admission. This proportion could already be greater in some parts of the country and may increase if referrals of cases of self-poisoning increase faster than the facilities for their assessment and management. The provision of social work and psychiatric expertise in casualty departments may be one means of preventing unnecessary medical admissions without risk to the patients. Dr Blake's and Dr Bramble's figures do not demonstrate, however, that any advantage would attach to medical teams taking over assessment from psychiatrists except that, by implication, assessments would be completed sooner by staff working on the ward full time. What the figures actually suggest is that if assessment of overdoses were left to house doctors there would be an increase in admissions to psychiatric units (by 19°U), outpatients (by 5O°'), and referrals to social services (by 140o). So for house doctors to assess overdoses would provide no economy for the psychiatric or social services. The study does not tell us what the consequences would have been for the six patients who the psychiatrists would have admitted but to whom the house doctors would have offered outpatient appointments. E J SALTER

Vitamin D deficiency.

Background: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascul...

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association.

Macrophages (MPs) are important for skeletal muscle regeneration in vivo and may exert beneficial effects on myogenic cell growth through mitogenic and antiapoptotic activities in vitro. However, MPs are highly versatile and may exert various, and even opposite, functions depending on their activation state. We studied monocyte (MO)/MP phenotypes and functions during skeletal muscle repair. Selective labeling of circulating MOs by latex beads in CX3CR1GFP/+ mice showed that injured muscle recruited only CX3CR1lo/Ly-6C+ MOs from blood that exhibited a nondividing, F4/80lo, proinflammatory profile. Then, within muscle, these cells switched their phenotype to become proliferating antiinflammatory CX3CR1hi/Ly-6C− cells that further differentiated into F4/80hi MPs. In vitro, phagocytosis of muscle cell debris induced a switch of proinflammatory MPs toward an antiinflammatory phenotype releasing transforming growth factor β1. In co-cultures, inflammatory MPs stimulated myogenic cell proliferation, whereas antiinflammatory MPs exhibited differentiating activity, assessed by both myogenin expression and fusion into myotubes. Finally, depletion of circulating MOs in CD11b–diphtheria toxin receptor mice at the time of injury totally prevented muscle regeneration, whereas depletion of intramuscular F4/80hi MPs at later stages reduced the diameter of regenerating fibers. In conclusion, injured skeletal muscle recruits MOs exhibiting inflammatory profiles that operate phagocytosis and rapidly convert to antiinflammatory MPs that stimulate myogenesis and fiber growth.

https://rupress.org/jem/article-pdf/204/5/1057/1161672/jem_20070075.pdf

Inflammatory monocytes recruited after skeletal muscle injury switch into antiinflammatory macrophages to support myogenesis

Intravascular haemolysis is a physiological phenomenon as well as a severe pathological complication when accelerated in various autoimmune, infectious (such as malaria) and inherited (such as sickle cell disease) disorders1. Haemoglobin released into plasma is captured by the acute phase protein haptoglobin, which is depleted from plasma during elevated haemolysis1. Here we report the identification of the acute phase-regulated and signal-inducing macrophage protein, CD163, as a receptor that scavenges haemoglobin by mediating endocytosis of haptoglobin–haemoglobin complexes. CD163 binds only haptoglobin and haemoglobin in complex, which indicates the exposure of a receptor-binding neoepitope. The receptor–ligand interaction is Ca2+-dependent and of high affinity. Complexes of haemoglobin and multimeric haptoglobin (the 2-2 phenotype) exhibit higher functional affinity for CD163 than do complexes of haemoglobin and dimeric haptoglobin (the 1-1 phenotype). Specific CD163-mediated endocytosis of haptoglobin–haemoglobin complexes is measurable in cells transfected with CD163 complementary DNA and in CD163-expressing myelo-monocytic lymphoma cells.

Identification of the haemoglobin scavenger receptor.

