Transfusion Transmission of Human Prion Diseases

Blood Product (Donor) Noninfectious and Infectious Testing and Modification

Blood transfusion begins with safe donor selection and testing. In the United States, the blood supply and transfusion are highly regulated. Blood transfusion safety is multifaceted, whereby each of the elements of the blood safety value chain, spanning donor recruitment and qualification, to collection, blood processing, testing, transfusion practice, and posttransfusion surveillance, must be optimized to minimize risk. Pathogen inactivation is a promising approach to decrease bacterial contamination of platelets, inactivate parasites and viruses, and decrease risks associated with emerging and unidentified pathogens. This article offers an overview of blood donor infectious and noninfectious testing in the United States.

The Three Glycotypes in the London Classification System of Sporadic Creutzfeldt-Jakob Disease Differ in Disease Duration

Sporadic Creutzfeldt-Jakob disease (sCJD) is the most common form of CJD and is believed to be caused by the misfolding and aggregation of endogenous prion protein. Several classification systems have been developed to correlate the molecular characteristics of these misfolded prions (PrP^Sc) to the heterogeneous clinical presentations of sCJD. A central component of these systems is glycotyping, which involves the interpretation of the results of western immunoblotting of the protease-resistant fragment of the misfolded prion protein (PrP^res). The two main classification systems differ in their recognition of a unique banding pattern on electrophoretic gels correlating to a putative clinical subtype. The perpetuation of both classification systems within scientific literature is, in part, due to a paucity of high-level evidence that conclusively addresses the merit of recognising each unique banding pattern. Here, 110 post-mortem confirmed cases of sCJD collected at the Australian Creutzfeldt-Jakob Disease Registry (ANCJDR) between 1993 and 2018 were analysed and classified as per the London classification system. The data presented here demonstrated that sCJD cases with 'type 1' and 'type 2' PrP^Sc as defined by the London classification system differ in their disease duration. No other differences in clinical phenotype or biological characteristics were found to be statistically significant. These findings highlight the importance of sample size and replicability in analyses of this rare disease process. Recognising these glycotypes as phenotypically distinct may represent 'best practice' in the collection and processing of sCJD samples within international registries for research purposes.

Sporadic Creutzfeldt-Jakob disease: A case report and review of literature

Creutzfeldt-Jakob Disease is a rare neurodegenerative disease and earlier diagnosis is usually difficult. Combining clinical features with electroencephalogram, laboratory parameters, and neuroimaging findings will facilitate the diagnosis.

Prevention of transfusion-transmitted infections

Since the 1970s, introduction of serological assays targeting virus-specific antibodies and antigens has been effective in identifying blood donations infected with the classic transfusion-transmitted infectious agents (TTIs; hepatitis B virus [HBV], HIV, human T-cell lymphotropic virus types I and II, hepatitis C virus [HCV]). Subsequently, progressive implementation of nucleic acid-amplification technology (NAT) screening for HIV, HCV, and HBV has reduced the residual risk of infectious-window-period donations, such that per unit risks are <1 in 1 000 000 in the United States, other high-income countries, and in high-incidence regions performing NAT. NAT screening has emerged as the preferred option for detection of newer TTIs including West Nile virus, Zika virus (ZIKV), and Babesia microti Although there is continual need to monitor current risks due to established TTI, ongoing challenges in blood safety relate primarily to surveillance for emerging agents coupled with development of rapid response mechanisms when such agents are identified. Recent progress in development and implementation of pathogen-reduction technologies (PRTs) provide the opportunity for proactive rather than reactive response to blood-safety threats. Risk-based decision-making tools and cost-effectiveness models have proved useful to quantify infectious risks and place new interventions in context. However, as evidenced by the 2015 to 2017 ZIKV pandemic, a level of tolerable risk has yet to be defined in such a way that conflicting factors (eg, theoretical recipient risk, blood availability, cost, and commercial interests) can be reconciled. A unified approach to TTIs is needed, whereby novel tests and PRTs replace, rather than add to, existing interventions, thereby ameliorating cost and logistical burden to blood centers and hospitals.

