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IntroductionSweden has been a pioneer in the prophylactic treatment of haemophilia. Magnetic resonance imaging (MRI) can detect small changes in joints and can therefore give an indication of a risk of developing arthropathy. AimTo use MRI to evaluate the outcome of the Swedish high-dose regimen and correlate the findings to age, bleeds, joint score and physical activity. MethodsThe study group comprised 48 Swedish male patients, mean age 25 years (range 12-33 years), with severe or moderate haemophilia A or B. Data on the Haemophilia Joint Health Score (HJHS) were available and physical activity was evaluated by a self-reported questionnaire. ResultsMRI score was recorded in 188 joints. Twenty out of 48 patients had a score of >= 1 (range 1-13) in 31 joints of which 3/31 scores were in the knees and 28/31 in the ankles. No correlation was found between the number of recorded bleeds and the MRI score or between HJHS and MRI score. There was no correlation between the physical activity and the number of joint bleeds per se, but a trend (OR 3.0) that those most physically active (19/48; 39.6%), more frequently had an MRI score of >= 1 with an overweight for the right ankle. ConclusionThe Swedish prophylactic model offers protection against haemophilia joint arthropathy but will still not prevent osteochondral changes in some patients at young age. MRI of the ankles can signal risk of future arthropathy and indicate need to modify the prophylactic regimen. Funding Agencies|Baxter Sweden AB (now part of Takeda)

INTRODUCTION: Genetic screening using high-throughput DNA sequencing has become a tool in diagnosing patients with suspected inherited bleeding disorders (IBD). However, its usefulness and diagnostic efficacy in children is unclear.AIM: To evaluate the diagnostic efficacy of genetic screening for IBD in children and downstream further testing.METHODS: After informed consent, children (

Registries will enable cohort studies to be performed, which are usually considered to be the best quality of observational studies. The quality of data of registries can be increased if is it possible to merge results ('crosstalk') between registries. A prerequisite for that is an agreed uniform core set of data to be collected and uniform definitions on the items to be collected. This paper discusses problems and barriers with existing registries and provides recommendations from an EMA workshop (European Medicines Agency), for core common data sets and how to secure the quality of data collected. The PedNet registry including >2200 children with haemophilia is presented as an example of a registry/cohort study.

Introduction Assay discrepancy in factor VIII activity between the one-stage and the chromogenic assays has been described in approximately one third of patients with non-severe haemophilia A. Whether assay discrepancy may also occur in patients with haemophilia B remains unknown. Aim This study compared the results from the one-stage and the chromogenic assays in patients with haemophilia B. Methods Plasma samples from patients with haemophilia B attending the haemophilia centre in Malmo, Sweden, were collected after a wash-out period of more than 7 days and analysed with both assays. Results Fifty samples from 36 patients were analysed. No discrepancy was found in patients with severe haemophilia B. Among the 44 plasma samples from patients with non-severe disease, 15 showed a twofold or greater difference between the results of the two methods, with the chromogenic method presenting the higher value (mean FIX:Cone-stage 0.02 vs. FIX:Cchromo 0.06 IU mL−1). Of these 15 samples, 14 were from seven individuals from five families with the same mutated amino acid at the N-terminal cleaving site of the activation peptide (FIX: c.572G>A; p.Arg191His or FIX: c.571C>T; p.Arg191Cys). These mutations were not observed in any patients with non-discrepant results. The reported bleeding frequency for these patients was low and indicative of a mild bleeding phenotype. Conclusion Our findings imply that assay discrepancy occurs for factor IX activity and that both type of assays are needed for a correct diagnosis and classification of haemophilia B. The underlying mechanism by which the mutation influences the assays remains to be determined.

