Humanistic burden of problem joints for children and adults with haemophilia.

INTRODUCTION: The "problem joint" (PJ) concept was developed to address patient-centric needs for a more holistic assessment of joint morbidity for people with haemophilia (PwH). AIM: To quantify the humanistic burden of PJs in PwH to further support validation of the PJ outcome measure. METHODS: Multivariable regression models evaluated the relationship between PJs and health-related quality of life (HRQoL, EQ-5D-5L) and overall work productivity loss (WPL) using data from the 'Cost of HaEmophilia: a Socioeconomic Survey' population studies (adults: CHESS II, CHESS US+; children/adolescents: CHESS-Paeds). Covariates included were haemophilia severity, age, comorbidities and education. RESULTS: The CHESS II sample included 292 and 134 PwH for HRQoL and WPL analyses, mean age 38.6 years (39% ≥1 PJ, 61% none). CHESS US+ included 345 and 239 PwH for HRQoL and WPL, mean age 35 years (43% ≥1 PJ, 57% none). CHESS-Paeds included 198 PwH aged 4-17 (HRQoL only), mean age 11.5 years (19% ≥1 PJ, 81% none). In CHESS II and CHESS US+, presence of PJs was associated with worse HRQoL (Both p < .001). Few CHESS-Paeds participants had PJs, with no significant correlation with HRQoL. In CHESS II, upper body PJs were significantly correlated to WPL (p < .05). In CHESS US+, having ≥1 PJ or upper and lower body PJs were significantly correlated to WPL (vs. none; both p < .05). CONCLUSION: This study has shown a meaningful burden of PJs on PwH, which should be considered in clinical and health policy assessments of joint health.

Novel manifestations of immune dysregulation and granule defects in gray platelet syndrome.

Gray platelet syndrome (GPS) is a rare recessive disorder caused by biallelic variants in NBEAL2 and characterized by bleeding symptoms, the absence of platelet α-granules, splenomegaly, and bone marrow (BM) fibrosis. Due to the rarity of GPS, it has been difficult to fully understand the pathogenic processes that lead to these clinical sequelae. To discern the spectrum of pathologic features, we performed a detailed clinical genotypic and phenotypic study of 47 patients with GPS and identified 32 new etiologic variants in NBEAL2. The GPS patient cohort exhibited known phenotypes, including macrothrombocytopenia, BM fibrosis, megakaryocyte emperipolesis of neutrophils, splenomegaly, and elevated serum vitamin B12 levels. Novel clinical phenotypes were also observed, including reduced leukocyte counts and increased presence of autoimmune disease and positive autoantibodies. There were widespread differences in the transcriptome and proteome of GPS platelets, neutrophils, monocytes, and CD4 lymphocytes. Proteins less abundant in these cells were enriched for constituents of granules, supporting a role for Nbeal2 in the function of these organelles across a wide range of blood cells. Proteomic analysis of GPS plasma showed increased levels of proteins associated with inflammation and immune response. One-quarter of plasma proteins increased in GPS are known to be synthesized outside of hematopoietic cells, predominantly in the liver. In summary, our data show that, in addition to the well-described platelet defects in GPS, there are immune defects. The abnormal immune cells may be the drivers of systemic abnormalities such as autoimmune disease.

The first Team Haemophilia Education meeting, 2015, Amsterdam, The Netherlands.

Haemophilia remains a complex disorder to diagnose and manage, requiring close cooperation between multidisciplinary healthcare professionals. There are still many unmet challenges in haemophilia care. The first Team Haemophilia Education (THE) meeting, held on 7-8 May 2015 in Amsterdam, The Netherlands, aimed to promote the optimal care of haemophilia patients through education of the multidisciplinary treatment team. This was achieved by reviewing the latest developments in haemophilia management, considering how these can be implemented in the clinic to improve patient care and providing a platform for networking and debate for all haemophilia treatment team members. Haemophilia treatment centres from several countries were asked to complete a premeeting online questionnaire to establish the biggest challenges that they face when managing patients. The concerns expressed were used to develop the agenda, which comprised a combination of formal presentations, case studies and informal workshops covering such topics as pharmacokinetics, laboratory assays and tailoring of treatment to individual patients. This report is a summary of the key developments in haemophilia care presented by various investigators and healthcare professionals at THE meeting 2015.

