Immunohematology Exam 5

Directed donations

The public's concern for the safety of the blood supply led to demands from potential recipients to choose their own donors. Although no substantial evidence exists that directed donations provide safer blood than allogeneic donations, most blood centers and hospitals participate in a directed-donor program. Donor requirements and testing must meet the same criteria as allogeneic donations. The donor collection, health history, and testing requirements are the same for directed donors as for routine blood donors. Policies regarding crossover to the general patient population, determination of the ABO phenotype before collection, additional fees, and time for unit availability vary among institutions. The 56-day interval between donations may be waived with the medical director's approval. Pretransfusion testing for directed donations follows the same protocols as allogeneic donations.

autologous donors

A voluntary donation of blood for use by the general patient population is called allogeneic. Any donation of blood reserved for the donor's own use at a later time is considered an autologous donation. Risk of disease transmission, transfusion reactions, or alloimmunization to RBCs, platelets, white blood cells, or plasma proteins is significantly reduced. Requirements for autologous donors are significantly different from the requirements for allogeneic donors and are described in the following section. Three general types of autologous procedures exist: preoperative collection, normovolemic hemodilution, and blood recovery. Preoperative autologous donation is the most common and necessitates careful tracking and handling to ensure units are available for surgery.

Hgb and Hct determination

Blood for the hemoglobin or hematocrit test is obtained from venipuncture or finger stick. For whole blood donation, recent FDA guidelines require that males have a minimum hemoglobin level of 13 g/dL (130 g/L) or minimum hematocrit of 39%. The minimum hemoglobin level will remain at 12.5 g/dL (125 g/L) or the minimum hematocrit is 38% for females. However, a variance will be possible for female donors to be permitted to donate at 12.0 g/dL if additional steps are taken to assure donor safety. This requirement ensures a sufficient hemoglobin level to allow the removal of a maximum of 525 mL, including samples drawn for testing, without harming the donor.

malaria screening

Blood is not tested for certain diseases, such as malaria and CJD; therefore questions regarding exposure and travel are important for screening purposes Plasmodium genus Malaria and prions screening is solely dependent on donor questioning, which determines acceptability or exclusion.

arm prep and venipuncture

Blood is usually drawn from the antecubital area. After an appropriate vein has been selected, the skin needs to be prepared for the venipuncture. Skin cannot be sterilized, but several methods are acceptable for disinfecting the drawing site. The venipuncture site is scrubbed with a 0.7% aqueous scrub solution of iodophor compound to remove surface dirt and bacteria and begin germicidal action. Next, a preparation solution of 10% povidone-iodine is applied, beginning at the intended venipuncture site and continuing outward in a concentric spiral. The area is allowed to air-dry for 30 seconds before being covered with sterile gauze. For donors sensitive to these solutions, another method should be designated by the blood bank physician, such as chlorhexidine (ChloraPrep 2%) and 70% isopropyl alcohol A tourniquet or blood pressure cuff inflated to 40 to 60 mm Hg makes the vein more prominent for venipuncture. A 16-gauge needle attached to a primary blood bag is inserted into a large, firm vein free of skin lesions. The usual donation time for a unit of whole blood is 8 to 12 minutes. Units requiring more than 15 minutes draw time may not be suitable for the preparation of platelets, fresh frozen plasma (FFP), or cryoprecipitated antihemophilic factor (CRYO). Frequent mixing of the blood during donation with the anticoagulant/preservative in the bag is critical to avoid blood clots and can be performed manually or with a mechanical mixing device. A balance system or electronic scale is used to monitor the volume of blood drawn. Either before or after donation, two to four specimen tubes used for testing, along with the segments, are filled before the needle is removed. After the needle is removed, pressure is applied to the venipuncture site over the gauze and the arm is elevated (elbow straight). The needle is disposed of in an appropriate biohazard container

Table 13.5 Temporary deferrals

Deferral Time = 2 weeks Reason for deferral = Measles (rubeola) vaccine Mumps vaccine Polio (oral) vaccine Typhoid (oral) vaccine Yellow fever vaccine Deferral Time = 4 weeks Reason for deferral = Varicella-zoster (chickenpox) vaccine German measles (rubella) vaccine Deferral Time = 6 weeks Reason for deferral = Conclusion of pregnancy Deferral Time = 12 months Reason for deferral = - Tattoos or permanent makeup (unless applied by a state-regulated facility with sterile needles and ink that is not reused) - Mucous membrane or skin penetration exposure to blood - Sexual contact with an individual at high risk for HIV - Incarceration in a correctional institution for >72 hr - Completion of therapy for syphilis - Transfusion of blood, components, human tissue, plasma-derived clotting factor concentrates - Human diploid cell-rabies vaccine after animal bite

Fresh Frozen Plasma

Fresh Frozen Plasma (FFP), Plasma Frozen within 24 Hours of Phlebotomy (PF24) Indications for Use FFP contains all the coagulation factors, including the labile factors V and VIII, which do not store well at temperatures greater than −18° C PF24 may have reduced levels of factors V and VIII compared with FFP. FFP and PF24 are indicated for the following situations: - Management of bleeding in patients who require coagulation factors II, V, X, or XI, when the concentrates are not available or are not appropriate - Abnormal coagulation assays resulting from massive transfusion - Management of patients anticoagulated with warfarin who are bleeding or require emergency surgery - Replacement solution for therapeutic plasmapheresis for the treatment of TTP and hemolytic uremic syndrome (plasma cryoprecipitate reduced can also be used for these patients) - Correction or prevention of bleeding complications in patients who have severe liver disease with multiple factor deficiencies - Management of patients with disseminated intravascular coagulation when the fibrinogen level is less than 100 mg/dL - Management of patients with rare specific plasma protein deficiencies

iron chelation

Iron overload can be treated with oral iron chelators, which bind to iron in the body and help remove it. Another way to avoid iron accumulation is red cell exchange therapy. With both sickle cell disease and thalassemias, iron chelation therapy must accompany blood transfusions to prevent the iron overload these patients experience because of multiple transfusions. The iron from normal red cell kinetics is neutralized, but the constant addition of cells of varying ages creates the iron excess that becomes stored and detrimental to many tissues.

post donation instruction

The donor is given postphlebotomy care instructions as follows: - Contact the donor center if there are any concerns regarding the safety of the blood or if you believe the blood should not be transfused. - Avoid smoking for 30 minutes; avoid alcohol until something has been eaten. - Drink more fluids than usual in the next 4 hours. - If dizziness or fainting occurs, lie down or sit with the head between the knees. - Caution donors who work at certain occupations who will be returning to work immediately (involving heights, construction, or machine operators). - Remove the bandage after a few hours. - Inform the blood center if any symptoms persist.

