Immune tolerance induction: What have we learned over time?

Development of inhibitory antibodies to infused factor VIII (FVIII) concentrates continues to be the most serious complication of haemophilia A management. Induction of immune tolerance by administering high doses of FVIII concentrate (antigen) and prothrombin complex concentrates to control bleeding was originated in the 1970s in Bonn, Germany, by Dr Hans-Hermann Brackmann, and became known as the Bonn protocol. ITI transformed the life of the index patient, who was 19 years of age when he began treatment, and dramatically improved the medical landscape for all patients with haemophilia and inhibitors. Over the past 40 years, variations to the Bonn protocol have been proposed. All protocols are effective although some are better suited than others for use in certain situations. The specific molecular defect in FVIII and the human leucocyte antigen (HLA) type of an individual with haemophilia are major codependent determinants to inhibitor development. Given the range of potential molecular defects and the staggering number of potential HLA types, it is likely that treatment arms of randomized studies in haemophilia represent highly diverse populations, which reduces the power of a study to demonstrate differences between treatments. Although available clinical guidelines and consensus recommendations for ITI therapy are not always in complete agreement, collectively the guidelines provide a reasonable level of guidance for administering ITI therapy under different clinical scenarios. Several studies of ITI therapy are ongoing with the aim of clarifying unresolved issues in haemophilia management including the role of von Willebrand factor in inhibitor eradication.

[Comprehensive Care Center Bonn from 1980 to 2009. Changes in the epidemiology and regional composition of the haemophilia population]. / Hämophilie-Zentrum Bonn 1980-2009. Wandel der Epidemiologie und der regionalen Zusammensetzung der Hämophilie-Population.

The Bonn Haemophilia Care Center provides patient care on a superregional level. The centre's large service area is, in part, due to the introduction of haemophilia home treatment and related to this the individualized prophylaxis in children and adults by Egli and Brackmann in Bonn in the early 1970s, that represented a milestone in German haemophilia therapy. Epidemiologic patient data from the two selected time points, 1980 and 2009, are evaluated to illustrate the change in the composition of the patient clientele. In 1980 a total of 639 patients were treated at the Bonn Haemophilia Center. 529 patients exhibited a severe form and 110 a non-severe form of the respective clotting disorder. In 2009 the Bonn Haemophilia Center took care for a total of 837 patients. There were 445 patients who suffered from a severe form of the considered clotting disorder while 392 showed a non-severe course. The number of less severely affected patients has increased significantly in 2009. Patients in 1980 were predominantly suffering from a severe form and most had to travel more than 150 km from their homes to the treatment center. In 2009 the number of patients living a medium-long distance from the care provider has significantly increased while the number of patients living more than 150 km from the center has decreased. Comparing 2009 to 1980 a growth of the center's regional character becomes apparent, especially when patient age and severity of the coagulation disorder are taken into consideration. The regional character was more strongly pronounced with milder disease severity and lower patient age. Due to the existence of well established primary haemophilia care in CCCs in Germany, the trend for the recent years is that the proportion of young patients that choose haemophilia care providers closer to their homes is increasing.

HLA genotype in patients with acquired haemophilia A.

Acquired haemophilia A (AH) is a rare bleeding disorder caused by an auto-antibody to coagulation factor VIII. It is associated with various autoimmune diseases, pregnancy, cancer or drug ingestion; however, in 50% of patients, no underlying disorder is found. In the present study, we investigated the association of HLA class I (A, B and Cw) and class II (DRB1 and DQB1) alleles with AH in a cohort of 57 patients. While no association with any class I allele was detected, a significantly higher frequency of DRB1*16 [odds ratio (OR) 10.2, 95%CI: 5.32-19.57, P < 0.0001] and DQB1*0502 (OR 2.2, 95%CI: 1.12-4.54, P < 0.05) was observed. In contrast, the frequency of DRB1*15 and DQB1*0602 alleles was found to be decreased in patients with AH corresponding to an OR of 0.4 for both HLA loci. Upon comparing the frequencies of these alleles with those of patients with congenital haemophilia A with inhibitors, the data demonstrate that the high risk alleles in patients with AH DRB1*16 and DQB1*0502 are found to be low risk alleles in patients with congenital haemophilia A with inhibitors (OR 1.1 and 1.5 respectively). Conversely, the alleles that exhibit low risk in AH DRB1*15 and DQB1*0602 are found to be high risk for haemophilia A inhibitor patients (OR 2.2 and 3.7 respectively). The pathophysiological reason for this finding remains unknown. It might be speculated that the presence or absence of the FVIII antigen and the various ability of HLA molecules to present the FVIII antigen to the T-cell receptor contribute to these findings.

