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Factor VIII antibody

Carol H Miao
Current treatment of hemophilia A (HemA) patients with repeated infusions of factor VIII (FVIII; abbreviated as F8 in constructs) is costly, inconvenient, and incompletely effective. In addition, approximately 25 % of treated patients develop anti-factor VIII immune responses. Gene therapy that can achieve long-term phenotypic correction without the complication of anti-factor VIII antibody formation is highly desired. Lentiviral vector (LV)-mediated gene transfer into hematopoietic stem cells (HSCs) results in stable integration of FVIII gene into the host genome, leading to persistent therapeutic effect...
2016: Thrombosis Journal
Bagirath Gangadharan, Mathieu Ing, Sandrine Delignat, Ivan Peyron, Maud Teyssandier, Srinivas V Kaveri, Sébastien Lacroix-Desmazes
The development of inhibitory antibodies to therapeutic FVIII is the major complication of replacement therapy in patients with hemophilia A. The first step in the initiation of the anti-FVIII immune response is FVIII interaction with receptor(s) on antigen-presenting cells followed by endocytosis and presentation to naive CD4+ T cells. Recent studies indicate a role for the C1 domain in FVIII uptake. We investigated whether charged residues in the C2 domain participate in immunogenic FVIII uptake. Co-incubation of FVIII with BO2C11, a monoclonal C2-specific IgG, reduced FVIII endocytosis by dendritic cells and presentation to CD4+ T cells, and diminished FVIII immunogenicity in FVIII-deficient mice...
October 6, 2016: Haematologica
S F Lax, K F Tamussino, P F Lang
Malignancies of the uterus metastasize by direct invasion of neighboring structures, lymphatically or hematogenously. Endometrial and cervical cancers lymphatically spread to the pelvic and para-aortic lymph nodes. For endometrial cancer the depth of myometrial invasion, lymphosvascular space involvement (LVSI) and a microcystic, elongated and fragmented (MELF) glandular invasion pattern are predictors for lymph node metastases. Metastases to the pelvic lymph nodes occur in approximately 10 % of endometrial cancer patients and in 30 % of these cases the para-aortic lymph nodes are also involved...
October 18, 2016: Der Pathologe
Edward Tuddenham
The declarative title is a fair summary of research described in this paper (Targeting Factor VIII expression to platelets for hemophilia A gene therapy does not induce an apparent thrombotic risk in mice)(10) , is a fair summary of research described in this paper, which is itself the 14th in a series from the group of researchers led by Montgomery who, since 2003 have progressively advanced the idea of storing factor VIII in platelets to treat hemophilia A. Why, one might ask, would one do such a thing when evolution has selected endothelial cells as both the site for synthesis and release of factor VIII complexed with Von Willebrand factor to provide the cofactor when and where needed?(1,2) The answer lies in the unfortunate fact that a high proportion of patients with hemophilia develop resistance to factor VIII due to alloimmunity to the protein, which is foreign to their immune system, leading to production of inhibitory antibodies to the cofactor...
October 17, 2016: Journal of Thrombosis and Haemostasis: JTH
N Bel Feki, S Zayet, I Ben Ghorbel, M-H Houman
The lupus anticoagulant-hypoprothrombinemia syndrome (LA-HPS) - the association of acquired factor II deficiency and lupus anticoagulant - is a rare disease that may cause a predisposition not only to thrombosis but also to severe bleeding. We are reporting on a 36-year-old female patient presenting with co-existing cerebral venous thrombosis and subdural hemorrhage. The coagulation screening showed a prolonged prothrombin time (PT), activated partial thromboplastin time (aPTT), and a normal fibrinogen level and platelet count...
October 12, 2016: Journal des Maladies Vasculaires
Amy M Lange, Ekaterina S Altynova, Giang N Nguyen, Denise E Sabatino
Factor VIII (FVIII) is a large glycoprotein that is challenging to express both in vitro and in vivo. Several studies suggest that high levels of FVIII expression can lead to cellular stress. After gene transfer, transgene expression is restricted to a subset of cells and the increased FVIII load per cell may impact activation of the unfolded protein response. We sought to determine whether increased FVIII expression in mice after adeno-associated viral liver gene transfer would affect the unfolded protein response and/or immune response to the transgene...
