Managing the risk of transmission of variant Creutzfeldt Jakob disease by blood products

Mammalian embryo culture media: now and into the future

For over 70years, since the culture of the first mammalian embryo in vitro , scientists have undertaken studies to devise and optimise media to support the manipulation and culture of gametes and embryos. This area of research became especially active in the late 1970s onwards following the successful birth of the first human in vitro fertilised embryo. This review summarises some of the key advances in mammalian embryo culture media over time based on a greater understanding of the biochemical milieu of the reproductive tract. It highlights how learnings from studies in mice and agricultural species have informed human culture media compositions, in particular the inclusion of albumin, growth factors, cytokines, and antioxidants into contemporary culture media formulations, and how these advances may then in turn help to inform and guide development of in vitro culture systems used in other arenas, in particular agriculture. Additionally, it will highlight how the introduction of new technologies, such as timelapse, can influence current trends in media composition and usage that may see a return to a single step medium.

Palliative care in Creutzfeldt-Jakob disease: looking back, thinking ahead

Creutzfeldt-Jakob disease (CJD) is a rare and fatal neurodegenerative disease for which there is no cure. However, it is difficult to diagnose and is unique in that it is both a genetic and transmissible disease. The disease is characterised by symptoms of a rapidly progressive dementia. Palliation is the only treatment and early diagnosis is an important aspect in relation to gaining speedy access to palliative and end-of-life care services. People with CJD may be cared for in a diversity of settings including; general hospital wards, neurological units, hospices; care homes and in their own home. Management of physical and psychosocial symptoms and dealing with family bereavement is complex and challenging. Due to the complexity of the physical symptoms input from clinicians with palliative care expertise is an important consideration. Given transmission risk and the latent incidence of infection in the general population, following the emergence of variant CJD; plus the recent hypothesis of a potential relationship between immune responses to COVID-19 and the acceleration of preclinical or evident neurodegenerative disease, there is a need for renewed interest in research in this field. Over the past 20 years, many thousands of articles have been published on CJD. These have been predominately in the medical and science literature and very few publications have addressed the nursing care of persons and families dealing with CJD. There is a need for renewed interest in the management of the disease by supportive and palliative care services.

Prospective surveillance study of haemophilia A patients switching from moroctocog alfa or other factor VIII products to moroctocog alfa albumin-free cell culture (AF-CC) in usual care settings

This prospective, open-label, postauthorisation safety surveillance study assessed clinically significant inhibitor development in patients with severe haemophilia A transitioning from moroctocog alfa or other factor VIII (FVIII) replacement products to reformulated moroctocog alfa (AF-CC). Males aged12 years with severe haemophilia A (FVIII:C) < 1 IU/dl), > 150 exposure days (EDs) to recombinant or plasma-derived FVIII products, and no detectable inhibitor at screening were enrolled. Primary end point was the incidence of clinically significant FVIII inhibitor development. Secondary end points included annualised bleeding rate (ABR), less-than-expected therapeutic effect (LETE), and FVIII recovery. Patients were assigned to one of two cohorts based on whether they were transitioning to moroctocog alfa (AF-CC) from moroctocog alfa (cohort 1; n=146) or from another recombinant or plasma-derived FVIII product (cohort 2; n=62). Mean number of EDs on study was 94 (range, 1–139). Six positive FVIII inhibitor results, as determined by local laboratories, were reported in four patients; none were confirmed by a central laboratory, no inhibitor-related clinical manifestations were reported, and all anti-FVIII antibody assays were negative. Median ABRs were 23.4 and 3.4 in patients categorised at baseline as following on-demand and prophylactic regimens, respectively; 86.5 % of bleeding episodes resolved after one infusion. LETE incidence was 0.06 % and 0.19 % in the on-demand and prophylaxis settings, respectively. FVIII recovery remained constant throughout the study. No new safety concerns were identified. This study found no increased risk of clinically significant FVIII inhibitor development in patients transitioning from moroctocog alfa or other FVIII replacement products to moroctocog alfa (AF-CC).

Haemophilia B: impact on patients and economic burden of disease

Worldwide, haemophilia is the most common hereditary bleeding disorder. The incidence of haemophilia B, however, is considerably less than haemophilia A and consequently appears to have received less attention in the research literature. This article aims to summarise the available evidence documenting the patient and economic burden associated with haemophilia B and current methods of disease management. Both the immediate and long-term clinical consequences of haemophilia B can have significant implications for patients in terms of functional limitations and diminished health-related quality of life (HRQOL). Evidence demonstrates that primary prophylaxis is the optimal strategy for replacing missing clotting factor IX (FIX) and managing haemophilia B. Use of recombinant FIX (rFIX) over plasma-derived FIX (pd-FIX) is also generally preferred for safety reasons. Prophylaxis using currently available rFIX products, however, requires a demanding regimen of intravenous infusions 2–3 times a week which may have significant implications for adherence and ultimately the long-term efficacy of such regimens. Only limited assessments of the cost-effectiveness of prophylactic versus on-demand FIX treatment regimens have been conducted to date. Prophylaxis, however, is generally more costly as greater quantities of FIX are consumed. Any reduction in FIX replacement dosing frequency is expected to improve patient adherence and contribute to improved clinical outcomes, further supporting the costeffectiveness of such interventions. Although a rare disease, as economic constraints for healthcare increase, generating further information regarding the key clinical, patient and economic outcomes associated with haemophilia B will be essential for supporting improvements in care for people with haemophilia B.

