Basics of Blood Management - part 7 doc

BLUKO82-Seeber March 14, 2007 16:4 Blood Banking 233 Table 17.5 Methods of pathogen elimination or inactivation. Used for what kind of blood products Method Description Kills what and what not Pasteurization [PI] Liquid plasma kept at 60 ◦ Cfor>10 h, with a stabilizer added or lyophilized protein kept at 50–70 ◦ Cupto144h or at >80 ◦ C for 72 h Kills a wide range of enveloped and nonenveloped viruses Steaming [PI] 10 h at 60 ◦ C at 1160 mbar Solvent–detergent (SD) [PI] Alkyl phosphates and detergents added Kills viruses with lipid envelopes; does not kill viruses without envelopes (e.g., HAV, parvovirus B19), bacteria, prions Platelets, unfractionated and fractionated plasma (SD-FFP), tests in blood pools Irradiation [PI] With γ -rays or UV light Cold sterilization [PI] β -Propiolactone and UV light Alcohol fractionation [PI] Reduces viruses Leukocyte reduction [PE] Filtration step in blood production process Nanofiltration [PE] Filter retains viruses E.g., parvovirus B19 (Immunoaffinity) chromatography [PE] Keeps only proteins back, reduces viruses Methylene blue (MB) activated by natural light (= phenothiazine color) [PI] Binds to proteins and nucleic acids, activated by natural light, denaturalized bound molecules (may be cancerogenous) Kills retroviruses, herpes viruses, West Nile virus (lipid enveloped viruses); does not kill intracellular viruses, bacteria, prions MB-FFP, platelets; not used any more for coagulation proteins, not usable for red cells (light absorbed by red color), tests in single donor aliquots Psoralen (S-59) with ultraviolet A (UVA)-light exposure [PI] Inactivates HIV, HCV, bacteria, inactivates T-cells (GvHD) S-59-UVA-FFP, platelet concentrates Gentian violet [PI] In endemic regions, parasite reduction for Chagas disease (cave: side effects) [PI], pathogen inactivation; [PE], pathogen elimination; FFP, fresh frozen plasma; GvHD, graft-versus-host disease. Faults of the safety layers The above-mentioned safety layers are all designed to increase the safety of the blood supply. However, there are major flaws in each of them. The detection and exclusion of donors at risk for diseases that are not screened for depends on the honest cooperation of the donor. When donors do not provide a complete history, donors may be counted eligible for donation when in fact they are not. This may indeed be the case when prospective donors are ashamed of their behavior or have other reasons not to report truthfully, resulting in a dangerous underreporting [23]. In many countries, donors are paid and often make a living on donating their blood. They are aware that they are not eligible for blood donation if they reveal a fact that may group them as a high-risk donor and are therefore reluctant to report certain facts relevant for donor selection. Also,evermore sophisticated screeningtestsdonotpro- vide absolute safety. Tests are sometimes unreliable, par- ticularly when staff is inadequately trained or when test kits are in short supply, as is frequently the case in developing countries. In fact, a recent report of WHO states that about one in five donations in developing countries is not sufficiently tested for viral agents [15]. For most of the agents transmittable by transfusion, there is no effective tool for donor screening and sometimes not even for testing, e.g., for babesiosis [24]. BLUKO82-Seeber March 14, 2007 16:4 234 Chapter 17 International traffic brings new agents not detected by conventional screening methods. The same is true of new, variant retroviruses. And even when tests are available, they are not universally applied. For instance, tests for HAV, HEV, parvovirus B19, Chagas disease, and malaria are not routinely used in the United States [1, 25]. In many African countries, blood is not tested for HCV, despite a high prevalence in the blood supply [26]. Serological tests performed in the window period and in immunosilent donors also do not detect present infections. Pathogen inactivation and elimination as an alternative or addition to serological tests may take care of more pathogens than screening methods. However, it cannot be known with absolute confidence whether the employed methods eliminate or inactivate all pathogens. The ac- tion of the methods is tested with model pathogens that are thought to be representative for all other pathogens. This assumption, however, is probably not true. Another problem with pathogen inactivation is that even inactivated nucleic acid is able to integrate into the genome of the recipient and may cause cancer [27]. Blood storage Whole blood can be stored for 6–8 hours at room temperature. After this time, it has to be transfused, processed and cooled (Table 17.6), or discarded. It is recommended either to cool down whole blood immediately or to keep blood at room temperature for 5–6 hours before it is fractionated. If blood is stored immediately after donation in cool condition, coagulation factors are preserved. How- ever, if it is stored at room temperature for some hours after donation, bacteria that may have been in the blood Table 17.6 Storage conditions of blood products. Maximum length of storage Product Storage condition Cryoprecipitate and fresh frozen plasma −18 to −25 ◦ C< 3mo ≤25 ◦ C24mo Granulocytes No storage possible Platelets 20–24 ◦ C5days Red cells 2–6 ◦ C 35–49 days, depending on legislation and additive can be phagocyted by white cells. When blood is stored for more than 24 hours at room temperature, white cells disintegrate and bacteria are released again. Bacterial contamination Blood storage comes with two major disadvantages for the blood. First, it develops storage lesions, as discussed else- where in this book. Second, it can be contaminated with bacteria. Bacterial contamination of blood products poses serious threats to the blood supply. In fact, in developed countries, the risks through bacterial contamination are much greater than that of all