The relevance of the bleeding severity in the treatment of acquired haemophilia - an update of a single-centre experience with 67 patients.

Acquired haemophilia (AH), an autoimmune disorder with clinical features ranging from harmless haematomas to life-threatening bleedings, still has a mortality rate of up to 25%. Owing to its low frequency (1-4 x 10(6)), standardized treatment protocols for its variable manifestations are not available. In case of prominent severe bleedings, the treatment should aim at rapid elimination of the antibody to protect patients from bleedings and on reinduction of long-term immune tolerance. Clinical data, short- and long-term treatment results of 67 patients diagnosed by our centre are presented. Patients were treated depending on their bleeding severity either by an immunosuppressive treatment alone, or in case of life-threatening bleedings, by a combined protocol (modified Bonn-Malmö protocol, MBMP) consisting of antibody depletion through immunoadsorption, intravenous immunoglobulin treatment, immunosuppression and high-dose factor VIII (FVIII) substitution. Mild bleedings occurred in two patients who were treated successfully alone by immunosuppression. Complete remission (CR) was achieved in 90% of the patients treated with MBMP (60). Of the six patients (10%) who achieved a partial remission (PR), four suffered from cancer. Mortality under MBMP was not seen. In contrast, five patients, in whom diagnosis of AH was delayed, experienced fatal outcome during surgical interventions before initiation of MBMP treatment. Prognosis in AH depends mainly on its prompt diagnosis. Treatment procedures should be adapted to bleeding severity and inhibitor titres. Under these conditions, AH is a potentially curable autoimmune disorder with an excellent prognosis.

Frequency of contamination of coagulation factor concentrates with novel human parvovirus PARV4.

Human parvovirus, PARV4 was identified in a plasma sample from a patient presenting with symptoms resembling acute HIV infection. Further strains of PARV4 and those of a closely related variant virus, were identified in plasma pools used in the manufacture of blood derivatives. DNA sequence analysis of these strains demonstrated two distinct PARV4 genotypes. It has subsequently been proposed that transmission of PARV4 occurs by parenteral routes. To investigate the risk of contamination of plasma-derived coagulation factor concentrates, we analysed 169 lots for PARV4 DNA by polymerase chain reaction. Positive samples were confirmed by nucleotide sequence analysis and quantification of the viral load. Twenty-one lots, representing eight different products were administered until the beginning of the 1980s and were not virally inactivated. Two lots examined were used in 1997, and 146 lots representing 13 products had been administered between October 2000 and February 2003. PARV4 DNA was detected in 7(33%) of the formerly administered lots, in one lot used in 1997, and in 13(9%) recently used lots. PARV4 genotype 2 DNA was predominantly present in the older concentrates, whilst genotype 1 was found more frequently in recently used lots. In three lots, both PARV4 genotypes were detected. Viral loads ranged between <100 and 10(5.8) copies mL(-1) of product, with higher viral loads in the older concentrates. The results show that PARV4 contamination can be detected in an appreciable proportion of clotting factor concentrates. Further studies are needed to determine whether or not PARV4 contamination of coagulation factors causes harm to the product recipients.

Successful pain treatment in arthropathic lower extremities by acupuncture in haemophilia patients.