Once-weekly prophylactic dosing of recombinant factor IX improves adherence in hemophilia B

Regular prophylactic treatment in severe hemophilia should be considered an optimal treatment. There is no general agreement on the optimal prophylaxis regimen, and adherence to prophylaxis is a main challenge due to medical, psychosocial, and cost controversies. Improved approaches in prophylaxis regimen of hemophilia B are needed to make patients’ lives easier. There is some evidence to support the efficacy of once-weekly prophylaxis. Longer sampling schedules are required for the determination of pharmacokinetic (PK) properties of factor IX (FIX). The half-life of FIX seems to be longer than previously described and is expected to be 34 hours. The clinical significance of maintaining a 1% trough level is widely debated in hemophilia B. The overall relationship between factor concentrate levels and incidence of joint bleeding was found to be very weak. Data also indicate that the distribution of FIX into an extravascular FIX compartment may contribute to hemostasis independently of circulating plasma FIX levels. Clinical assessment of the frequency and severity of bleeds remain an important measure of the efficacy of treatment. Role of PK-guided therapy remains to be established. Two prospective randomized studies had evaluated the efficacy and safety of 100 IU/kg once-weekly prophylaxis with nonacog alfa, and this prophylaxis regimen was found to be associated with lower annual bleeding rate compared with on-demand treatment in adolescents and adults with moderately severe-to-severe hemophilia B. Secondary prophylaxis therapy with 100 IU/kg nonacog alfa once weekly reduced annual bleeding rate by 89.4% relative to on-demand treatment. Residual FIX may be supportive of effectiveness. Once-weekly prophylaxis was well tolerated in the two studies, with a safety profile similar to that reported during the on-demand treatment period. To individually tailor treatment to clinical response and to minimize costs of factor concentrate, it would be of interest to investigate the efficacy of lower doses of the drug administered once a week.

Rh(O)D immune globulin products for prevention of alloimmunization during pregnancy

PURPOSE

The pharmacologic properties of Rhesus (Rh) immune globulin (RhIG) and clinical data on its effectiveness in preventing Rh-antigen alloimmunization in pregnant women are reviewed.

SUMMARY

RhIG is a human plasma derivative that targets red blood cells (RBCs) positive for Rh(O) antigen (also called D antigen). In the United States and other countries, the widespread use of RhIG has markedly reduced the occurrence of hemolytic disease of the fetus and newborn (HDFN), a devastating condition caused by D-antigen sensitization of a pregnant woman via exposure to fetal RBCs (usually during detachment of the placenta in labor) that results in a maternal immune response leading to severe hemolysis in the fetus. Routine administration of RhIG at 26-30 weeks' gestation and again within 72 hours of delivery has been shown to be highly effective in preventing maternal Rh alloimmunization, with very low rates of D-antigen sensitization (in the range of 0-2.2%) reported in multiple studies of at-risk women. The four RhIG products currently available in the United States have common clinical indications but differ in certain attributes. Pharmacists can play an important role in guiding other clinicians on the rationale for the use of RhIG, important differences between products, and appropriate timing of RhIG therapy.

CONCLUSION

Routine administration of RhIG to women at risk for Rh alloimmunization is clinically effective and has made HDFN a rare clinical event. The available RhIG products are not the same and should be carefully reviewed to ensure that they are administered safely.

An alarming presentation of Creutzfeldt-Jakob disease following a self-inflicted gunshot wound to the head

Transmissible spongiform encephalopathies (TSE), also known as prion diseases, are characterized by rapid and fatal neurological decline. They not only detrimentally affect the patient, but also present additional challenges to healthcare systems due to the infectivity of the tissues and the difficulty of inactivating the prion. The most common TSE is Creutzfeldt-Jakob disease (CJD), which can occur after familial, spontaneous or acquired transmission. TSEs received more attention after the development of variant CJD (vCJD), also known as Mad Cow Disease, in the UK during the mid-1990s. Unlike familial or spontaneous CJD, this variant was connected to consumption of cattle contaminated with the prion disease, bovine spongiform encephalopathy.This development increased interest in the etiology of CJD and other TSEs and the risk it presents as an infectious disease. The following details the case of a 59-year-old male infected with CJD presented to our level II trauma center for treatment following a self-inflicted gunshot wound to the head.

Nonacog gamma, a novel recombinant factor IX with low factor IXa content for treatment and prophylaxis of bleeding episodes

Nonacog gamma is a new recombinant factor IX to treat factor IX deficiency. It is indicated for control of bleeding episodes, perioperative management and routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children with hemophilia B. Nonacog gamma was first approved in the USA in June 2013 under the trade name RIXUBIS followed by market approvals in Australia and the EU in 2014, and marketing authorization decision is pending in Japan. Nonacog gamma is derived from a recombinant Chinese hamster ovary cell line using a state of the art biotechnological manufacturing process. Recombinant factor IX is produced by Baxter's protein-free fermentation technology, which was first developed for ADVATE. The product is purified and formulated in the absence of any human or animal-derived protein. Nonacog gamma was characterized both in comprehensive in vitro and in vivo non-clinical studies as well as in an extensive clinical trial program.