Blood component preparation

The facility's inventory requirements and the drawing location usually determine the number of satellite bags, or the "bag configuration," used for collecting blood from donors. The primary bag can have as many as four additional bags attached. Storage temperature and time constraints after collection also affect which components are to be prepared. For example, if platelets are to be prepared from a whole blood donation, the unit must not be allowed to cool below room temperature (20° C to 24° C). The platelets must be separated from whole blood within 8 hours. If platelets are not to be separated from the unit of whole blood, units are stored at 1° C to 6° C before component preparation. The AABB Technical Manual provides detailed procedures for the preparation of blood components: - After the whole blood unit is centrifuged at a light spin, the platelet-rich plasma (PRP) is expressed or pushed through the attached tubing into an empty satellite bag. The RBCs remain in the original bag, and the tube between the plasma and red cells is heat sealed and cut. - If collected in an additive system, the additive solution is added to the RBCs. Prestorage leukocyte reduction may be performed at this step. The RBCs are sealed and split from the remaining bags and refrigerated at 1° C to 6° C. - The PRP unit is centrifuged again at a heavy spin, which causes the platelets to sediment to the bottom of the bag. All but about 50 to 70 mL of plasma is removed from the platelets. The additional plasma that remains with the platelets is required to maintain a pH of 6.2 or higher during the storage period. The platelets are sealed and allowed to "rest" for a period of at least 1 hour before they are stored on a rotator that maintains continuous gentle agitation. Platelet concentrates are stored at 20° C to 24° C for a maximum period of 5 days.

complications of chemotherapy

The oncology patient in the hospital undergoes a combined treatment regimen of physical (radiation) and chemical therapies (chemotherapy) mostly targeting rapid cellular division. Most chemotherapeutic agents act by slowing down or inhibiting DNA replication or interfering with the DNA translation process to stop cell division. Chemotherapeutic agents are not specific for the target cancer or clone of cells. Epithelial cells of the gastrointestinal tract and germinal epithelium of the hair follicles are also particularly affected. In the bone marrow, hematopoietic cells that differentiate into megakaryocytes, erythrocytes, and leukocytes are reduced. As treatment progresses, platelet, leukocyte, hemoglobin, and hematocrit levels decrease. The most common complications are bleeding, anemia, and infection. Careful monitoring of laboratory results and clinical conditions associated with bleeding and anemia is necessary to determine component therapy. Transfusion support with irradiated blood products after intensive chemotherapy and radiation therapy is common. In some patients, multiple platelet transfusions often cause refractoriness or the inability to achieve therapeutic increments. When alloantibodies to HLA antigens cause refractoriness, HLA-matched platelets may become necessary. Colony-stimulating factors are becoming more widely used in preventing infection and bleeding risks associated with chemotherapy

Hepatitis E

Hepatitis E is spread in much the same way as hepatitis A, through an oral-fecal route. Therefore donated blood is not tested.

Table 13.1 Conditions for Indefinite or Permanent Deferral

- History of viral hepatitis after eleventh birthday - Confirmed positive test for hepatitis B surface antigen - Reactive test to antibodies to hepatitis B core on more than one occasion - Present or past clinical or laboratory evidence of infection with hepatitis C virus, human T-cell lymphotropic virus, or HIV - History of babesiosis or Chagas disease - Family history of CJD - Recipient of dura mater or human pituitary growth hormone - Risk of vCJD - Use of a needle to administer nonprescription drugs KEY = HIV, Human immunodeficiency virus; CJD, Creutzfeldt-Jakob disease; vCJD, variant Creutzfeldt-Jakob disease.

irradiated red blood cells

AABB Standards require irradiation of cellular components (RBCs and platelets) if the donor unit is from a blood relative of the intended recipient or the donor unit is HLA-matched for the recipient. Irradiation can be performed with a gamma irradiator (cesium-137 or cobalt-60 radioisotopes), linear accelerators, UV-A irradiation, and nonradioisotope equipment (x-rays). The required dose of irradiation is 2500 cGy/rad, or 25 Gy, in the middle of the canister, and the lowest dose should be 1500 cGy/rad. Periodic verification and documentation of dose delivery are required Irradiation induces erythrocyte membrane damage that causes RBC units to have a higher plasma potassium level and a decrease in ATP and 2,3-DPG levels. Cell activities that are not dependent on reproduction (notably platelet activation and oxygen delivery) are not significantly affected by irradiation. The expiration date of irradiated RBCs is changed to 28 days after irradiation if the available shelf life exceeds 28 days. If the irradiated cells are not given to the originally intended recipient, they can be returned to the inventory and transfused to another patient.

additive solutions

Additive solutions (AS-1, AS-3, AS-5, or AS-7) are provided as an integral part of the collection bag system. After the whole blood is collected in CPD or CP2D and the plasma is separated from the RBCs, the additive solution bag is allowed to flow into the RBCs to enhance red cell survival and function. More plasma can be removed from the RBC units because the additive solution is added to maintain red cell metabolism during storage. The amount of additive solution is either 100 mL for a 450-mL whole blood collection or 110 mL for a 500-mL collection. AS-1, AS-5, and AS-7 solutions contain mannitol along with saline, adenine, and dextrose. AS-3 contains additional sodium citrate and does not contain mannitol. AS-7 contains sodium bicarbonate in its formulation. These preservatives are designed to minimize hemolysis during storage to less than 1%.5 The 100-mL additive solution must be added within 72 hours of the whole blood collection. In addition to extending the storage to 42 days from collection, the additive solution reduces the unit's red cell viscosity and improves the flow rate during administration because the hematocrit values of these units range from 55% to 65%.