Introduction: Currently the most serious treatment complication of haemophilia is the inhibitor development (ID), i.e. neutralizing antibody development. Aim: This nationwide multicentre study in Finland evaluated the incidence and risk factors of ID in previously untreated patients (PUPs) with severe haemophilia A (FVIII:C < 0.01 IU mL−1). Methods: We enrolled all PUPs (N = 62) born between June 1994 and May 2013 with at least 75 exposure days (EDs) to screen ID during follow-up extending to September 2013. Results: Thirteen ID (21% of 62) occurred; 10 (16% of 62) with high titre. Fifty-one patients (82%) were on primary prophylaxis (regular prophylaxis before the age of 2 and before the first joint bleed) from the median age of 11.4 months, 90% via a central venous access device. The initial product was rFVIII in 63% and pd-FVIII in 37%, moreover in 24% pd-FVIII was switched to rFVIII concentrate during the 75 EDs. Non-transient inhibitors developed in 9/51 (17.6%; 13.7% high titre) children with primary and in 4/11 (36.4%; 27.3% high titre) patients with secondary prophylaxis (P = 0.24). Overall, 74% had a high-risk genotype similarly distributed among the prophylaxis groups. The history of a major bleed enhanced ID (aHR, 4.0; 95% CI, 1.2–13.7), whereas FVIII treatment intensity or source and early implantation of ports did not increase ID risk. Conclusion: The cumulative incidence of ID was low notwithstanding prevalent high-risk mutations. Despite patient-related risk factors, our management involving early intensive primary prophylaxis via ports helps to prevent bleeds and lower the incidence of inhibitors. (Less)

Haemophilia B is caused by a heterogeneous spectrum of mutations. Mutation characterization is important in genetic counselling, prenatal diagnosis and to predict risk of inhibitor development.To study the mutation spectrum, frequency of unique recurrent mutations, genotype-phenotype association and inhibitor development in a population-based study of the complete Swedish haemophilia B population.The study included, facilitated by centralized DNA diagnostics, the complete registered Swedish haemophilia B population (113 families: 47 severe, 22 moderate and 44 mild), each represented by a single patient. Mutation characterization was performed by conventional sequencing of all exons and haplotyping by genotyping of single nucleotide variants and microsatellites.A mutation was found in every family: eight had large deletions, three had small deletions (10 base pair) and 102 had single base pair substitutions (69 missense, 26 nonsense, four splice site and three promoter). Ten novel mutations were found and were predicted to be deleterious. Sixteen mutations (one total gene deletion, 14 substitutions and one acceptor splice site) were present in more than one family. Of the single nucleotide mutations (37/102), 36% arose at CpG sites. Haplotyping of families with identical mutations and present analyses showed that the frequency of unique mutations was at least 65%. Inhibitors developed in 9/47 (19%) patients with severe haemophilia B.The spectrum of haemophilia B mutations reveals at least 65% of the families carry a unique mutation, but with more inhibitor patients than reported internationally, probably as a result of many 'null' mutations.

To facilitate early prophylaxis, step-up regimens starting prophylaxis with infusions 1xweek(-1) were introduced. Choice of initial regimen may affect outcome. This study aims to classify initial prophylactic regimens and compare them on short-term outcome. From the European Paediatric Network for Haemophilia Management' (PedNet) registry, patients with severe haemophilia A without inhibitors, born 2000-2012, receiving prophylaxis were included. Treatment centres were classified according to the initial frequency of prophylactic infusions and the age at reaching infusions >= 3 x week(-1). Bleeding, and central venous access device (CVAD) use were compared at age 4 years. In 21 centres with 363 patients, three regimens were identified: (i) start prophylaxis with >= 3 x week(-1) infusions before age three (full: 19% of centres, 18% of patients); (ii) start 1-2 x week(-1), increasing frequency as soon as possible (asap), reaching >= 3 x week(-1) before age three (43% of centres, 36% of patients); (iii) start 1-2 x week(-1), increasing frequency according to bleeding (phenotype), reaching >= 3 x week(-1) after age three (38% of centres, 46% of patients). Prophylaxis was started at median 1.2 years on the full and asap regimen vs 1.8 years on the phenotype regimen. Complete prevention of joint bleeds was most effective on the full regimen (32% full vs. 27% asap and 8% phenotype), though at the cost of using most CVADs (88% full vs. 34% asap and 22% phenotype). The three prophylaxis regimens identified had different effects on early bleeding and CVAD use. This classification provides the first step towards establishing the optimum prophylactic regimen. (Less)