BAX326 (RIXUBIS): a novel recombinant factor IX for the control and prevention of bleeding episodes in adults and children with hemophilia B

Hemophilia B management has improved considerably since the introduction of high-purity plasma-derived factor IX (pdFIX) products in the early 1990s. Recombinant FIX (rFIX) was introduced more recently and has potential safety advantages over the older blood-based products. Until recently, only one such product, nonacog alfa (BeneFIX(®), Pfizer, Inc.), has been available. However, a new rFIX product, BAX326 (RIXUBIS, Baxter Healthcare Corp.), has now been approved by the US Food and Drug Administration. BAX326 undergoes rigorous virus elimination and purification steps during manufacture, and has low activated FIX activity, which confers low thrombogenic potential in humans. Preclinical studies showed promising pharmacokinetic and safety profiles, and these early findings have since been expanded in a series of prospective, multicenter, clinical studies. Foremost among these is a pivotal phase I/III study of BAX326 and its use in routine prophylaxis or on-demand treatment in patients aged 12-65 years with severe (FIX level <1%) or moderately severe (FIX level ≤2%) hemophilia B. This study confirmed the pharmacokinetic equivalence of BAX326 and nonacog alfa, and showed a significant reduction in annualized bleeding rate with BAX326 prophylaxis compared with on-demand treatment (79% versus historic controls; p < 0.001). The hemostatic efficacy of BAX326 was rated as 'excellent' or 'good' in 96% of bleeds. BAX326 was also associated with statistically significant and clinically meaningful improvements in physical health-related quality of life. Results are similarly encouraging in a pediatric study in children aged up to 12 years and in a study in hemophilia B patients undergoing surgery. A further study showed safe transition, with no inhibitor formation in any patient, from treatment with a pdFIX product to BAX326. Overall, the safety profile of BAX326 in clinical trials has been strong, with no inhibitor or specific antibody formation, thrombosis, or treatment-related serious adverse events or anaphylaxis.

Pathogen inactivation and removal methods for plasma-derived clotting factor concentrates

Pathogen safety is crucial for plasma-derived clotting factor concentrates used in the treatment of bleeding disorders. Plasma, the starting material for these products, is collected by plasmapheresis (source plasma) or derived from whole blood donations (recovered plasma). The primary measures regarding pathogen safety are selection of healthy donors donating in centers with appropriate epidemiologic data for the main blood-transmissible viruses, screening donations for the absence of relevant infectious blood-borne viruses, and release of plasma pools for further processing only if they are nonreactive for serologic markers and nucleic acids for these viruses. Despite this testing, pathogen inactivation and/or removal during the manufacturing process of plasma-derived clotting factor concentrates is required to ensure prevention of transmission of infectious agents. Historically, hepatitis viruses and human immunodeficiency virus have posed the greatest threat to patients receiving plasma-derived therapy for treatment of hemophilia or von Willebrand disease. Over the past 30 years, dedicated virus inactivation and removal steps have been integrated into factor concentrate production processes, essentially eliminating transmission of these viruses. Manufacturing steps used in the purification of factor concentrates have also proved to be successful in reducing potential prion infectivity. In this review, current techniques for inactivation and removal of pathogens from factor concentrates are discussed. Ideally, production processes should involve a combination of complementary steps for pathogen inactivation and/or removal to ensure product safety. Finally, potential batch-to-batch contamination is avoided by stringent cleaning and sanitization methods as part of the manufacturing process.

Blood Supply Testing for Infectious Diseases

Blood transfusion is a lifesaving intervention that has an essential role in patient management within health care systems. It is the responsibility of governments to ensure that safe and sufficient supplies of blood are available and accessible to all patients requiring transfusion. The provision of safe and efficacious blood for transfusion involves a number of processes, including assessment of the suitability of prospective blood donors to donate blood, blood collection, processing, and testing of blood donations, and the issue of blood and its transfusion to the patients. While blood transfusion can be lifesaving, there are associated risks, particularly the transmission of blood-borne infections including human immunodeficiency virus and hepatitis B and C viruses.

Screening for transfusion-transmissible infections (TTIs) to exclude blood donations at risk of transmitting infection from donors to recipients is a critical part of the process of ensuring that transfusion is as safe as possible. Effective screening for evidence of the presence of the most common and dangerous TTIs can reduce the risk of transmission to very low levels. Blood transfusion services should therefore establish efficient systems to ensure that all donated blood is correctly screened for the appropriate TTIs and that only nonreactive blood is issued for transfusion to patients.