Prion Diseases

Prions diseases are uniformly fatal neurodegenerative diseases that occur in sporadic, genetic, and acquired forms. Acquired prion diseases, caused by infectious transmission, are least common. Most prion diseases are not infectious, but occur spontaneously through misfolding of normal prion proteins or genetic mutations in the prion protein gene. Although most prion diseases are not caused by infection, they can be transmitted accidentally. Certain infection control protocols should be applied when handling central nervous system and other high-risk tissues. New diagnostic methods are improving premortem and earlier diagnosis. Treatment trials have not shown improved survival, but therapies may be available soon.

Creutzfeldt-Jakob disease lookback study: 21 years of surveillance for transfusion transmission risk

BACKGROUND

Transfusion transmission of human prion diseases has been observed for variant Creutzfeldt-Jakob disease (vCJD), but not for the classic forms of prion disease (CJD: sporadic, genetic, and iatrogenic). Although the presence of prions or misfolded prion proteins in blood has been documented in some patients with the most common form of CJD, sporadic CJD, no transfusion-transmitted cases of CJD have been recognized. Since 1995, the American Red Cross has conducted a lookback study of the recipients of blood products from donors who develop CJD to assess the risk of blood-borne CJD transmission in the United States.

STUDY DESIGN AND METHODS

Blood donors subsequently diagnosed with confirmed or probable CJD were enrolled and the consignees were asked to identify the recipients of their blood products. These donors' transfusion recipients are traced annually with the National Death Index to see if they subsequently die of CJD.

RESULTS

To date, 65 CJD donors have been enrolled along with 826 of their blood recipients. These recipients have contributed 3934 person-years of follow-up and no transfusion-transmitted cases of CJD have been recognized.

CONCLUSION

From this study, as well as other epidemiologic studies, there is no evidence of CJD transfusion transmission; this risk remains theoretical.

Binding of Pollutants to Biomolecules: A Simulation Study

A number of cases around the world have been reported where animals were found dead or dying with symptoms resembling a thiamine (vitamin B) deficiency, and for some of these, a link to pollutants has been suggested. Here, we investigate whether biomolecules involved in thiamin binding and transport could be blocked by a range of different pollutants. We used in silico docking of five compound classes (25 compounds in total) to each of five targets (prion protein, ECF-type ABC transporter, thi-box riboswitch receptor, thiamin pyrophosphokinase, and YKoF protein) and subsequently performed molecular dynamics (MD) simulations to assess the stability of the complexes. The compound classes were thiamin analogues (control), pesticides, veterinary medicines, polychlorinated biphenyls, and dioxins, all of which are prevalent in the environment to some extent. A few anthropogenic compounds were found to bind the ECF-type ABC transporter, but none binds stably to prion protein. For the riboswitch, most compounds remained in their binding pockets during 50 ns of MD simulation, indicating that RNA provides a promiscuous binding site. In both YKoF and thiamin pyrophosphokinase (TPK), most compounds remain tightly bound. However, TPK biomolecules undergo pollutant-induced conformational changes. Although most compounds are found to bind to some of these targets, a larger data set is needed along with more quantitative methods like free energy perturbation calculations before firm conclusions can be drawn. This study is in part a test bed for large-scale quantitative computational screening of interactions between biological entities and pollutant molecules.

Adverse Transfusion Reactions in Critically Ill Patients

Although transfusion therapy in the past 30 years has achieved high levels of safety, severe adverse reactions can still complicate a red blood cell, plasma, or platelet transfusion. Adverse events can be either of infectious nature (Infectious Adverse Reactions to Transfusion–IARTs) or noninfectious (NIARTs). The former are due to viruses, bacteria, or protozoa present in the transfused component. Medical doctors faced with an infectious disease in a hospitalized patient should always collect an accurate clinical history that must include transfusion of blood components and take into consideration that the viral/bacterial/protozoan infection could be related to a transfusion event. If a transfusion-transmitted infection is suspected, the clinician must contact the transfusion center that will provide a look-back of the blood products and a follow-up of the involved donors.

NIARTs may be of immunological and nonimmunological nature. This chapter provides an overview of pathogenesis, presentation, therapy, and prevention of the main NIARTs. Finally, organizational measures for the management of NIARTs are presented, in order to ensure the highest possible level of safety for the patients.