transfusion-transmittable diseases taken together. Red blood cells, since they are stored in a cold en- vironment, are not likely to be significantly bacterially contaminated. Pathogens usually found in red cell concentrates can survive cold conditions and can multiply at lower temperature. Yersinia enterocolica, Serratia, and Pseudomonas are most commonly implicated pathogens. Up to 1:65,000 units were reported to contain Y. e nterocol- ica [16]. The exact incidence of bacterial contamination in developed countries, however, is not known. Variations were observed and may be due to underrecognition, underreporting, and regional variation. When red cells contaminated with bacteria are transfused, the transfusion is often lethal. More often, platelet concentrates are bacterially contaminated. Since they are stored at about 22 ◦ C, they provide ideal conditions for the multiplication of bacteria. Most often, platelet concentrates host skin germs, such as Staphylococcus epidermidis and Staphylococcus aureus, and Streptococcus spp. About 1 in 1000–3000 platelet units is bacterially contaminated [21, 28]. It is estimated that 1 in 4200 platelet transfusion events leads to septic compli- cations. Pooled platelets carry a higher risk for bacterial contamination, since more phlebotomies are needed to collect the platelets [28, 29], with more chances of intro- ducing bacteria into the final product. As well, stored autologous blood may bebacterially contaminated. It is even more likely to be bacterially contaminated, since the autologous units are not tested as rigor- ously as donated units and arestored longer, with maximal chance for bacterial growth. To prevent bacterial contamination, a thorough donor screening—to make sure that only healthy patients without bacteremia are donating—is the first step. Then, a strictly sterile phlebotomy is essential, since most of the germs in the donated blood are thought to enter the unit during the donation procedure. But the best disinfection BLUKO82-Seeber March 14, 2007 16:4 Blood Banking 235 methods do not prevent bacteria from entering the collection bag. A further measure for the reduction of bacterial contamination is predonation sampling. The first 10–20 mL of donated blood is let into another bag to be discarded since it contains the most bacteria. During blood storage, the few organisms introduced into the donated blood may multiply. Keeping up the cold chain reducessuch bacterial growth. However,itis difficult to store normal platelets in the cold, since they rapidly lose their viability and are thus removed from the human circulation quickly. Cold storage of platelets may still be possible, given the addition of protecting agents (DMSO, Thrombosol). Nevertheless, cold platelet storage is time- consumingandbrings toxic effectsto plateletsand patients [21]. The last step toward reduction of transfusion of bacterially contaminated blood is to detect bacterial contamination. Changes in pH, appearance of the unit, screening with Gram’s staining or fluorescent microscopy, microbiological detection methods (RNA probes), and automated culture systems have been employed in this regard. Monitoring the production of CO 2 or the reduction of oxygen in the unit—as it is caused by metabolism of growing bacteria—can be used in an automated fashion to detect bacteria in the units [30]. Many other technolo- gies have been developed to detect bacteria in blood [21]. Ideally, detection of bacteria in blood units is performed shortly beforetransfusion, sincedetection ismost sensitive at that point. Leukocyte reduction and depletion Another procedure performed during the storage of blood is leukocyte depletion. Controversy exists whether leukocyte depletion is better performed before or after storage. But it is generally agreed upon that a lower number of leukocytes in red cells or platelets comes with advantages. The amount of leukocytes in blood products differs. Whole blood contains 3 × 10 9 leukocytes per unit, buffy-coat removal reduces the leukocyte count to less than 2 × 10 8 and leukocyte depletion filtration to less than 5 × 10 6 [31]. Leukocyte depletion filtration removes not only necrotic leukocytes but also oxygen radicals, infection mediators, and pathogens (CMV, HTLV [1], and possibly prions causing variant Creutzfeldt–Jacob disease [16]). It seems to be valid that leukocyte reduction reduces CMV infection, febrile nonhemolytic transfusion reactions, and HLA (human leukocyte antigen) alloimmunization. Other immunological benefits of leukocyte reduction or depletion are suggested, but are not ac- cepted by all. These include a reduction of the danger of graft-versus-host reactions, reperfusion damage, alloimmunization, decreased nonresponsiveness to platelet transfusions, and impairment of red cell metabolism in stored blood. Some countries adopted a policy of universal leukocyte depletion, while others deplete leukocytes only in transfusions for patients at high risk for adverse effects [32]. Irradiation of blood products In special situations, blood is irradiated during storage. This is done to prevent viable lymphocytes to enter the recipient and to elicit GvHD. Irradiation damages the DNA of lymphocytes. All granulocyte concentrates are irradiated since they contain many lymphocytes. Other products are irradiated to prevent GvHD in susceptible individuals, among them transplant recipients and babies who undergo intrauterine transfusions. From whole blood to cellular components Apart from apheresis donations, all donated blood is whole blood collected in an anticoagulant. Developing countries transfuse 37–75% of the donated blood as whole blood. In developed countries, only about16%of all transfusions are whole blood transfusions [15]. Most whole blood donations in developed countries are therefore not used for immediate transfusion, but are simply the raw material for the production of blood products. The basic method to separate whole blood