Treatment of hemophilia B: focus on recombinant factor IX

Hemophilia B is a recessive X-linked bleeding disorder characterized by deficiency of the coagulation factor IX (FIX). In hemophilia B patients the severity of the bleeding phenotype is related to the degree of the FIX defect. Hemophilia B treatment has improved greatly in the last 20 years with the introduction first of plasma-derived and then of recombinant FIX concentrates. Replacement therapy may be administered through on-demand or prophylaxis regimens, but the latter treatment modality has been shown to be superior in prevention of hemophilic arthropathy and in improvement of patients' quality of life. The purpose of this narrative review is to summarize the current knowledge on treatment strategies for hemophilia B, focusing on recombinant FIX products either clinically used or in development. There is only one rFIX product that is licensed to treat hemophilia B patients; from the analysis of the literature data presented in this review, the authors conclude that this rFIX product has demonstrated an excellent safety profile and excellent clinical efficacy for halting and preventing bleeds in hemophilia B patients. While prophylaxis has emerged as the best therapeutic strategy for such patients because of its ability to prevent hemophilic arthropathy and to improve patients' quality of life, the pharmacokinetically tailored dosing of rFIX is another key point when planning hemophilia B treatment, as it allows optimization of the factor concentrate usage. Further clinical studies are needed to better assess the safety and efficacy (ie, the incidence of adverse reactions and inhibitor development) of newer rFIX products.

Haemophilia B: current pharmacotherapy and future directions

INTRODUCTION

Hemophilia B is a rare hereditary hemorrhagic disorder characterized by deficiency of the clotting factor IX (FIX). Hemophilia B patients experience mild to severe bleeding complications according to the degree of FIX defect. Nowadays, the most challenging complication of individuals with hemophilia B is the development of alloantibodies, which render the standard replacement therapy with FIX concentrates ineffective, exposing them to a significantly increased morbidity and mortality.

AREAS COVERED

This review summarizes the most important events leading to the development of the current FIX products available for the treatment of hemophilia B patients. In addition, it focuses on the more recent advances in the production of new FIX molecules aimed at improving the clinical management of such patients.

EXPERT OPINION

Although the availability of plasma-derived FIX concentrates has greatly improved the clinical management of hemophilia B patients, the introduction of FIX products using recombinant DNA technology has represented the most significant therapeutic progress in hemophilia B therapy, ensuring an advanced level of safety. The development of rFIX products with extended half lives will further improve the therapeutic armamentarium for hemophilia B patients.

Current options and new developments in the treatment of haemophilia

Haemophilia A and B are X-linked bleeding disorders due to the inherited deficiency of factor VIII or factor IX, respectively. Of the approximately 1 per 5000-10000 male births affected by haemophilia, 80% are deficient in factor VIII and 20% are deficient in factor IX. Haemophilia is characterized by spontaneous and provoked joint, muscle, gastrointestinal and CNS bleeding leading to major morbidity and even mortality if left untreated or under-treated. The evolution of haemophilia management has been marked by tragedy and triumph over recent decades. Clotting factors and replacement strategies continue to evolve for patients without inhibitors. For patients with an inhibitor, factor replacement for acute bleeding episodes and immune tolerance, immune modulation and extracorporeal methods for inhibitor reduction are the cornerstone of care. In addition, adjuvant therapies such as desmopressin, antifibrinolytics and topical agents also contribute to improved outcomes for patients with and without inhibitors. The future direction of haemophilia care is promising with new longer-acting clotting factors and genetic therapies, including gene transfer and premature termination codon suppressors. With these current and future treatment modalities, the morbidity and mortality rates in patients with haemophilia certainly will continue to improve.

Low risk of inhibitor formation in haemophilia A patients following en masse switch in treatment to a third generation full length plasma and albumin-free recombinant factor VIII product (ADVATE®)

Previous studies have suggested that development of inhibitors in previously treated patients (PTPs) may be attributable to a switch in factor VIII (FVIII) therapeutic product. Consequently, it is widely recognized that inhibitor development must be assessed in PTPs following the introduction of any new FVIII product. Following a national tender process in 2006, all patients with haemophilia A in Ireland changed their FVIII treatment product en masse to a plasma and albumin-free recombinant full-length FVIII product (ADVATE(®)). In this study, we retrospectively reviewed the case records of Irish PTPs to evaluate risk of inhibitor formation following this treatment switch. One hundred and thirteen patients participated in the study. Most patients (89%) had severe haemophilia. Only one of 96 patients with no inhibitor history developed an inhibitor. Prior to the switch in his recombinant FVIII (rFVIII) treatment of choice, this child had only experienced three exposure days (EDs). Consequently, in total he had only received 6 EDs when his inhibitor was first diagnosed. In keeping with this lack of de novo inhibitor development, we observed no evidence of any recurrent inhibitor formation in any of 16 patients with previously documented inhibitors. Similarly, following a previous en masse switch, we have previously reported that changing from a Chinese hamster ovary cell-produced to a baby hamster kidney cell-produced rFVIII was also associated with a low risk of inhibitor formation in PTPs. Our cumulative findings from these two studies clearly emphasizes that the risk of inhibitor development for PTPs following changes in commercial rFVIII product is low, at least in the Irish population.

The risk of transmitting prion disease by blood or plasma products

Various experimental studies have shown infectivity in blood in relation to bovine spongiform encephalitis (BSE) and variant Creutzfeldt-Jakob disease (vCJD). Human to human transmission vCJD infection has been reported via transfusion of non-leukocyte-reduced red cells and, probably, via factor VIII concentrates. A number of precautionary measures are in place but uncertainties remain, especially concerning the number of BSE-infected people in the population. Additional measures such as prion filtration need consideration.