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions. 

https://www.ahajournals.org/doi/pdf/10.1161/CIR.0000000000001052

Heart Disease and Stroke Statistics—2022 Update: A Report From the American Heart Association

The current issue of Transfusion Medicine and Hemotherapy is dedicated to novel aspects of emerging infectious threats in transfusion medicine. The articles in this issue focus on Plasmodium [1, 2] and viral threats like West Nile virus (WNV) and SARS-CoV-2 [3, 4], reflecting current national test strategies and requirements. In recent 2 years, issues related to the SARS-CoV-2 pandemic have dominated medical reporting. Since early 2020, all blood establishments worldwide are challenged by the SARS-CoV-2-pandemic. The transfusion medical facilities were able to ensure the supply of blood products during the pandemic, even under very difficult conditions. Beyond this, transfusion medicine facilities also played a role in overcoming the crisis, whether by providing COVID-19 convalescent plasma [5], by SARS-CoV-2 testing [6], by vaccination campaigns [7], or establishing laboratory tests in the context of the complications associated with vaccination [8]. At the onset of the pandemic, the situation of SARS-CoV-2-infected blood donors was unclear with respect to the transfusion-transmission (TT) risk of the virus: Chinese investigators reported the detection of SARS-CoV-2 RNA in the plasma of asymptomatic blood donors already during the spring 2020, indicating the possible risk of transmitting SARS-CoV-2 by transfusion [9]. Meanwhile, considerably more data on possible TT of SARS-CoV-2 are available. In this context, Kieley et al. [4] present an updated and comprehensive review of SARS-CoV-2 and blood safety. By the current available data, the risk of transfusion-transmitted SARSCoV-2 infection can be reassessed and considered as only theoretical. However, focusing on one dramatically emerging pathogen should not underestimate new threats and require alertness for current sometimes undervalued and future infectious diseases in transfusion medicine. In particular, other, sometimes old and already known infectious agents that are endemic in developing countries should be observed. Due to climate change, global migrations caused by touristic travel or migration due to events like war or other political or economic reasons, previously rather rare infectious agents can increasingly come into the focus of the blood transfusion services in nonendemic countries. Especially, populations with little or minimal health screening amplify the infectious risk. Vectors (arthropods) for some agents like Plasmodium are not widespread and cannot be introduced in temperate climates. However, due to changes in the global climate, a further spread of vectors as well as infectious agents can be observed here. A good example of this is relevance of WNV for transfusion safety in Germany, which was considered to be a nonendemic country until 2018. Main factor for the introduction of WNV in Germany was probably global warming: increasing temperatures in Germany enable the transmission of WNV even by an already present vector (Culex sp) [10]. Therefore, in the last years, autochthonous mosquito-borne WNV infections in humans were reported indicating a continuous circulation in the affected areas of central-east Germany. Frank et al. [3] describe the German situation regarding spread of WNV by presenting the current data which are generated according to the Infection Protection Act and the Transfusion Act. They display measures in blood donation to minimize TT infections, give insights into the surveillance of WNV, and summarize blood donor regulation.

/pdf/emerging-pathogens-novel-and-well-known-infectious-threats-1pq430y1.pdf

Emerging Pathogens: Novel and Well-Known Infectious Threats in Transfusion Medicine

Elution erythrozytärer Antikörper

The implementation of nucleic acid amplification techniques (NAT) over the last two decades has totally revolutionized the field of transfusion medicine and blood safety. Several blood services started to screen for viral pathogens (HIV-1, HCV, HBV) with NAT on a voluntary basis in Germany in 1997. Later, the Paul-Ehrlich Institut (PEI) required that from April 1, 1999, NAT testing for HCV RNA is performed on all donations for the release of therapeutic blood components. The routine application of NAT required validation using appropriate standard reagents. In order to address this area scientifically, the WHO (World Health Organization) International Working Group on the Standardization of Gene Amplification Techniques (SoGAT) for the Virological Safety Testing of Blood and Blood Products was established at the National Institute for Biological Standards and Control (NIBSC), UK, in 1995. The purpose of this group is to promote the standardization of amplification methods through the exchange of information on scientific aspects of the technology, exchange of data on its evaluation for the testing of products, and the organization of international collaborative studies for the development, evaluation and provision of reference materials and working standards. Numerous in-house working reagents and reference panels existed in the pre-SoGAT era that used a variety of units, e.g. genome equivalents/ml, copies/ml or PCR-detectable units/ml. The solution was to establish internationally accepted standards against which all working reagents could be calibrated [1,2,3].