is differential centrifugation. After centrifugation, the cells are found in layers according to their density: red cells, white cells, platelets, plasma. The simplest way to separate whole blood is to divide it into cells and plasma (e.g., in a system with two blood bags). Plasma is frozen immediately after donation (−30 ◦ C) to maintain the maximum possible coagulation factor activity. The cellular part of this centrifugation is called erythrocyte concentrate. Granted, white cells and platelets are also in the cellular compartment. However, they are mostly inactivated during storage. A more sophisticated way to separate blood is to divide it into three parts: red cells, plasma, and the buffy coat. Buffy coat is the layer that contains white cells and platelets. This is done since buffy coat causes many of the unwanted effects of transfusion. Dividing whole blood in three parts is also performed by differential centrifugation using a three-bag-system. After centrifugation, the upper BLUKO82-Seeber March 14, 2007 16:4 236 Chapter 17 layer (plasma) is transferred into the first bag and then the buffy coat (containing about 70% white cells, 90% platelets, and 10% red cells) is transferred into the second bag. The remaining red cells in the third bag constitute the red cell concentrate. Additives Donated blood, as well as certain blood products, contains additives. They are needed to prevent coagulation and to prolong storage time. The obviously most important additive for blood donation is an anticoagulant. Modern anticoagulants contain not only an anticoagulating principle but also compounds that provide metabolic substrates for cell metabolism. Formerly, ACD (acidum citricum, sodium citrate, dextrose) was used. ACD red cells can be stored up to 21 days. Another anticoagulant, CPD (citrate, phosphate, and dextrose), is also available. The phosphate is added to buffer the lactate that develops during metabolism of stored red cells. It is also possible to add purine nu- cleotides, such as adenine, to the anticoagulant (CPD-A). They aid in the synthesis of ATP and 2,3-DPG and prolong the viability of thered cells. The standard anticoagulant for collection of whole blood, today, is CPD-A. This solution allows for whole blood storage up to 35 days. Red cell concentrates can also be stored in special additives, such as SAG-M (sodium, adenine, glucose, mannitol), PAGGS-sorbit (phosphate, adenine, guanosine, glucose, sorbit), Adsol or AS-3. These solutions may allow storage of red cells for up to 49 days. The solutions contain sodium chloride, glucose derivatives, adenine, mannitol, and other ingredients. Red cell concentrates in additive solutions contain less isoagglutinins than red cell concentrates resuspended in plasma. There are also additives for platelets. These include different so-called platelet additive solutions and Composol. While the solutions are perceived to have some advantages (e.g., making washing and prolonged storage of platelets possible), they seem to impair the functionality of stored platelets [33, 34]. Red cell concentrates There are different kinds of red cell concentrates. They are sourced either from whole blood donations or are gained by an apheresis procedure. Red cell concentrates made by apheresis come with relatively stable red cell content, with interunit variation of only 6%.In contrast, red cellconcen- trates made from whole blood donations vary widely in their content of red cells, with up to twofold variations [35]. The crudest red cell concentrates are made from whole blood donations and simply contain the cellular portion of centrifuged blood including white cells and platelets.Otherred cell concentrates from wholeblood donations are buffy-coat-free, that is, with reduced amounts of white cells and platelets. Leukocyte depletion filtration of red cell concentrates further reduces the amount of leukocytes in the unit. Efforts are under way to stan- dardize red cell concentrates and to reduce the variabil- ity of the contents. It was proposed that a single unit of red cells should be delivered with 50 g hemoglobin and in additive solutions that may be able to reduce storage lesions [36]. Red cell concentrates contain residues of plasma and plasma proteins, including antibodies. Sometimes, the amount of plasma in red cell concentrates is reduced by diluting the red cells in additive solution rather than in plasma. When patients react allergically to foreign proteins or when the presence of plasma proteins (antibodies) may be detrimental, red cell concentrates can also be washed with saline to remove almost all plasma. Last but not least, red cells can also be treated so that their antigens are disguised, presumably making red cell concentrate transfusions blood group independent. Red cell concentrates are usually stored at low temperature, namely, normal refrigerator temperature (4 ◦ C). This temperature reduces the metabolic rate of the red cells and possible bacterial growth. On the other hand, freezing must be prevented which would lead to hemolysis of the red cells. Nevertheless, despite improved storage conditions, red cells suffer storage lesions [37]. After some days of storage, the oxygen dissociation curve is shifted to the left and red cells cannot easily release oxygen. Depend- ing on the storage time, red cells tend to aggregate and to form stacks, called “rouleau” formation [38]. Changes of the red cell membrane occur during storage as well. The membrane loses lipids and finally the cell becomes stiff and spherocytic. Besides, new antigens may be expressed on the membrane during storage [39]. So, compatibility testing performed before storage may no longer be valid after storage. Platelet concentrates Platelet concentrates come in two different forms: random donor platelets, which are pooled from four to eight whole blood donations, and single donor apheresis platelets. Random donor platelet concentrates contain a minimum of 5.5 × 10 10 