prophylaxis. Such a great risk difference has not been reported elsewhere to our knowledge. Estimated cost-elasticities indicated that annual costs of prophylaxis would increase by approximately the same proportion as a potential increase in the price of factor concentrate and decrease less than proportionately with a reduction in prescribed dose kg(-1). For on-demand, the annual costs would increase by approximately the same proportion as an increase in the prescribed dose kg(-1).

On-demand vs. prophylactic treatment for severe haemophilia in Norway and Sweden: differences in treatment characteristics and outcome.

Using an 11-year panel of 156 Norwegian and Swedish patients with severe haemophilia, and including retrospective case-book data from birth, we compared the differences in the haemophilia-related resource use between on-demand and prophylactic treatment. Patients treated on-demand had more surgery (arthrodeses, prostheses implantations and synovectomies) and more days lost from work. Median annual factor-concentrate consumption among adults (18+) was 211,000 IU [interquartile range (IQR) 154,000-268,000] or 3,024 IU kg-1 year(-1) for patients on prophylactic treatment and 55,000 IU (IQR 28,000-91,000) for on-demand patients (780 IU kg(-1) year(-1)). This was partly explained by the fact that the median dose per kg body weight was twice as great 28, (IQR 24-32) for prophylaxis compared with 14 (IQR 12-16) for on-demand. Prescribed dose per kg body weight was found to be an important factor explaining the variation in total annual factor-concentrate consumption per patient for both types of treatment. Other variables included in the panel-data regression analysis were the number of weeks on secondary prophylaxis for on-demand patients and age, body weight and type of haemophilia for children (0-17 years) on prophylaxis. Differences were consistently substantial and will affect both costs and benefits of the two treatment strategies.

Experience with a new percutaneous port system, Percuseal, for intravenous injection in patients with haemophilia, von Willebrand disease and severe alpha1-antitrypsin deficiency.

We have implanted a new port system (Percuseal) in altogether 13 patients with haemophilia A, B, von Willebrand disease and alpha1-antitrypsin deficiency in order to facilitate venous access. The Percuseal system differs from subcutaneous ports, such as Port-a-Cath, in that the upper part of the device protrudes above the skin. In this way, the patient can easily puncture the port membrane under the guidance of his eyes without penetrating the skin. In the present study cohort, a number of complications occurred. These were mainly caused by repeated local infections (in five patients), which made it necessary to replace the ports in three of the patients and to permanently remove the ports as the first option in two of the patients. In one patient, the port was removed because of inconvenience when doing physical exercise. In one additional patient, a severe systemic infection occurred, causing spondylitis. Despite the high infection rate, most patients considered the device very convenient to use. Because of the side-effects seen in our study, the Percuseal port in its present form is not to be recommended for regular use. A reconstruction of the port, making it smaller and giving it an antibacteriostatic cap, may possibly make this kind of port system a feasible alternative to use in order to improve pharmacoeconomics in the prophylactic treatment of haemophilia and patients with alpha1-antitrypsin deficiency.

Overall haemostatic potential can be used for estimation of thrombin-activatable fibrinolysis inhibitor-dependent fibrinolysis in vivo and for possible follow-up of recombinant factor VIIa treatment in patients with inhibitors to factor VIII.

Thrombin generation induced by recombinant factor VIIa (rFVIIa) in patients with haemophilia and/or inhibitors to factor VIII/IX could enhance generation of thrombin-activatable fibrinolysis inhibitor (TAFI), a recently described link between coagulation and fibrinolysis. TAFI is unstable and it is not easy to measure its active form in vivo. Overall haemostatic potential (OHP) is a novel method for haemostasis estimation, based on determination of the fibrin aggregation curve in which tiny amounts of thrombin are used for activation of clotting. We measured OHP in six patients with inhibitors to factor VIII before injection of rFVIIa and 10 and 120 min thereafter. Overall fibrinolytic potential (OFP) and clot lysis time (CLT) analysed by this method could be used for indirect estimation of TAFI generation. We found no change in pro-TAFI and total TAFI antigen before and after treatment with rFVIIa. OHP was almost undetectable before treatment but increased into the range of normal pooled plasma 10 and 120 min after rFVIIa treatment, as did CLT. However, after addition of potato tuber carboxypeptidase inhibitor, a specific inhibitor of TAFI, the shortening of CLT was lower than that in NPP. OFP was increased in patient plasma both 10 and 120 min after treatment compared with NPP. There was a strong positive correlation between pro-TAFI concentration and shortening of CLT after PTCI addition and a negative correlation between pro-TAFI concentration and OFP 10 min after rFVIIa injection. Thus, rFVIIa normalizes OHP and CLT 10 min after injection. While this improvement slightly decreases, but still exists after 2 hours, it suggests efficacy in bleeding prevention using a protocol based on rFVIIa administration every 2 hours.

