The mantra of blood safety: time for a new tune?

The Evolution of the Safety of Plasma Products from Pathogen Transmission-A Continuing Narrative

Chronic recipients of plasma products are at risk of infection from blood-borne pathogens as a result of their inevitable exposure to agents which will contaminate a plasma manufacturing pool made up of thousands of individual donations. The generation of such a pool is an essential part of the large-scale manufacture of these products and is required for good manufacturing practice (GMP). Early observations of the transmission of hepatitis by pooled plasma and serum led to the incorporation of heat treatment of the albumin solution produced by industrial Cohn fractionation of plasma. This led to an absence of pathogen transmission by albumin over decades, during which hepatitis continued to be transmitted by other early plasma fractions, as well as through mainstream blood transfusions. This risk was decreased greatly over the 1960s as an understanding of the epidemiology and viral aetiology of transfusion-transmitted hepatitis led to the exclusion of high-risk groups from the donor population and the development of a blood screening test for hepatitis B. Despite these measures, the first plasma concentrates to treat haemophilia transmitted hepatitis B and other, poorly understood, forms of parenterally transmitted hepatitis. These risks were considered to be acceptable given the life-saving nature of the haemophilia treatment products. The emergence of the human immunodeficiency virus (HIV) as a transfusion-transmitted infection in the early 1980s shifted the focus of attention to this virus, which proved to be vulnerable to a number of inactivation methods introduced during manufacture. Further developments in the field obviated the risk of hepatitis C virus (HCV) which had also infected chronic recipients of plasma products, including haemophilia patients and immunodeficient patients receiving immunoglobulin. The convergence of appropriate donor selection driven by knowledge of viral epidemiology, the development of blood screening now based on molecular diagnostics, and the incorporation of viral inactivation techniques in the manufacturing process are now recognised as constituting a "safety tripod" of measures contributing to safety from pathogen transmission. Of these three components, viral inactivation during manufacture is the major contributor and has proven to be the bulwark securing the safety of plasma derivatives over the past thirty years. Concurrently, the safety of banked blood and components continues to depend on donor selection and screening, in the absence of universally adopted pathogen reduction technology. This has resulted in an inversion in the relative safety of the products of blood banking compared to plasma products. Overall, the experience gained in the past decades has resulted in an absence of pathogen transmission from the current generation of plasma derivatives, but maintaining vigilance, and the surveillance of the emergence of infectious agents, is vital to ensure the continued efficacy of the measures in place and the development of further interventions aimed at obviating safety threats.

"Missing minorities" in blood donation: Rethinking blood procurement in Europe as a citizenship regime

Although European blood collection organizations are currently obtaining sufficient and safe blood from the majority population, they report having difficulty recruiting first and second-generation immigrants from non-European countries. Most existing studies on these underrepresented groups, who have been coined the "missing minorities" in blood donation, have adopted an instrumental approach that focuses on the development of targeted recruitment strategies to overcome specific barriers to donation faced by members of these minorities. Although this approach does offer several short-term benefits, our central argument is that it is one-sided in its questioning of the non-participation of ethnic minorities. The literature currently lacks research on how the blood procurement system is failing to include minorities. Drawing on recent social theory, we seek a broader sociological understanding of minority under-representation in blood donor populations by shifting the analytic focus toward a critical examination of the main pillars of the procurement system within the European context. This paper advances a novel analytical framework based on two general propositions. First, we apply the literature on "citizenship regimes" to argue that blood donation is part of one specific institutionalization of citizenship and solidarity. We then reconceptualize the "problem" of missing minorities in European blood donation as an application for social change, suggesting avenues related to blood collection as a way of renegotiating minority-majority relations of solidarity.

Detection of Trypanosoma cruzi antibodies in multitransfused patients in Colombia

INTRODUCTION

Chagas disease is a public health problem in Latin America. Even though vector-borne infection is the most important transmission mode for this disease, other modes such as transfusions require evaluation.

OBJECTIVE

To describe the prevalence of T. cruzi infection in multitransfused patients.

