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Biomedical subjects

G Auerswald

Publications and source records attributed to G Auerswald.

At least 19 recordsLinked to original sources

Evaluation of pharmacokinetics, efficacy and safety of Immunate solvent detergent in previously treated patients with severe haemophilia A.

Immunate Solvent Detergent (S/D) is a plasma derived, purified, human factor VIII (FVIII) - von Willebrand factor (VWF) complex subjected to two virus inactivation/removal processes: S/D and vapor heat treatment. This prospective, multicentre, three-part clinical study evaluated the pharmacokinetics (in comparison to the predecessor product Immunate), efficacy and safety of Immunate S/D in 56 previously treated patients with severe haemophilia A. Subjects received Immunate S/D on-demand, as a prophylactic regimen or both. The results of the pharmacokinetic population demonstrate that Immunate and Immunate S/D were equivalent with respect to the FVIII - and to the retrospectively VWF - parameters assessed. A total of 623 bleeding episodes were reported in 47/56 subjects. The duration of prophylaxis ranged from 0.1-5.2 months with a total of 175.6 months. The median number of bleeds per month in subjects on prophylaxis was 0 (range 0-10). Ninety-six percent of bleeding episodes were rated as having an excellent or good response. For most bleeding episodes (89%), subjects required only one infusion with a mean dose of 29.6 IU kg(-1). No FVIII inhibitory antibodies were observed in any subject. No related serious adverse events were reported. Thus, the introduction of S/D treatment did not alter the PK characteristics and function of VWF and FVIII molecules of Immunate S/D which is effective and safe for treatment of bleeding episodes, management of surgical procedures, and prophylaxis.

Detergents↗

Prophylaxis in rare coagulation disorders -- factor X deficiency.

Factor X (FX) is a vitamin K-dependent protease that plays a central role in the blood coagulation cascade. Deficiency of FX is one of the rarest congenital coagulation disorders, resulting in a variable clinical phenotype. The molecular basis for FX deficiency is characterised by a large number of gene mutations and polymorphisms. The Greifswald Registry of FX deficiency was started in 1998 and aims to investigate the relationship between genetic mutations and the clinical severity of the disease. To date, 34 of 102 patients have been treated for severe bleeding episodes or for surgical procedures. Only seven patients, six of whom are children, receive regular prophylaxis with Factor IX (FIX) concentrate (FIX HS, ZLB Behring; also containing approximately 800IU FX). In all cases, the bleeding episodes are well controlled without any serious treatment-related complications.

Adolescent↗

Factor X deficiency: clinical manifestation of 102 subjects from Europe and Latin America with mutations in the factor 10 gene.

Inherited factor X deficiency (FXD) is a rare (1:1,000,000) recessive bleeding disorder. The clinical and laboratory phenotypes of FXD are poorly correlated and few regional studies on the genotype and the clinical manifestations of FXD are known. To understand the association between clinical manifestations and causative genotype, detailed evaluation of bleeding pattern in a high number of patients is needed. This international study analysed the phenotype and genotype of 102 subjects from Central Europe (Germany, Poland and Slovakia) and Latin America (Costa Rica and Venezuela) with causative mutations in the F10 gene, via sequencing. Twenty-eight homozygous, seven compound-heterozygous and 67 heterozygous FXD subjects were characterized. Twenty-nine different causative mutations, including 15 novel mutations, were analysed. Spontaneous bleeding symptoms in 42 symptomatic individuals (26 homozygous, seven compound heterozygous and nine heterozygous) comprised easy bruising (55%), haematoma (43%), epistaxis (36%), haemarthrosis (33%), intracranial haemorrhage (ICH; 21%), and gastrointestinal (GI) haemorrhage (12%). The manifestation of bleeding symptoms in 9 of 67 (13%) symptomatic heterozygous subjects is described. The bleeding patterns of the enrolled patients showed differences that are associated with the types of F10 mutation, and the corresponding genotypes. The homozygous patients were evaluated for genotype-phenotype correlation. The results suggested that ICH seems to be associated with the F10 mutation Gly380Arg, and possibly with the mutations IVS7-1G>A and Tyr163delAT. A tentative association of other mutations to severe symptoms such as haemarthrosis and GI haemorrhage is reported. The severity of FXD, the genotype-phenotype association, and the results of regional studies are discussed.

Adolescent↗

Health status and health-related quality of life of children with haemophilia from six West European countries.