Acupuncture is successfully used in the treatment of degenerative osteoarthritis. The treatment of haemophilic arthropathies can require strong painkillers with severe side-effects. Therefore, a special yet simple acupuncture technique was evaluated in the treatment of these joint problems. Twelve patients with a factor VIII activity<1% and at least one painful arthropathy in both lower extremities were included in this single-blinded study. The non-treated side served as a control. Treatment was assessed by a visual analogue scale (VAS) and an orthopaedic clinical examination. Only one needle was inserted at the rear fontanelle once per week and in 15 cycles. Ten of 12 patients showed an improvement of their pain perception. The average VAS could be reduced from 6.8 to 5.0. The side not receiving treatment showed a reduction from 4.1 to 4.0. No side-effects were observed. Even though interpretation of our data are limited due to the small patient numbers, significant improvement of the VAS after treatment suggests that acupuncture has a measurable positive effect in pain management for haemophilic arthropathy of the lower extremities.

[The modified Bonn Malmö protocol (MBMP) in the treatment of acquired haemophilia A]. / Das modifizierte Bonn-Malmö-Protokoll in der Behandlung der erworbenen Hemmkörperhämophilie -- Eine multimodale Therapiestrategie.

BACKGROUND AND OBJECTIVE: Autoantibodies directed against clotting factors can induce life threatening bleeding with a mortality rate up to 22%. Although the incidence of the disease is low (1-4 x 10(-6)), costs of treatment due to long-term clotting factor substitution can be enormous. Aim of an optimal treatment strategy should be to control bleedings by a rapid and safe elimination of the inhibitor and reinducing long-term immune tolerance. PATIENTS AND METHODS: Treatment of 48 patients with acquired haemophilia A (m=20, f =28, age 61.3 (SD 16.4)), the largest patient collective world-wide, was monitored for a mean of 48 months. Three patients received only conservative treatment. 45 patients were treated intensively by a multimodal strategy including: 1. immunoadsorption for antibody elimination; 2. FVIII substitution; 3. intravenous immunoglobulin substitution and 4. immunosuppression. The times required for inhibitor elimination, factor VIII substitution and the duration of the MBMP were documented. RESULTS: In 45 patients with a high titre critical bleeding was controlled immediately after the initiation of MBMP. There were no deaths from bleeding or the treatment. Inhibitor levels decreased to undetectable levels within a median of 3 days (95% CI, 3-7 days), factor substitution was terminated within a median of 13 days (95% CI, 10-16 days) and the treatment was completed within a median of 15 days (95% CI, 13-17 days). The overall response rate for complete remission (CR) was 91%. When cancer patients were excluded, the CR rate was 97%. CONCLUSION: Considering the short duration and amount of factor VIII substitution, the short time of hospitalization and the long-term median follow up of 48 months without bleeding events, the MBMP appears to have a modifying effect on the immunological response.

Analysis of mRNA in hemophilia A patients with undetectable mutations reveals normal splicing in the factor VIII gene.

BACKGROUND: haemophilia A (HA) is characterized by partial or total deficiency of factor VIII (FVIII) protein activity. It is caused by a broad spectrum of mutations in the FVIII gene. Despite tremendous improvements in mutation screening methods, in about 2% of HA patients no DNA change could be found, even after sequencing the whole coding part of the FVIII gene including the flanking splice sites, as well as the promotor and the 3' UTR regions. OBJECTIVES, PATIENTS AND METHODS: In the present study we performed a detailed RNA analysis of three groups of patients. The first included control patients with known splicing defects, the second included two patients with already identified nucleotide changes close to splicing sites, that could potentially alter the normal splicing process, and a third group of 11 unrelated patients whose genomic DNA have already been screened for mutations by DHPLC and direct sequencing with no mutation being identified. RESULTS: Both candidate splice site mutations were shown to result in either skipping or alternative splicing of at least one exon, therefore these DNA changes must be considered as causal for the patients' HA phenotype. In contrast, no abnormalities on the RNA level were observed in any of 11 unrelated patients without mutations in the FVIII gene. CONCLUSIONS: These findings exclude mutations that could be located deep in the introns and affecting either normal splicing or lead to mechanisms causing some unknown rearrangements of the FVIII gene. In fact, our results point to the presence of still unknown factor(s) causing HA, which might be either allelic or in the close proximity of the FVIII gene or non-allelic associated with other genetic loci that are involved in the processing of the FVIII protein.

