Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The evolution of transfusion or infusion therapies for diseases requiring specific protein replacements (e.g., hemophilia A and B and severe combined immunodeficiency syndrome) was dramatic over the second half of the 20th century. Unfortunately, it was accompanied by extreme manifestations of transfusion-transmitted diseases, such as human immunodeficiency virus (HIV), hepatitis B, and hepatitis C. The milestones of both the replacement therapies and the associated diseases are discussed in this presentation, which focuses on the technologic advances that resulted in even more "pure" replacement therapies for plasma-protein diseases. From donor screening to the development of viral attenuation techniques, every facet of production for these products was impacted by the exigent push for viral safety created by HIV and hepatitis. Almost invariably, this negatively affects total product yield. At the beginning of the 21st century, success in making plasma products safe from recognized and potential pathogens has dramatically increased societal pressures to produce a zero-risk, plasma-derived protein therapy. However, past improvements and low theoretic risks for future pathogen contamination have increased product cost. This is associated with a possible decrease in the overall supply of these plasma proteins because of the reduced numbers of acceptable donors and the loss of protein from expanded attenuation technology. These impacts and the role of dynamic societal and scientific pressures on these decision processes are discussed.
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PMID:History of plasma-product safety. 1144 15

Thirty patients affected by hemophilia A or B or von-Willebrand's disease and chronic posttransfusional active HCV hepatitis who developed major side effects during the course of a previous treatment with recombinant interferon-alpha (IFN-alpha) were studied. In all patients IFN-alpha therapy had to be discontinued and those who achieved a primary serologic and viral response to HCV relapsed within a few months. After a washout period, patients were retreated with human leukocyte IFN-alpha, 6 MU thrice weekly for 12 months. In about 90% of patients, a primary response, with normal AST and GGT values and undetectable HCV-RNA, was achieved within the third month of treatment and for the entire duration of treatment none of the patients had to discontinue therapy because of severe adverse reactions. During posttherapy follow-up only one patient relapsed. The human leukocyte IFN-alpha regimen looks to be very effective and safe for carriers of inherited clotting disorders who developed major side effects with recombinant IFN-alpha therapy for HCV-related chronic hepatitis.
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PMID:Human leukocyte interferon-alpha treatment for chronic HCV-related hepatitis in hemophilic patients previously intolerant to other interferons-alpha. 1185 62

The introduction of plasma-derived human factor VIII (FVIII) and later human recombinant FVIII (rFVIII) has potentially allowed patients suffering from hemophilia A to have a quality of life and life expectancy similar to the population at large. One of the major achievements in molecular biology over the past 15 years was the sequencing of the gene coding for FVIII, leading eventually to the ability to isolate the human gene for FVIII and transfect cells to produce human rFVIII. The first rFVIII products, which are native full-length FVIII molecules, have proved to have an excellent efficacy and safety profile in patients with hemophilia A. Initial concerns about a potential increased inhibitor formation have not been confirmed so far but long-term pharmacovigilance of inhibitor formation is still ongoing. To date, no transmission of hepatitis or human immunodeficiency virus (HIV) attributable to rFVIII products has been reported. However, a theoretical risk of transmission of infectious disease does exist as long as nonsynthetic proteins are used during the production process. The next-generation native rFVIII has been developed to minimize the exposure of patients to animal or human plasma-derived proteins. This has been achieved through major changes to the process of production of rFVIII from baby hamster kidney cells (BHK). This change has included the introduction of a solvent/detergent step and, of more importance, the introduction of a purification procedure without using albumin as a stabilizer. Finally, the rFVIII (BHK) is formulated using sucrose as the final stabilizer to produce the sucrose formulated rFVIII referred to as rFVIII-FS. This article summarizes the recently published pharmacokinetic, safety, and efficacy data for the native rFVIII-FS and compares its clinical profile with that of the first-generation rFVIII.
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PMID:First and next generation native rFVIII in the treatment of hemophilia A. What has been achieved? Can patients be switched safely? 1209 89