plasma cryoprecipitate reduced

After the removal of CRYO from FFP, the remaining plasma unit can be refrozen. The refreezing must occur within 24 hours of the thawing. The product is relabeled "Plasma, Cryoprecipitate Reduced" and is stored at −18° C or lower for 1 year from the date of collection. The CRYO-poor plasma (CPP) is used primarily in the treatment of TTP because it contains ADAMTS13, the protein that is reduced in TTP. Albumin and coagulation factors II, V, VII, IX, X, and XI remain in the same concentrations as in FFP. Once thawed for use, CPP has a 5-day expiration date and should be stored at 1° C to 6° C.

rejuvenation

Although the procedure is not routine, it may be necessary to restore 2,3-DPG and ATP levels in RBC units collected in CPD or CPDA-1 during storage or up to 3 days after expiration with a solution containing pyruvate, inosine, phosphate, and adenine. The rejuvenation solution extends the expiration date for freezing or transfusing the RBC unit, which may be necessary when a rare or autologous unit is involved. Rejuvenated RBCs require washing to remove the inosine before transfusion because it may be toxic to the recipient.

red blood cell apharesis donation

Apheresis is a category of procedures in which whole blood is removed from a donor or patient, a component is separated by mechanical means, and the remainder of the blood is returned • Red cell apheresis: two units of RBCs are removed Donors who meet certain criteria levels may have two units of RBCs removed by apheresis. Current FDA guidelines require donors to be larger and have higher hematocrit values than for single RBC donations. For male donors, the minimum weight is 130 lb and the minimum height is 5 feet 1 inch; female donors must weigh at least 150 lb and be 5 feet 5 inches tall. Both male and female donors must also have a hematocrit of 40% or higher. Donors are also deferred for 16 weeks after a double RBC donation. Saline infusion is used to minimize volume depletion Apheresis was originally performed manually. The process involved removing a unit of whole blood, centrifuging it, removing the desired component, and returning the remaining blood before removing the next unit. At the present time, apheresis is routinely performed with a cell-separator machine. Centrifugal force is used to separate the blood into components based on their specific gravity. The blood flows directly from the donor's arm into the centrifuge bowl, a specific component is removed, and the remainder of the blood is returned to the donor; all of this occurs within a closed system. Depending on the procedure and the equipment used, the process can take 30 minutes to 2 hours. The procedure can be performed by intermittent or continuous flow. An intermittent flow process involves one venipuncture; blood is removed, centrifuged, and returned in alternating steps. A continuous flow procedure necessitates a venipuncture in both arms; blood is removed from one arm, centrifuged, and returned in the other arm.

Fig 15.6 Sterile connection device.

Applications of sterile connection devices • Addition of a bag while preparing components • Pooling of components • Preparation of pediatric units • Addition of leukocyte reduction filter • Removing samples for testing

Table 16.10 Contributing Factors Associated with Anemia in Chronic Renal Disease

Cause | Effect Elevated uremia = Altering of RBC shape, causing their premature removal Dialysis procedure = Shearing of RBCs Low erythropoietin level = Low RBC production

Chagas disease

Chagas disease, or American trypanosomiasis, is a disease endemic in Central and South America caused by the protozoan parasite Trypanosoma cruzi. Infection usually results after contact with feces of infected reduviid bugs. Transmission is also possible by transfusion. Infected individuals can experience severe heart or intestinal problems, which usually occur many years after the initial infection The CDC estimates that more than 300,000 persons with T. cruzi infection live in the United States. These infected individuals acquired Chagas disease in endemic countries and not while residing in the United States. Because cases of transfusion-transmitted Chagas disease have been reported in the United States, some blood collection facilities with many immigrants from endemic areas perform an ELISA or chemiluminescent assay test to detect the antibodies to T. cruzi. The test is approved for screening donors of whole blood, plasma, and serum samples for cell, organ, and tissue donors (heart beating). In response to the availability of a licensed test, multiple large blood-collecting facilities implemented testing in 2007. The rarity of donor seroconversion in the United States prompted one-time testing of blood donors. In 2010 the FDA issued guidance that recommended screening a U.S. blood donor once for T. cruzi infection

Table 15.1 Anticoagulant-Preservative Composition: Purpose and Storage Limits

Chemical | Purpose Dextrose = Supports ATP generation by glycolytic pathway Adenine = Acts as substrate for red cell ATP synthesis Citrate = Prevents coagulation by chelating calcium, also protects red cell membrane Sodium biphosphate = Prevents excessive decrease in pH Mannitol = Osmotic diuretic acts as membrane stabilizer RED CELL ANTICOAGULANT/PRESERVATIVE | Storage limit (days) CPD/citrate-phosphate-dextrose = 21 CP2D/citrate-phosphate-2-dextrose = 21 CPDA-1/citrate-phosphate-dextrose-adenine = 35 AS-1 (Adsol); AS-5 (Nutricel)/dextrose, adenine, mannitol, saline = 42 AS-3 (Optisol)/dextrose, adenine, saline, citrate = 42 AS-7 (SLOX)/dextrose, adenine, mannitol, saline, citrate, sodium bicarbonate = 42

Table 13.6 Physical Examination Requirements

Criteria Checked | Acceptable limit Appearance = in good health Hemoglobin = ≥12.5 g/dL (125 g/L) Females | 13.0 g/dL (130 g/L) Males Hematocrit = ≥38% Females | ≥39% Males Blood pressure = Systolic 90-180 mm | Diastolic: 50-100 mm Temperature = ≤37.5° C (99.5° F) Pulse = 50-100 beats/minute Weight = Minimum 110 lb (50 kg) Age = Conform to applicable state law or >16 years

von Willebrands - cryo AHF

Cryoprecipitated AHF is used only in urgent situations when the preferred concentrate is not available. The administration of coagulation factor concentrate has the potential to cause the development of antibodies, or "inhibitors," to one or more of the factors, which can lead to further bleeding episodes.