Emerging trends in plasma-free manufacturing of recombinant protein therapeutics expressed in mammalian cells

Mammalian cells are the expression system of choice for therapeutic proteins, especially those requiring complex post‐translational modifications. Traditionally, these cells are grown in medium supplemented with serum and other animal‐ or human‐derived components to support viability and productivity. Such proteins are also typically added as excipients and stabilizers in the final drug formulation. However, the transmission of hepatitis B in the 1970s and of hepatitis C and HIV in the 1980s through plasma‐derived factor VIII concentrates had catastrophic consequences for hemophilia patients. Thus, due to regulatory concerns about the inherent potential for transmission of infectious agents as well as the heterogeneity and lack of reliability of the serum supply, a trend has emerged to eliminate the use of plasma‐derived additives in the production and formulation of recombinant protein therapeutics. This practice began with products used in the treatment of hemophilia and is progressively expanding throughout the entire industry. The plasma‐free method of producing recombinant therapeutics is accomplished by the use of both cell culture media and final product formulations that do not contain animal‐ or human‐derived additives. A number of recombinant therapeutic proteins for the treatment of several different diseases have been produced by plasma‐free processes, with the objective of improving safety by eliminating blood‐borne pathogens or by reducing immunogenicity. This review describes the factors that drove the development of plasma‐free protein therapeutics and provides examples of advances in manufacturing that have made possible the removal of human and animal‐derived products from all steps of recombinant protein production.

Paracrine diffusion of PrP(C) and propagation of prion infectivity by plasma membrane-derived microvesicles

Cellular prion protein (PrP^c) is a physiological constituent of eukaryotic cells. The cellular pathways underlying prions spread from the sites of prions infection/peripheral replication to the central nervous system are still not elucidated. Membrane-derived microvesicles (MVs) are submicron (0.1–1 µm) particles, that are released by cells during plasma membrane shedding processes. They are usually liberated from different cell types, mainly upon activation as well as apoptosis, in this case, one of their hallmarks is the exposure of phosphatidylserine in the outer leaflet of the membrane. MVs are also characterized by the presence of adhesion molecules, MHC I molecules, as well as of membrane antigens typical of their cell of origin. Evidence exists that MVs shedding provide vehicles to transfer molecules among cells, and that MVs are important modulators of cell-to-cell communication. In this study we therefore analyzed the potential role of membrane-derived MVs in the mechanism(s) of PrP^C diffusion and prion infectivity transmission. We first identified PrP^C in association with the lipid raft components Fyn, flotillin-2, GM1 and GM3 in MVs from plasma of healthy human donors. Similar findings were found in MVs from cell culture supernatants of murine neuronal cells. Furthermore we demonstrated that PrP^Sc is released from infected murine neuronal cells in association with plasma membrane-derived MVs and that PrP^Sc-bearing MVs are infectious both in vitro and in vivo. The data suggest that MVs may contribute both to the intercellular mechanism(s) of PrP^C diffusion and signaling as well as to the process of prion spread and neuroinvasion.

From mad cows to sensible blood transfusion: the risk of prion transmission by labile blood components in the United Kingdom and in France

Transfusion transmission of the prion, the agent of variant Creutzfeldt-Jakob disease (vCJD), is now established. Subjects infected through food may transmit the disease through blood donations. The two nations most affected to date by this threat are the United Kingdom (UK) and France. The first transfusion cases have been observed in the UK over the past 5 years. In France, a few individuals who developed vCJD had a history of blood donation, leading to a risk of transmission to recipients, some of whom could be incubating the disease. In the absence of a large-scale screening test, it is impossible to establish the prevalence of infection in the blood donor population and transfused patients. This lack of a test also prevents specific screening of blood donations. Thus, prevention of transfusion transmission essentially relies at present on deferral of "at-risk" individuals. Because prions are present in both white blood cells and plasma, leukoreduction is probably insufficient to totally eliminate the transfusion risk. In the absence of a screening test for blood donations, recently developed prion-specific filters could be a solution. Furthermore, while the dietary spread of vCJD seems efficiently controlled, uncertainty remains as to the extent of the spread of prions through blood transfusion and other secondary routes.

Once-weekly epoetin beta therapy in patients with solid tumours and chemotherapy-induced anaemia: a randomized, double-blind, dose-finding study