The aims of the study were to define the frequency, outcome and reasons for prenatal diagnosis (PND) in Sweden during a 30-year period in order to study trends and changes. The study population, from the Swedish nationwide registry of PND of haemophilia, consisted of 54 women, compromising >95% of all, who underwent PND (n = 90) of haemophilia during 1977-2013. PND was performed by amniocentesis (n = 10), chorionic villus sampling (n = 64) or by analysis of foetal blood (n = 16). A total of 27/90 foetuses were found to have haemophilia. Sixteen went to termination and the remaining 11 were born during the end of the study period (2000-2013). Three of 90 pregnancies were terminated due to findings other than haemophilia and 3/90 PNDs led to miscarriage. In the 30 families with known haemophilia, PNDs (n = 55) were used in 27/55 cases for 'psychological preparation' and in 23/55 cases with the aim to terminate the pregnancy. A subgroup of women (n = 17) who consecutively underwent PND in the years 1997-2010 were further interviewed. For 11/17, being a carrier had a negative effect on the decision to become pregnant, and in 11 cases PND had influenced their decision to conceive. Our study show that PND of haemophilia is stable over time but increasingly used during the last decade as a psychological preparation for having a child with haemophilia as compared to earlier where more terminations of pregnancies were conducted.

Progressive joint destruction resulting from intra-articular bleeding is the major morbidity affecting patients with haemophilia (PWH), particularly those with inhibitors. Advances in understanding the detrimental processes set in motion by the exposure of joints to bleeding have shaped current management methods. However, to achieve optimal joint health in PWH, in addition to achieving haemostasis at the bleeding vessel, it may be appropriate to explore experimentally other conceptual frameworks. These include the possibilities that markers might help to identify individuals at the risk of more rapid joint deterioration, that clotting factors may have additional local action within tissues, and that outcomes might be improved with therapies that directly address wound healing and inflammation. Joint assessment tools are important. Conventional radiography is frequently used, but given the possibility of subclinical joint bleeds, accurate non-invasive imaging tools are required to detect soft tissue and cartilage changes. Magnetic resonance imaging and ultrasonography can prove valuable here. New imaging techniques should help to increase understanding of the biological basis of early events in haemophilic arthropathy. The optimal way to measure outcomes in haemophilia is to use several methods - in addition to imaging methods, a 360° approach will use physical, functional and quality-of-life instruments. In PWH, inhibitor development complicates treatment of joint bleeds and increases the risk of developing arthropathy. A new therapeutic approach for joint bleeds in inhibitor patients divides treatment into two phases: bleed control, with bypassing agent therapy until bleeding has definitely ceased, followed by regular dosing to prevent rebleeds until synovial recovery is complete.

Regular replacement therapy (prophylaxis) for haemophilia has been shown to prevent development of disabling arthropathy and to provide a better quality of life compared to treatment on demand; however, at a substantially higher cost. Calculations based on pharmacokinetic principles have shown that shortening dose intervals may reduce cost. The aim of this prospective, randomized, crossover pilot study was to address whether daily dosing is feasible, if it reduces concentrate consumption and is as effective in preventing bleeding as the standard prophylactic dosing regimen. In a 12 + 12 month crossover study, 13 patients were randomized to start either their own previously prescribed standard dose, or daily dosing adjusted to maintain at least the same trough levels as obtained with the standard dose. Ten patients completed the study. A 30% reduction in cost of factor concentrates was achieved with daily prophylaxis. However, the number of bleeding events increased in some patients in the daily dosing arm and patients reported decreased quality of life during daily prophylaxis. Daily treatment had a greater impact on daily life, and the patients found it more stressful.Prophylaxis with daily dosing may be feasible and efficacious in some patients. A substantial reduction of factor consumption and costs can be realized, but larger studies are needed before the introduction of daily prophylaxis into clinical routine can be recommended.

To investigate disease causing mechanism in haemophilia A patients without detectable mutation. Screening for F8 mutations in 307 haemophilia A patients using: re-sequencing and inversion PCR, reverse transcription (RT-PCR) of mRNA, MLPA analysis, haplotyping using SNP and microsatellite markers. No F8 mutations were detected in 9 of the 307 patients (2.9%) using re-sequencing and inversion PCR. MLPA analysis detected duplication in exon 6 in one patient and RT-PCR showed no products for different regions of mRNA in four other patients, indicating failed transcription. No obvious associations were observed between the phenotypes of the nine patients, their F8 haplotypes and the putative mutations detected. The mutation-positive patients carrying the same haplotypes as the mutation-negative patients show a multitude of different mutations, emphasizing the lack of associations at the haplotype level. VWF mutation screening and factor V measurements ruled out type 2N VWD and combined factor V and VIII deficiency respectively. To further investigate a possible role for FVIII interacting factors the haplotypes/diplotypes of F2, F9, F10 and VWF were compared. The nine patients had no specific haplotype/diplotype combination in common that can explain disease. Duplications and faulty transcription contribute to the mutational spectrum of haemophilia A patients where conventional mutation screening fail to identify mutations.