2016: Molecular Therapy. Methods & Clinical Development
Moanaro Biswas, Geoffrey L Rogers, Alexandra Sherman, Barry J Byrne, David M Markusic, Haiyan Jiang, Roland W Herzog
Development of antibodies (inhibitors) against coagulation factor VIII (FVIII) is a major complication of intravenous replacement therapy in haemophilia A (HA). Current immune tolerance induction (ITI) regimens are not universally effective. Rituximab, a B cell-depleting antibody against CD20, has shown mixed results for inhibitor reversal in patients. This study aims to develop a combinatorial therapy for inhibitor reversal in HA, using anti-murine CD20 (anti-mCD20) antibody and rapamycin, which targets both B and T cell responses...
September 29, 2016: Thrombosis and Haemostasis
Philip M Zakas, Harrison C Brown, Kristopher Knight, Shannon L Meeks, H Trent Spencer, Eric A Gaucher, Christopher B Doering
Optimization of a protein's pharmaceutical properties is usually carried out by rational design and/or directed evolution. Here we test an alternative approach based on ancestral sequence reconstruction. Using available genomic sequence data on coagulation factor VIII and predictive models of molecular evolution, we engineer protein variants with improved activity, stability, and biosynthesis potential and reduced inhibition by anti-drug antibodies. In principle, this approach can be applied to any protein drug based on a conserved gene sequence...
September 26, 2016: Nature Biotechnology
Chirag Sheth, Amandeep Gill, Sumeet Sekhon
Acquired factor VIII deficiency (acquired hemophilia A) is a rare condition characterized by the acquisition of autoantibodies that affect the clotting activity of factor VIII (fVIII). The most common manifestation in affected patients is a hemorrhagic diathesis. This disorder is associated with autoimmune diseases, pregnancy, postpartum period, drugs, and malignancy. Management of this condition begins with attempts to arrest an acute bleed based on the site and severity of bleeding and inhibitor titer. The next priority is eradication of the fVIII antibodies using immunosuppressive therapies...
2016: Journal of Community Hospital Internal Medicine Perspectives
Marion Delcroix, Kim Kerr, Peter Fedullo
Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of pulmonary embolism. As for most rare diseases, epidemiologic data are scarce, but recent registries suggest an incidence of at least 5 per million inhabitants per year. A history of massive or recurrent acute pulmonary embolism is observed in most patients with CTEPH, but the proportion of patients who develop CTEPH after acute pulmonary embolism is a matter of debate, further complicated by the possible misdiagnosis of CTEPH as acute pulmonary embolism...
July 2016: Annals of the American Thoracic Society
Jan Hartmann, Stacy E Croteau
A surge in therapeutic clinical trials over recent years is paving the way for transformative treatment options for patients with hemophilia. The introduction of recombinant factor concentrates in the early 1990s facilitated the use of prophylactic replacement as standard care for hemophilia rather than on-demand treatment. This has revolutionized health outcomes for hemophilia patients, enabling participation in physical activities and reducing debilitating, chronic joint damage. Challenges of prophylactic factor infusion include the frequency of infusions needed to maintain factor levels greater than 1%, patient adherence, reliable intravenous access, and development of neutralizing alloantibodies ("inhibitors")...
August 26, 2016: American Journal of Hematology
Stephan G Dixon, Carl T Bruce, Charles J Glueck, Robert A Sisk, Robert K Hutchins, Vybhav Jetty, Ping Wang
AIM: Our specific aim was to document the pathoetiologic importance of thrombophilia among females presenting with severe ischemic retinal vein (RVO) or retinal artery (RAO) occlusion, without typical risk factors, and to emphasize that the ophthalmologists' diagnosis of thrombophilia has important diagnostic and therapeutic downstream ramifications for nonocular thrombosis, including reproductive outcomes. METHODS: We evaluated familial and acquired thrombophilia in 60 females with RVO (central RVO, n=52; branch RVO, n=8) and 16 with RAO (central RAO, n=11; branch RAO, n=5)...
2016: Clinical Ophthalmology
K M Lövgren, H Søndergaard, S Skov, B Wiinberg
In haemophilia A (HA) management, antidrug antibodies, or inhibitors, are a serious complication that renders factor VIII (FVIII) replacement therapy ineffective, increases morbidity and reduces quality of life for affected patients. Inhibitor development aetiology is multifactorial and covers both genetic and therapy related risk factors. Many therapy-related risk factors have proven difficult to confirm due to several confounding factors and the small study populations available. However, clinical studies indicate that e...
September 2016: Haemophilia: the Official Journal of the World Federation of Hemophilia
Waqar Waheed, Salman Aljerdi, Barbara Decker, Mary Cushman, Robert W Hamill
Cerebral venous thrombosis (CVT) is an uncommon disorder associated with diverse processes. We report a patient who, while receiving desmopressin and contraceptive pills (OCP), developed straight sinus thrombosis. Clinical assessment and laboratory investigations revealed untreated hyperthyroidism and a hypercoagulable state, characterised by high levels of von Willebrand factor, factor VIII coagulant activity and IgM cardiolipin antibody. The clinical picture improved with anticoagulation, treatment of hyperthyroidism and discontinuation of OCP and desmopressin...