A multicentre, international, cross-sectional study was carried out in the frame of field testing of the first haemophilia-specific quality-of-life (QoL) questionnaire (Haemo-QoL). The aim of this paper is to describe health status and health care and their impact on QoL in haemophilic children in Western Europe. Children aged 4-16 years with severe haemophilia without inhibitors were enrolled by 20 centres in France, Germany, Italy, the Netherlands, Spain and the United Kingdom. Clinical information was collected by the physicians with a medical documentation form. Health-related QoL (HRQoL) of children was assessed with Haemo-QoL, available for three age groups. Clinical data were available in 318 patients, 85.5% with haemophilia A. The mean age at first bleeding was 11 months, at first joint bleed 25 months. Functional joint impairments were found in 11.3%. Prophylaxis treatment was given to 66.7% of children in whom breakthrough bleeds occurred 0.4 times a month compared to 1.1 bleeds in children receiving on-demand treatment. A significantly higher factor consumption was found only in the two younger age groups of prophylaxis patients compared to on-demand patients. HRQoL was satisfactory in this cohort: young children were impaired mainly in the dimension 'family' and 'treatment', whereas older children had higher impairments in the so-called 'social' dimensions, such as 'perceived support' and 'friends'. Health care of children in Western Europe is progressively improving with a large diffusion of home treatment and prophylaxis. This provides a high level of health status and HRQoL, being better in haemophilic adolescents on prophylaxis.

Adolescent↗

Pharmacokinetics of activated recombinant coagulation factor VII (NovoSeven) in children vs. adults with haemophilia A.

To establish the pharmacokinetic profile of activated recombinant coagulation factor VII (rFVIIa; NovoSeven in children with haemophilia A, and to compare it with the pharmacokinetic profile in adults with haemophilia A. Twelve children (2-12 years) received one single dose of rFVIIa 90 and 180 micrograms kg(-1) in randomized order separated by a washout period of 48 h to 1 month. Six adults (18-55 years) received a single dose of rFVIIa 90 micrograms kg(-1). The pharmacokinetic analyses were based on a non-compartmental method. In children, the plasma level of FVII increased proportionally with the dose. The total body clearance normalized for body weight was significantly faster in children than in adults (FVII:C, 58 vs. 39 mL kg(-1) h(-1) and FVIIa, 78 vs. 53 mL kg(-1) h(-1), P < 0.05). A trend towards a larger volume of distribution at steady-state in children than in adults was observed (P > 0.05). Dose proportionality was established for plasma concentrations of FVII in children with haemophilia A at the dose levels investigated (90 and 180 micrograms kg(-1) rFVIIa). Following administration of rFVIIa 90 micrograms kg(-1), significantly faster clearance was observed in children compared with adults, suggesting that higher doses of rFVIIa may be needed to achieve the same plasma levels as in adults.

Child↗

Treatment patterns and cost-of-illness of severe haemophilia in patients with inhibitors in Germany.

To evaluate current treatment patterns and resource utilization as well as related cost in the management of severe haemophilia patients with inhibitors in Germany, a cost-of-illness study was conducted. Generally, data were generated by structured literature search. Missing data were collected by expert interviews. All data were validated by a panel of German experts in haemophilia care. In Germany, immune tolerance therapy (ITT) is first-line therapy in inhibitor management for children in the initial year after inhibitor development, particularly for high responders (HR). In adult HR patients ITT is applied but to a remarkably lower extent than in children. To treat bleeding episodes, factor VIII (FVIII) is first-line therapy in low responders (LR). For paediatric HR patients, bleeds are mainly treated with recombinant FVIIa (rFVIIa). In adult HR patients, activated prothrombin complex concentrate (aPCC) and rFVIIa are more equally distributed as treatment options. Treatment costs were calculated for paediatric patients (15 kg) and adult patients (75 kg) from third party payers' perspective. Cost for ITT ranges from Euro 70,290 (2 months; LR) to Euro 3 812,400 (24 months; with aPCC; HR) in a paediatric patient. For an adult patient ITT cost ranges from Euro 287,500 (6 months; LR) to Euro 17,253,000 (36 months; HR). For on average 12.5 acute bleeds, average annual treatment costs amount to Euro 77,000 for a child and Euro 354,000 for an adult. Assessing the results it has been taken into consideration that ITT can last longer and annual number of bleeds can be extremely higher than on average 12.5 episodes. This indicates more health care resource consumption in some patients.

Adult↗

Continuous infusion of B-domain deleted recombinant factor VIII (ReFacto) in patients with haemophilia A undergoing surgery: clinical experience.