platelets per unit in the pool and BLUKO82-Seeber March 14, 2007 16:4 Blood Banking 237 have a volume of about 150–450 mL. The random donor platelet concentrate can be made either from platelet-rich plasma (PRP-platelets) or by centrifugation of the buffy coat (BC-platelets). For the BC-platelets, the buffy coat gained through standard centrifugation of blood is resuspended in plasma. This is stored for some hours while it is rocked, increasing the amount of platelets gained. Afterward, the mix is centrifuged (“soft spin”) and the platelet and plasma are used, while the leukocytes are discarded. As an alternative, buffy coats can also be pooled, mixed with plasma or an additive, and then centrifuged. For PRP-platelets, whole blood is first centrifuged slowly so that platelet-rich plasma separates from the red cells. After transfer of this platelet-rich plasma, it is spun again to separate plasma from platelets. Single donor platelet units are made by apheresis. The minimum of platelets is 3 × 10 11 platelets [40] in a volume of 150–300 mL. The yield of apheresis depends on the donor andon themethodused. Oneto three unitsof donor platelets can be obtained from one donor, depending on his/her initial platelet count. Pooled platelet concentrates and apheresis platelets may be therapeutically equivalent and may have a similar pattern of side effects [41]. However, this is not universally agreed upon [42]. It was claimed that apheresis platelets are better preserved than platelet concentrates made from whole blood. A significant difference between apheresis and random donor platelets is that transfusion of a unit of pooled platelets leads to a higher donor exposure than single-donor platelets. Storage of platelet concentrates occurs at room temperature (about 22 ◦ C) under gentle agitation. The length of platelet storage depends on the container and the method of collection and processing. A closed system can store platelets for up to 5 days, whereas an open system (e.g., for washing and resuspension of platelets in platelet suspension medium) typically can store platelets for 24 hours only [41]. During storage, some platelet concentrates undergo special treatment. Some units are split or hyperconcentrated for intrauterine or neonatal use. Some units are irradiated or leukocyte-depleted. After collection and during storage, several steps of quality control of platelet concentrates are indicated. Which these are and how they are performed depend on the legislation and the money available. Platelets should be tested for microbial contamination (serological tests, NAT) and red cell serological tests are performed (blood group, etc). Visual inspection for any abnormalities (tur- bidity, color changes, damaged container, excessive air, etc.) prior to issue of the platelet unit is usually standard. The pH of the platelet concentrates must be between 6.4 and 7.4 [41]. During storage, platelets gain their energy in metabolic processes thatproduce CO 2 and H 2 CO 3 . This leads to a decrease of the pH. To counteract this, bags with increased gas permeability are used and the bag design is changed to a better concentrate–surface ratio. Additive solutions for platelets may come with benefits and may even allow for cold storage. To reduce pathogens in the platelet concentrate, agents may be added. Photoin- activation of viruses and bacteria may be possible when methylene blue is added (MB-platelets). Also, solvent– detergent methods were described as a means to inactivate pathogens intheplatelet concentrate(SD-platelets). How- ever, there are not yet enough experiences with pathogen- inactivated platelets. Granulocytes Collection ofgranulocytes isdifficult.The normal amount of circulating granulocytes is 30 × 10 7 /kg. For therapy, a daily dose of more than 15 × 10 7 /kg is recommended. Therefore, special measures must be taken to obtain a significant amount of granulocytes. Either the buffy coats of several donations are pooled or a single donor is prepared specifically to donate granulocytes by apheresis. The blood of patients with chronic lymphatic leukemia circles enough granulocytes toprovide forthedonation.Such patients are sometimes asked to donate. More often, though, donors are asked to take prednisone or they are administered granulocyte colony-stimulating factor. In order for a donor to donate sufficient amounts, daily donations or alternate day donations are requested. This reduces the risk of multiple donor exposure for the patient, but puts the donor at risk [43]. This shows that granulocyte donations are problematic. They are rarely prescribed. When they are given, they are given ABO and RhD compatible, since they contain many red cells [43]. Granulocyte concentrates cannot be stored and are therefore prepared for immediate transfusion. They should be transfused within 6 (–24) hours after donation. Fresh frozen plasma Fresh frozen plasma (FFP) is plasma that is derived from one unit of donated blood by centrifugation. It is frozen to at least −18 ◦ C within 8 hours after donation. When thawed, it can be kept refrigerated for up to 24 hours [40] before use. Storage in the frozen state is needed to prevent rapid loss of the coagulation factor activity which would BLUKO82-Seeber March 14, 2007 16:4 238 Chapter 17 occur within hours after storage at room temperature. In some countries, standard FFPs are held in quarantine for 4 months, since they are allowed to be infused only after the next donation when the donor presents healthy. Some countries also provide plasma units derived from pooled plasma and are treated with solvent–detergent (SD-FFP) or methylene blue (MB-FFP) to reduce viral transmission. It is not necessary to keep such plasma under quarantine. Plasma fractionation Plasma is a mix of thousands of compounds, is unique for every individual, and differs in the individual over time, sometimes even changing within minutes. Plasma isthus a most heterogenous and volatile