Switching to recombinant factor IX Fc fusion protein prophylaxis results in fewer infusions, decreased factor IX consumption and lower bleeding rates.

In the phase 3 B-LONG [Recombinant Factor IX Fc Fusion Protein (rFIXFc) in Subjects with Haemophilia B] study, rFIXFc dosed every 1-2 weeks was safe and efficacious in previously treated subjects with haemophilia B. To date, there are no evaluations of transitioning from conventional to long-acting factor IX (FIX) prophylaxis. This post-hoc analysis of B-LONG subjects compared prophylaxis with other FIX products and rFIXFc. Pre- and on-study data were analysed to assess dosing regimen, weekly FIX consumption and annualized bleeding rates (ABRs). Population pharmacokinetics models were used to generate FIX activity profiles with rFIXFc and recombinant FIX prophylaxis. Thirty-nine subjects, previously treated prophylactically, were evaluated. Prior to study, most subjects (69·2%) received twice-weekly FIX infusions; on study, subjects infused rFIXFc once every 1-2 weeks with c. 30-50% reductions in weekly consumption. On-study estimated mean ABRs were lower than pre-study estimated mean ABRs. Models predicted that rFIXFc administered 50 iu/kg weekly and 100 iu/kg every 10 d would maintain steady-state FIX trough levels ≥1 iu/dl in 95·4% and 89·2% of subjects, respectively. These results indicate that patients receiving rFIXFc prophylaxis can markedly reduce infusion frequency and FIX consumption, have a greater likelihood of maintaining FIX activity >1 iu/dl and experience fewer bleeding episodes compared with prior FIX prophylaxis.

Long-acting recombinant factor IX Fc fusion protein (rFIXFc) for perioperative management of subjects with haemophilia B in the phase 3 B-LONG study.

In the phase 3 B-LONG (Recombinant Factor IX Fc Fusion Protein [rFIXFc] in Subjects With Haemophilia B) study, rFIXFc demonstrated a prolonged half-life compared with recombinant factor IX (rFIX), and safety and efficacy for prophylaxis and treatment of bleeding in subjects with moderately-severe to severe haemophilia B. In this B-LONG sub-analysis, rFIXFc was evaluated for efficacy in subjects requiring major surgery. Dosing was investigator-determined. Assessments included dosing, consumption, bleeding, transfusions and haemostatic response. A population pharmacokinetics model of rFIXFc was used to predict FIX activity. Twelve subjects underwent 14 major surgeries (including 11 orthopaedic surgeries); most subjects (11/12) received rFIXFc prophylaxis before surgery (range, ~2 weeks-12 months). Investigators/surgeons rated haemostatic responses as excellent (n = 13) or good (n = 1). In most surgeries (85·7%), haemostasis from the pre-surgical dose until the end of surgery was maintained with a single rFIXFc infusion. Blood loss was consistent with similar surgeries in subjects without haemophilia. The strong correlation (R(2) = 0·9586, P < 0·001) between observed and population pharmacokinetic model-predicted FIX activity suggests surgery did not impact rFIXFc pharmacokinetics. No unique safety concerns or inhibitors were observed. In conclusion, rFIXFc was safe and efficacious, with prolonged dosing intervals and low consumption, when used perioperatively in haemophilia B. Surgery did not appear to alter rFIXFc pharmacokinetics.

Adenovirus-associated virus vector-mediated gene transfer in hemophilia B.