CMV

Cytomegalovirus (CMV) is a widespread infection that can be transmitted through transfusion. Transmission occurs through the transfusion of intact white cells contained in cellular blood components. In most individuals, CMV infection is asymptomatic, but mononucleosislike symptoms are occasionally reported. For immunosuppressed patients, including premature infants, exposure to CMV may cause motor disabilities, mental retardation, and even death. In addition, CMV-seronegative recipients of organ or hematopoietic cell transplants are at increased risk of transfusion-transmitted CMV infection. Tests to detect antibody to CMV are not required for blood donors and are usually performed only on a portion of the blood collected. Units that test negative for CMV are set aside for intrauterine transfusion or blood replacement for premature infants and immunocompromised adults. CMV testing for antibodies can be performed by ELISA, latex agglutination, or hemagglutination CMV-reduced-risk blood products can also be achieved by leukocyte reduction because the virus resides within intact white cells. The estimated transmission of CMV by antibody negative is 1% to 2% compared with a 2% to 3% risk with leukocyte reduction

Hep B vaccine

HBsAg is the antigen used to make hepatitis B vaccine. Because of the large amount of HBsAg present, it is possible to test for the antigen directly. By the mid-1970s, donor screening for HBsAg was implemented. Enzyme and chemiluminescent immunoassays, described earlier in this chapter, are used to screen donors.

HTLV-1

HTLV-I has been associated with adult T-cell leukemia, a rare neoplasm, and tropical spastic paraparesis and HTLV-I-associated myelopathy, a semiprogressive neurologic disease HTLV-I and HTLV-II are transmitted through cellular blood products, breast milk, sexual contact, contaminated needles, and injection drug users 1997, the requirement to test for antibody to HTLV-II was added to the requirement to test for antibody to HTLV-I. The two are combined into one assay. There is no FDA- approved confirmatory test for HTLV. However, the Western blot is commonly used as a supplemental test for confirmation of a positive HTLV antibody result. The screening assays detect IgG antibody to HTLV-I and HTLV-II

Table 14.3 Hepatitis Viruses

Hepatitis A Transmission = enteric; oral and fecal Incubation (days) = 15-50 Classification= picornavirus Nucleic Acid = RNA Donor Testing = no Hepatitis B Transmission = parenteral; sexual; perinatal Incubation (days) = 60-150 Classification= Hepadnavirus Nucleic Acid = DNA Donor Testing = yes Hepatitis C Transmission = parenteral; sexual; perinatal Incubation (days) = 14-300 Classification= flavivirus Nucleic Acid = RNA Donor Testing = yes Hepatitis D Transmission = parenteral; sexual; perinatal Incubation (days) = 30-50 Classification= satellite Nucleic Acid = RNA Donor Testing = no Hepatitis E Transmission = enteric; oral and fecal Incubation (days) = 21-42 Classification= Calicivirus Nucleic Acid = RNA Donor Testing = no

Hepatitis A

Hepatitis A, also known as infectious hepatitis, is usually transmitted by fecal contamination and oral ingestion. The hepatitis A virus (HAV) circulates in the bloodstream only during the initial phase of infection, when an individual is usually too ill to donate; however, if blood is collected while the virus is circulating, it can be transmitted by transfusion. Because transfusion transmission is extremely rare, donated blood is not tested for hepatitis A antigen or antibody.

Table 15.3 details! Conditions causing platelet refractoriness or poor response to platelet transfusion

Immune HLA alloantibodies Platelet alloantibodies Autoantibodies Nonimmune SplenomegalyMedicationsSepsisActive bleedingDisseminated intravascular coagulation (DIC) Fever

surrogate markers

In 1986 anti-HBc and alanine aminotransferase (ALT) were added as surrogate markers. Anti-HBc is an antibody to the inner portion or core of the hepatitis B antigen. These antibodies generally appear after HBsAg is detected but before the manifestation of hepatitis symptoms Surrogate markers: disease markers such as antibodies or elevations in enzymes that can be used as indicators for other potential infectious diseases; often used when direct testing is not available

testing for bacterial contamination

In March 2004 the AABB added a new testing requirement for bacterial contamination in apheresis platelets and platelet concentrates. This requirement was implemented because bacterial contamination is an important cause of transfusion morbidity and mortality. This testing is performed on the blood products rather than on the donor blood samples. Despite careful attention to phlebotomy techniques, blood processing, and storage requirements, it is impossible to eliminate the possible contamination with microbial organisms. Bacteria originating from the donor during phlebotomy or an unsuspected bacteremia can multiply more readily in blood components stored at room temperature. Platelet components are stored at 20° C to 24° C to maintain their viability and function. These products provide an excellent environment for the growth of any bacteria. Normal skin flora account for the most common source of contamination isolated from platelet components. Severe transfusion reactions from bacterial contamination include fever, shock, and disseminated intravascular coagulation. Bacteria proliferate to a lesser extent in refrigerated RBCs.

Preop collection for autologous donation

In preoperative collection, the blood is drawn and stored before the anticipated transfusion. This procedure is used for stable patients scheduled for surgical procedures likely to necessitate blood transfusion. It is especially useful for patients with rare antibodies that make crossmatching allogeneic units difficult or for patients whose religious beliefs do not allow allogeneic transfusions. Patients being treated for bacteremia are ineligible to be autologous donors. The preoperative blood collection process begins with a written order from the patient's physician. Informed consent must be obtained from the patient (donor), with written notification that all test results are released to the patient's physician. Criteria for donor selection do not include high-risk questions. The collecting facility's medical director establishes guidelines concerning the autologous donor's health for donation eligibility. Donors are not restricted by age; the ability of younger patients to donate is determined more by the size of the patient. For patients weighing less than 110 lb, the volume of blood collected and the amount of anticoagulant used should be proportionately less. The patient (donor) hemoglobin concentration should be no less than 11 g/dL. The hematocrit should be no less than 33%. Blood collection should be completed more than 72 hours before surgery. In addition to the routine labeling of the blood bag, the name of the donor, the recipient name, identification number, the blood group, and the name of the hospital must be included along with the phrase "for autologous use only." The ABO and D phenotype must be determined at the collecting facility. If the blood is transfused outside the collecting facility, infectious disease testing must be performed before shipping. At a minimum, the first unit shipped within each 30-day period must be tested. A repeatedly reactive viral test does not necessarily mean that the unit is destroyed with allogeneic units. With permission of the patient's physician and the receiving facility's transfusion service, autologous units can ship after a biohazard label has been affixed. Autologous units that are not used cannot be crossed over to the general inventory because they do not meet the same donation and testing requirements as allogeneic donations. Special procedures must exist (either manual or computerized) to ensure that the units are located and transfused to the intended recipient. A system must exist to identify the units for transfusion to the recipient before any directed or allogeneic units are transfused. The extent of pretransfusion testing for autologous donations varies in individual facilities. Some facilities perform a crossmatch in addition to a check on ABO and D phenotyping.