Anaemia is common in patients receiving chemotherapy, causing symptoms that have a major impact on quality of life (QoL). Epoetin beta rapidly increases haemoglobin (Hb) levels and improves QoL in anaemic patients with a variety of tumours. This was a randomized, double-blind, parallel-group, dose-finding study assessing the efficacy and safety of once-weekly epoetin beta in patients with solid tumours receiving chemotherapy. Adult patients with anaemia (Hb < 11 g/dL) were randomized to receive epoetin beta 30,000 IU or 20,000 IU once weekly for 12 weeks. All patients received oral iron supplementation. Haemoglobin levels, transfusion need and QoL [Functional Assessment of Cancer Therapy-fatigue (FACT-F) subscale score] were assessed at regular intervals. Fifty patients were randomized; 30 patients received epoetin beta 30,000 IU once weekly and 20 received 20,000 IU once weekly. Mean (+/- SD) increase in Hb from baseline to week 12 was 1.75 +/- 2.15 g/dL in the 30,000 IU group (P = 0.008 vs. baseline) and 1.04 +/- 1.75 g/dL in the 20,000 IU group (non-significant). Haemoglobin response (increase in Hb >or=2 g/dL from baseline) was observed in 78.3% of patients receiving epoetin beta 30,000 IU and 66.7% receiving epoetin beta 20,000 IU. Improvements in FACT-F subscale score were significantly (P < 0.001) correlated with increases in Hb level. Transfusion use was low during the study in both groups. Both epoetin beta regiments were well tolerated and there were no dose-dependent adverse events. Epoetin beta 30,000 IU once weekly is an effective and well-tolerated treatment of anaemia in patients with solid tumours.

The variant Creutzfeldt-Jakob Disease: Risk, uncertainty or safety in the use of blood and blood derivatives?

It has been long since French physician Jean-Baptiste Denys carried out the first successful blood transfusion to a human being. Using bird feathers as canules, sheep blood was transfused to a young man. The patient died soon after Denys' treatment and Denys was accused of murder. In the XXI century, known as the biotechnology century, we face new challenges in Medicine. New emerging and reemerging diseases, such as Creutzfeldt-Jakob disease (CJD) or "mad cow disease" and its human variant (vCJD), challenge the biosafety aspects of a widely extended and extremely useful technique, that is, the perfusion of blood, of its derived components and of other pharmacological products obtained from plasma. To face these new challenges we need innovative prevention strategies.

Recombinant proteins in therapeutics: haemophilia treatment as an example

One of the most spectacular advances in the history of scientific knowledge was the discovery of deoxyribonucleic acid (DNA) by Watson and Crick in 1953. This enabled certain proteins to be prepared in this way for their therapeutic use in clinical practice. Today, in the first decade of the 21st century, hundreds of therapeutic proteins have been produced recombinantly and about 50 of them have been approved for clinical use. Because of the specific procedure used for obtaining these products, which is based on expressing a atherapeutica gene from a fragment of DNA in a cell to produce a functional protein that is free from any human or animal component, they are especially acleana and thus the therapy of choice for many current diseases. The immediate question is: why are recombinant products not used more extensively given their high efficacy and maximum safety? In short, we are faced with an interesting but also unfortunate paradox of pharmacology that greater progress in therapeutic procedures is not always associated with greater introduction of those resources that are safest, for the simple reason that they are more costly.

Reducing the risk of transfusion-transmissible viral infection through blood donor selection: the Australian experience 2000 through 2006

BACKGROUND

Selection of voluntary donors who are at low risk of transfusion-transmissible viral infection (TTVI) is central in maintaining the safety of the blood supply. Evaluation of its effectiveness and the dynamics of the process may offer opportunities to further improve transfusion safety.

STUDY DESIGN AND METHODS

The impact of donor selection on prevalence of TTVI was analyzed in all allogeneic donations in Australia between July 2000 and June 2006 by interviewing donors found to have a TTVI. The presence and disclosure of infective risks was reassessed.

RESULTS

A total of 6.3 million donations were tested; of these, 1,449 (0.02%) were repeat-reactive for a TTVI and were discarded. This comprised 605 (42%) positive for the presence of hepatitis B, 818 (56%) positive for the presence of hepatitis C, 18 (1%) positive for the presence of human immunodeficiency virus, and 20 (1%) positive for the presence of human T-cell lymphotropic virus-I and/or -II (HTLV-I/II). This prevalence was 50 to 350 times lower than in the Australian population. In 1,158 cases (80%), an infective risk was identified; 509 donors (44%) had more than one. The most common identified were country of birth and parental ethnicity (n = 682, 26% of risks), tattoos and/or piercings (n = 448, 18%), and intravenous drug use (n = 302, 12%). In 302 cases (21%) disclosure at predonation screening would have resulted in deferral. Factors influencing nondisclosure included temporal remoteness and perceptions that laboratory testing rendered disclosure unnecessary.

CONCLUSION

These findings affirm the effectiveness of current stringent donor selection criteria in reducing the residual risk of TTVI. Ongoing donor education regarding the importance of risk disclosure is required.

Coagulation factor concentrates: past, present, and future

Clotting factor transfusions are vital for people with diseases such as haemophilia. In the 1970s and 1980s, transfusions with pooled plasma led to a devastatingly high number of recipients becoming infected with blood-borne pathogens such as HIV and hepatitis C. This epidemic triggered the development of virus-free factor concentrates through a combination of improved donor selection and screening, effective virucidal technologies, and recombinant protein expression biotechnology. There is now a wide range of recombinant factor concentrates, and an impressive safety record with respect to pathogen transmission. However, remaining therapeutic challenges include the potential threat of transmission of prions and other pathogens, the formation of inhibitory alloantibodies, and the international disparity that exists in product availability due to differences in licensure status as well as prohibitively high costs. In the future, it is likely that bioengineered recombinant proteins that have been modified to enhance pharmacokinetic properties or reduce immunogenicity, or both, will be used increasingly in clinical practice.