liquid.Wholeplasmaused for therapeutic reasons consists mostly of compounds not really needed for therapeutic use. Transfusing whole plasma comes, therefore, with avoidable dangers and is often a waste of resources. Therefore, dividing plasma into different compounds (fractionation) makes sense. Frac- tionation saves resources, reduces risks for the recipient, and increases the financial gain for the manufacturer of the blood product. Commercially available plasma fractions are produced by fractionation of pools of source plasma, consisting of thousands of plasma portions from different donors. Plasma for fractionation is collected either by centrifugation of whole blood donations or by plasma apheresis. Apheresis plasma is often preferred. It is collected commercially and several blood tests are not required for apheresis plasma (e.g., tests for intracellular pathogens). Methods to fractionate plasma Fractionation makes use of different properties of plasma constituents. Differences in hydrophilia, size, sedimenta- tion behavior, affinity to specific media, and movement in electrophoresis are starting points for fractionation. precipitation When certain salts (sodium chlorate, sodium sulfate), organic solvents (alcohol), metal ions (calcium, magne- sium), polymers (polyethylene glycol), fatty acids (capry- lat), or other acids are added to plasma, some plasma protein monomers aggregate. The aggregates are heavier than the rest of the plasma and sink to the bottom of the vessel. The aggregates can beremoved from theplasmapool. Care must be taken that the proteins are not denaturized during precipitation and that the precipitating agents are easily removable after the precipitation process is finished. The prototype of the use of precipitation is the famous Cohn’s fractionation see below [6, 7]. Precipitation is used by industry to divide plasma into different crude parts or to concentrate a certain protein or a group of proteins in a solution. A combination of different precipitating compounds is used to receive a product that has a relatively high concentration of the needed protein. It is not possible, however, to purify a protein through precipitation only. Crystallization is a special form of precipitation. It leads to very pure proteins, since not much of the mother liquid is included in the protein crystals. However, the time needed to crystallize plasma proteins does not make this method suitable for industrial mass production of plasma fractions. chromatography The term chromatography refers to a variety of physical methods to separate complex mixtures such as plasma. The components to be separated are distributed between two phases: a stationary phase and a mobile phase, which percolates through the stationary phase. One important kind of chromatography ision exchange chromatography. Anions or cations bound to a matrix (stationary phase) bind proteins that are either cations or anions, respectively. When plasma is brought into con- tact with the matrix, proteins with certain acidic or basic groups (e.g., gamma-carboxyl groups of prothrombin complex proteins) are bound to the ions on the matrix, while other proteins are not. After flushing plasma that is not bound to the matrix, the proteins on the matrix are released and used. It is even possible to release the proteins on the matrix in afractionated fashion, so thattheproteins are further purified. With ion exchange chromatography, proteins are handled very gently. Gel chromatography can be used to separate proteins according to their size. Porous molecules with different pore sizes are used to retain small molecules in the pores and to have bigger molecules travel through. Gel chromatography is often used to remove small contaminating molecules from a blood product. Affinity chromatography is a relatively new, yet very often used, method to fractionate plasma. It uses specific interactions of proteins with a ligand bound to a matrix. Such interactions can be determined by natural transport properties (e.g., vitamin B 12 is usedas ligandand binds vitamin B 12 -binding globulin), enzyme–substrate- or enzyme–inhibitor relations, or antigen–antibody interactions. Affinity chromatography is especially used to BLUKO82-Seeber March 14, 2007 16:4 Blood Banking 239 Whole plasma thawed, centrifuged cryoprecipitate (rich in FVIII, fibrinogen, fibronectin) ethanol precipitation up to 8% Cohn's fraction I (rich in prothrombin complex, C1-inhibitor, fibrinogen, FXIII) Remaining plasma ethanol precipitation up to 25% Cohn's fraction II/ III (rich in ATIII, IgG) Remaining plasma ethanol precipitation up to 40%, pH 5.8 Cohn's fraction IV Remaining plasma ethanol precipitation with 40%, pH 4.8 Cohn's fraction V (rich in albumin) Remaining plasma Cryo-poor plasma Fig 17.1 Cohn’s fractionation. gain proteins out of the plasma that are present in very low concentrations only. Production of blood fractions Plasma can be fractionated in many different ways. Since source plasma is expensive, industrial fractionation tries to use as many plasma proteins of the source plasma as possible. The methods by which this is done differ and depend on the proteins needed and the manufacturer’s preference. Today’s fractionation still resembles the fractionation proposed by Cohn in 1940. In a stepwise approach, plasma is first divided into crude fractions. Later, the crude fractions may be used therapeutically (e.g., cryoprecipitate) or serve as the basis for the production of even purer plasma proteins. An example of Cohn’s fractionation is shown in Fig. 17.1. Based on this classical fractionation model of Cohn, many different plasma products can be produced. Consider the following example shown in Fig. 17.2 [44]. Interaction between blood banks and clinicians Blood banks provide the clinicians with valuable information for transfusion therapy [45]. The most often requested information is that about blood groups and blood compatibility, as determined by the