BACKGROUND: Hemophilia B, an X-linked disorder, is ideally suited for gene therapy. We investigated the use of a new gene therapy in patients with the disorder. METHODS: We infused a single dose of a serotype-8-pseudotyped, self-complementary adenovirus-associated virus (AAV) vector expressing a codon-optimized human factor IX (FIX) transgene (scAAV2/8-LP1-hFIXco) in a peripheral vein in six patients with severe hemophilia B (FIX activity, <1% of normal values). Study participants were enrolled sequentially in one of three cohorts (given a high, intermediate, or low dose of vector), with two participants in each group. Vector was administered without immunosuppressive therapy, and participants were followed for 6 to 16 months. RESULTS: AAV-mediated expression of FIX at 2 to 11% of normal levels was observed in all participants. Four of the six discontinued FIX prophylaxis and remained free of spontaneous hemorrhage; in the other two, the interval between prophylactic injections was increased. Of the two participants who received the high dose of vector, one had a transient, asymptomatic elevation of serum aminotransferase levels, which was associated with the detection of AAV8-capsid-specific T cells in the peripheral blood; the other had a slight increase in liver-enzyme levels, the cause of which was less clear. Each of these two participants received a short course of glucocorticoid therapy, which rapidly normalized aminotransferase levels and maintained FIX levels in the range of 3 to 11% of normal values. CONCLUSIONS: Peripheral-vein infusion of scAAV2/8-LP1-hFIXco resulted in FIX transgene expression at levels sufficient to improve the bleeding phenotype, with few side effects. Although immune-mediated clearance of AAV-transduced hepatocytes remains a concern, this process may be controlled with a short course of glucocorticoids without loss of transgene expression. (Funded by the Medical Research Council and others; ClinicalTrials.gov number, NCT00979238.).

Prophylaxis with a recombinant factor VIII Fc in hemophilia A: long-term follow-up on joint health, efficacy, and safety from phase 3 studies in children and adults.

Background: Recurrent joint bleeds are a major cause of morbidity in severe hemophilia. Prophylaxis with efmoroctocog alfa (a recombinant factor VIII Fc fusion protein, [rFVIIIFc]) has demonstrated benefits beyond bleed control, including joint health maintenance. Objectives: To assess long-term efficacy and safety of rFVIIIFc prophylaxis in severe hemophilia A in phase 3 pivotal (A-LONG/Kids A-LONG) and extension (ASPIRE) studies. Methods: Longitudinal analysis included pooled data from A-LONG/Kids A-LONG and ASPIRE. Subgroup analyses investigated outcomes in modified Hemophilia Joint Health Score or Hemophilia Joint Health Score and target joints in subjects with 4 to 5 years follow-up on individualized prophylaxis (IP), and those with the highest annualized bleeding rate (ABR) quartile during Year 1 of IP. Results: Overall, rFVIIIFc consumption remained stable and low ABRs were maintained, with a median treatment duration of 4.2/3.4 years in subjects from A-LONG/Kids A-LONG, respectively. Median overall ABR also remained low (1.0-2.0) in subjects on IP for 4 to 5 years. Sustained improvements in modified Hemophilia Joint Health Score or Hemophilia Joint Health Score were demonstrated over a median follow-up of 3.7 years. In subjects from A-LONG/Kids A-LONG, 99.6% (n = 234)/100% (n = 9) of evaluable baseline target joints were resolved, with no recurrence in 95%/100% of target joints. In IP subjects within the highest ABR quartile in Year 1, continued improvements were observed over a median follow-up of 4.3 years in ABR and joint health, without increased factor consumption. No inhibitors or treatment-related serious adverse events were reported. Conclusion: Previously treated subjects of all ages receiving long-term prophylaxis with rFVIIIFc had sustained clinical benefits, including improved joint health and low ABR.

Improvement in pain-related quality of life in patients with hemophilia A treated with rFVIIIFc individualized prophylaxis: post hoc analysis from the A-LONG study.