Prion protein and the red cell

PURPOSE OF REVIEW

This review focuses on transfusion-transmission of variant Creutzfeldt-Jakob disease by red cell preparations.

RECENT FINDINGS

Recently, three cases of probable transmission of variant Creutzfeldt-Jakob infectivity by transfusion of red cell preparations have been described in humans. Experiments on transmissible spongiform encephalopathies affecting rodents have led to the conclusion that infectivity in red cell preparations is not bound to the red cells themselves but contained within the suspending medium from which it can be removed by filtration.

SUMMARY

Red cell preparations are the main transfusion product provided by blood services. If experiments demonstrating significant removal of rodent transmissible spongiform encephalopathy infections by filtration of red cell preparations are applicable to variant Creutzfeldt-Jakob in humans then a method for rendering human red cell preparations safe for transfusion is provided.

Emerging zoonoses and vector-borne infections affecting humans in Europe

The purpose of this study was to assess and describe the current spectrum of emerging zoonoses between 2000 and 2006 in European countries. A computerized search of the Medline database from January 1966 to August 2006 for all zoonotic agents in European countries was performed using specific criteria for emergence. Fifteen pathogens were identified as emerging in Europe from 2000 to August 2006: Rickettsiae spp., Anaplasma phagocytophilum, Borrelia burgdorferi, Bartonella spp., Francisella tularensis, Crimean Congo Haemorrhagic Fever Virus, Hantavirus, Toscana virus, Tick-borne encephalitis virus group, West Nile virus, Sindbis virus, Highly Pathogenic Avian influenza, variant Creutzfeldt-Jakob disease, Trichinella spp., and Echinococus multilocularis. Main risk factors included climatic variations, certain human activities as well as movements of animals, people or goods. Multi-disciplinary preventive strategies addressing these pathogens are of public health importance. Uniform harmonized case definitions should be introduced throughout Europe as true prevalence and incidence estimates are otherwise impossible.

Erythropoietic therapy for the treatment of anemia in patients with cancer: a valuable clinical and economic option

BACKGROUND

Healthcare organizations must evaluate the cost effectiveness of the alternative therapies that are available to treat anemia and improve quality of life (QoL) of patients with cancer, that is, erythropoietic protein therapy and blood transfusion.

METHODS

Pharmacoeconomic studies that evaluated the cost of not treating anemia or treating with transfusion or erythropoietic protein therapy were reviewed and compared. Studies of individual erythropoietic proteins (epoetin alfa, epoetin beta or darbepoetin alfa) were also assessed. As no prospective trials have compared the erythropoietic proteins, retrospective studies and the results of separate trials were analyzed. The database searched for this review was PubMed (open date to August 2006). Recent conference abstracts were also searched (2003-July 2006).

RESULTS

There is a high cost associated with anemia in cancer patients. Treatment of anemia is likely to lead to increased hemoglobin (Hb) levels and improved QoL as principal outcomes. Therefore, in assessing erythropoietic protein versus transfusion, it is more appropriate to use Hb or QoL as endpoint rather than quality adjusted life year. Studies with the former approach showed that erythropoietic protein therapy is more cost effective than transfusion. Also, its cost effectiveness should be improved with the use of evidence-based guidelines for patient selection and more tailored utilization. Increasing evidence suggests there might be differences among the erythropoietic proteins in terms of response rate, speed of response, and need for dose escalation.

CONCLUSION

Significant costs are incurred when anemia in cancer is not treated. Erythropoietic protein therapy is more cost effective than blood transfusion for the treatment of cancer-related anemia. Transfusion should be reserved for patients with poor responses to erythropoietic protein or for the emergency setting, when rapid improvement in Hb is required.

Is there a real risk of transmitting variant Creutzfeldt-Jakob disease by donor sperm insemination?

Although >99% of cases of Creutzfeldt-Jakob disease (CJD) are caused by spontaneous or inherited mutations in the prion protein, 'variant' CJD (vCJD) arose from dietary exposure to meat products infected with the bovine spongiform encephalopathy prion. While European and Canadian sperm donor candidates are rejected for significant CJD risk factors, American sperm donors are managed like blood donors (excluding all men who spent > or =3 months in the UK during 1980-1996 or > or =5 years in Europe since 1980), even though no evidence exists for sexual transmission of prion disease. This study surveyed international experts on either prions/prion disease or donor sperm/cryobanking as to the risk of vCJD transmission via semen/donor spermatozoa (45/104 replied). Consensus expert opinion was that the risk of transmission was <1:10,000,000, even for UK men, hence ultra-conservative risk avoidance would have minimal impact on public safety. Defining 'high vCJD risk' should be based on knowledge rather than fear, and due caution founded upon quantifying real risks rather than avoiding theoretical risks. Women seeking treatment using donor spermatozoa should be allowed to judge the negligible risk of vCJD infection in comparison with acceptable everyday risks, and given the choice of accepting spermatozoa from donors screened according to European-style criteria.

vCJD and blood transfusion in the United Kingdom

A study was set up in the UK in 1997 to examine whether there is any evidence that variant Creutzfeldt-Jakob disease (vCJD) is transmitted by blood transfusion. To date, the study has identified three probable cases of vCJD transmission by blood transfusion, including two clinical cases and one pre- (or sub-) clinical case.