Haemophilic arthropathy of the hip in children--prognosis and long-term follow-up.

The aim of this study was to report on the long-term follow-up of haemophilic children with avascular femoral head necrosis and to determine whether radiographic findings at initial diagnosis have any prognostic value. Seven patients with avascular necrosis of the femoral head were clinically and radiographically observed over a period of 5-50 years. The average age of patients at first diagnosis was 7.1 years. At follow-up, three of seven patients claimed to have occasional mild pain in the affected hip, four of seven showed loss of range of motion in the hip joint and two of seven patients showed a limp. Only one patient was clinically completely inconspicuous. The radiographically measured caput-collum-diaphysis angle at follow-up was pathologic in four cases and in one case a lateral subluxation of the femoral head was found. There was marked deformation of the femoral head in three of seven cases and a further two hips showing slight incongruency. Owing to the small patient-number, a statement concerning the prognostic value of defined radiographic signs cannot be made. As expected, the more 'risk signs' radiographically found, the higher the likelihood that patients will suffer arthrosis at a later stage. We propose that a clear distinction between haemophilic arthropathy of the hip and Legg-Calvé-Perthes disease should be made. In cases where radiographic changes are also found in the vicinity of the acetabulum, it is indicative for haemophilic arthropathy.

[2% Haemophilia A patients without mutation in the FVIII gene]. / 2% Hämophilie-A-Patienten ohne Mutation im FVIII-Gen.

In Germany, approximately 6,000 patients are suffering from haemophilia A. Screening methods cover 97% of the mutations. For the other patients the coding sequences of the FVIII gene have to be sequenced in total. Out of 1,350 patients, no mutation was observed in 80 patients. In 5 patients, we observed an inversion in intron 1. Known mutations were detected in 16 patients, and in 19 cases novel mutations were characterized (14 in coding regions and 5 in flanking introns). The mutations are mainly base pair substitutions, small deletions or insertions (max. 4 bp) and predicted to cause amino acid exchanges or frameshifts leading to premature stop codons. Moreover, 5 polymorphisms were identified in exons 14 and 26 as well as in introns 7 and 19. Further studies are necessary to identify their causative effects. Surprisingly, in 23 patients out of this subgroup of 80, no mutation was identified in the FVIII gene. Therefore, mutations in non-coding areas or even in other genes have to be considered responsible for the haemophilia A like phenotype. One of them codes for the von Willebrand factor (vWF). We confirmed in two of our cases mutations in the vWF gene.

[Significance of mutation analysis in patients with haemophilia A]. / Bedeutung der Mutationsdiagnostik bei Patienten mit Hämophilie A.

Haemophilia A represents the most frequent hereditary bleeding disorder in humans. The disease is caused by mutations within the factor VIII gene leading to decreased or absent factor VIII activities with a bleeding tendency depending on the degree of factor VIII deficiency. Nowadays, the causative mutations can be routinely detected and have substantially improved diagnostic and understanding of the pathophysiology of haemophilia A. Identification of the gene defects in haemophilic families have enabled fast and save carrier diagnosis. The correlation of the genetic defects with the clinical course revealed that the type of mutation represents the most important genetic predisposing factor for inhibitor formation, the most severe complication of treatment with factor VIII concentrates. Mitigated clinical courses of haemophilia A were shown to be due to special types of mutations or the presence of concomitant thrombophilic mutations. Molecular models of the factor VIII protein allowed to investigate the effects of specific mutations thus giving new insights in the structure/function relationship of the factor VIII molecule. These findings might promote the development of novel recombinant factor VIII concentrates with higher efficacy, longer half life and reduced immunogenicity.