Haemarthroses (intra-articular haemorrhages) are a frequent finding typically observed in patients with haemophilia. Diagnosis and treatment of these bleeding episodes must be delivered as early as possible. Additionally, treatment should ideally be administered intensively (enhanced on-demand treatment) until the resolution of symptoms. Joint aspiration plays an important role in acute and profuse haemarthroses as the presence of blood in the joint leads to chondrocyte apoptosis and chronic synovitis, which will eventually result in joint degeneration (haemophilic arthropathy). Ultrasonography (US) is an appropriate diagnostic technique to assess the evolution of acute haemarthrosis in haemophilia, although magnetic resonance imaging remains the gold standard as far as imaging techniques are concerned. Some patients experience subclinical haemarthroses, which eventually tend to result in some degree of arthropathy, especially in the ankles. Nowadays, the most effective way of protecting these patients is primary prophylaxis, which in practice changes severe haemophilia into moderate haemophilia, preventing or at least minimizing the occurrence of haemarthrosis. If primary prophylaxis is, for whatever reason not an option, secondary prophylaxis and enhanced on demand treatment should be considered. Two alternatives are available for inhibitor patients: (i) control of haemostasis using by-passing agents (rFVIIa or aPCCs) either as enhanced on demand treatment or secondary prophylaxis, as appropriate, following the same basic principles used for non-inhibitor patients and (ii) immune tolerance induction (ITI) to eradicate the inhibitor.

The rationale for long-term prophylaxis in more severe forms of von Willebrand's disease (VWD) is obvious, as mucosal bleeding and haemophilia-like joint bleeds resulting in chronic morbidity may occur. However, the experience with prophylactic treatment in this group is scanty. An international VWD Prophylaxis Network (VWD PN) was established in 2006. The VWD PN will investigate prophylaxis with retrospective and prospective studies. Eighteen centres in Europe and North America are recruiting patients and an additional 40 centres are preparing for or evaluating participation. In the absence of randomized prospective studies for most rare bleeding disorders, guidelines for prophylaxis are a subject of controversy. In situations where there is a strong family history of bleeding, long-term prophylaxis is administered in selected cases. Short intervals of prophylaxis can also be given before some surgeries or during pregnancy. The benefits of prophylaxis must be balanced by the risk of side effects. Therefore, it is essential to delineate its management in a specialized comprehensive care environment. In haemophilia, decades of clinical experience and numerous retrospective and, recently, prospective studies clearly demonstrate that prophylactic treatment is superior to on-demand treatment, regardless of whether the outcome is the number of joint- or life-threatening bleeds, arthropathy evaluated by X-ray or MRI, or quality of life measured by generic or haemophilia-specific instruments. Optimal prophylactic treatment should be started early in life (primary prophylaxis) but various options exist for the dose and dose interval. These depend on the objective of treatment in the individual patient, which, in turn, is dependent on resources in the health care system. (Less)

Data from prospective studies clearly demonstrate the efficacy of prophylactic treatment of haemophilia in reducing joint- or life-threatening bleeding and the associated consequences for quality of life. Debate remains, however, regarding the optimal implementation of prophylaxis. Our aim in this review was to identify a best practice approach to factor replacement prophylaxis in boys with haemophilia. We evaluate prophylactic treatment regimens currently used in Swedish, Canadian and French centres and highlight key issues, including the optimal age for starting prophylaxis, the optimal treatment dosage/schedule and patient compliance.