Adverse effects of human immunoglobulin therapy

Human immunoglobulin (IG) is used for IgG replacement therapy in primary and secondary immunodeficiency, for prevention and treatment of certain infections, and as an immunomodulatory agent for autoimmune and inflammatory disorders. IG has a wide spectrum of antibodies to microbial and human antigens. Several high-titered IGs are also available enriched in antibodies to specific viruses or bacterial toxins. IG can be given intravenously (IGIV), intramuscularly (IGIM) or by subcutaneous infusions (SCIG). Local adverse reactions such as persistent pain, bruising, swelling and erythema are rare with IGIV infusions but common (75%) with SCIG infusions. By contrast, adverse systemic reactions are rare with SCIG infusions but common with IGIV infusions, occurring as often as 20% to 50% of patients and 5% to 15% of all IGIV infusions. Systemic adverse reactions can be immediate (60% of reactions) occurring within 6 hours of an infusion, delayed (40% of reactions) occurring 6 hours-1 week after an infusion, and late (less than 1% of reactions), occurring weeks and months after an infusion. Immediate systemic reactions such as head and body aches, chills and fever are usually mild and readily treatable. Immediate anaphylactic and anaphylactoid reactions are uncommon. The most common delayed systemic reaction is persistent headache. Less common but more serious delayed reactions include aseptic meningitis, renal failure, thromboembolism, and hemolytic reactions. Late reactions are uncommon but often severe, and include lung disease, enteritis, dermatologic disorders and infectious diseases. The types, incidence, causes, prevention, and management of these reactions are discussed.

Blood component recalls and market withdrawals: frequency, reasons, and management in the United States

In a previous article, we reviewed the management of blood component recalls and withdrawals (G. Ramsey. Transfusion Med Rev 2004;18:36-45). Since then, US rates of recall and biological product deviation for blood components have improved significantly, particularly with regard to reduced recalls for donor infectious disease risks or testing. However, analysis of the current data from the US Food and Drug Administration suggests that 1 (0.4%) in 250 blood components is involved in market withdrawals and quarantines, with 1 in 5800 components formally recalled. Most of these units, unfortunately, had already have been transfused. The U.S. Food and Drug Administration has issued several recent guidances that address transfusion service actions for dealing with specific infectious disease problems. This present article updates our 2004 recommendations as to when to notify physicians about transfused nonconforming blood components.

Consumers' understanding and concerns about bovine spongiform encephalopathy (BSE): comparison among Canadian, American, and Japanese consumers

In spite of much analysis of the impact of bovine spongiform encephalopathy (BSE) on consumer perceptions and meat purchases, there has been little explicit analysis of the level of BSE knowledge. In this study the role of knowledge about BSE was examined in Canada, the United States, and Japan. In addition, the level of knowledge was linked to human health concerns regarding BSE and whether there is agreement with paying a premium for beef with BSE animal tests. From a public policy perspective, understanding whether higher or lower knowledge is linked to public concern and desire for market intervention might help in the design of risk communication in any future animal disease outbreak. Should lack of knowledge about the disease be related to a public desire for market intervention (animal testing, for example), then an increase in detailed information about how humans might contract the disease might change public pressure for intervention. As compared to U.S. and Canadian respondents, Japanese respondents are more knowledgeable regarding the ways in which humans might be exposed to the human variant of BSE (variant Creutzfeldt-Jakob disease, vCJD) and are more concerned about the disease. However, U.S. respondents are more willing to pay a premium for beef tested to ensure that it will not result in vCJD. Japanese respondents who are more knowledgeable about BSE are more concerned about the risk of BSE to human health. In Canada, subjects who are more knowledgeable about the ways in which humans attain vCJD are less concerned about the risk of BSE to human health. Knowledge of the ways in which humans develop vCJD does not significantly influence concerns about the risk of BSE to human health in the United States or willingness to pay for BSE-tested beef in any of the three countries. The links between knowledge and concerns about BSE and between knowledge and agreement with paying premiums for BSE-tested beef were estimated for each country using ordered probit regressions.