leukocyte reduced red blood cells

Leukocytes remaining in RBC units have been implicated in adverse transfusion reactions and immunization to leukocyte antigens. A reaction caused by leukocytes can be extremely uncomfortable for a patient, causing shaking chills or an increase in temperature, or both, soon after initiating the RBC transfusion. Intact or fragmented membranes and cytokines produced by leukocytes during RBC storage are responsible for febrile reactions. Reduction in leukocytes before RBC storage is optimal because it reduces the leukocyte fragments and cytokines that increase during storage. The use of leukocyte-reduced RBCs has become standard practice in many hospitals. The use of leukocyte-reduced RBCs for trauma patients, who may not benefit from these more expensive products, remains controversial. The standard 170-μm blood filter does not remove leukocytes. White blood cell removal is best accomplished by the use of commercially available leukocyte removal or leukocyte reduction filters.

Neonatal and Pediatric Transfusion issues

Neonatal and pediatric transfusion issues are significantly different from transfusion issues for adults because of the small size, hemoglobin changes, and erythropoietin response in early infancy. Ill neonates are more likely to receive RBC transfusions than other hospitalized patients The switch from fetal to adult hemoglobin begins at about 32 weeks' gestation. For this reason, preterm infants have a higher level of fetal hemoglobin than infants born at term. The change from fetal to adult hemoglobin occurs during the first few weeks of life, and the process causes a condition called physiologic anemia of infancy. In a full-term infant of normal birth weight, this change is well tolerated; however, treatment is often necessary in an infant born prematurely with low birth weight In addition to the shift in hemoglobin, the need for frequent laboratory tests contributes to the need for transfusions. Iatrogenic blood loss is the most common indication of transfusion in a preterm infant with low birth weight. Newborns do not compensate for hypovolemia as well as adults do Erythropoietin production in an infant is believed to be triggered in the liver, which is less responsive to low levels of oxygen. The lower level of response to low oxygen levels (hypoxia) protects the infant from generating an excess of red cells (polycythemia) during fetal life but does not allow an effective response to anemia in the immature infant. The response of a newborn to hypothermia is also different from an adult's response. The metabolic rate, hypoglycemia, and acidosis can cause the temporary cessation of breathing, or apnea. Apnea may lead to hypoxia, hypotension, and cardiac arrest. For this reason, a monitored blood warmer is often used to administer RBCs, especially for exchange transfusions. The ability to metabolize citrate and potassium is more difficult for newborns because of their immature liver and kidneys. For this reason, washed or fresh red cells are often indicated for newborns. Because potassium increases when blood is irradiated, washing irradiated RBCs is also recommended. The transfusion of fresh blood to maximize the level of 2,3-diphosphoglycerate (2,3-DPG), which decreases during storage, is also important in newborns because of their limited ability to compensate for hypoxia. In neonates, hemoglobin levels less than 13 g/dL during the first 24 hours of life initiates a clinical consideration of an RBC transfusion. In addition, an ill neonate's loss of approximately 10% blood volume will trigger a transfusion evaluation. RBC transfusions are usually given in small volumes prepared from (pediatric) multiple-pack systems that allow preparation of several aliquots from a single donor unit. Infants do not form red cell antibodies during the first 4 months of age; therefore crossmatching is not indicated. Antigen-negative blood must be provided if a maternal red cell alloantibody is detected in infant's plasma or serum. Group O, ABO-identical, or ABO-compatible blood that is D-negative or the same as the infant's D type can be released during the first 4 months of age. However, before non-group O RBCs can be issued, testing of the infant's plasma or serum is required to detect passively acquired maternal anti-A or anti-B and should include an antiglobulin phase. Transfusion-transmitted cytomegalovirus (CMV) is a risk to preterm infants weighing less than 1200 g who are born to seronegative mothers or to mothers whose CMV status is unknown. This risk is avoided by providing irradiated CMV antibody-negative blood to neonates. In addition, leukocyte reduction, using highly efficient leukocyte removal filters, is recommended because CMV resides within the white blood cell

Nucleic acid amplification technology (NAT)

Nucleic acid amplification technology (NAT) for blood screening detects the presence of viral nucleic acid, DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in donation samples. The technique requires the extraction of nucleic acid from donor plasma followed by amplification to detect the viral genetic sequences. A specific RNA/DNA segment of the virus is targeted and amplified in vitro. The amplification step enables the detection of low levels of the virus in the original sample. It increases the amount of specific target to a level that is easily detectable. The presence of specific nucleic acid indicates the presence of the virus itself. The blood donation is likely to be infectious. The advantage of NAT is the detection of very low numbers of viral copies in the bloodstream before the appearance of antibodies. The possibility of detecting the virus during the serologic window period—the period from time of infection to detection of antibody in serologic laboratory assays—is enhanced with NAT technology These test systems were first introduced in 1999 for screening of HIV and HCV RNA.10 Plasma samples were tested in minipools of 16 to 24 donors. The sensitivity of NAT allowed for the pooling of these donors. If a minipool NAT result was negative, all donations in that pool were considered negative for HIV and HCV RNA. A positive minipool NAT result required further separation of donor plasma samples to identify the source of the positive test. Donations nonreactive on additional testing were released for transfusion. Donations that reacted positive at the individual sample level were regarded as positive for the viral nucleic acid and could not be released for transfusion. Fully automated systems are now available for donor viral nucleic acid testing. These systems use multiplex assay platforms that can detect HIV RNA, HCV RNA, and HBV DNA in a single reaction chamber. The FDA has approved the systems for testing individual samples (ID-NAT) or pools of 6 to 16 donor plasma samples (MP-NAT). The FDA requires permanent deferral for any donor who has a reactive result on NAT screen for HIV, HCV, or HBV using an individual (unpooled) sample. The RNA viruses routinely tested using NAT technology are HIV, HCV, and WNV in addition to HBV, a DNA virus. Polymerase chain reaction (PCR) testing and transcription-mediated amplification are two examples of testing procedures using NAT