Prophylaxis is defined as the regular administration of clotting factor concentrates to prevent bleeding. Extensive data from observational studies and a recent randomized controlled trial (have established that early prophylactic treatment prevents bleeds and arthropathy in boys with severe haemophilia. The initiation of prophylaxis in young children remains challenging. To prevent arthropathy, prophylaxis should be started early, before the onset of joint damage. Alternative strategies of starting include starting before the age of 2 years, or starting before the third joint bleed. Dose and frequency vary between the original Swedish regime of 20-40 IU kg(-1) three times per week and lower dosed and step up regimes starting with 50 IU kg(-1) once weekly and rapidly increasing dose and frequency in case of bleeds. In the second decade, most patients on prophylaxis learn self-infusion. Self-management warrants confirmation of adequate knowledge of the disease. Increasing self-management concurring with major physical and psychological changes may cause reduced adherence. The challenge is to promote adherence and continue to prevent bleeds during this important period of rapid growth. The third decade of life often represents a change in lifestyle. Patients may get a job and periods of physical activity may be more confined. About two thirds of patients experiment with discontinuing prophylaxis in their early twenties, and 20-30% with mild bleeding patterns switch to on-demand treatment for prolonged periods or even permanently. The challenge is to optimize efficiency by individualizing prophylactic dose and frequency according to lifestyle and bleeding pattern. Inhibitors may develop in up to 30% of patients with severe haemophilia. Especially those with high titre inhibitors are at increased risk of developing target joints and severe arthropathy. The use of prophylactic treatment with bypassing agents in inhibitor patients is increasing. Early studies report in a significant reduction of bleeds, including intracranial bleeds, and improvement in quality of life. Data on results of primary prophylaxis in patients with inhibitors to prevent arthropathy are not yet available.

Surgery in infants and young children with haemophilia, when preceded by accurate diagnosis and accompanied by safe and effective factor prophylaxis, is not associated with a significant risk of haemorrhage. Haemophilic newborns undergoing circumcision or major surgery prior to diagnosis and in the absence of appropriate haemostatic prophylaxis remain as a concern. Inhibitor development has replaced haemorrhage as the major surgical complication in the developed world, largely because of the intensity of treatment used to secure haemostasis. For that reason only, essential surgery should be performed. Intracranial haemorrhage (ICH) during the neonatal period affects 3.5-4.0% of all haemophilia boys in countries with a good standard of health care, which is considerably (40-80 times) higher than expected in the normal population. Because of the high frequency of sporadic cases, ICH in the neonatal period can only be partially prevented by improved carrier diagnosis and counselling. Infections and thrombosis are the major serious complications of central venous lines. Large differences are seen in the frequency of these complications, the most plausible explanations are probably related to the protocol used for device care, the quality of education and the compliance of the users, an issue addressed in an on-going study.

Although up to 30% of babies born with haemophilia do not have a family history of the disorder, the remaining 70% are born in families where haemophilia has been diagnosed. It has been estimated that for each male with haemophilia, there are five potential female carriers. Such women will benefit from knowledge of both their genetic (mutation present or not) and phenotype (level of plasma factor activity) status. Genetic counselling services to provide information and testing, together with plasma factor measurement, should be offered where available to all women at risk of being carriers. It is critical that women know their plasma factor measurement as they may have mild haemophilia (factor 5-30%, reference range 50-150%) which requires management at times of medical and surgical procedures and following trauma. Close liaison between adult and paediatric haemophilia centres and obstetric-gynaecology units is important to ensure that clinical carers identify and address carriers' needs. Genetic testing should be performed only after a potential carrier has been counselled and supported to receive such information. There is no coercion to accept such testing. An advantage of genetic testing is to then discuss pre-implantation genetic diagnosis which is an ex-vitro form of prenatal diagnosis. This can assist couples at risk of having a child with haemophilia who wish to reduce their anxieties about reproduction. Approximately 4% of boys with haemophilia, born in countries with good maternal care, will have intracranial haemorrhage in the neonatal period. There are no high-level evidence-based guidelines for the management of delivery or of the newborn with haemophilia. Obstetricians or other birth attendants need to be advised of the possibility of delivery of a boy with haemophilia and seek support from a haemophilia specialist during the pregnancy. The mother can then be monitored and plans for delivery be developed between her medical consultants and discussed with her. It is always preferable for a carrier to know of her genetic and phenotypic status before becoming pregnant so that she is informed as to her options and requirements for safe delivery.