type and screen (T&S) as well as by the type and cross-match (T&C). A T&S determines the ABO and rhesus blood groups of the patient’s red cells (typing), and the patient’s serum Purified PCC Virus-removed PCC solid phase extraction with anion-exchange resin (matrix, Sephadex; ligand, DEHE) solvent–detergent treatment chromatography removes solvent–detergent reagents and some proteases nanofiltration formulation, sterile filtration, freezing Final PCC Starting material: cryo-poor plasma Virus-inactivated PCC Protein C, S, FII, VII, IX, X bind to the resin and are removed afterward = PCC Fig 17.2 Fractionation of a prothrombin complex concentrate (PCC). BLUKO82-Seeber March 14, 2007 16:4 240 Chapter 17 is screened for the presence of unexpected antibodies (screening) by incubating it with selected reagent red cells (screen cells). Screen cells have a known antigenic makeup and are selected in a way so that all common red cell antigens capable of inducing clinically significant red cell antibody reactions are present. If the antibody screen is pos- itive, the unexpected antibody must be identified before antigen-negative compatible red cells can be located. This usually takes several hours. A T&C includes not only typing of the cells but also cross-matching the patient’s blood with a specific unit of blood. In a cross-match, the patient’s serum is incu- bated with red cells from a specific donor unit to verify in vitro compatibility. A cross-match is performed either as a short (immediate spin) incubation intended solely to verify ABO compatibility or as a long incubation to verify compatibility with other red cell antigens. The immediate spin cross-match takes 5–10 minutes, while the long incubation takes at least 45 minutes. Blood banks play an important role not only in deter- mining the blood group of patients and test compatibility of patient blood and transfused blood but also in the detection of autoantibodies and alloantibodies. For a blood manager, this is important to treat hemolytic anemia and difficult pregnancies. Such information is vital to avoid hemolytic diseases in the newborn. Maximum blood order schedule A maximum blood order schedule is a table of elective procedures that lists whether a T&S is called for or how many units of blood are typically ordered. This schedule helps to limit needless cross-matching and to manage the stock of blood more effectively. A maximum blood order schedule is developed by retrospectively analyzing how much blood is typically transfused (T) in patients undergoing a certain procedure and how much blood is typically cross-matched for the procedures (C). The C/T ratio tells how effectively blood is ordered. The ideal ratio is 1.0; a realistic one is 2–3. The higher the value, the more blood is cross-matched unnecessarily. When more than two units are cross-matched on average for one unit actually transfused, the schedule needs to be revised [46]. A T&C is acceptable if there is at least 10% chance for the patient to getatransfusion. The number of units cross- matched should be chosen so that 90% of patients have sufficient units available. In locations where regularly sufficient blood is available, a T&C may only be ordered when transfusion is actually administered. A T&S is usually ordered whenthere is onlyasmallchance of transfusion. The procedures for which it is ordered depend on the anxiety level of the surgeon and his/her confidence in the blood bank to supply what he/she calls for in case of extreme emergency. Hospital transfusion committee A place where blood banks and clinicians meet is the hospital transfusion committee. This committee is the exten- sion of the national hemovigilance system and corrobo- rates policies and guidelines advocated by national and hospital standards. In detail, the hospital-based transfusion committees review the transfusion practice in the hospital, develop and implement quality assessment procedures, and try to improve patient care through specific in-service education. It also investigates transfusion reactions and, when indicated, files reports. Besides, the committee helps to conserve blood components and reduce costs. Key points r Layers of blood safety include (1) donor education, (2) selection and deferral, (3) postdonation product quarantine, (4) a national vigilance system, and (5) blood- related procedures, namely, screening and pathogen reduction or inactivation. r The layers of blood transfusion safety are endangered by missing donor honesty, insufficient screening for transfusion-transmittable infections, and unsatisfactory pathogen reduction and elimination. r Blood storage introduces further problems into the blood pool. Bacterial contamination and storage lesions seem to be the most important. r Blood is rarely transfused as whole blood. Rather, it is divided into its cellular components and plasma. Plasma is further divided into plasma fractions. This allows for a targeted therapy. r Blood bank personnel are a valuable source of information for a blood manager. Questions for review r What are the safety layers of blood safety? What flaws do they have? BLUKO82-Seeber March 14, 2007 16:4 Blood Banking 241 r What is the difference between pathogen reduction and pathogen inactivation? What agents and methods are used for these processes and what are their limitations? r What is a blood fraction? r What is Cohn’s fractionation and how is it performed? r Explain the following terms: type and screen, type and cross-match, hemovigilance, maximum blood order schedule, postdonation product quarantine. Suggestions for further research How are blood banks networking internationally? What are the politics about this business? Read more about the blood business. A good starting point is Gilbert M. Gaul’s series on the blood business, which was published in 1989 in the Philadelphia Inquirer. Many more articles can be found on the Web. Homework Visit a place where platelet concentrates aremade