Preclinical deposition of pathological prion protein in muscle of experimentally infected primates

Prion diseases are transmissible fatal neurodegenerative disorders affecting humans and animals. A central step in disease progression is the accumulation of a misfolded form (PrP^Sc) of the host encoded prion protein (PrP^C) in neuronal and non-neuronal tissues. The involvement of peripheral tissues in preclinical states increases the risk of accidental transmission. On the other hand, detection of PrP^Sc in non-neuronal easy-accessible compartments such as muscle may offer a novel diagnostic tool. Primate models have proven invaluable to investigate prion diseases. We have studied the deposition of PrP^Sc in muscle and central nervous system of rhesus monkeys challenged with sporadic Creutzfeldt-Jakob disease (sCJD), variant CJD (vCJD) and bovine spongiform encephalopathy (BSE) in preclinical and clinical stage using biochemical and morphological methods. Here, we show the preclinical presence of PrP^Sc in muscle and central nervous system of rhesus monkeys experimentally infected with vCJD.

Blood still kills: six strategies to further reduce allogeneic blood transfusion-related mortality

After reviewing the relative frequency of the causes of allogeneic blood transfusion-related mortality in the United States today, we present 6 possible strategies for further reducing such transfusion-related mortality. These are (1) avoidance of unnecessary transfusions through the use of evidence-based transfusion guidelines, to reduce potentially fatal (infectious as well as noninfectious) transfusion complications; (2) reduction in the risk of transfusion-related acute lung injury in recipients of platelet transfusions through the use of single-donor platelets collected from male donors, or female donors without a history of pregnancy or who have been shown not to have white blood cell (WBC) antibodies; (3) prevention of hemolytic transfusion reactions through the augmentation of patient identification procedures by the addition of information technologies, as well as through the prevention of additional red blood cell alloantibody formation in patients who are likely to need multiple transfusions in the future; (4) avoidance of pooled blood products (such as pooled whole blood-derived platelets) to reduce the risk of transmission of emerging transfusion-transmitted infections (TTIs) and the residual risk from known TTIs (especially transfusion-associated sepsis [TAS]); (5) WBC reduction of cellular blood components administered in cardiac surgery to prevent the poorly understood increased mortality seen in cardiac surgery patients in association with the receipt of non-WBC-reduced (compared with WBC-reduced) transfusion; and (6) pathogen reduction of platelet and plasma components to prevent the transfusion transmission of most emerging, potentially fatal TTIs and the residual risk of known TTIs (especially TAS).

Multiorgan detection and characterization of protease-resistant prion protein in a case of variant CJD examined in the United States

BACKGROUND

Variant Creutzfeldt-Jakob disease (vCJD) is a prion disease thought to be acquired by the consumption of prion-contaminated beef products. To date, over 200 cases have been identified around the world, but mainly in the United Kingdom. Three cases have been identified in the United States; however, these subjects were likely exposed to prion infection elsewhere. Here we report on the first of these subjects.

METHODOLOGY/PRINCIPAL FINDINGS

Neuropathological and genetic examinations were carried out using standard procedures. We assessed the presence and characteristics of protease-resistant prion protein (PrP(res)) in brain and 23 other organs and tissues using immunoblots performed directly on total homogenate or following sodium phosphotungstate precipitation to increase PrP(res) detectability. The brain showed a lack of typical spongiform degeneration and had large plaques, likely stemming from the extensive neuronal loss caused by the long duration (32 months) of the disease. The PrP(res) found in the brain had the typical characteristics of the PrP(res) present in vCJD. In addition to the brain and other organs known to be prion positive in vCJD, such as the lymphoreticular system, pituitary and adrenal glands, and gastrointestinal tract, PrP(res) was also detected for the first time in the dura mater, liver, pancreas, kidney, ovary, uterus, and skin.

CONCLUSIONS/SIGNIFICANCE

Our results indicate that the number of organs affected in vCJD is greater than previously realized and further underscore the risk of iatrogenic transmission in vCJD.