[Characterization of factor VIII antibody epitopes from haemophilia A patients using cellulose bound FVIII peptide libraries]. / Charakterisierung von Faktor-VIII-Antikörperepitopen mit Faktor-VIII-Peptid-Bibliotheken.

Approximately 30% of patients suffering from severe haemophilia A develop antibodies against factor VIII (FVIII) neutralizing the effect of the pro-coagulant activity of intravenously injected FVIII as a complication of replacement therapy. Generally, various epitopes on the FVIII molecule are bound by these antibodies. The detailed structure of such epitopes is unknown. In this study epitopes on the FVIII molecule are identified using solid phase bound peptide arrays carrying the whole amino acid sequence of FVIII as small oligopeptides. The binding of FVIII antibodies by specific peptide sequences on the array indicates potential epitopes. FVIII antibodies of inhibitor patients and healthy blood donors are currently investigated by this method. Identified epitopes may lead to new concepts in therapy aiming at avoidance of inhibitor formation or improvement of inhibitor eradication. As participant of the 'haemophilia A' consortium dealing with genotype/phenotype correlation in haemophilia A we investigate, if the site or type of the mutation correlates with the epitopes, and if there is any relation between epitopes and clinical course. Furthermore, the influence of epitopes on therapeutical effects and the outcome of immune tolerance induction is under scrutiny.

[The national GTH haemophilia registry as database within the scope of the German human genome project]. / Das bundesweite GTH-Hämophilie-Register als Datenbasis im Rahmen des Deutschen Human-Genom-Projekts.

The Committee of Haemophilia of the GTH has established a central registry for all German centers treating patients with haemophilia. The intention was to establish a suitable system for collecting and analyzing epidemiological data relevant to bleeding disorders. The registry provides the database within the scope of the German Human-Genome-Project. The set goal is the complete molecular characterization of the genetic mutations on chromosome X of haemophilia A patients in Germany and subsequent correlation with the phenotype. An electronic network is applied for communication. A Java-application was developed for online electronic data acquirement by the participating centers. Offline data entry and sending encrypted data carriers is possible, too. A high level of security is assured by personalized access. Data are anonymized and scrambled by secure encoding. The concept was confirmed by the official data security offices. A considerable improvement for the epidemiological sciences and a better basis on therapy for patients with bleeding disorders is expected. Furthermore the registry is available for other scientific projects.

[Gathering and evaluation of phenotype data of haemophilia A patients for correlation with genotype data]. / Erfassung und Bewertung phänotypischer Parameter von Hämophilie-A-Patienten und Korrelation mit dem Genotyp.

Haemophilia A is caused by a genetic defect of the factor VIII gene resulting in complete or considerable functional loss of factor VIII molecule within blood. The high bleeding risk of patients can be prevented by intravenous injections of factor VIII protein. However, 25% of patients affected with severe haemophilia, develop factor VIII antibodies against the concentrate substituted. Within this study we try to comprise the phenotypic parameters (e. g. detailed documentation of disease course, basic laboratory values) and the therapy-associated data (e. g. applicated type and amount of factor VIII, number of substitutions, factor VIII recovery, inhibitor development and inhibitor elimination). We hope to identify differences of variable therapeutic treatments on course of disease as already identified for the factor VIII gene defects. At least we expect that certain mutations and mutation types, respectively, can be referred to typical phenotypes and similar course of treatment protocols.

Long-term follow-up after osteotomy for haemophilic arthropathy of the knee.