Baylis et al. [4] give a fine overview on the history and actual developments of standardization of NAT for blood-borne pathogens in this issue of Transfusion Medicine and Hemotherapy. The current WHO International Standards (IS) for NAT and the International Reference Panels for different genotypes are described here in detail. The great advantage of the development of IS is the physically defined International Unit (IU), which allows the worldwide comparability of NAT test results and the replacement of standard preparations under maintenance of this measurement unit for the first time. Today, IS are widely used for the validation of newly developed NAT assays, e.g. by in vitro diagnostic (IVD) manufacturers, and for the calibration of secondary standards which are commonly used as run controls or in quality assurance proficiency panels.

It is difficult to cross-reference molecular assays or to validate novel NAT assays without well characterized reference materials. The lack of an IS for West Nile virus (WNV) RNA, for example, hindered the determination of the analytical sensitivity (95% limit of detection). Therefore, the German authority PEI required the use of the Health Canada WNV Reference Reagent or similarly calibrated secondary standards for the quantification of assays. These standards are expressed in copies/ml and make comparison of results more difficult.

In addition to the standardization of NAT by the use of IS, the periodic review of the actual performance of methods is the second main pillar of quality assurance and quality control. Moreover, participation in external quality assurance programs is necessary. Several programs for proficiency testing for infectious diseases have been established in molecular diagnostics in Europe, including EQUALqual, a project proposed under the auspices of the European Communities Confederation of Clinical Chemistry and Laboratory Medicine (EC4) and funded by the European Commission, and several commercially available programs provided by, for example, Quality Control for Molecular Diagnostics (QCMD, UK), the United Kingdom National External Quality Assessment Service (NEQAS, UK), the Reference Institute for Bioanalytics (RfB, Germany), and the Institute for Standardization and Documentation in Medical Laboratory (INSTAND, Germany) [5]. Recently, a novel format for a personalized external quality assurance program (EQAP) was described that provides a collaborative trial for genomic detection of eight viruses simultaneously: HAV, HBV, HCV, HIV-1, HIV-2, parvovirus B19 (B19V), WNV and human cytomegalovirus (HCMV) [6]. The so-called MultiVir NAT is organized by the RfB, Germany. This EQAP enables flexible participation regarding the testing of 1-8 different transfusion-relevant viruses, qualitatively and/or quantitatively, and provides result reporting within 4 weeks. Barcoded samples can be processed as routine samples in an automated PCR workflow.

Compared to viral pathogens, the transfusion-relevant bacteria have been neglected regarding quality assurance and quality control. Bacterial contamination of platelet concentrates (PC) remains a persistent problem in transfusion medicine. The residual risk of transfusion-related bacterial infections is currently 8- to 200-fold higher than the residual risk of virus infections (e.g. HIV-1, HCV or HBV). Platelets are the main focus of bacterial contamination, due to the storage temperature of 22 °C providing optimal growth conditions for a broad range of bacteria. Nevertheless, fatal septic reactions have also been reported after transfusion of contaminated red cell concentrates. The maximum shelf life for platelets was reduced from 5 to 4 days in Germany to increase blood safety. Alternatively, rapid screening methods for bacterial detection in platelets have been optimized over the last decade and are now available for routine screening [7].