Creutzfeldt-Jakob disease and blood transfusion: results of the UK Transfusion Medicine Epidemiological Review study

BACKGROUND AND OBJECTIVES

This paper reports the results to 1 March 2006 of an ongoing UK study, the Transfusion Medicine Epidemiological Review (TMER), by the National CJD Surveillance Unit (NCJDSU) and the UK Blood Services (UKBS) to determine whether there is any evidence that Creutzfeldt-Jakob disease (CJD), including sporadic CJD (sCJD), familial CJD (fCJD), and variant CJD (vCJD) is transmissible via blood transfusion.

MATERIALS AND METHODS

Sporadic CJD and fCJD cases with a history of blood donation or transfusion are notified to UKBS. All vCJD cases aged > 17 years are notified to UKBS on diagnosis. A search for donation records is instigated and the fate of all donations is identified by lookback. For cases with a history of blood transfusion, hospital and UKBS records are searched to identify blood donors. Details of identified recipients and donors are checked against the NCJDSU register to establish if there are any matches.

RESULTS

CJD cases with donation history: 18/31 vCJD, 3/93 sCJD, and 3/5 fCJD cases reported as blood donors were confirmed to have donated labile components transfused to 66, 20, and 11 recipients respectively. Two vCJD recipients have appeared on the NCJDSU register as confirmed and probable vCJD cases. The latter developed symptoms of vCJD 6.5 years and 7.8 years respectively after receiving non-leucodepleted red blood cells (RBCs) from two different donors who developed clinical symptoms approximately 40 and 21 months after donating. A third recipient, given RBC donated by a further vCJD case approximately 18 months before onset of clinical symptoms, had abnormal prion protein in lymphoid tissue at post-mortem (5-years post-transfusion) but had no clinical symptoms of vCJD. CJD cases with history of transfusion: Hospital records for 7/11 vCJD and 7/52 sCJD cases included a history of transfusion of labile blood components donated by 125 and 24 donors respectively. Two recipients who developed vCJD were linked to donors who had already appeared on the NCJDSU register as vCJD cases (see above). No further links were established.

CONCLUSION

This study has identified three instances of probable transfusion transmission of vCJD infection, including two confirmed clinical cases and one pre- or sub-clinical infection. This study has not provided evidence, to date, of transmission of sCJD or fCJD by blood transfusion, but data on these forms of diseases are limited.

Methods to Minimize the Risks of Creutzfeldt-Jakob Disease Transmission by Surgical Procedures: Where to Set the Standard?

New prion-related disorders have emerged over the past 20 years, of which the most notable in the human context is variant Creutzfeldt-Jakob disease (CJD). This disorder is a challenge to medical and public health professionals seeking early detection and diagnosis, provision of therapy, and support for persons affected and a better understanding of transmission risks. The risk of iatrogenic transmission of the disease remains a significant threat, given the well documented cases of CJD transmission via surgery, organ transplantation, and blood transfusion. This review discusses our current understanding of the prevalence of variant CJD, the distribution of tissue infectivity, and new methods for the decontamination of surgical instruments. A comparison of emerging technologies is provided on the basis of our current perception of surgical risk to identify methods that are likely to provide sufficient safety margins and to stimulate debate about the standards needed to protect against variant CJD and CJD transmission.

In vitro functional test of two subclasses of an anti-RhD antibody produced by transient expression in COS cells

For over 35 years hemolytic disease of the fetus and newborn (HDFN) due to RhD has been effectively prevented by anti-RhD antibodies obtained from alloimmunized women or deliberately immunized men. However, due to the reduced number of immunized women and for ethical reasons it is foreseen that other sources of anti-RhD will be needed. One such source is recombinant human antibodies. Here we describe the construction of plasmids encoding two subclasses (IgG1 and IgG3) of an anti-RhD antibody, their transient expression in COS cells, and subsequent functional characterization of the antibodies with regard to specificity and ability to mediate a respiratory burst. The recombinant anti-RhD antibodies were specific for the RhD antigen and were able to mediate a respiratory burst. Thus these antibodies might be of use as future rhesus prophylaxis.

Metabolic fingerprinting in disease diagnosis: biomedical applications of infrared and Raman spectroscopy

The ability to diagnose the early onset of disease, rapidly, non-invasively and unequivocally has multiple benefits. These include the early intervention of therapeutic strategies leading to a reduction in morbidity and mortality, and the releasing of economic resources within overburdened health care systems. Some of the routine clinical tests currently in use are known to be unsuitable or unreliable. In addition, these often rely on single disease markers which are inappropriate when multiple factors are involved. Many diseases are a result of metabolic disorders, therefore it is logical to measure metabolism directly. One of the strategies employed by the emergent science of metabolomics is metabolic fingerprinting; which involves rapid, high-throughput global analysis to discriminate between samples of different biological status or origin. This review focuses on a selective number of recent studies where metabolic fingerprinting has been forwarded as a potential tool for disease diagnosis using infrared and Raman spectroscopies.