BACKGROUND: Pain, a common symptom of hemophilia, begins early in life primarily due to joint bleeding. Recurrent bleeding adversely affects patients' pain-related physical functioning, which can negatively impact their quality of life (QoL). OBJECTIVE: Post hoc analysis of data from the A-LONG study (NCT01181128), to assess change over time in pain-related QoL in patients with severe hemophilia A treated prophylactically with recombinant factor VIII Fc fusion protein (rFVIIIFc). METHODS: Patients who completed Haem-A-QoL (17-65 years) and EQ-5D-3L (⩾12-65 years) questionnaires at baseline (BL) and end of study (EoS). Individual-level changes were assessed using three pain-related items of the Haem-A-QoL 'Physical Health' domain and the pain/discomfort item of EQ-5D-3L. Distributions of responses (EoS versus BL) were compared using McNemar's test. RESULTS: A significantly greater proportion of patients reported they did not experience painful swellings (n = 87; 66% versus 46%, p < 0.01) or pain in their joints (n = 89; 42% versus 27%; p < 0.05) at EoS versus BL. The proportion of patients who did not find it painful to move numerically increased at EoS versus BL (n = 86; 47% versus 38%; p = NS). A significantly greater proportion of patients reported no pain/discomfort at EoS versus BL (n = 116; 45% versus 34%; p < 0.05). CONCLUSION: This study reports the effect of FVIII prophylaxis on patient-reported measures of pain over time in patients with severe hemophilia A. The results of this post hoc analysis showed improvements in pain from BL to EoS in patients receiving rFVIIIFc individualized prophylaxis indicating effective pain management, a key component of patient care.

Diagnosis and management of von Willebrand disease in the United Kingdom.

The UK treatment strategy for von Willebrand disease (VWD) is based on consensus guidelines produced by the United Kingdom Haemophilia Centre Doctors' Organization (UKHCDO) relating to the diagnosis and management of VWD. Selection of therapeutic products suitable for treatment of this complex inherited bleeding disorder is based on the observed response. Desmopressin (DDAVP), an analog of vasopressin, is the recommended treatment in individuals who respond to this drug on trial infusion. DDAVP clearly has no effect in type 3 VWD but may have variable clinical effect in individuals with other subtypes or may be contraindicated in some cases. In patients where DDAVP treatment is unsuitable, replacement factor concentrate containing von Willebrand factor (VWF) is the recommended alternative. Relevant concentrates are available for all patients in the United Kingdom, and treatment is administered by a network of 67 hemophilia treatment centers that also provide specialist care for individuals diagnosed with VWD. Patients diagnosed with the condition are registered on a national inherited bleeding disorder database administered by the UKHCDO on behalf of the Department of Health to aid in service planning and commissioning. Genetic testing is employed in the United Kingdom in certain situations, which is also performed in accordance with current UKHCDO guidelines.

Identification of type 1 von Willebrand disease patients with reduced von Willebrand factor survival by assay of the VWF propeptide in the European study: molecular and clinical markers for the diagnosis and management of type 1 VWD (MCMDM-1VWD).

The decreased survival of von Willebrand factor (VWF) in plasma has been implicated as a mechanism in a subset of type 1 von Willebrand disease (VWD) patients. We have previously reported that the ratio of plasma levels of VWF and its propeptide (VWFpp) can be used to identify patients with reduced VWF survival. In this study, we report the assay of VWFpp and VWF:Ag in 19 individuals recruited from 6 European centers within the MCMDM-1VWD study. Eight individuals had a VWF:Ag level less than 30 IU/dL. Seven of these patients had a robust desmopressin response and significantly reduced VWF half-life that was predicted by a markedly increased steady-state plasma VWFpp/VWF:Ag ratio. VWF mutations previously associated with reduced VWF survival were identified in each of the 7 individuals. Thus, a substantially increased ratio of steady-state VWFpp/VWF:Ag predicted a reduced VWF half-life in patients with markedly decreased VWF:Ag levels. These data indicate that a reduced VWF survival is found in a subpopulation of patients with type 1 VWD. The systematic assay of both plasma VWF and the VWF propeptide in moderately severe type 1 VWD patients may identify patients with a reduced VWF survival phenotype.