Haemophilia patients with inhibitors characteristically have impaired joint function and reduced health-related quality of life (HRQoL). This analysis examined whether secondary prophylaxis with recombinant activated factor VII (rFVIIa) improves HRQoL vs. conventional on-demand therapy in patients with haemophilia with inhibitors and frequent bleeds. After a 3-month preprophylaxis period, 22 patients received daily rFVIIa prophylaxis (90 or 270 microg kg(-1)) for 3 months, followed by 3 months' postprophylaxis. Days of hospitalization, absence from school/work and mobility aids requirements were recorded. HRQoL was assessed by EuroQoL (EQ-5D) questionnaire, visual analogue scale (VAS), derived Time to Trade-Off (TTO) scores and Quality Adjusted Life Years (QALYs). rFVIIa prophylaxis significantly (P < 0.0001) reduced bleeding frequency vs. prior on-demand therapy. Hospitalization (5.9% vs. 13.5%; P = 0.0026) and absenteeism from school/work (16.7% vs. 38.7%; P = 0.0127) decreased during prophylaxis; these effects tended to be maintained during postprophylaxis. HRQoL (evaluated by EQ-5D) tended to improve during and after rFVIIa prophylaxis. Notably, pain decreased and mobility increased in 40.9% and 27.3% of patients, respectively, at the end of the postprophylaxis period vs. preprophylaxis. Median VAS score increased from 66 to 73 (P = 0.048), and TTO scores suggested better HRQoL (0.62 vs. 0.76; P = 0.054) during postprophylaxis than preprophylaxis. Small to moderate changes in effect sizes were reported for VAS and TTO scores. Median QALYs were 0.68 (VAS) and 0.73 (TTO). Reductions in bleeding frequency with secondary rFVIIa prophylaxis were associated with improved HRQoL vs. on-demand therapy.

Infections and technical problems are the most frequent complications when using implantable central venous access devices in patients with haemophilia. There are two major experiences reported concerning infections in noninhibitor patients: one is approximately 0.2 infections per 1000 days and the other approximately 1.0 (0.7-1.6) per 1000 days. Infections are more frequent in inhibitor patients and approximately one infection per 6-12 months of use can be expected. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not carried out in most of these series. In studies where this has been done, a high frequency of abnormalities on venograms has been seen in some but not in others. The final decision to use a central line has to take into account the medical goal, the patient's bleeding tendency, the social situation and the expected risk of complications at the particular haemophilia centre. Some of the complications may be reduced by adequate aseptic measures both during implantation and in subsequent use, and by clear basic routines for surveillance of the systems and repeated education of the users.

Participants in an international conference on prophylactic therapy for severe haemophilia developed a consensus summary of the findings and conclusions of the conference. In the consensus, participants agreed upon revised definitions for primary and secondary prophylaxis and also made recommendations concerning the need for an international system of pharmacovigilance. Considerations on starting prophylaxis, monitoring outcomes, and individualizing treatment regimens were discussed. Several research questions were identified as needing further investigation, including when to start and when to stop prophylaxis, optimal dosing and dose interval, and methods for assessment of long-term treatment effects. Such studies should include carefully defined cohorts, validated orthopaedic and quality-of-life assessment instruments, and cost-benefit analyses.

A multicentre study was performed in Sweden and the Netherlands, comparing effects of two prophylactic regimens in 128 patients with severe haemophilia, born 1970-90. 42 Swedish patients (high-dose prophylaxis), were compared with 86 Dutch patients (intermediate-dose prophylaxis). Patients were evaluated at the date of their last radiological score according to Pettersson. Annual clotting factor consumption and bleeding frequency were registered for a period of three years before evaluation. Patients in the high-dose group were younger at evaluation (median 15.2 vs. 17.9 years), started prophylaxis earlier (median 2 vs. 5 years), and used 2.19 times more clotting factor kg-1 year-1. Patients treated with high-dose prophylaxis had fewer joint bleeds (median 0.3 year-1 vs. 3.3 year-1) and the proportion of patients without arthropathy as measured by the Pettersson score was higher (69% vs. 32%), however, the age-adjusted difference in scores (median 0 points vs. 4 points) was small and at present not statistically significant. Clinical scores and quality of life were similar. These findings suggest that, compared with intermediate-dose prophylaxis, high-dose prophylaxis significantly increases treatment costs and reduces joint bleeds over a period of 3 years, but only slightly reduces arthropathy after 17 years of follow-up.

The paediatric care of children with haemophilia in developed countries should focus on the health of the child, not on the disorder. Gene therapy offers the hope of an ultimate 'cure' for the disorder, but until this is a viable proposition, patients should be given more control over their treatment, and the focus should be on 'self-monitored and self-adjusted' prophylaxis. New instruments for measuring joint function and radiographic changes, and quality of life are valuable tools in improving the treatment of paediatric care for children with haemophilia.