Hepatitis B

Originally called serum hepatitis, HBV was the first known hepatitis virus transmitted by blood transfusion. It can also be transmitted parenterally, by sexual contact, and perinatally. The rate of new HBV infections has declined by approximately 82% since 1991. The decline has been greatest among children born since 1991, when routine vaccination of children was first recommended During HBV infection, the viral envelope material, the surface antigen or HBsAg, is detected in the blood before the antibody to the core antigen (anti- HBc) is produced. The FDA requires donor screening for HBsAg, anti-HBc, and HBV-DNA. Parenterally: by routes other than the digestive tract, including needle stick and transfusion Perinatally: exposure before, during, or after the time of birth

Hemophilia A - F VIII

Other factor deficiencies are hemophilia A (factor VIII deficiency) and hemophilia B (factor IX deficiency). Factors VIII and IX are needed for the intrinsic pathway of fibrin formation. The clinical characteristics of coagulation deficiencies are prolonged bleeding, bleeding into joints, and subcutaneous bleeds. Most of the hemostatic disorders are treated with factor concentrates or DDAVP.

chronic renal disease

Patients undergoing dialysis have many hematologic complications that necessitate transfusion therapy, usually in the form of RBC support. The high uremic content of the blood leads to altered red cell shapes; this prevents the red cells from traversing the spleen without being removed prematurely by macrophages, which results in hemolytic anemia. The act of dialysis itself causes a shearing of the red cells, which can contribute to hemolysis. These patients fail to produce sufficient levels of erythropoietin because of the nonfunctioning kidney; therefore an erythrocyte production problem adds to the anemic condition.

platelet concentrates

Platelet concentrates prepared from a unit of whole blood, as described in the section on blood component preparation, contain at least 5.5 × 10^10 platelets per unit and, under optimal conditions, should elevate the platelet count by about 5000 μL in a recipient weighing 75 kg. Platelets prepared from whole blood are also referred to as random donor platelets or platelet concentrates.

apheresis platelets and pH

Quality control must also include the pH, which must be greater than or equal to 6.2 at the end of the allowable storage period

frozen red blood cells

RBCs can be frozen for long-term preservation to maintain an inventory of rare units or to extend the availability of autologous units. Freezing extends storage up to 10 years from collection when stored at or below −65° C. To prepare RBC units for freezing, glycerol is added as a cryoprotective agent to prevent cell dehydration and the formation of ice crystals, which causes cell hemolysis. Glycerol is slowly added to the unit for a final glycerol concentration of 40% weight per volume. The unit is transferred to a polyolefin or polyvinyl chloride bag and placed in a metal or cardboard canister to prevent breakage at low temperatures. Units can subsequently be stored at −65° C for up to 10 years from the date of collection Freezing can also be accomplished with a lower glycerol concentration if a liquid nitrogen freezer is used. This method is not as common for RBC storage. Glycerol concentration is approximately 20%, and the initial freezing temperature is −196° C (temperature of liquid nitrogen). Maximum storage temperature is −120° C for 10 years

look-back

RECIPIENT TRACING (LOOK-BACK) Look-back constitutes of a series of actions taken by a blood establishment when donor test results indicate infection with hepatitis, HIV, HTLV, WNV, or Chagas disease. These steps are performed on prior donations from that donor. These prior blood products were possibly donated during the window period of infection when screening tests were negative but infectious agent was present in the donor's blood. Immediate retrieval and quarantine of prior existing products from that donor shall occur within three calendar days of reactive HIV or HCV test results and within one week of reactive HBsAg, anti-HBc, or anti-HTLV screening tests Look-back activities within the blood collection facility may include the following actions: - Quarantine of prior collections from that donor that remain in inventory - Notification of facilities (eg, hospitals, clinics) that received these products to quarantine prior collections - Further testing of the donor, if not deceased - Destruction or relabeling of potentially infectious prior collections Responsibilities of the transfusion service in the look-back process are as follows: - Process to identify recipients, if appropriate, of blood or components from donors subsequently found to have, or be at risk for, relevant TTIs - Notification, if appropriate, of the recipient's physician or recipient as specified in FDA regulations and recommendations

massive transfusion

Rapid blood loss, or hemorrhage, initiates a series of complicated physiologic responses that involve the nervous, hormonal, and circulatory systems. Acute blood loss of greater than 30% of the total blood volume may lead to hemorrhagic shock. Severe hemorrhage affects electrolyte metabolism and oxygen transport, which ultimately increases the heart rate and the stress on internal organs. Prolonged hypotension and extensive tissue damage can result in cardiac and renal failure. Disseminated intravascular coagulation (DIC) is a pathologic activation of the coagulation cascade that may be caused by hemorrhage, which would further complicate the ability to control bleeding The most important goal in treating acute blood loss is the restoration of blood volume through the control of hemorrhage and replacement of intravascular volume to prevent shock. Infusing sufficient fluid volume to maintain adequate blood flow and blood pressure for tissue oxygenation is critical. Initial symptoms that occur with blood loss are the result of volume depletion, not depletion of red cells. Immediate volume restoration with crystalloid or colloid solutions is usually recommended. Other methods to control hemorrhagic shock include early transfusion of plasma, platelets, and red blood cells (RBCs) with minimal crystalloid use. RBC transfusions in trauma situations are usually urgent and of significant quantity. Adverse metabolic effects can occur from the transfusion of large quantities of stored blood over a short period. One blood volume exchanged within 3 to 4 hours can cause significant acute metabolic disturbances, such as citrate toxicity, hypothermia, and coagulation abnormalities. Coagulation abnormalities resulting in microvascular bleeding have been attributed to the dilution of platelets and coagulation factors occurring with two or three volume exchanges and the consumption of platelets and coagulation factors from extensive bleeding. Antifibrinolytics such as tranexamic acid may be administered to control bleeding

Fig 16.1 Symptoms associated with hypovolemia and transfusion goals in treatment of trauma patients

Symptoms of hypovolemia • Reduced arterial pressure • Hypotension • Cooling of extremities • Oliguria (reduced urine output) • Acidosis • Increased respiration • Decreased central venous pressure Priorities in Massive Transfusion • Correct hypovolemia with crystalloids • Optimize oxygen-carrying capacity • Maintain hemostasis: platelets and coagulation factors • Correct or avoid metabolic disturbances • Maintain intravascular volume with colloids

serologic test for syphilis

Syphilis is a venereal disease caused by the spirochete bacterium Treponema pallidum. Although the most common method of transmission is direct sexual contact, at least one case of transmission has occurred through transfusion. The FDA mandated donor testing for syphilis in the 1950s. This test was the first infectious disease screening performed on blood donations. Serologic testing for syphilis has been performed on donor samples for more than 60 years. The routine storage of RBCs at refrigerated temperatures limits the survival of T. pallidum, but platelets stored at room temperature could transmit the organisms. Donated blood can be tested by various methods, including rapid plasma reagin (RPR), hemagglutination tests, and the fluorescent treponemal antibody absorption test.