Propelling Healthcare with Advanced Therapy Medicinal Products: A Policy Discussion.

Recent advances in biomedicine are opening the door to new approaches, and treatment and prevention are being transformed by novel medicines based on genetic engineering, innovative cell-based therapies and tissue-engineered products, and combinations of a medical device with embedded cell or tissue components. These advanced therapy medicinal products (ATMPs) hold one of the keys to making a reality of genuinely personalised medicine. There are an estimated 450 companies across the globe working on the development of gene therapies and more than 1,000 clinical trials underway worldwide, and some 20-30 new ATMPs filings are expected in Europe annually over the next 5 years. But challenges confront the sector, complicating the translation from research into patient access. Scientific, clinical development and regulatory issues are compounded by limited experience with clinical and commercial use, limited manufacturing know-how, high costs, and difficulties in accessing development funding and investment. Pricing and reimbursement and market access issues are an additional challenge, particularly in Europe, where unfamiliarity with the technology and uncertainty over the use of real-world evidence induce caution among clinicians, health technology assessment bodies and payers. There is a need for a review of the suitability of the regulatory and market access framework for these products, focused development of data, public/private partnerships, and fuller collaboration governments, doctors, insurers, patients, and pharmaceutical companies. This paper makes specific recommendations for all stakeholders, ranging from early dialogue on potential products, linking of clinical data and patient registries or standardisation of control frameworks, to a comprehensive approach to evidence generation, assessment, pricing, and payment for ATMPs.

Clinical Considerations for Capsid Choice in the Development of Liver-Targeted AAV-Based Gene Transfer.

As gene transfer with adeno-associated virus (AAV) vectors is starting to enter clinical practice, this review examines the impact of vector capsid choice in liver-directed gene transfer for hemophilia. Given that there are multiple clinical trials completed and ongoing in this field, it is important to review the clinical evidence, particularly as a range of AAV-vector serotypes including AAV2, AAV5, AAV8, and AAV10 have been tested. Although there have been a number of successful trials, the development of two investigational AAV vectors for hemophilia B has been discontinued because they did not meet efficacy and/or safety expectations. Whether this difference between success and failure of gene transfer approaches reflects capsid choice, vector design, manufacturing system, or other variables is a question of great interest. Here, we examine the body of evidence across trials to determine the possible influences of serotype choice on key clinical outcomes such as safety, vector clearance, treatment eligibility, occurrence of transaminase elevations, activation of capsid-directed cytotoxic T cell responses, and clinical efficacy. In summary, gene transfer requires a balance between achieving sufficient transgene expression and minimizing destructive immune responses, which may be affected by AAV-vector serotype choice.

Efficacy and safety of simoctocog alfa (Nuwiq®) in patients with severe hemophilia A: a review of clinical trial data from the GENA program.

Simoctocog alfa (human-cl rhFVIII, Nuwiq®) is a 4th generation recombinant FVIII (rFVIII), without chemical modification or fusion with any other protein/fragment. Nuwiq® is produced in a human embryonic kidney cell line (HEK293F), which ensures human-specific post-translational protein processing. Nuwiq® was evaluated in seven prospective clinical studies in 201 adult and pediatric previously treated patients (PTPs) with severe hemophilia A. The NuProtect study in 110 previously untreated patients (PUPs) is ongoing. The mean half-life of Nuwiq® was 15.1-17.1 h in PTP studies with adults and adolescents, and 12.5 h in children aged 2-12 years. Clinical trials in PTPs demonstrated the efficacy and safety of Nuwiq® in the prevention and treatment of bleeds and as surgical prophylaxis. In the NuPreviq study of pharmacokinetic (PK)-guided personalized prophylaxis in 66 adult PTPs, 83% of patients had no spontaneous bleeds during 6 months of personalized prophylaxis and 57% were treated ⩽2 per week. No FVIII inhibitors were detected in PTPs after treatment with 43,267 injections and >80 million IU of Nuwiq®. Interim data for 66 PUPs with ⩾20 exposure days to Nuwiq® in NuProtect demonstrated a low cumulative high-titer inhibitor rate of 12.8% [actual incidence 12.1% (8/66)] and convincing efficacy and safety.