Comprehensive hemophilia treatment centers (HTCs) were first inaugurated more than 50 years ago. In 1976, a federally funded HTC network was created in the United States, making multidisciplinary care for patients with hemophilia and other inherited bleeding disorders available throughout the country for the first time. Education of the patient and healthcare professional in the management of bleeding became a mainstay of these programs. The HTCs began surveillance of the complications of treatment, such as hepatitis and HIV. The high rate of HIV infection in the hemophilia population from contaminated clotting factor concentrates forced an adaptation of HTCs to manage the medical and psychosocial consequences of these diseases. In addition, expanded surveillance for potential new therapy-associated complications became a legacy of these efforts. From the HIV era until the present, HTCs have undertaken expanded clinical research (drawing on a new scientific understanding regarding hemostasis and new knowledge regarding the management of quality of life) to study new methods to improve the well-being of patients with hemophilia. The further research has extended to phase 1 gene transfer trials for hemophilia A and B. Although the prospect for a complete cure for patients with hemophilia is some time away, HTCs in the 21st century continue to vigorously research a cure. In the interim, the HTC model continues to provide essential services that are being reassessed in light of new scientific information to prevent the complications that have defined the clinical picture of hemophilia.
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PMID:Comprehensive care for hemophilia and related inherited bleeding disorders: why it matters. 1293 11

Arthropathies and joint deformities in patients with severe hemophilia result in prolonged immobilization, reduced physical activity, and predispose them for osteoporosis. This can lead to an increasing tendency of bone fragility and fractures in patients after trivial trauma. The aim of this study was to find out (i) the prevalence of osteoporosis in hemophilia patients and (ii) the association of osteoporosis with hemophilic arthropathy and related restricted physical activity. In this case-control study, 50 consecutive severe hemophilia patients aged between 20 and 50 years were evaluated for osteoporosis with measurement of bone mass density (BMD) by a DEXA scan and values were compared with that of 50 sex matched normal healthy controls. Major joints of the limbs were evaluated to determine the extent of joint damage and related disability. Forty-two patients had severe hemophilia A and 8 patients severe hemophilia B (efficient factor activity < 0.01 U/ml). BMD values (gms/cm(2)) of lumbar spine and left hip of the patients were significantly lower than that of controls (0.825 vs. 0.939; P < 0.0001 and 0.725 vs. 0.938; P < 0.0001, respectively). The incidence of osteoporosis (T score: -2.5 or more) was significantly higher in hemophiliacs. Incidence of fractures in adult life was also significantly higher in hemophiliacs compared to controls (12% vs. 0%). There was statistically significant correlation between joint evaluation scores and BMD of hip, but not with that of the lumbar spine. There was no correlation between Hepatitis-C virus status and BMD of any site. This shows that development of osteoporosis is a significant problem in patients with severe hemophilia in this country. Hence appropriate preventive measures such as early treatment and adequate mobilization, exercises, encouragement to participate in sporting activities, early assessment of bone density, and administration of anti-osteoporotic therapy is recommended.
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PMID:Osteoporosis in young haemophiliacs from western India. 1727 14