Antibody Screen

The antibody screen detects unexpected blood group antibodies in the donor's plasma. Anti-A and anti-B are not detected by this test. The antibodies considered most important are those clinically significant antibodies produced after exposure to foreign red cell antigens after transfusion or pregnancy. The method used to perform the antibody screen should detect clinically significant antibodies. Donor samples can be tested separately or in pools. The screening cells can be separate or pooled. Standard tube, gel technology, solid- phase, and microplate techniques are used in addition to automated techniques. If a clinically significant antibody is detected, the donor's plasma and platelet components are not used for transfusion purposes. RBC products that have not been washed, frozen, or deglycerolized contain minimal amounts of the donor's plasma. If these blood products are used for transfusion, the antibody interpretation is required on the label of the RBC component.

donor screening

The screening of each donor can be divided into four phases: registration, educational materials, health history interview, and physical examination. The screening process includes information on the donation process and potential adverse consequences of blood donation. In addition, a questionnaire is provided to the donor to assess any risky behaviors, medications, travel, and other factors with potential impact to donor and recipient safety. A physical examination of the donor is included with parameters set for blood donation. Two phrases are used in the donation process: donor eligibility and suitability of the donation. The donor's eligibility is the determination that the donor is qualified to donate blood and blood components. The suitability of the donation means a determination of whether the donation is acceptable for transfusion or for further manufacturing use. Registration => education materials => health history interview => physical examination

therapeutic apheresis goals

Therapeutic apheresis involves the removal of abnormal cells, plasma, or plasma constituents from a patient's blood to achieve a clinical benefit. The replacement fluid varies with the condition and the portion that is removed. The goal may be to: - Supply an essential substance that is absent - Reduce the quantity of a particular antibody - Modify mediators of inflammation - Clear immune complexes - Replace cellular elements

therapeutic phlebotomy

Therapeutic phlebotomy is performed to withdraw blood from a patient for medical reasons. Although the removal of blood does not cure the disease, it can help treat the patient's symptoms. Common indications for therapeutic phlebotomy include polycythemia, hemochromatosis, and porphyrias. Blood collected from donors with hereditary hemochromatosis, which is a disorder of iron metabolism, can be put into the blood supply if the blood center meets certain FDA criteria. The FDA has permitted variances regarding labeling and frequency of collection. The service to the donor for phlebotomy must be free of charge, regardless of the donor's eligibility.

Table 16.3 Risk Factors for Bleeding during Cardiac Surgery

Time on pump Age of patient Previous cardiac surgery Type of surgery: valve replacement, CABG, or both Preoperative medications: aspirin and anticoagulant Heparin effect Hypothermia decreases platelet function CABG, Coronary artery bypass graft.

pooled platelets

To achieve a therapeutic dose, platelet concentrates are pooled for transfusion in adults. Pooling is accomplished by transferring the platelet concentrates into a transfer set, while being careful not to contaminate the ports. An approximate dose is 1 unit per 10 kg of patient body weight, yielding pools of 6 to 10 platelets. This platelet pooling method creates an "open system," which causes the expiration of the pooled product to change to 4 hours from the start of pooling. The pooled platelets should be stored at 20° C to 24° C with gentle agitation until transfusion. Platelets can also be pooled using a commercial prestorage pooling bag, which maintains an expiration date of the oldest component in the pool, up to 5 days. Units selected for pooling should be type specific or type compatible due to the presence of some RBCs in each unit. A unique pool number is placed on the final container, and all units present in the pool must be documented.

diversion pouch

To prevent potential contamination with epidermal cells and potential bacteria entering the donor unit, AABB standards require the use of collection containers that divert the first 10 to 20 mL of blood into a "diversion pouch" when platelet products are to be prepared from whole blood donations

washed red blood cells

Washing RBCs with normal saline may be indicated for patients who react to the small amount of plasma proteins that remain in a unit of RBCs. Reactions can be allergic, febrile, or anaphylactic. A patient with IgA deficiency and clinically significant anti-IgA requires washed RBCs if a transfusion is indicated. Washed RBCs may also be used in intrauterine or neonate transfusions Washing is accomplished with approximately 1000 to 2000 mL of 0.9% saline using the automatic blood cell processor described for deglycerolizing frozen RBCs. Washing is associated with a loss of up to 20% of the original RBCs and is no longer considered an effective method of removing leukocytes

Western blot test

Western blot: test that separates and identifies viral antigens according to molecular weight using viral antibodies in an electrophoretic procedure HIV RNA and the Western blot tests can be useful as confirmatory testing for a reactive HIV-1 antibody screening result

plastic overwraps

When thawing CRYO and FFP in a water bath, plastic overwraps prevent contamination of entry ports used for administration.