In this study the long-term value of corrective osteotomy around the knee was evaluated by means of clinical and radiographic parameters. Between 1974 and 1984 we performed 52 corrective osteotomies in the vicinity of the knee on patients affected by haemophilic arthropathy. Forty-two patients (45 osteotomies) were adequately followed-up at an average 11.6 years postoperatively. Using the clinical score of the Advisory Committee of the World Federation of Haemophilia, 38 patients showed a postoperative improvement, five remained clinically unchanged and two showed deterioration. Range of motion of the knee joint did not significantly improve postoperatively. The radiographic Pettersson score showed only a marginal decrease by an average 0.003 points at the time of follow-up. Only one patient needed subsequent joint replacement of both knees, on the left side 13 years after osteotomy and on the right side 8 years after osteotomy. Even in cases of marked radiographic joint destruction, corrective osteotomy shows acceptable long-term clinical results, underlining the feasibility of this management option in the treatment of haemophilic arthropathy of the knee. Although moderate cartilage degenerations in the femoropatellar complex and in the contralateral compartment can be tolerated, this therapy should primarily be contemplated for those patients where damage is unicompartmental and a corresponding axial deviation is found. Particularly the younger patient can benefit from this treatment option in that joint replacement may possibly wholly be avoided or at least postponed to a later stage of life.

Clinical and radiographic scores in haemophilic arthropathies: how well do these correlate to subjective pain status and daily activities?

Haemophilic patients who reached adulthood before the establishment of prophylactic treatment frequently show multiple and substantial arthropathies. The aim of this study was to determine to what extent haemophiliac's subjective impairment due to arthropathies correlates with objective clinical and radiographic parameters. By means of a questionnaire and a visual analogue scale, we consulted 79 haemophiliacs concerning their joint-pain status, how these were treated and to what extent their daily activities had been affected. Using a scoring system suggested by the Advisory Committee of the World Federation of Haemophilia, clinical evaluation was performed. Radiographs of 60 patients were assessed by means of the Petterson scale. The results were statistically compared. We found a significant correlation between pain intensity and clinical pathology as well as between pain intensity and radiographic joint damage for both knees and for the right ankle. The number of painful joints correlated well with the number of clinically/radiographically affected joints. The more pronounced the objective damage to joints, the more frequently patients claimed to have constant pain, depressive episodes and a dependency on pain-relieving medication. The more pronounced the objectively assessed damage to the knee and ankle joint, the higher the likelihood that the patient suffers from severe joint pain and reduction of activity. Treatment of painful symptoms from arthropathies is often insufficient. Scores and questionnaires may help to define the haemophiliacs pain status more clearly, thereby offering a possibility of assessment and long-term observation.

[Do polymorphisms of the SDF1 and CCR2b genes modify the course of hepatitis C or HIV/HCV co-infection?]. / Beeinflussen Polymorphismen des SDF1- und CCR2b-Gens den Verlauf der Hepatitis C und der HIV/HCV-Koinfektion?

BACKGROUND AND OBJECTIVE: Complementary to the CCR5-Delta32 mutation polymorphisms in the genes of CCR2b (CCR2b-V64 I) and stromal derived factor (SDF)-1 (SDF-1 3'A) affect the course of the human immunodeficiency virus (HIV) infection. While the CCR5-Delta32 mutation is also increased in chronic hepatitis C virus (HCV) infection it is unclear, whether the CCR2b-V64 I and the SDF-1 3'A polymorphisms also are associated with chronic HCV infection. METHODS: We analyzed the frequencies of the CCR2b-V64I and SDF1 - 3'A mutation in patients with HIV/HCV coinfection (n = 130), HIV infection (n = 105), HCV infection (n = 153) and 112 healthy blood donors. We stratified each group into homozygous mutations, heterozygous mutations and homozygous wild types, respectively. The resulting subsets were compared with respect to HIV and HCV loads, CD4 and CD8 cell counts. RESULTS: The mutant SDF1 - 3'A allele was found at 20.3 % frequency in patients with HCV infection and at 20.4 % frequency in patients with HIV/HCV coinfection, respectively. It was present in 27.1 % of the patients with HIV infection and 27.9 % of the healthy controls (not significant). The number of SDF-1 3) A homozygous patients was highest in patients with HIV/HCV coinfection and significantly different compared to the Hardy-Weinberg equilibrium (p = 0.010, chi (2) = 9.15). However, CD4- and CD8-cell counts or viral loads were not affected by this mutation. The frequency of the CCR2b-V64 I allele was similar in all patient groups. However, CCR2b-V64 I heterozygous patients showed HIV loads that were threefold lower than in CCR2b wildtype patients (22.9 x 103 vs. 6.4 x 103 copies/ml, not significant). Furthermore, hepatitis C viral loads were reduced roughly by 30 %. CONCLUSION: These results suggest that the SDF1 - 3'A and CCR2b-V64I mutations do not affect the course of HCV and HIV/HCV infection in the same manner as does the CCR5-Delta32 mutation.