Hemophilia B is an X-linked genetic disorder that typically results from chronic circulating deficiency of blood coagulation factor IX (FIX) (1). While the occurrence of hemophilia B is significantly less frequent than hemophilia A (factor VIII, deficiency) it has received special attention as a model for gene therapy. This is because hemophilia B is one of the least complicated genetic diseases from the point of view of demonstrating the proof of principle of a gene therapy protocol. Specifically, hemophilia B is a single gene recessive disorder and a wide range of tissues can be targeted for FIX gene delivery and strict regulation of FIX expression is not required. In addition, the 2.8 kb FIX cDNA is much smaller than the 9 kb FVIII cDNA, and FIX expression in transfected mammalian cells has been less problematic than FVIII expression (2). Since clinical severity of bleeding episodes closely corresponds to a patient's FIX activity, achieving even partial restoration of normal FIX levels in the bloodstream can alleviate internal bleeding. Individuals with FIX levels less than 1% of normal experience severe symptomatic episodes but providing roughly 5% of normal levels (i.e., 250 ng/mL plasma) can significantly reduce the frequency and severity of bleeding episodes and reduce long term complications (3). Treatment of hemophilia B primarily relies on intravenous injections of FIX protein purified from pooled human plasma, or very recently, on newly developed recombinant FIX. Treatment is applied typically only when bleeding episodes have occurred or are expected, for example, in case of a trauma or surgery. Although the risk of viral transmission of HIV and hepatitis viruses has been largely eliminated the absolute safety of any product derived from blood cannot be guaranteed. Furthermore, supplies of factor concentrates are limited and costs (especially if prophylactic treatment is being considered) are high. Thus, the application of gene therapy to hemophilia, whereby long-term correction of factor IX deficiency might be achieved, would be extremely useful.
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PMID:Ex Vivo Stromal Cell Electroporation of Factor IX cDNA for Treatment of Hemophilia B. 2144 54

We previously compared the expression of several human factor VIII (fVIII) transgene variants and demonstrated the superior expression properties of B domain-deleted porcine fVIII. Subsequently, a hybrid human/porcine fVIII molecule (HP-fVIII) comprising 91% human amino-acid sequence was engineered to maintain the high-expression characteristics of porcine fVIII. The bioengineered construct then was used effectively to treat knockout mice with hemophilia A. In the current study, we focused on optimizing self-inactivating (SIN) lentiviral vector systems by analyzing the efficacy of various lentiviral components in terms of virus production, transduction efficiency and transgene expression. Specifically, three parameters were evaluated: (1) the woodchuck hepatitis post-transcriptional regulatory element (WPRE), (2) HIV versus SIV viral vector systems and (3) various internal promoters. The inclusion of a WPRE sequence had negligible effects on viral production and HP-fVIII expression. HIV and SIV vectors were compared and found to be similar with respect to transduction efficiency in both K562s and HEK-293T cells. However, there was an enhanced expression of HP-fVIII by the SIV system, which was evident in both K562 and BHK-M cell lines. To further compare expression of HP-fVIII from an SIV-based lentiviral system, we constructed expression vectors containing the high expression transgene and a human elongation factor-1 alpha, cytomegalovirus (CMV) or phosphoglycerate kinase promoter. Expression was significantly greater from the CMV promoter, which also yielded therapeutic levels of HP-fVIII in hemophilia A mice. Based on these studies, an optimized vector contains the HP-fVIII transgene driven by a CMV internal promoter within a SIV-based lentiviral backbone lacking a WPRE.
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PMID:Generation of an optimized lentiviral vector encoding a high-expression factor VIII transgene for gene therapy of hemophilia A. 2299 97

Factor IX deficiency (hemophilia B) is less common than factor VIII deficiency (hemophilia A), and innovations in therapy for hemophilia B have generally lagged behind those for hemophilia A. Recently, the first sustained correction of the hemophilia bleeding phenotype by clotting factor gene therapy has been described using recombinant adeno-associated virus (AAV) to deliver factor IX. Despite this success, many individuals with hemophilia B, including children, men with active hepatitis, and individuals who have pre-existing natural immunity to AAV, are not eligible for the current iteration of hemophilia B gene therapy. In addition, recent advances in recombinant factor IX protein engineering have led some hemophilia treaters to reconsider the urgency of genetic cure. Current clinical and preclinical approaches to advancing AAV-based and alternative approaches to factor IX gene therapy are considered in the context of current demographics and treatment of the hemophilia B population.
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PMID:Gene therapy in an era of emerging treatment options for hemophilia B. 2614 16


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