MATERIALS AND METHODS

We detected IgG antibodies against T. cruzi by two immunoassays in samples from multitransfused patients in four hospitals located in Bogotá and Medellín, Colombia. We analyzed the association with known risk factors, and we calculated the odds ratios (OR) with 95% confidence intervals using Stata 11™ statistical software.

RESULTS

In total, 479 samples were tested. Overall, T. cruzi antibody prevalence was 1.88% (nine patients). Five were onco-hematological patients, two were hemodialyzed, one had thalassemia, and one had suffered acute blood loss. We found no hemophilia patients. There was no association between known risk factors for transfusion-transmitted infection (such as the number of transfusion events, number of blood units and type of blood component) and the presence of anti-T. cruzi antibodies in this study. Only the hepatitis C virus infection showed a positive association with the presence of anti-T. cruzi antibodies (OR=5.68, 95% CI: 1.36-23.63).

CONCLUSIONS

The results of this study showed a low frequency of T. cruzi infection in multitransfused patients, suggesting that the risk of transfusion infection in Colombia is low. Known risk factors for transfusion-related infection were not associated with the presence of anti-T. cruzi antibodies.

Chagas disease and transfusion medicine: a perspective from non-endemic countries

In the last decades, increasing international migration and travel from Latin America to Europe have favoured the emergence of tropical diseases outside their "historical" boundaries. Chagas disease, a zoonosis endemic in rural areas of Central and South America represents a clear example of this phenomenon. In the absence of the vector, one of the potential modes of transmission of Chagas disease in non-endemic regions is through blood and blood products. As most patients with Chagas disease are asymptomatic and unaware of their condition, in case of blood donation they can inadvertently represent a serious threat to the safety of the blood supply in non-endemic areas. Since the first cases of transfusion-transmitted Chagas disease were described in the last years, non-endemic countries began to develop ad hoc strategies to prevent and control the spread of the infection. United States, Spain, United Kingdom and France first recognised the need for Trypanosoma cruzi screening in at-risk blood donors. In this review, we trace an up-to-date perspective on Chagas disease, describing its peculiar features, from epidemiological, pathological, clinical and diagnostic points of view. Moreover, we describe the possible transmission of Chagas disease through blood or blood products and the current strategies for its control, focusing on non-endemic areas.

Transfusion transmitted Chagas disease: is it really under control?

Transfusion transmitted Chagas disease was recognized as a medical problem more than 50 years ago. However, little attention was paid to it by Transfusion Medicine, medical authorities or regulatory agencies as a major problem and threat (especially after the advent of HIV/AIDS); perhaps because it was mainly restricted to tropical regions, usually in less developed countries. With the intense human migratory movement from developing to developed countries, it became more common and evident. The scope of this review is to cover the main transfusional aspects of American trypanosomiasis (Chagas disease), including the main strategies to prevent it through donor questionnaires, specific serological testing and alternative methods such as leukofiltration and pathogen reduction procedures, in order to increase the blood safety in both developing and developed countries.

A new liquid intravenous immunoglobulin with three dedicated virus reduction steps: virus and prion reduction capacity

BACKGROUND AND OBJECTIVES

A new 10% liquid human intravenous immunoglobulin (US trade name: Gammagard Liquid; European trade name: KIOVIG) manufactured by a process with three dedicated pathogen inactivation/removal steps (solvent/detergent treatment, 35-nm nanofiltration and low pH/elevated temperature incubation) was developed. The ability of the manufacturing process to inactivate/remove viruses and prions was investigated.

MATERIALS AND METHODS

Virus and prion removal capacities were assessed with down-scale spiking experiments, validated for equivalence to the large-scale process.

RESULTS

Lipid-enveloped viruses were completely inactivated/removed by each of the three dedicated virus clearance steps, and for human immunodeficiency virus 1 (HIV-1) and pseudorabies virus (PRV), also by the upstream cold ethanol fractionation step. Relevant non-enveloped viruses [i.e. hepatitis A virus (HAV) and parvovirus B19 (B19V)] were effectively removed by nanofiltration and the cold ethanol fractionation step, and partial inactivation of non-enveloped viruses was achieved by low pH incubation. Overall log reduction factors were > 20.0 for HIV-1, > 18.1 for bovine viral diarrhoea virus, > 16.3 for West Nile virus, > 10.0 for influenza A virus subtype H5N1, > 21.8 for PRV, 12.0 for HAV, > 12.1 for encephalomyocarditis virus, 10.6 for B19V and 10.3 for mice minute virus. Prions (Western blot assay) were completely removed (> or = 3.2 mean log reduction) by a step of the cold ethanol fractionation process.