Quality management and quality assurance in haemophilia care: a model at the Bonn haemophilia centre.

The severe clotting defects associated with the diagnosis of severe haemophilia A and B require a quality management and quality assurance system designed to avoid both bleeding sequelae (such as damaged joints) through early on-demand or prophylactic treatment in a home-care setting, and side-effects such as infectious diseases (hepatitis A-G and human immunodeficiency virus), allergic reactions, haemolysis and if possible inhibitor formation, by using highly purified, virus-inactivated or recombinant products in which the factor VIII and IX proteins are as natural as possible. As the intravenous injection of the required clotting factor is entrusted to the patients in home treatment, the haemophilia centre has to check treatment protocols and, when necessary, joint and muscle status. In addition, it is imperative to ensure the safety of the product, and checks must be carried out to make sure that batch numbers are recalled as soon as possible if side-effects are observed. These are the reasons for several Acts of Parliament in Germany requiring special treatments and regular checks (the Disabled Act, recommendations by the German Medical Council, the Transfusion Act). Thus, at the haemophilia centre in Bonn we have established a special quality management and quality assurance system taking into account the great number of patients (> 800), the often considerable distance between the centre and the patient, and the aforementioned regulations and laws. Quality management involves dealing with daily practicalities such as 24-h availability of a physician, medical technologist and nurse, careful instruction of patient and family in home care, genetic counselling, regular laboratory tests (especially recovery time, half-life, inhibitors and gene defects, clinical chemistry and serology) and clinical investigations (especially joint and muscle status). It also includes co-operation with family doctors and different departments at our university hospital (e.g. orthopaedic, microbiology), daily conferences with staff, information for nursery schools, schools, training institutions and/or the workplace in case of emergency, and cooperation with German haemophilia foundations. For quality assurance, several self-controlling systems are in place, such as distribution of concentrate, laboratory data, treatment protocols, joint and muscle status and bleeding tendencies. All these and more are double-checked and interactive, controlling data and activities with the help of EDP. Exceptional staff motivation and patient compliance are important for this quality system.

European data of a clinical trial with a sucrose formulated recombinant factor VIII in previously treated haemophilia A patients.

To increase the safety of antihaemophilic treatment, the production process of full-length recombinant factor VIII (FVIII) KOGENATE Bayer (Kogenate FS) has been modified. Human albumin is no longer added as stabilizer during purification and in final formulation. Instead, the new KOGENATE Bayer production process uses sucrose as a stabilizer in the formulation and adds solvent/detergent virus inactivation step. An European clinical trial was carried out in Germany and France in previously treated patients with severe haemophilia A who had more than 100 exposure days to exogenous FVIII. Pharmacokinetic data was analysed according to one-stage and chromogenic assays. Efficacy and safety during home therapy and in surgical procedures were evaluated; inhibitor formation was carefully monitored. Safety and efficacy were evaluated in 33 European patients for 24 months. Patients received more than 13 million IU KOGENATE Bayer. Over 75% of patients accrued more than 100 exposure days with the new product. Of 875 bleeding episodes, 90.7% were treated with 1 or 2 infusions and 75.8% of responses to treatment were rated as 'excellent' or 'good'. Prophylactic treatment was the most common mode of therapy (60.7% of infusions). The product was well-tolerated and FVIII recovery studies were consistent throughout the study period. Only 0.26% of adverse events were reported to be drug related. No evidence of de novo inhibitor formation was observed. Overall, KOGENATE Bayer was efficacious, safe and well-tolerated for the treatment of haemophilia A in multitransfused patients.