Adenovirus-associated antibodies in UK cohort of hemophilia patients: A seroprevalence study of the presence of adenovirus-associated virus vector-serotypes AAV5 and AAV8 neutralizing activity and antibodies in patients with hemophilia A.

BACKGROUND: Current treatment for severe hemophilia A is replacement of deficient factor. Although replacement therapy has improved life expectancy and quality, limitations include frequent infusions and high costs. Gene therapy is a potential alternative that utilizes an adeno-associated virus (AAV) vector containing the human genetic code for factor 8 (FVIII) that transduces the liver, enabling endogenous production of FVIII. Individuals with preexisting immunity to AAV serotypes may be less likely to benefit from this treatment. OBJECTIVES: This study measured seroprevalence of antibodies to AAV5 and 8 in an UK adult hemophilia A cohort. PATIENTS/METHODS: Patients were recruited from seven hemophilia centres in the UK. Citrated plasma samples from 100 patients were tested for preexisting activities against AAV5 and 8 using AAV transduction inhibition and total antibodies assays. RESULTS: Twent-one percent of patients had antibodies against AAV5 and 23% had antibodies against AAV8. Twenty-five percent and 38% of patients exhibited inhibitors of AAV5 or AAV8 cellular transduction respectively. Overall seroprevalence using either assay against AAV5 was 30% and against AAV8 was 40% in this cohort of hemophilia A patients. Seropositivity for both AAV5 and AAV8 was seen in 24% of participants. CONCLUSIONS: Screening for preexisting immunity may be important in identifying patients most likely to benefit from gene therapy. Clinical studies may be needed to evaluate the impact of preexisting immunity on the safety and efficacy of AAV mediated gene therapy.

Evaluation of thromboelastography for monitoring recombinant activated factor VII ex vivo in haemophilia A and B patients with inhibitors: a multicentre trial.

Predicting the clinical effect of bypassing agents such as recombinant activated factor VII in haemophilia patients with inhibitors is hampered by the limited availability of reliable laboratory monitoring tools. This multicentre, open-label trial aimed to explore the dose-response relationship between recombinant activated factor VII concentration and thromboelastography parameters in blood samples from patients with haemophilia A or B with inhibitors in a nonbleeding state. Citrated whole blood samples from 16 patients (>or=16 years) with haemophilia A or B were spiked ex vivo with recombinant activated factor VII (1.2, 1.6, 2.0, 2.6, 3.0, 3.5 microg/ml), corresponding approximately to doses of 90-270 microg/kg. Samples were analysed by Thromboelastograph or Rotation Thromboelastography (three United States and three European centres, respectively) within 30 min (final lipidated recombinant tissue factor 1: 17 000; final CaCl2 15 mM). Thromboelastograph/Rotation Thromboelastography parameters showed large intersubject variation in the baseline profiles. There was a clear effect when recombinant activated factor VII was added; however, a clear concentration-response relationship was only detected for one patient. This is likely due to the fact that the curves were not sufficiently abnormal that led to reduced assay sensitivity. Our preliminary results suggest that thromboelastography may potentially be a clinically useful tool for monitoring changing concentrations of recombinant activated factor VII in haemophilia patients, but only when the baseline curve is significantly abnormal. Thus, test conditions may need to be optimized before Thromboelastograph/Rotation Thromboelastography can be utilized for all inhibitor patients.

An investigation of the von Willebrand factor genotype in UK patients diagnosed to have type 1 von Willebrand disease.