Inhibitors in the Swedish population with severe haemophilia A and B: a 20-year survey.

AIM: To survey the entire population (n = 116) afflicted with severe haemophilia A or B born in Sweden over a 20-y period (1980-1999), and to examine the epidemiological, genetic and clinical aspects of development of inhibitors to factors VIII and IX (FVIII/FIX). METHODS: One hundred of the subjects had haemophilia A and 16 had haemophilia B. All of these subjects had received prophylactic treatment and had a check-up of inhibitor status at least twice a year. Sixty-one were born between 1980 and 1989 and 55 between 1990 and 1999. RESULTS: Nineteen percent (19/100) of those with haemophilia A and 37% (6/16) with haemophilia B developed inhibitors at 12-18 mo of age, after exposure to FVIII/FIX concentrates for an average of 14 d in the case of haemophilia A and 16 d in haemophilia B. All patients with inhibitors carried mutations that impaired protein synthesis. The high incidence of FIX inhibitors may have been due to the large number of complete deletions (13%) in the Swedish haemophilia B population. Patients with haemophilia A showed no significant increase (p = 0.65) in incidence of inhibitors (n = 10/48, total incidence 21%) in the 1990s, when they were treated mainly with recombinant products, as compared to the 1980s (n = 9/52, 17%), when they received intermediate/high-purity plasma-derived concentrates. CONCLUSION: Our population-based study verifies that genotype has a general impact on the incidence of FVIII/FIX inhibitors, and that recombinant FIII/FIX concentrates are not a predisposing factor for inhibitor development.

Characterization of inhibitors to FVIII with an ELISA in congenital and acquired haemophilia A.

Different methods can be used for the detection and quantification of inhibitors or antibodies to coagulation factor VIII (FVIII). Traditionally, clotting assays have been used, in particular the Bethesda assay. These assays have, however, several shortcomings, due to the complex reaction kinetics of some inhibitors and a low sensitivity to low-titre antibodies. In addition, a universal FVIII inhibitor standard is lacking. Furthermore, clotting assays do not detect noninhibitory antibodies. Use of ELISAs has been described and FVIII from various commercially available FVIII concentrates has been used as target antigen in the assays. In the present study, we systematically explored the influence of different FVIII concentrates on the performance of an ELISA for detection of FVIII antibodies. The described ELISA was also used for further characterization of FVIII inhibitors in patients with acquired and congenital haemophilia A. We found that the source of FVIII had a substantial impact on the frequency of antibody detection. Albumin-free recombinant FVIII as target antigen gave the highest sensitivity for the assay, whereas plasma-derived concentrates containing a high level of von Willebrand factor (vWF) gave the lowest sensitivity. Presumably vWF interferes with the binding of antibodies to FVIII. We suggest that albumin-free recombinant FVIII should be used as target antigen when ELISAs are used for detection of FVIII antibodies.

Breastfeeding does not influence the development of inhibitors in haemophilia.

Our aim was to test the hypothesis that breastfeeding may reduce development of inhibitors in male infants with haemophilia by inducing an oral immune tolerance to factor VIII. To achieve that goal, we performed a structured epidemiological survey comprising all males born with severe haemophilia A (in all 100 patients, 19 with inhibitors) or haemophilia B (in all 16 patients, six with inhibitors) in Sweden in 1980-99. Our results show no protective effect of breastfeeding.

Use of recombinant factor VIIa (NovoSeven) in patients with Glanzmann thrombasthenia.

Recombinant factor VIIa (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) appears effective and relatively safe for the treatment of bleeding and for surgical prophylaxis in patients with Glanzmann thrombasthenia as reported to the International Registry on rFVIIa and Congenital Platelet Disorders. One of the shortcomings of the Registry data is the heterogeneity of treatment protocol, including dosage, number of doses used, duration of treatment before declaration of failure, and mode of rFVIIa administration (bolus v continuous infusion). The data are not yet sufficient to define optimal regimens for various indications such as the type of bleeding or the type of procedures. The place of this drug compared to platelet transfusion in the overall management of patients with Glanzmann thrombasthenia will need to be determined in relationship to a number of challenges and unresolved issues in the clinical care of these patients. These issues include: how to improve local measures for patients with mucosal bleeds, optimal management of young women during menarche, optimal platelet transfusion regimens for various indications, the relationship between antiplatelet antibodies detected by monoclonal antibody-specific immobilization of platelet antigens (MAIPA) and effectiveness of platelet transfusion, whether there are other biological tests that may correlate with effectiveness of platelet transfusion, and management of pregnancy and delivery regarding antiplatelet immunization.