Prophylactic treatment of haemophilia has been gaining acceptance as the optimal therapeutic option in an increasing number of haemophilia centres in the developed world in recent years. This paper focus on three aspects of prophylactic therapy: when to start treatment, venous access and the dose/dose interval. Evidence is in favour of prophylactic treatment to be started at an early age using either a peripheral vein with 1-2 injections per week and a successive increase in the frequency depending on the child and the veins, or, using a Port-A-Cath which allows a better prophylactic coverage by infusions preferably every second day in haemophilia A and every third day in haemophilia B.

Professor Inga Marie Nilsson (1923-99) was a pioneer in the field of bleeding and thrombo-embolic disorders and made several major scientific contributions during her career. To honour her memory, colleagues from all over the world were invited to cover several aspects of haemostasis by giving state-of-the-art lectures at an international symposium in Malmo on September 22-23, 2000, chaired by Professors Lou Aledort and Erik Berntorp. Colleagues of Professor Nilsson in Malmo gave a short introduction to each topic. A short review of the meeting will be presented.

Ten patients, who had been treated according to the Malmo model for immune tolerance induction (ITI), were analysed regarding treatment with clotting factors and chemotherapy during the time period between inhibitor detection and ITI. Of the patients who were successfully rendered tolerant (n=6) all but one had received treatment with FVIII, either alone (n=1), or combined with cyclophosphamide (n=4). Of the patients who did not become tolerant, three of four had received treatment with FVIII during the inhibitor period but only one with FVIII and chemotherapy. The total amount of treatment received was in general much lower in the group that did not become tolerant. In individual cases, it appeared very clear that the inhibitor level and anamnestic response was substantially reduced prior to the ITI using the Malmo treatment model. We conclude that treatment of acute bleeds during the inhibitor period may be of importance for ITI and that the different response rates published for different immune tolerance regimens most likely do not reflect the true response rate for the respective regimen.

A survey was made of the current status of treatment of haemophilic boys at 20 centres in 16 European countries and includes approximately 1500 of the estimated 6500 haemophiliacs in the participating countries. Many mild haemophiliacs are not seen, or seen infrequently, at haemophilia centres and this requires study. Nine of 18 centres provide continuous prophylaxis to 80-100% of their patients, five centres provide it to 55-80% and the remaining four centres to 15-40% of the boys. The median dose given was 6240 U kg-1 year-1 (range 3120-7800). Four centres administered only recombinant concentrates to children with severe haemophilia A, while seven centres administered recombinant concentrates to 75-90% and the remaining centres to less than 50% of the boys (two centres

Haemophilia B, an X-linked recessive bleeding disorder characterized by lack or deficiency of factor IX, has been shown to be caused by any of a variety of DNA abnormalities (partial or total deletions, nonsense or missense mutations). Since in most countries carrier detection is based on factor IX coagulant activity (FIX:C) assay, this study was designed to determine whether carriers' FIX:C values are dependent on the severity of haemophilia (mild, moderate or severe) or on the genetic anomaly in the family. FIX:C concentrations were studied in 28 obligate carriers, 39 women known to carry the mutation and 33 verified noncarriers subgrouped by severity of disorder or genetic anomaly. No significant subgroup differences in FIX:C values were found, thus suggesting the level of FIX:C concentrations in carriers to be unaffected by the severity of haemophilia, or by its expression (i.e. deficient or dysfunctional factor IX). The specificity and sensitivity of FIX:C analysis for the purpose of carrier diagnosis was judged by receiver operating characteristic curve analysis, where an FIX:C cut-off level of 75 IU dL-1 was found to be optimal (sensitivity 93% and specificity 88%).

Anaphylaxis/anaphylactoid reactions have recently been reported after few treatments with factor IX concentrates in patients with haemophilia B at the same time as inhibitors to factor IX were demonstrated. In some of these cases nephrotic syndrome has appeared during immune tolerance induction (ITI) with high doses of factor IX concentrates. Gene deletions seem to be associated with a high risk of developing antibodies to factor IX. This report presents two brothers with deletion of 1 bp in exon f of the factor IX gene. Both showed anaphylactoid reactions and they were desensitized using slow i.v. injections of factor IX. At the time of anaphylaxis, inhibitors of factor IX in a low titre could be demonstrated. The elder brother responded well after a short time on ITI and has no spontaneous bleedings on regular prophylaxis although in a somewhat higher dose than expected. On the other hand, in spite of comparable regimens, the younger brother has so far been resistant to ITI. Moreover, during treatment with extremely high doses of factor IX concentrate he developed nephrotic syndrome which only slowly subsided after treatment with corticosteroids and withdrawal of factor IX.