organ transplants

Transfusion support for kidney, heart, lung, and liver transplants is varied because of the nature of the organ. Because of the complicated surgery on a vascular organ, liver transplantation can be associated with massive hemorrhage. Hemostatic problems are major complications of liver transplant because of the role the liver plays in the synthesis of factors and clearance of coagulation inhibitors. The preexisting liver disease also contributes to the excessive bleeding during the procedure. Historically, significant blood loss at the time of liver transplantation has been treated with large autologous transfusions of RBCs, FFP, platelets, and cryoprecipitate. Drugs are given along with the blood products to help correct metabolic and coagulation abnormalities. However, the trend in liver transplantation demonstrates a decreased blood loss and decreased usage of blood products Heart and heart-lung transplants have similar product usage as cardiac surgery, outlined previously. Cardiopulmonary bypass can affect hemostasis secondary to hypothermia, heparin use, priming fluid used for the bypass instrument, and duration of surgery. A ventricular assist device (VAD), which is a relatively new therapeutic option for patients with end-stage heart failure awaiting heart transplant, can also contribute to the need for transfusion support during implantation and after surgery. Platelet and hemostatic defects may be caused by the surface of the device and flow characteristics. Transfusions should be limited to leukocyte-reduced components to avoid sensitization and increase complications caused by human leukocyte antigen (HLA) antibodies. Graft survival is enhanced with HLA-matched donor-recipient combinations, particularly if the recipient is demonstrating HLA antibodies. Graft survival of renal transplants is also improved with living donors. ABO compatibility is critical to the success of vascularized grafts, such as livers, kidneys, and hearts, but it is not essential in tissue grafts, such as bone, heart valves, skin, and cornea. In the 1970s kidney allografts had a higher rate of survival if patients were given blood transfusions before undergoing renal transplantation. In the 1980s transfusion to induce tolerance in patients before kidney transplants was replaced by the use of cyclosporine for immunosupression. Erythropoietin has also reduced the need for transfusion in patients with kidney disease. When RBCs are transfused, leukocyte-reduced products have decreased the alloimmunization to HLA antigens. When a potential kidney transplant recipient develops HLA antibodies, obtaining a compatible kidney becomes more challenging.

West Nile Virus (WNV)

WNV is a mosquitoborne flavivirus that manifests symptoms ranging from a mild febrile illness to encephalitis, coma, and death. WNV has been present in the United States since 1999. Before 2002 the human infection was generally believed to occur via infected mosquitoes. In 2002 transfusion transmission was identified as the cause of WNV infection in at least 21 people. The persistent low-level transmission of WNV by transfusion continued in 2003 and led to the implementation of nationwide donor screening for WNV using NAT in 2003. In 2009 the FDA recommended NAT testing of individual donations rather than minipools at times of increased geographic WNV activity. WNV ID-NAT prevents diluting the donor samples, which already contain a low concentration of the viral RNA load during that period. Data from the CDC describe the disease cases reported by week of illness onset from 1999 to 2014. Outbreaks occur during the summer months. In 2012 WNV transmission season was the most severe since 2003. In this outbreak, a total of 5674 human cases of WNV, including 286 deaths, were reported to the CDC. Of the total reported cases, 51% were neuroinvasive disease cases, including meningitis, encephalitis, or acute flaccid paralysis. According to AABB's WNV Biovigilance Network, 752 WNV-reactive donations were identified in 2012. Due to the unpredictable nature of annual outbreaks and the potential for cases of breakthrough transfusion transmissions, the AABB has suggested refinements of the criteria for transitioning from minipool to individual NAT testing. Routine donor blood screening for WNV continues to improve blood safety

CPDA-1 citrate phosphate dextrose adenine

Whole blood is the unmodified component, drawn from a donor, which consists of erythrocytes, leukocytes, platelets, and plasma proteins with the anticoagulant-preservative solution. Whole blood is stored in a monitored refrigerator at 1° C to 6° C for 21 days if collected in CPD or for 35 days if collected in CPDA-1. Additive solutions cannot be added to whole blood to increase the storage period.

transport of RBCs

Whole blood or RBCs that are packaged for shipping must be maintained between 1° C and 10° C. Containers used for shipping must be validated periodically to ensure their effectiveness for shipping at wide ranges of outdoor temperatures Frozen units are shipped on dry ice. Because frozen products are brittle, they must be wrapped carefully. As dry ice evaporates, the extra space created allows the units to move about in the box and potentially break. Platelets must be maintained as close as possible to 20° C to 24° C during shipping. Discontinuation of the agitation of platelets during transportation should not exceed 24 hours On receipt of a shipment of blood components, the temperature and appearance of the units must be observed and recorded. Container closure and attached segments should also be inspected. Units that are received out of the designated temperature range must be evaluated for their suitability for transfusion. The shipping facility should be notified if the product is unacceptable. Questionable units should be quarantined until a responsible person determines the disposition. Shipping records, including details of problems and the outcomes, must be maintained

Key

p. 301 donor screening p.306 Table 13.1 p.308 Table 13.5 p. 309 Hgb and Hct determination p. 310 Table 13.6 p. 311-313 post donation instruction, arm prep and venipuncture, diversion pouch p. 314 Preop collection for autologous donation, autologous donors p. 315 Directed donations p.315-317 therapeutic phlebotomy, red blood cell apharesis donation, plasmapharesis p. 318, 323 malaria screening p. 325 serologic test for syphilis, Antibody Screen p. 329 NAT p. 330 Hepatitis A p. 330 Table 14.3 p. 330 Hepatitis B p.331 Hepatitis E p. 331 Hep B vaccine p.332 surrogate markers p. 334 HTLV-1, Western blot test p.334-335 West Nile p. 335-336 Chagas disease p. 336-337 look-back p. 337 CMV p. 337 testing for bacterial contamination p. 345 additive solutions, Table 15.1 p. 347 rejuvenation p. 348 Blood component preparation p. 350 CPDA-1 p. 351 leukocyte reduced red blood cells p. 352 Fig 15.6 p. 352-353 frozen red blood cells, washed red blood cells p. 354 irradiated red blood cells p. 355-356 pooled platelets, platelet concentrates, Table 15.3 details!, apheresis platelets and pH p. 357 Fresh Frozen Plasma, plastic overwraps p. 359 plasma cryoprecipitate reduced p.361-363 transport of RBCs p. 369-371 massive transfusion, Fig 16.1 p. 372-373 Neonatal and Pediatric Transfusion issues, Table 16.3 p. 374 organ transplants p. 377 therapeutic apheresis goals p. 379 complications of chemotherapy, chronic renal disease p. 380 Table 16.10 p. 382 von Willebrands - cryo AHF, iron chelation p. 382 - Hemophilia A - F VIII

plasmapharesis

plasma is removed Collection of plasma by apheresis is designated as either frequent or infrequent. For an infrequent plasmapheresis program, donors do not donate more often than once every 4 weeks. The donor must weigh at least 110 lb. Plasmapheresis more often than once every 4 weeks necessitates that total plasma protein, IgG, and IgM levels be monitored at 4-month intervals