Forty families diagnosed by UK centres to have type 1 VWD were recruited. Following review, six families were re-diagnosed to have type 2 VWD, one to have a platelet storage pool disorder, and one family was determined to be unaffected. Direct DNA sequencing of the promoter region and all exons and intronic boundaries of the VWF gene identified six mutations likely to be causative of VWD in index cases of nine of the 32 (28%) confirmed type 1 VWD families. These included R1205H (3614G > A) VWD Vicenza, P1648fsX45 (4944delT), D141G (422A > G) and three splice site mutations: 3108 + 5G > A, 7437 + 1G > A and 3379 + 1G > A. The Y1584C (4751A > G) polymorphism was present in eight additional families. No significant VWF gene mutation or polymorphism was identified in 15 of the 32 type 1VWD index cases (47%). Haplotype studies were performed using a panel of VWF polymorphisms to investigate the segregation in families of VWD phenotype with the VWF gene. In 13 of the 32 families it was likely that VWD segregated with the VWF gene. In eight families (25%) VWD clearly did not segregate with the VWF gene. We suggest that mutation screening of the VWF gene has limited general utility in genetic diagnostic and family studies in type 1 VWD. If genetic studies are performed, the incomplete penetrance and variable expressivity of type 1 VWD must be taken into account. Unless linkage of VWD phenotype with the VWF gene can be clearly demonstrated, the results of any genetic family studies should be interpreted with caution.

Von Willebrand factor modulates factor VIII immunogenicity: comparative study of different factor VIII concentrates in a haemophilia A mouse model.

The development of an immune response towards factor VIII (FVIII) remains the major complication of haemophilia A replacement therapy. Product-related risk factors have recently been identified on the basis of epidemiological studies, but the mechanism is not understood. To this end, various commercially available FVIII concentrates were administered by the IV route to FVIII-knockout mice and the resulting immune response was characterised. Significantly higher inhibitor titres (Bethesda assay) were observed for one recombinant FVIII and one plasma-derived FVIII product depleted in von Willebrand factor (VWF). Inhibitor titres were reduced upon pre-incubation of FVIII with purified VWF. Epitope specificity of anti-FVIII IgG was characterised using FVIII-fragments produced in E. coli. Concentrates with no or reduced VWF-level elicited antibodies recognising predominantly the acidic a1 and a3 regions. Addition of VWF prior to injection also modified the epitope specificity. FVIII concentrates, therefore, show qualitative and quantitative variations in immunogenicity, which are at least partly modulated by VWF.

Autotransplantation of unmanipulated bone marrow into scarred myocardium is safe and enhances cardiac function in humans.

Stem cell transplants into damaged myocardium may have the potential to improve cardiac function. We investigated the safety of transplanting unmanipulated autologous bone marrow into infarcted myocardium of patients undergoing coronary bypass surgery and assessed its efficacy to improve cardiac function. Fourteen patients with one or more areas of transmural myocardial infarction were studied. Autologous bone marrow was obtained by sternal bone aspirate at the time of surgery, diluted in autologous serum at a ratio of 1:2, and then injected 1 cm apart into the mid-depth of the left ventricular scar. There were no deaths, no perioperative myocardial infarctions, and no significant ventricular arrhythmias. Dobutamine stress echocardiography demonstrated overall improvement in the global and regional left ventricular function 6 weeks and 10 months after surgery. Of 34 infarcted left ventricular segments, 11 were injected with bone marrow alone, 13 were revascularized with a bypass graft alone, and 10 received bone marrow transplantation and a bypass graft in combination. Only the left ventricle segmental wall motion score of the areas injected with bone marrow and receiving a bypass graft in combination improved at low dose and at peak dobutamine stress. These findings suggest that transplantation of unmanipulated autologous bone marrow into scar tissue of the human heart is safe and enhances cardiac function only when used in combination with myocardial revascularization. This benefit can be seen after 6 weeks of the bone marrow transplant and is maintained after 10 months of follow-up.