The validation and head-to-head comparison of these rapid bacterial detection methods, however, represent a complicated process. An important criterion for the evaluation of an analytical method is the determination of the lower detection limit, requiring defined standards. However, standards are not yet available for microbiological diagnostics and are, thus, produced by each laboratory individually. Ascertaining the target values of these standards is extremely problematic because no metrologically correct measuring system for these parameters exists. Additionally, reference methods for bacterial quantification are not available. Target values for the so-called standards are, therefore, attained using either the routine methods biologically characterizing the standard or the same method used to screen the sample material. The routine methods used in microbiology are less reliable (incorrect and imprecise). The current practice is quantification via either i) bacterial titer expressed as colony-forming units (CFU) or ii) the nucleic acid molecule for detection expressed in copies or genome equivalents. Currently, defined, qualified microbiological standards are not yet available, with the exception of the WHO Repository of Platelet Transfusion Relevant Bacteria Reference Strains, which were designed for the low-titer spiking of blood components with a guaranteed ability to multiply in PC. The International Society of Blood Transfusion (ISBT) Working Party Transfusion-Transmitted Infectious Diseases (WP-TTID), Subgroup Bacteria, organized an international study on bacteria standards to be used as a tool for development, validation, and comparison of both bacterial screening and pathogen reduction methods [8].

Vollmer et al. [9] present data in this issue on the first three individual collaborative trials for the detection of bacterial contamination in PC. The problems of standardization of bacterial detection methods with cultural and rapid methods were described in this study. Compared to viral parameters, an EQAP for the detection of bacterial contamination in PC has some special requirements: i) bacteria are supposed to have the ability to proliferate because some test principles are dependent on cell viability, but ii) titers have to be constant between sample setup and execution of analysis to obtain the highest reproducibility of results. This promising approach enables the head-to-head comparison of rapid and cultural bacterial detection systems for the first time. A special challenge is that the bacterial titer (expressed as CFU) is not static in samples or blood components, because microorganisms have the ability to proliferate during storage. By contrast, there is a direct correlation between viral load and copy number determined by NAT for viral approaches. For viral NAT assays, standardization was achieved by using well characterized reference material, i.e. calibrated material using a common standard unit (IU). For bacteria, there are several problems and questions regarding the establishment of a standard preparation. Bacteria are living organisms and, in contrast to viruses, are changeable regarding their metabolism.

Altogether, this issue of Transfusion Medicine and Hemotherapy provides an insight into the history and new developments of the standardization of diagnostics, and challenges and difficulties concerning the improvement of blood safety.

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Standardization of Diagnostics in Blood Safety.

HLA-Antikörper-Absorption

Abstract Bacterial contamination of blood components, especially of platelet concentrates (PCs), represents the highest infectious risk in blood transfusion. Although the incidence of platelet bacterial contamination is approximately one per 2000 units, the urgent need for a method for the routine screening of PCs to improve safety for patients had not been considered for a long time. Besides the culturing systems, which will remain the gold standard, rapid methods for sterility screening will play a more important role in transfusion medicine in the future. In particular, the nucleic acid amplification techniques (NAT) are powerful tools in bacterial screening assays. The combination of excellent sensitivity and specificity, low contamination risk, ease of performance and speed, has made real-time PCR technology an appealing alternative to conventional culture-based testing methods. When using real-time PCR for the detection of bacterial contamination, several points have to be considered. The main focus refers to the choice of the target gene, the assay format, the nucleic acid extraction method, depending on the sample type, and the evaluation of an ideal sampling strategy. However, several factors like the bacterial-derived nucleic acid contamination of amplification reagents or laboratory materials, the impracticability and the costs have limited the use of NAT until now. Attempts to reduce the amount of contaminating nucleic-acids from reagents in real-time PCR have been described, but none of these methods have proved to be very effective or may lower the sensitivity of the assay. Recently, a number of broad-range NAT assays targeting the 16S rDNA or 23S rRNA for detection of bacteria based on real-time technology have been reported. This review will give a short survey of current approaches to and limitations of the application of real-time PCR for bacterial detection in blood components, with emphasis on PCs.

Real-time NAT-based methods for detection of bacterial contamination in blood products / Real-time NAT-basierte Methoden zur Entdeckung bakterieller Kontamination in Blutprodukten

Jens Dreier

Papers

Emerging Pathogens: Novel and Well-Known Infectious Threats in Transfusion Medicine

Elution erythrozytärer Antikörper

Standardization of Diagnostics in Blood Safety.

HLA-Antikörper-Absorption

Real-time NAT-based methods for detection of bacterial contamination in blood products / Real-time NAT-basierte Methoden zur Entdeckung bakterieller Kontamination in Blutprodukten