and have somebody explain how it works. Go to the hospital blood bank and find out what steps are required in releasing a unit of blood for a patient. Check the status of the national blood transfusion system, including the following: r Who is the highest responsible person or organization for transfusion safety? r Who is there to do the actual work of blood transfusion service? r What measures are taken to control the facilities that provide blood? r What is the percentage of donors who are voluntary, nonremunerated? r What tests are regularly performed on all blood products? r What monitoring systems are there for adverse effects of transfusions and for the appearance of pathogens in blood? Exercises and practice cases You are presented with the following numbers. What does your maximum blood-ordering schedule look like? Number of Type of surgery Cross-matches patients (number of times preformed transfused performed during during the during the the last 12 mo) last 12 mo last 12 mo Appendectomy (126) 16 1 Cholecystectomy (54) 36 3 Gastrectomy (14) 14 5 Hip replacement (22) 21 8 Coronary artery bypass graft (54) 54 16 Meningeoma resection (8) 71 Prostatectomy (abdominal) (30) 30 10 References 1 Pomper, G.J., Y. Wu, and E.L. Snyder. Risks of transfusion- transmitted infections:2003. Curr OpinHematol,2003. 10(6): p. 412–418. 2 European Parliament and the Council. Directive 2002/98/EC 27 January 2003. OJEU, 2003. p. L 33/30. 3 Huestis, D.W.Russia’sNational Research Center for Hematol- ogy: itsrolein thedevelopment of blood banking. Transfusion, 2002. 42(4): p. 490–494. 4 Fantus, B. Therapy of the Cook County Hospital (blood preservation). JAMA, 1937. 109: p. 128–132. 5 Starr,D. Medicine, money, andmyth: anepic history ofblood. Transfus Med, 2001. 11(2): p. 119–121. 6 Cohn, E.J., et al. 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Turner.Managing therisk oftransmis- sion of variant Creutzfeldt Jakob disease by blood products. Br J Haematol, 2006. 132(1): p. 13–24. BLUKO82-Seeber March 14, 2007 16:4 242 Chapter 17 11 Rock, G., et al. Automated collection of blood components: their storage and transfusion. Transfus Med, 2003. 13(4): p. 219–225. 12 Klein,H.G. Willblood transfusionever be safeenough? Trans- fus Med, 2001. 11(2): p. 122–124. 13 Busch, M., et al. Oversight and monitoring of blood safety in the United States. Vox Sang, 1999. 77(2): p. 67–76. 14 Linden, J.V. and G.B. Schmidt. An overview of state efforts to improve transfusion medicine. The New York state model. Arch Pathol Lab Med, 1999. 123(6): p. 482–485. 15 WHO Blood transfusion safety and clinical technology, S., Blood Transfusion Safety: Information Sheet for National Blood Programmes. Available at www.who.int. 16 Uhl, L. Infectious risks of blood transfusion. Curr Hematol Rep, 2002. 1(2): p. 156–162. 17 Pelletier, J.P., S. Transue, and E.L. Snyder. Pathogen inactivation techniques. Best Pract Res Clin Haematol, 2006. 19(1): p. 205–242. 18 Fischer, G., W.K. Hoots, and C.Abrams. Viral reduction techniques: types and purpose. Transfus Med Rev, 2001. 15(2, Suppl 1): p. 27–39. 19 Pamphilon, D. Viral inactivation of fresh frozen plasma. Br J Haematol, 2000. 109(4): p. 680–693. 20 Roback, J.D., et al. The Role of photochemical treatment with amotosalen and UV-A light in the prevention of transfusion- transmitted cytomegalovirus infections. Transfus Med Rev, 2006. 20(1): p. 45–56. 21 Palavecino, E. and R. Yomtovian. Risk and prevention of transfusion-related sepsis. Curr Opin Hematol, 2003. 10(6): p. 434–439. 22 Caspari, G., et al. Pathogen inactivtion of cellular blood products – more security for the patients or less? Transfus Med Hemother, 2003. 30: p. 261–263. 23 Fielding, R., T.H. Lam, and A. Hedley. Risk-behavior reporting by blood donors with an automated telephone system. Transfusion, 2006. 46(2): p. 289–297. 24 Leiby, D.A. Babesiosisand blood transfusion: flying under the radar. Vox Sang, 2006. 90(3): p. 157–165. 25 Becker, J.L. Vector-borne illnesses and the safety of the blood supply. Curr Hematol Rep, 2003. 2(6): p. 511–517. 26 Imarengiaye, C.O., et al. Risk of transfusion-transmitted hep- atitis C virus in a tertiary hospital in Nigeria. Public Health, 2006. 120(3): p. 274–278. 27 Mueller-Eckhardt, C. and V. Kiefel. Transfusionsmedizin,3rd edn. Springer-Verlag, Heidelberg, 2004. 28 Goodnough, L.T. Risks of blood transfusion. Crit Care Med, 2003. 31(12, Suppl): p. S678–S686. 29 Walther-Wenke, G., et al. Bacterial contamination of platelet concentrates prepared by different methods: results of stan- dardized sterility testing in Germany. Vox Sang, 2006. 90(3): p. 177–182. 30 Fournier-Wirth, C., et al. Evaluation of the enhanced bacterial detection system for screening of contaminated platelets. Transfusion, 2006. 46(2): p. 220–224. 31 Innerhofer, p. and G. K ¨ uhbacher. Immunomodulation mechanisms following transfusion of allogeneic and autologous erythrocyte concentrates. Infus TherTransfus Med, 2002. 29: p. 118–121. 32 Heddle, N.M. Evidence-based clinical reporting: a need for improvement. Transfusion, 2002. 42(9): p. 1106–1110. 33 Keuren, J.F., et al. Platelet ADP response deteriorates in syn- thetic storage media. Transfusion, 2006. 46(2): p. 204–212. 34 Ringwald, J., et al. Washing platelets with new additive solutions: aspects on the in vitro quality after 48 hours of storage. Transfusion, 2006. 46(2): p. 236–243. 35 Sweeney, J.D.Standardization of the red cell product. Transfus Apher Sci, 2006. 34(2): p. 213–218. 36 Hogman, C.F. and H.T. Meryman. Red blood cells intended for transfusion: quality criteria revisited. Transfusion, 2006. 46(1): p. 137–142. 37 Ho, J., W.J. Sibbald, and I.H. Chin-Yee. Effects of storage on efficacy of red cell transfusion: when is it not safe? Crit Care Med, 2003. 31(12, Suppl): p. S687–S697. 38 Hessel, E. and D. Lerche. Cell surface alterations during blood-storage characterized by artificial aggregation of washed red blood cells. Vox Sang, 1985. 49(2): p. 86–91. 