This retrospective, open-label, non-comparative study evaluated continuous infusion of recombinant factor VIII (ReFacto), B-domain deleted recombinant FVIII (BDDrFVIII), in patients with haemophilia A undergoing surgery and requiring >5 consecutive days of treatment. Sixteen patients from eight centres underwent a total of 20 procedures. Haemostatic outcome was assessed as 'excellent' or 'good' in 75% of procedures, and target FVIII:C levels were maintained throughout the continuous infusion period. The reported volume of blood loss during surgery was also within the normal range for non-haemophilic patients for the type of surgery performed. Red blood cell transfusions were required to balance excessive blood loss during BDDrFVIII continuous infusion in eight (40%) procedures (seven patients), five with bleeding or requiring volume replacement and three to treat anaemia secondary to blood loss. Non-serious adverse events considered by investigators as possibly or probably related to BDDrFVIII continuous infusion were infrequent (n = 5) considering the duration of treatment (n =239 cumulative days of continuous infusion), and all of these were mild-to-moderate in severity. No thromboembolic complications were reported except for one case of thrombophlebitis occurring at the infusion site. Only two patients (four events) experienced serious adverse bleeding; BDDrFVIII was otherwise well-tolerated. These data show that continuous infusion of BDDrFVIII provides reliable haemostasis and is an effective and well-tolerated regimen for patients with haemophilia A undergoing surgery.

Adolescent↗

Thrombosis in inherited factor VII deficiency.

Thrombosis in congenital factor (F) VII deficiency was investigated through extensive phenotypic and molecular-genetic studies. Patients with a history of thrombosis among 514 entries in the FVII Deficiency Study Group database were evaluated. Thrombotic events were arterial in one case, disseminated intravascular coagulation in another and venous in seven. Gene mutations were characterized in eight patients: three were homozygous, three compound heterozygous and two heterozygous. FXa and IIa generation assays were consistent with the genetic lesions. One patient was heterozygous for the FV Leiden and one for the FIIG20210A mutation. In seven patients, surgical interventions and/or replacement therapies had a close temporal relationship with thrombosis, while in the remaining, events were apparently spontaneous. Thromboses were not associated with any specific age, phenotype, mutation zygosity or thrombophilic abnormalities. In particular, severe FVII deficiency did not seem to offer protection from strong thrombosis risk factors such as surgery and replacement therapy.

Adolescent↗

Detection of all anti-factor VIII antibodies in haemophilia A patients by the Bethesda assay and a more sensitive immunoprecipitation assay.

Plasmas from 40 haemophilia A patients enrolled in a study by the paediatric group of the German Society on Thrombosis and Hemostasis were tested by the Bethesda assay for inhibitor antibodies and by a more sensitive immunoprecipitation assay (IP) for all antifactor VIII antibodies. Of the 26 severe, 11 moderate and three mild haemophiliacs, 18, two, and none, respectively, had positive Bethesda titres after several factor VIII infusions. In 275 plasmas with Bethesda titres of 0, 0.6--1.0, > 1--5, and > 5--655, the IP responses were 0-238, 0--61, 0--786, and 43--6141, respectively, and a reliable positive IP titre was > 4.2. The overlapping ranges of IP titres indicated large differences in the ratio of inhibitory to noninhibitory antibodies in individual plasmas. In five of seven patients with Bethesda titres of 0.6--1, the IP titres were < 4.2, suggesting a lack of precision of Bethesda titres < or = 1. Detection of the primary immune response was found in only three patients by IP assay before a positive Bethesda assay. This precludes early, reliable testing of which patients will be immunologically responsive. In four patients undergoing immune tolerance therapy, antifactor VIII antibodies were still detectable by the IP assay in the absence of a Bethesda titre, which indicates that antibodies were completely eradicated in none of the patients. Our results show that the use of both the Bethesda and IP assays can provide more accurate detection of antifactor VIII antibodies in all patients.

Antibodies↗

Prevalence and outcome of intracranial haemorrhage in haemophiliacs--a survey of the paediatric group of the German Society of Thrombosis and Haemostasis (GTH).

UNLABELLED: A survey among centres of the paediatric group of the GTH was performed to evaluate the prevalence and outcome of haemophiliacs with intracerebral haemorrhage. A questionnaire sent to the centres covered the following points: number of patients with severe, moderate and mild haemophilia A and B; for each patient with ICH: birth date, age at bleeding, aetiology and neurological sequelae. Overall, 30 ICH in 744 haemophiliacs (4.0%) were reported by 17/40 centres (42.5%). There was no significant difference between the prevalence of patients with haemophilia A and B (3.5% vs. 6.3%) and among the age groups. Bleeding was diagnosed within 1 week of birth in 11/27 patients (41%). For 3 patients, no age-related information was given. The most important factor was trauma (17/30 = 57%), either during birth (9/30 = 30%) or later in life (8/30 = 27%). Seizures were common, occurring in 19/30 patients (63%). As 1 patient died after posttraumatic ICH, the neurological outcome of 29 patients could be evaluated. Psychomotor and statomotor retardation and cerebral palsy were reported in 17/29 (59%), 15/29 (51%) and 13/29 (45%) patients respectively. Only 7/29 (24%) showed no neurological sequelae. Severity of deficits was not correlated with birth date but to age at bleeding. Older children showed a better neurological outcome than neonates. CONCLUSION: The frequency and outcome of ICH in haemophiliacs have not changed in our cohort over the past 20 years. Trauma at birth is an important risk factor for ICH in patients with haemophilia A or B. Intracranial haemorrhages in older children are rare, and a better outcome may be expected.

