Safety Of Blood Components Research Articles

Transfusion-transmissible infections.

Infectious agents, including viruses, bacteria, and parasites, can be transmitted by human blood products. Of major importance are viruses such as human immunodeficiency virus types 1 and 2 (HIV-1/2), hepatitis B virus (HBV), hepatitis C virus (HCV), and human T-cell lymphotropic virus types I and II (HTLV-I/II). Also, other viruses such as cytomegalovirus, Epstein-Barr virus, human parvovirus B19, and hepatitis A and G viruses can be transmitted by blood products. Various methods are used to prevent transmission of blood-borne agents to recipients, such as donor selection, testing donated blood for various infectious agents, and viral inactivation of plasma derivatives. With all these precautionary measures, the estimated risk for infection by screened blood components in Europe and the United States is approximately 1 in 50,000 to 1.6 million (for HBV, HCV, and HIV-1/2) transfused blood components. In the future, the safety of blood components may be increased by testing donated blood by nucleic acid amplification techniques and by photochemical decontamination of cellular blood components.

Contribution of nucleic acid amplification techniques to the safety of blood components in France.

Contribution of nucleic acid amplification techniques to the safety of blood components in France.

Inactivation of viruses, bacteria, protozoa, and leukocytes in platelet concentrates.

Despite the increased safety of blood achieved through continued improvements in donor testing, concern remains about the safety of blood components. Transfusion of cellular components has been implicated in transmission of viral, bacterial, and protozoan diseases. While it is commonly recognized that hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), and the retroviruses, such as human immunodeficiency virus (HIV) and the human lymphotrophic viruses (HTLV) can be transmitted through cellular components, other pathogens are emerging as potentially significant transfusion-associated infectious agents. For example, transmission of protozoan infections due to trypanosomes and babesia have been reported. In addition to viral and protozoal infectious agents, bacterial contamination of platelet concentrates continues to be reported; and may be an under reported transfusion complication. More importantly, new infectious agents may periodically enter the donor population before they can be definitively identified and tested for to maintain consistent safety of the blood supply. The paradigm for this possibility is the HIV pandemic which erupted in 1979. During the past decade a number of methods to inactivate infectious pathogens in blood components, including platelets, have been developed. This technology is now entering the clinical trial phase.

The BEST Working Party of the International Society of Blood Transfusion: an international effort to improve the quality of blood components

The Biomedical Excellence for Safer Transfusion (BEST) Working Party of the International Society of Blood Transfusion was formed with the aim of improving the quality and safety of blood components. An outline of the aims, working methodology, and results after the first 4 years of activity of the BEST Working Party is presented. Seven studies have been performed, evaluating techniques for counting residual white cells in white cell-reduced red cells, platelet quality control, and cellular harvests in blood components prepared with different methods. Areas of possible interest in the near future include stem cells, platelet crossmatching, and virus inactivation of blood components. An important BEST feature is the sharing of information gathered through collections of large sets of data from routine settings, so as to produce a reliable picture of the "real world." Such information could prove useful to those in charge of developing recommendations and guidelines.

The use of blood products in paediatrics

Transfusing children with blood and blood products requires special consideration of the patient's size, disease status and immunocompetence. Despite improved quality and safety of blood components the continuing risk of viral transmission dictates that every attempt should be made to reduce exposure to homologous blood. While many guidelines apply to all paediatric patients there are specific requirements for neonates, children with bone marrow failure and haemoglobinopathies, and children receiving large volume transfusions during surgery. These will therefore be discussed separately.

The Safety of Blood Components and Derivatives

An overview of the steps taken to ensure the safety of blood components and derivatives is provided. A brief discussion of hereditary bleeding disorders (hemophilia A, B, and von Willebrand's disease) is included, and the safety of derivatives available for their treatment is discussed, as well as the method of production and the level of safety of derivatives such as factor VIII and factor IX concentrates.

Future directions in blood transfusion medicine

Few would question that blood transfusion has been one of the greatest medical advances. The provision of safe blood component therapy has always been a primary consideration of the blood transfusion services, however, the increased centralisation of transfusion services resulted in a dearth of clinical transfusion expertise at the hospital and patient level. The introduction of in vivo blood cell separators into clinical medicine and to a greater extent the appearance of HIV infection became the stimuli to an increased clinical and consumer awareness of the potential hazards of blood transfusion. The old question of What is a Safe Blood Transfusion? will be addressed and possible new answers given. Careful and scientific analysis of the risk/benefit equation for blood component therapy is of paramount importance if patients are to receive appropriate therapy with the minimum risk. 1. A transfusion should have a clearly defined indication and supply, in adequate amount, the functional component/s needed by the patient. 2. The infusion should not be associated with any ill effects. 3. There should be no delayed sequelae from the transfusion and it should not transmit disease, 4. The safely and efficacy of future transfusion therapy should not be jeopardized. 5. The transfusion should be administered with due care and adequate monitoring to ensure that the anticipated aims are achieved and any adverse effects are quickly noted and appropriate action instituted. Unfortunately, it is clearly impossible for all these criteria to be fulfilled with certainty. As with any form of therapy there is an element of uncertainty, and risk is acceptable if the potential gains are sufficient.

Postoperative Fibrinolysis

<h3>Abstract</h3> Gamma-irradiation of blood products is mandatory to avoid graft versus host disease in patients with immunosuppressed clinical conditions. Pathogen inactivation techniques were implemented to optimize safe blood component supply. The INTERCEPT treatment uses amotosalen together with UVA irradiation. The functional and molecular implications of these essential treatments have not yet been systematically assessed. The irradiation-induced inactivation of nucleic acids may actually be accompanied with modifications of chemically reactive polyunsaturated fatty acids, known to be important mediators of platelet functions. Thus, here we investigated eicosanoids and related fatty acids released upon treatment and during platelet storage for 7 days, complemented by the analysis of functional and metabolic consequences of these treatments. In contrast to gamma-irradiation, here we demonstrate that UVA treatment attenuated the formation of ALOX12-products such as 12-HETE and 12-HEPE but induced the formation of trans-arachidonic acids in addition to 11-HETE and HpODEs. Metabolic and functional issues like glucose consumption, lactate formation, platelet aggregation and clot firmness hardly differed between the two treatment groups. <i>In vitro</i> synthesis of trans-arachidonic acids (trans-AA) out of arachidonic acid in the presence of β-mercaptoethanol suggested that thiol radicals formed by UVA treatment are responsible for the INTERCEPT-specific effects observed in platelet concentrates. It is plausible to assume that trans-AA and other UVA-induced molecules may have specific biological effects on the recipients, which need to be addressed in future studies. <h3>Key points</h3> A previously unrecognized radical mechanisms for the generation of trans-fatty acids by UVA was identified Irradiation with UVA was found to immediately affect the generation of polyunsaturated fatty acid oxidation products