Human prion diseases in the United States

BACKGROUND

Prion diseases are a family of rare, progressive, neurodegenerative disorders that affect humans and animals. The most common form of human prion disease, Creutzfeldt-Jakob disease (CJD), occurs worldwide. Variant CJD (vCJD), a recently emerged human prion disease, is a zoonotic foodborne disorder that occurs almost exclusively in countries with outbreaks of bovine spongiform encephalopathy. This study describes the occurrence and epidemiology of CJD and vCJD in the United States.

METHODOLOGY/PRINCIPAL FINDINGS

Analysis of CJD and vCJD deaths using death certificates of US residents for 1979-2006, and those identified through other surveillance mechanisms during 1996-2008. Since CJD is invariably fatal and illness duration is usually less than one year, the CJD incidence is estimated as the death rate. During 1979 through 2006, an estimated 6,917 deaths with CJD as a cause of death were reported in the United States, an annual average of approximately 247 deaths (range 172-304 deaths). The average annual age-adjusted incidence for CJD was 0.97 per 1,000,000 persons. Most (61.8%) of the CJD deaths occurred among persons >or=65 years of age for an average annual incidence of 4.8 per 1,000,000 persons in this population. Most deaths were among whites (94.6%); the age-adjusted incidence for whites was 2.7 times higher than that for blacks (1.04 and 0.40, respectively). Three patients who died since 2004 were reported with vCJD; epidemiologic evidence indicated that their infection was acquired outside of the United States.

CONCLUSION/SIGNIFICANCE

Surveillance continues to show an annual CJD incidence rate of about 1 case per 1,000,000 persons and marked differences in CJD rates by age and race in the United States. Ongoing surveillance remains important for monitoring the stability of the CJD incidence rates, and detecting occurrences of vCJD and possibly other novel prion diseases in the United States.

Antibody-based immunotherapeutic attempts in experimental animal models of prion diseases

BACKGROUND

There has been a dramatic decrease in the risk of transmission of bovine spongiform encephalopathy to humans. In contrast, the risk of human-to-human transmission of variant Creutzfeldt-Jakob disease (vCJD) via medical treatments became potentially high since 4 vCJD cases were reported to be possibly transmitted through blood transfusion in the UK. However, no treatments are yet available for curing prion diseases.

OBJECTIVE

Conversion of the normal prion protein, PrP(C), to the amyloidogenic PrP, PrP(Sc), plays a pivotal role in the pathogenesis. Recently, certain anti-PrP or anti-37/67-kDa laminin receptor (LRP/LR) antibodies were shown to have the potential to cure chronically infected cells, clearing PrP(Sc) from the cells. This has raised the possibility of antibody based-immunotherapy for prion diseases. This article aims to introduce and discuss the recently published attempts of immunotherapy in prion diseases.

METHODS

Bibliographic research was carried out using the PubMed database. Patent literature was searched using the UK Intellectual Property Office website.

RESULTS/CONCLUSION

No satisfying consequences in animals could be detected with anti-PrP antibodies directly infused into the brains of animals by the intraventricular route or by anti-PrP or anti-LRP/LR single chain fragment antibodies directly delivered into the brain by virus vector-mediated gene transfer. This is probably because such delivery systems failed to deliver the antibodies to the neurons relevant for the treatments.

Prion proteins in subpopulations of white blood cells from patients with sporadic Creutzfeldt-Jakob disease

Recent cases of prion transmission in humans following transfusions using blood donated by patients with asymptomatic variant Creutzfeldt-Jakob disease (CJD) implicate the presence of prion infectivity in peripheral blood. In this study, we examined the levels of the normal, cellular prion protein (PrPC), and the disease-causing isoform (PrPSc) in subpopulations of circulating white blood cells (WBCs) from patients with sporadic (s) CJD, age-matched neurological controls and healthy donors. Though widely distributed, the highest levels of PrPC were found in a subpopulation of T lymphocytes: approximately 12,000 PrPC molecules were found per CD4+CD45RA-CD62L- effector memory T helper cell. Although platelets expressed low levels of PrPC on their surface, their high abundance in circulation resulted in the majority of PrPC being platelet associated. Using quantitative fluorescence-activated cell sorting analysis, we found that neither WBC composition nor the amount of cell-surface PrPC molecules was altered in patients with sCJD. Eight different WBC fraction types from the peripheral blood of patients with sCJD were assessed for PrPSc. We were unable to find any evidence for PrPSc in purified granulocytes, monocytes, B cells, CD4+ T cells, CD8+ T cells, natural killer cells, nonclassical gamma delta T cells, or platelets. If human WBCs harbor prion infectivity in patients with sCJD, then the levels are likely to be low.