[New in vitro analysis tested: bleeding time is still the best method for evaluation of primary hemostasis]. / Ny in vitro-analys prövad: blödningstid fortfarande bästa metod för test av den primära hemostasen.

The need is great for a simple, cheap and readily accessible method for the evaluation of primary hemostasis in work-ups at both out-patient clinics and units caring for surgical or intensive care patients. PFA-100 is a recently introduced instrument for in vitro testing of platelet function. We report experiences from Stockholm, Gothenburg and Malmo of PFA-100 measurements performed on samples from healthy controls and from patients with von Willebrand disease or platelet disorders. It is shown that the PFA-100 system has a high sensitivity for von Willebrands disease, while the sensitivity for hereditary platelet dysfunction is low. In its present design this new device could not replace the template bleeding time as a screening test for primary hemostasis.

An approach to study the viral safety of plasma-derived products in previously treated, non-infected patients.

Using the polymerase chain reaction (PCR), we designed a study concept to evaluate the safety of plasma derivatives in previously treated patients who are non-infected by the specific viruses studied. Several product lots can be studied in a single patient, with a study period for each lot of 3 months. In the present study 19 patients were included for treatment with Baxter Hyland Immuno's PCR-screened factor VIII concentrate Immunate (n=7), factor IX concentrate Immunine (n=10), the by-passing agent FEIBA plus Immunine (n=1), and the protein C concentrate Ceprotin (n=1). PCR testing for hepatitis B, C or HIV genomic material in patient samples was done as well as serological testing. All patients remained negative for the tested markers. All seven Immunate patients completed three treatment periods with three different lots of the study drug. The median study period was 282 days and the median dose 115 000 units, with a median of 115 exposure days. Five of the 10 Immunine patients completed three treatment periods and four patients, two treatment periods. One Immunine patient was discontinued from the study for reasons unrelated to the study drug administration. The median study period was 305 days and the median total dose 82 200 units, with a median of 88 exposure days. Our study presents a new design to approach the evaluation of viral safety of new plasma derivatives in previously treated, non-infected patients (NIPs) and offers several advantages over the currently recommended studies using testing for serological markers of infection in previously untreated patients (PUPs).

Haemophilia B mutations in Sweden: a population-based study of mutational heterogeneity.

The present series comprises all families (n = 77) with haemophilia B in Sweden and may be considered to be representative for the purposes of a population-based study of mutational heterogeneity. The 77 families (38 severe, 10 moderate, 29 mild) had 51 different mutations in total. Thirteen families had total, partial or small deletions, two had mutations in the promoter, eight families had splice site mutations, 14 had nonsense and the remaining 41 had missense mutations. Ten of the mutations, all C-->T or G-->A, recurred in 1--6 other families. Using haplotype analysis of seven polymorphisms in the factor IX (FIX) gene, we found that the 77 families carried 65 unique, independent mutations. Of the 48 families with severe or moderate haemophilia, 23 (48%) had a sporadic case of haemophilia compared with 31 families out of 78 (40%) in the whole series. Five of those 23 sporadic cases carried de novo mutations, 11 out of 23 of the mothers were proven carriers and, in the remaining seven families, it was not possible to determine carriership. Eleven of the 48 patients (23%) with severe haemophilia B developed inhibitors and all of them had deletions or nonsense mutations. Thus, 11 out of 37 (30%) patients with severe haemophilia B as a result of deletion/nonsense mutations developed inhibitors compared with 0 out of 11 patients with missense mutations. The ratio of male to female mutation rates was 5.3 and the overall mutation rate was 5.4 x 10(-6) per gamete per generation.

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.

Factor VIII inhibitors in two families with mild haemophilia A: structural analysis of the mutations.

The development of inhibitory antibodies against coagulation factor VIII (FVIII) in patients with mild haemophilia A is uncommon. We describe here two families in which three or two members have developed inhibitors, suggesting a familial predisposition. The mutations found, in the A2 (Arg593Cys) and C1 domains (Tyr2105Cys), have been reported to give rise to inhibitor development in single individuals in addition to the family cluster we describe, strongly suggesting that these amino acid substitutions give rise to a more immunogenic protein. The analysis of structural models of activated factor VIII revealed that Arg593 is solvent-exposed and involved in a network of electrostatic interactions while Tyr2105 is partially buried and has hydrophobic interactions essentially with Ile2144. All these residues are strictly conserved in the FVIII amino acid sequence from man, pig and mouse, suggesting, at least, that they have structural roles. We propose that the two mutations in these families could cause mild haemophilia A because they induce local conformational changes (and possible secretion or intermolecular interaction problems, e.g., with von Willebrand factor) compatible with immunogenicity and production of inhibitors against the infused wild-type FVIII.

Primary prophylaxis in severe haemophilia should be started at an early age but can be individualized.