2016: BMJ Case Reports
J Mahlangu, P Paz, M Hardtke, F Aswad, J Schroeder
INTRODUCTION: The most serious and challenging complication of haemophilia treatment is development of inhibitors to replacement factors VIII or IX. Innovative therapies currently being explored for patients with haemophilia and inhibitors include BAY 86-6150, a modified recombinant activated factor VII (FVIIa). Immunogenicity remains a substantial barrier in this endeavour. AIM: To present safety and efficacy results of the BAY 86-6150 study in patients with inhibitors and report detailed analysis of epitope mapping in a patient who developed anti-BAY 86-6150 antibodies...
August 8, 2016: Haemophilia: the Official Journal of the World Federation of Hemophilia
Jennifer L Schneider, Sathy V Balu-Iyer
Development of unwanted immune responses against therapeutic proteins is a major clinical complication. Recently, we have shown that exposure of Factor VIII in the presence of phosphatidylserine (PS) induces antigen-specific hyporesponsiveness to Factor VIII rechallenge, suggesting that PS is not immune suppressive, but rather immune regulatory in that PS converts an immunogen to a tolerogen. Since PS is exposed in the outer leaflet during apoptosis, we hypothesize that PS imparts tolerogenic activity to this natural process...
October 2016: Journal of Pharmaceutical Sciences
Ruth A Ettinger, Pedro Paz, Eddie A James, Devi Gunasekera, Fred Aswad, Arthur R Thompson, Dana C Matthews, Kathleen P Pratt
Factor VIII (FVIII) neutralizing antibodies ("inhibitors") are a serious problem in hemophilia A (HA). The aim of this study was to characterize HLA-restricted T-cell responses from a severe HA subject with a persistent inhibitor and from two previously studied mild HA inhibitor subjects. MHCII tetramers corresponding to both of the severe HA subject's HLA-DRA-DRB1 alleles were loaded with peptides spanning FVIII-A2, C1 and C2 domains. Interestingly, only one epitope was identified, in peptide FVIII2194-2213, and it was identical to the HLA-DRA*01-DRB1*01:01-restricted epitope recognized by the mild HA subjects...
July 28, 2016: Blood
Vybhav Jetty, Charles J Glueck, Richard A Freiberg, Ping Wang
Venous thromboembolism is uncommon after knee arthroscopy, and there are no guidelines for thromboprophylaxis in elective routine knee arthroscopy. Preoperative evaluation of common thrombophilias should provide guidance for postarthroscopy thromboprophylaxis in otherwise healthy patients who are at high risk for venous thromboembolism. This study assessed 10 patients with venous thromboembolism after total hip or knee arthroplasty. Patients were assessed if venous thromboembolism occurred within 6 months after knee arthroscopy (n=10) or total hip or knee arthroplasty (n=21)...
July 25, 2016: Orthopedics
K M Lövgren, H Søndergaard, S Skov, B Wiinberg
INTRODUCTION: The most serious complication in haemophilia A (HA) replacement therapy with coagulation factor VIII (FVIII) is neutralizing antibodies, i.e. inhibitors. It has been hypothesized that danger signals generated during a bleed might have an adjuvant effect on the immune response to FVIII in on-demand treatment, increasing the inhibitor risk. AIM: To compare the antibody response to treatment with recombinant human FVIII (rhFVIII) in relation to induced knee joint bleeds and treatment without concurrent bleeds in a HA rat model...
September 2016: Haemophilia: the Official Journal of the World Federation of Hemophilia
I Diaz, K Bolloré, E Tuaillon, P Lapalud, M Giansily-Blaizot, J P Vendrell, J F Schved, G Lavigne-Lissalde
INTRODUCTION: Approximately, 25% of haemophilia A (HA) patients treated by factor VIII (FVIII), develop antibodies, known as inhibitors, neutralizing the activity of infused FVIII. This immune response involves B cells (BC), including FVIII-specific memory B cells (MBC). Production of anti-FVIII antibodies after stimulation of FVIII-specific MBC suggests a role of these cells in the immune response to FVIII. Animal models allowed the study of circulating FVIII-specific cells, however few data are available on HA patients...
September 2016: Haemophilia: the Official Journal of the World Federation of Hemophilia
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