At the haemophilia centre in Malmo, Sweden, regular prophylactic treatment is begun at 1-1 1/4 years of age, before the onset of joint bleeds. The dose and dose interval are optimised by means of pharmacokinetic studies to determine the individual patient's FVIII or IX metabolism, the goal of maintaining a level > 1% of normal being taken as a guideline which experience has shown to yield satisfactory control of bleeding diathesis. An optimal model for prophylactic treatment needs to be applicable to haemophiliacs and acceptable to health authorities in a majority of the countries in the world. To fulfill these criteria, the Swedish model, which has been shown to yield most satisfactory outcome, can hopefully be further refined in the future. Were continuous infusion, using a recombinate concentrate with a prolonged half-life, technically feasible and socially acceptable to the child, we would probably have attained the optimal model of prophylactic treatment. (Less)

The aim of the current study was to determine which pregnant carriers of haemophilia are at particularly high risk for having notably negative psychological reactions in association with prenatal diagnosis (PND) by fetal blood sampling of offspring haemophilia. Among 29 carriers of haemophilia A or B, notable psychiatric or psychosomatic symptoms in association with PND were significantly related to the woman's having a negative view of herself in general and of being a gene carrier, a planned pregnancy, high education, a good general knowledge of haemophilia and a guiding philosophy of life. Women with strong negative reactions significantly more often reported signs of depressive mood at follow-up. The results suggest that giving more information and promoting increased knowledge about the disease and the PND procedure will, by itself, not help women to cope better emotionally. Provision of prospective psychosocial support is recommended.

The aim of the study was to investigate the feasibility of optimizing prophylactic dosing of factor VIII by the use of individual pharmacokinetic data. Twenty-one patients were enrolled in a randomized cross-over study on standard dosage regimens vs. dosing according to pharmacokinetic principles. The study period was 2 x 6 months. Using single-dose pharmacokinetic data for each patient, plasma factor VIII procoagulant activity (FVIII:C) curves following various doses and intervals were computer-simulated. From these calculations, a suitable dosage was chosen. FVIII:C was also repeatedly measured during study periods. Trough levels of FVIII:C, numbers of spontaneous joint bleedings and amounts of factor concentrate used during the two study periods were compared for each patient. There was a close correlation between predicted and measured values of FVIII:C. As the half-lives of FVIII:C in the patients varied from 7.8 to 18.3 h, it was obviously beneficial to base the dosage on individual pharmacokinetic data. Fourteen patients completed both study periods. Mean trough level of exogenous FVIII:C was raised from 0.89 (SD 0.73) U dL -1 during standard dosage to 2.2 (1.5) U dL -1 during pharmacokinetic dosage. Concomitantly, mean 6-month consumption of factor VIII was decreased from 124,000 (SD 30,000) units to 84,000 (31,000) units. Numbers of reported bleedings were generally similar during both periods. The study demonstrates the usefulness of individual pharmacokinetics as a tool for cost-effective utilization of factor VIII in the prophylactic treatment of haemophilia A.

The optimal mode of delivery of a haemophilia carrier expecting a child is still a matter of uncertainty and debate. The aim of this commentary/review is to suggest that normal vaginal delivery should be the recommended mode of delivery for the majority of carriers, based on review of studies on obstetric aspects of haemophilia. About 2.0-4.0% of all haemophilia boys born in countries with a good standard of health care will suffer from ICH during the neonatal period. This is an average figure including all modes of delivery and regardless of whether the carrier status of the mother or the haemophilia status of the foetus was known or not at the time of delivery. On the basis of current literature, one may conclude that the risk of serious bleeding in the neonate affected with haemophilia is small in conjunction with normal vaginal delivery. It should be possible to further reduce the low frequency of complications if appropriate precautions are taken when planning the delivery in pregnant woman with known carrier status, if the sex of the foetus is known and, even more, when the haemophilia status of the foetus is known. Instrumental delivery such as use of vacuum extraction and foetal scalp monitors must be avoided at delivery of carriers.