Transfusion-transmitted infectious diseases

A spectrum of blood-borne infectious agents is transmitted through transfusion of infected blood donated by apparently healthy and asymptomatic blood donors. The diversity of infectious agents includes hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency viruses (HIV-1/2), human T-cell lymphotropic viruses (HTLV-I/II), Cytomegalovirus (CMV), Parvovirus B19, West Nile Virus (WNV), Dengue virus, trypanosomiasis, malaria, and variant CJD. Several strategies are implemented to reduce the risk of transmitting these infectious agents by donor exclusion for clinical history of risk factors, screening for the serological markers of infections, and nucleic acid testing (NAT) by viral gene amplification for direct and sensitive detection of the known infectious agents. Consequently, transfusions are safer now than ever before and we have learnt how to mitigate risks of emerging infectious diseases such as West Nile, Chikungunya, and Dengue viruses.

Transfusion-related mortality: the ongoing risks of allogeneic blood transfusion and the available strategies for their prevention

As the risks of allogeneic blood transfusion (ABT)-transmitted viruses were reduced to exceedingly low levels in the US, transfusion-related acute lung injury (TRALI), hemolytic transfusion reactions (HTRs), and transfusion-associated sepsis (TAS) emerged as the leading causes of ABT-related deaths. Since 2004, preventive measures for TRALI and TAS have been implemented, but their implementation remains incomplete. Infectious causes of ABT-related deaths currently account for less than 15% of all transfusion-related mortality, but the possibility remains that a new transfusion-transmitted agent causing a fatal infectious disease may emerge in the future. Aside from these established complications of ABT, randomized controlled trials comparing recipients of non-white blood cell (WBC)-reduced versus WBC-reduced blood components in cardiac surgery have documented increased mortality in association with the use of non-WBC-reduced ABT. ABT-related mortality can thus be further reduced by universally applying the policies of avoiding prospective donors alloimmunized to WBC antigens from donating plasma products, adopting strategies to prevent HTRs, WBC-reducing components transfused to patients undergoing cardiac surgery, reducing exposure to allogeneic donors through conservative transfusion guidelines and avoidance of product pooling, and implementing pathogen-reduction technologies to address the residual risk of TAS as well as the potential risk of the next transfusion-transmitted agent to emerge in the foreseeable future.

Lack of evidence of transfusion transmission of Creutzfeldt-Jakob disease in a US surveillance study

BACKGROUND

Since 2004, several reported transfusion transmissions of variant Creutzfeldt-Jakob disease (vCJD) in the United Kingdom have reawakened concerns about the possible risk of similar transmissions of nonvariant or classic forms of CJD.

STUDY DESIGN AND METHODS

Patients with a CJD diagnosis and a history of donating blood were reported to the study coordinator. Through review of blood distribution and hospital records, the recipients of blood components from these donors were identified. We then determined each recipient's vital status and, if deceased, the cause(s) of death identified by matching the recipient's personal identifiers with the Centers for Disease Control and Prevention's National Death Index database. We conducted such searches after recipients were enrolled in this study and annually thereafter for those who remained alive.

RESULTS

The study included a total of 36 blood donors who subsequently developed CJD and 436 recipients. Through 2006, 91 of these recipients were still alive, 329 were deceased, and 16 were lost to follow-up. After transfusion, these three groups had survived a total of 2096.0 person-years. A total of 144 recipients survived 5 years or longer after transfusion and 68 of them had received blood donated 60 or fewer months before the onset of CJD in the donor. We identified no recipient with CJD.

CONCLUSIONS

The current results of this large, ongoing lookback study show no evidence of transfusion transmission of CJD. They reinforce the conclusion that the risk, if any, of transfusion transmission of prion disease by CJD donors is significantly lower than the comparable risk of such transmission by vCJD donors.