39 Krugluger, W., M. Koller, and p. Hopmeier. Development of a carbohydrate antigen during storage of red cells. Transfusion, 1994. 34(6): p. 496–500. 40 Fritsma, M.G. Use of blood products and factor concentrates for coagulation therapy. Clin Lab Sci, 2003. 16(2): p. 115–119. 41 British Committee for Standards in Haematology. Guidelines for the use of platelet transfusions. Br J Haematol, 2003. 122: p. 10–23. 42 Arnold, D.M., et al. In vivo recovery and survival of apheresis and whole blood-derived platelets: a paired comparison in healthy volunteers. Transfusion, 2006. 46(2): p. 257–264. 43 Yeghen, T. and S. Devereux. Granulocyte transfusion: a review. Vox Sang, 2001. 81(2): p. 87–92. 44 Josic, D., L. Hoffer, and A. Buchacher. Preparation of vitamin K-dependent proteins, such as clotting factors II, VII, IX and X and clotting inhibitor protein C. J Chromatogr B Analyt Technol Biomed Life Sci, 2003. 790(1–2): p. 183–197. 45 Yazer, M.H. The blood bank “black box” debunked: pretransfusion testing explained. CMAJ, 2006. 174(1): p. 29–32. 46 Napier, J.A.F., et al. Guidelines for implementation of a maximum surgical blood order schedule. ClinLab Haematol, 1990. 12: p. 321–327. [...]... cell saver (intra- and postoperatively) 261 Homework r r r Find out who is in charge of blood transfusion risk management and quality assurance at your hospital and ask for an opinion on blood management Explain the risks and benefits of blood transfusion and appropriate blood management procedures to a patient Find a reliable source from which to figure out the risks of infection with blood- borne diseases... Immunomodulation r Progression of HIV Not indicated r Prevention of TA-GvHD r In noncellular blood components such as FFP, cryoprecipitate and blood products prepared from pooled blood Key points r Stored allogeneic blood products are unpredictable in use and most of the ingredients are unknown r Medical decision-making is often made using the mnemonic BRAND ◦ Benefits of transfusions: Decades of research in the... risk of TTIs (see the chapter on blood banking) A clinician must rely on the blood bank for appropriately tested blood and cannot do much to reduce the incidence of TTIs per given unit However, the clinician is in the unique position of being able to reduce the incidence of TTIs calculated per patient Skilful blood management can considerably reduce the amount of blood transfused and the number of patients... The implications of blood transfusions for patients with non-ST-segment elevation acute coronary syn- 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 dromes: results from the CRUSADE National Quality Improvement Initiative J Am Coll Cardiol, 2005 46(8): p 1490– 1495 Blair, S.D., et al Effect of early blood transfusion on gastrointestinal haemorrhage Br J Surg, 1986 73 (10): p 78 3 78 5 Marik, P.E and... following partial exchange transfusion in the polycythemic newborn: a systematic review Arch Dis Child Fetal Neonatal Ed, September 20, 2005 59 Yamada, S., et al History of blood transfusion before 1990 is a risk factor for stroke and cardiovascular diseases: the Japan 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 263 Collaborative Cohort Study (JACC Study) Cerebrovasc Dis, 2005 20(3): p 164– 171 Yamada,... identification of risk factors for wound infection after lower extremity oncologic surgery Ann Surg Oncol, 2003 10 (7) : p 77 8 78 2 Innerhofer, P., et al Risk for postoperative infection after transfusion of white blood cell-filtered allogeneic or autologous blood components in orthopedic patients undergoing primary arthroplasty Transfusion, 2005 45(1): p 103–110 Sauaia, A., et al Autologous blood transfusion... 2000 95(8): p 270 9– 271 4 78 Dzik, W.H Microchimerism after transfusion: the spectrum from GVHD to alloimmunization Transfus Sci, 1995 16(2): p 1 07 108 79 Lee, T.H., et al Survival of donor leukocyte subpopulations in immunocompetent transfusion recipients: frequent longterm microchimerism in severe trauma patients Blood, 1999 93(9): p 31 27 3139 80 Lee, T.H., et al High-level long-term white blood cell... further purpose of this chapter is to help clinicians see why adjustment of current practice toward a more outcome-oriented approach to the medical use of blood, that is, blood management, is needed Objectives of this chapter 1 Describe what is known about the benefits of allogeneic transfusions 2 List different methods used to define a “transfusion trigger” and state the limitations of such 3 Explain... and increase interleukin-8 Hepatogastroenterology, 2001 48(42): p 1669–1 674 54 Apostolidis, S.A., et al Effect of ranitidine on healing of normal and transfusion-suppressed experimental anastomoses Tech Coloproctol, 2004 8(Suppl 1): p s104–s1 07 55 Collard, K.J Is there a causal relationship between the receipt of blood transfusions and the development of chronic lung disease of prematurity? Med Hypotheses,... the part of the physician to reduce the incidence of bacterially contaminated transfusions The simplest way to reduce bacteria transfusion is to avoid transfusions If this is not desired, pretransfusion inspection of the blood component for signs indicative of bacterial contamination, adherence to preset storage times and re-warming periods and sterile handling of blood aid in reducing the incidence of . implementation of a maximum surgical blood order schedule. ClinLab Haematol, 1990. 12: p. 321–3 27. BLUKO82-Seeber March 14, 20 07 17: 7 18 Transfusions. Part I: cellular components and plasma Medical use of. whole blood to cellular components Apart from apheresis donations, all donated blood is whole blood collected in an anticoagulant. Developing countries transfuse 37 75 % of the donated blood as. 1 57 165. 25 Becker, J.L. Vector-borne illnesses and the safety of the blood supply. Curr Hematol Rep, 2003. 2(6): p. 511–5 17. 26 Imarengiaye, C.O., et al. Risk of transfusion-transmitted hep- atitis

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