CONCLUSIONS

Introducing three dedicated virus-clearance steps in the manufacturing process of immunoglobulins from human plasma provides high margins of safety.

Method for discovering novel DNA viruses in blood using viral particle selection and shotgun sequencing

Rapid identification of viruses is needed to monitor the blood supply for emerging threats. Here we present a method that meets these criteria and allows for the shotgun sequencing of novel, uncultured DNA viruses directly from human blood. This method employs selection based on the physical properties of viruses combined with sequence-independent amplification and cloning. We show that both single- and double-stranded DNA viruses can be recovered from blood samples using this approach. In addition, we report the discovery of novel anellovirus sequences in the blood of healthy donors. PCR primers designed to amplify these novel anellovirus sequences were then used to verify the presence of these viruses in the general donor population.

Strengthening the service continuum between transfusion providers and suppliers: enhancing the blood services network

As the cost of health care increases, the focus on cost containment grows. The pressure to reduce costs comes at the same time the public focus is on ensuring a zero-risk blood supply. The blood supply has never been safer or more expensive. With the relative vanquishing of transfusion-transmitted diseases, noninfectious risks now exceed infectious risks. This has resulted in a call to refocus blood safety efforts on interconnected processes that link a unit of blood from its volunteer blood donor to the patient. Additional costs in the blood supply chain will create new pressures on an already taxed system that gets little additional reimbursement with each new safety initiative. Opposing interests have created a tenuous relationship between the blood supplier and the transfusion provider. This adversarial relationship does not benefit the ultimate stakeholder, the patient. It is time to create a service partnership that is built on access, cost, and quality. Initiatives must be undertaken at a local, regional, and national level. Locally, blood suppliers and transfusion providers must reevaluate policies that are focused on individual gain and reinvent policies that will reward improvements in the overall system and expand cooperative services. Regionally, both blood suppliers and transfusion providers need to consolidate services to gain cost and quality benefits without compromising the competitive nature of the industry. Nationally, the creation of a strategic plan will help ensure that a mutually beneficial relationship focused on the patient is created between the blood supplier and transfusion provider at all levels. Development of such a plan would benefit the transfusing and supplying parties by identifying areas of common interest and how each may facilitate the achievement of shared benefits.

Predeposit autologous donation in spinal surgery: a multicentre study

BACKGROUND

Allogeneic blood transfusions (ABT) are often necessary in elective spine surgery because of perioperative blood loss. Preoperative autologous blood donation (PABD) has emerged as the principal means to avoid or reduce the need for ABT. Consequently, a multicentre study was conducted to determine the yield and efficacy of PABD in spine surgery and the possible role of recombinant human erythropoietin (EPO) in facilitating PABD.

METHODS

We retrospectively reviewed the hospital charts and blood bank records from all consecutive spine surgery patients who were referred for PABD. Data were obtained from two A-category hospital blood banks and one general hospital. Although we collected data from 1994, the analytic study period was from the last quarter of 1995 to December 2003. Fifty-four (7%) out of 763 patients referred for PABD were rejected, and medical records were available for 680 patients who were grouped into spinal fusion (556; 82%) and scoliosis surgery (124;18%). EPO was administered to 120 patients (17.6%). From 1999 to 2003, PABD steadily increased from 60 to 209 patients per year.

RESULTS

Overall, 92% of the patients were able to complete PABD, 71% were transfused, and almost 80% avoided ABT. PABD was more effective in fusions (86%) than in scoliosis (47%). Blood wastage was 38%, ranging from 18% for scoliosis to 42% for fusions. EPO allowed the results in the anaemic patients to be improved.

CONCLUSIONS

Therefore, despite the limitations of this retrospective study, we feel that PABD is an excellent alternative to ABT in spine surgery. However, the effectiveness of PABD may be enhanced if associated with other blood-saving techniques.