Transfusion Transmitted Diseases

This chapter discusses the various diseases transmitted by blood transfusion. This transfusion transmitted diseases (TTD) can be caused by viruses, protozoa and prions. The mitigation of transfusion transmission of infectious agents is mentioned to be based on donor selection and donor testing. A table is presented that illustrates the potential transfusion transmitted agents. Hepatitis viruses are transmitted through transfusion and result in inflammation of the liver, jaundice, hepatomegaly and anorexia and both hepatitis B and hepatitis C typical hepatitis viruses transmitted through transfusion. Several other viruses transmitted through transfusion of infected blood include human immunodeficiency virus, human t-cell lymphotropic virus and herpesviruses. The protozoans transmitted due to transfusion include Plasmodium, Trypanosoma and Leishmania. Prion diseases results from the benign form of the prion protein changing to an insoluble protease-resistant form, which leads to the formation of plagues in the brain. Another transfusion transmitted disease called transmissible spongiform encephalopathies (Creutzfeldt-Jakob disease) is described.

Guidelines for the use of fresh frozen plasma

Recommendations, which aim at standardising and rationalising clinical indications for the transfusion of fresh frozen plasma (FFP) in Belgium, were drawn up by a working group of the Superior Health Council. For this purpose the Superior Health Council organised an expert meeting devoted to "Transfusion Guidelines: Pathogen reduction, products and indications for the transfusion of plasma" in collaboration with the Belgian Haematological Society.The experts discussed the indications for the transfusion of FFP, pathogen reduction for FFP and the practical issues of administering FFP and plasma-derived concentrates. The recommendations formulated by the experts were validated by the working group with the purpose of harmonising FFP transfusion in Belgian hospitals.

Surveillance for Creutzfeldt-Jakob disease in China from 2006 to 2007

Background

Human transmissible spongiform encephalopathies (HTSE), or Creutzfeldt-Jakob disease (CJD), is a group of rare and fatal diseases in central nervous system. Since outbreak of bovine spongiform encephalopathy (BSE) and variant CJD, a worldwide CJD surveillance network has been established under the proposition of WHO. In China, a national CJD surveillance system has started since 2002. The data of CJD surveillance from 2006 to 2007 was analyzed.

Methods

Total 12 provinces are included in CJD surveillance system. The surveillance unit in each province consists of one or two sentinel hospitals and the provincial CDC. All suspected CJD cases reported from CJD surveillance were diagnosed and subtyped based on the diagnostic criteria for CJD issued by WHO.

Results

Total 192 suspected CJD cases were reported and 5 genetic CJD, 51 probable and 30 possible sporadic CJD (sCJD) cases were diagnosed. The collected sCJD cases distribute sporadically without geographical clustering and seasonal relativity and the highest incidences in both probable and possible sCJD cases appeared in the group of 60–69 year. The most common three foremost symptoms were progressive dementia, cerebellum and mental-related symptoms. The probable sCJD patients owning both typical EEG alteration and CSF protein 14-3-3 positive have more characteristic clinical syndromes than the ones having only one positive. The polymorphisms of codon 129 of all tested reported cases shows typical patterns of Han Chinese as previous reports, that M129M are predominant whereas M129V are seldom.

Conclusion

Chinese CJD patients possessed similar epidemiological and clinical characteristics as worldwide.

The hazards of blood transfusion in historical perspective

The beginning of the modern era of blood transfusion coincided with World War II and the resultant need for massive blood replacement. Soon thereafter, the hazards of transfusion, particularly hepatitis and hemolytic transfusion reactions, became increasingly evident. The past half century has seen the near eradication of transfusion-associated hepatitis as well as the emergence of multiple new pathogens, most notably HIV. Specific donor screening assays and other interventions have minimized, but not eliminated, infectious disease transmission. Other transfusion hazards persist, including human error resulting in the inadvertent transfusion of incompatible blood, acute and delayed transfusion reactions, transfusion-related acute lung injury (TRALI), transfusion-associated graft-versus-host disease (TA-GVHD), and transfusion-induced immunomodulation. These infectious and noninfectious hazards are reviewed briefly in the context of their historical evolution.