Age Distribution↗

German recommendations for immune tolerance therapy in type A haemophiliacs with antibodies.

Haemophilia A is the most common X-chromosomal-linked congenital bleeding disorder and is caused by decreased activity of blood coagulation factor VIII. Affected individuals develop a variable phenotype of haemorrhages, mainly into joints and muscles depending on the amount of the residual factor VIII. The exogenous factor VIII-substitution by plasma-derived or recombinant products are the only treatments either on demand or prophylactically. The most important complication of treatment is the development of inhibitors that affect about 20%-50% of the severe cases. These antibodies neutralize the therapeutic effect of factor VIII-concentrates, leading to recurrent bleeding episodes, progredient joint damages and sometimes life-threatening situations. The only chance for a complete and permanent eradication of the inhibitors in these patients is the induction of Immune-Tolerance (ITT) to substituted factor VIII by the application of high-doses of factor VIII. The treatment demands a strict compliance of the patient and a much higher effort of the physician, to non-compared inhibitor patients. Requirements for a consistent realization of the ITT to increase the successful outcome was carried out by German Haemophilia Center Directors.

Antibodies↗

Factor VIII inhibitors in patients with hemophilia A: epidemiology of inhibitor development and induction of immune tolerance for factor VIII.

Factor (F) VIII inhibitor development remains one of the most serious complications in the treatment of hemophilia A. Former and recent studies on inhibitor development revealed that patients with severe hemophilia A and positive inhibitor family history are at highest risk of developing an inhibitor. Comparison of recent inhibitor incidence studies on previously untreated patients indicate that the risk of inhibitor development under treatment with recombinant FVIII concentrates is comparable to the inhibitor incidence under FVIII substitution by plasma-derived concentrates. However, longer observation periods are necessary to draw final conclusions. Since inhibitor development may result in inefficacy of FVIII concentrates in the treatment of severe bleedings, the induction of immune tolerance (IT) is still of main concern. Various regimens to induce IT by application of FVIII concentrates have been conducted up to now. Success rate appears to be influenced by low to high responder status, number of exposure days before onset of treatment, and dosage of therapeutic regimen. Especially, discontinuation of IT therapy seems to be associated with failure of therapy. Taking into account available data on IT therapy, we recommend early onset of a high dosage regimen in high responder patients as soon as possible after inhibitor detection, as this is associated with higher success rate and shorter elimination time.

Adolescent↗

A new type of congenital dysfibrinogen, fibrinogen Bremen, with an A alpha Gly-17 to Val substitution associated with hemorrhagic diathesis and delayed wound healing.

We have identified a new type of A alpha Gly-17 to Val substitution in a congenital dysfibrinogen, fibrinogen Bremen, derived from a 15-year-old boy having manifested easy bruising and delayed wound healing. The functional abnormality was characterized by altered fibrin monomer polymerization, which became evident by increasing the salt concentration and pH. A synthetic tetrapeptide with a sequence of the amino-terminal segment of normal fibrin alpha-chain, Gly-Pro-Arg-Val, substantially inhibited polymerization of both normal and the patient-derived fibrin monomers. A synthetic tetrapeptide with the Bremen type sequence of Val-Pro-Arg-Val inhibited polymerization of the patient's fibrin monomers partially at a peptide: fibrin monomer molar ratio of 4,000:1, and that of normal one at a much higher ratio of 10,000:1. Likewise, a synthetic peptide Ala-Pro-Arg-Val with a replacement of the Gly residue by another aliphatic amino acid Ala inhibited similarly the patient's fibrin monomer polymerization. Thus, the hypothetical two-pronged socket-like structure consisting of the alpha-amino group of the amino-terminal Gly and the guanidino group of an Arg at position 3 of the normal fibrin alpha-chain seems to be restored considerably in the mutant fibrin alpha-chain at low ionic strengths and pH's, despite the replacement of the amino-terminal Gly by another aliphatic amino acid Val.

Adolescent↗