The frequency of joint bleeds and orthopaedic joint scores were evaluated in 121 patients with severe haemophilia who had started prophylactic treatment with clotting factor concentrates at least once weekly before the age of 10. 75 of the patients started before the age of 3, 31 at the age of 3-5 and 15 at the age of 6-9. Each subgroup was evaluated separately. In addition, a regimen of one infusion weekly was compared with that of two (haemophilia B) or three (haemophilia A) infusions weekly in each patient. A significant decrease in the overall number of joint bleeds per year was found after shortening the infusion interval (P<0.005), but the individual bleeding pattern varied. In survival analysis of the first pathologic joint score event, those who started prophylaxis before the age of 3 had a better outcome overall than those starting at later ages (P=0.001). However, in subgroup analysis, no significant difference was seen in the annual number of joint bleeds and the development of arthropathy between those starting with, or shifting to, the more intensive regimen before the age of 3 and those that were put on this regimen at the age of 3-5. Age at start of prophylaxis was found to be an independent predictor for the development of arthropathy (P=0.0002), whereas dose and infusion interval at start were not. Our data emphasize the importance of starting replacement therapy during the first years of life. However, it seems that when beginning the regimen it can be individualized and adjusted according to the bleeding pattern. In this way, the need for a venous access system may be assessed on an individual basis.

Comparison of various D-dimer tests for the diagnosis of deep venous thrombosis.

Analyses of D-dimers in plasma are frequently used as diagnostic tools for deep venous thrombosis (DVT). Enzyme-linked immunosorbent assays (ELISAs) are considered to be the method of choice for quantitative assays, but are time consuming. Therefore, we have assessed plasma levels of D-dimers in patients with clinically suspected DVT using quantitative (Asserachrom D-Di ELISA and TintElize), semiquantitative (Minutex latex, D-Di latex, NycoCard D-Dimer) and qualitative (INSTANT.I.A) assays. Phlebography was used as the gold standard to verify or exclude the suspected diagnosis. We conclude that the fast assays, INSTANT.I.A and Minutex, have essentially the same negative predictive value [91% and 89%, respectively, using a cut-off value < 0.5 mg/l fibrinogen equivalent units (FEU)] for excluding DVT as the Asserachrom D-Di ELISA and TintElize tests (92%). The D-Di Latex assay had a negative predictive value of 82% (cut-off < 0.5 mg/l FEU) and turned out to be less useful in our material. The NycoCard D-dimer assay had a negative predictive value of 100% when using the cut-off value < 0.5 mg/l FEU, but this was substantially lower when the cut-off was changed to < or = 0.5 mg/l. Thus, we conclude that several fast tests offer a simpler and more rapid way of determining plasma levels of D-dimer than conventional ELISA methods without loss of clinical usefulness in excluding DVT.

[Centralized care is the basis of care programs for hemophilia patients]. / Centraliserad vård grundläggande i vårdprogram för blödarsjuka.

Haemophilia is a rare and potentially life-threatening disease. In Sweden, with a population of approximately 8.5 million, about 350 people suffer from the more severe forms of haemophilia or von Willebrand disease. Meticulous management is important if the patients are to be spared chronic disability and serious treatment complications. The disease is lifelong and affects psychosocial aspects of life among patients and their families. With the help of a grant from the Swedish Board of Halth and Welfare, a care programme has been designed to guarantee Swedish haemophiliacs comparable and optimal care. The programme has been drawn up by representatives of the three haemophilia centres in Sweden (at University Hospital, Malmö, Sahlgrenska University Hospital, Gothenburg, and Karolinska Hospital, Stockholm) in co-operation with the World Federation of National Haemophilia Organisations. To ensure optimal individual application of the programme, individualised management strategies and patient information leaflets have been prepared.

APC resistance and other haemostatic variables during pregnancy and puerperium.

Forty-eight healthy pregnant women were studied prospectively and longitudinally. Blood sampling was performed at 10-15, 23-25, 32-34 and 38-40 weeks of gestation, within one week and at eight weeks postpartum. Classic and modified activated protein C ratio decreased as pregnancy progressed. In the third trimester 92% of the ratios measured with the classic test were above the lower reference level whereas all modified test ratios were normal. Slight activation of blood coagulation was shown with increased levels of prothrombin fragment 1+2, soluble fibrin and D-dimer. Fibrinogen, factor VIII and plasminogen activator inhibitor type I and type 2 increased. Protein S and tissue plasminogen activator activity decreased. Protein C remained unchanged. No correlation was found between the decrease in classic APC ratio and changes in factor VIII, fibrinogen, protein S, prothrombin fragment 1+2 or soluble fibrin, nor between the increase in soluble fibrin and changes in prothrombin fragment 1+2, fibrinogen and D-dimer.