MLS Blood Bank
Red blood cell units that contain CPD (citrate-phosphate-dextrose) can be stored for up to how many days? 21 days 28 days 35 days 42 days
21 days Red blood cell units that contain CPD or CP2D may be stored for up to 21 days. Irradiated red cell units may be stored for up to 28 days or the original expiration date, whichever occurs first. Red cell units that contain CPDA-1 may be stored for up to 35 days. Red cell units that contain an additive solution may be stored up to 42 days.
From the IgG molecule illustration, which region is the heavy chain?
A = Heavy chain B = Light chain C = Antigen binding site D = Variable region
Which one of the following blood groups usually reacts LEAST strongly with anti-H? 0 B A2 A1
A1 The amount of H antigen found on red cells is at its greatest amount on O cells, followed by A2, B, A2B, A1, and A1B. Of the blood groups that are listed, A1 has the least amount of H antigen and therefore would react least strongly with anti-H.
The serum of which of the following individuals may agglutinate group A1 cells? A2 individual A1B individual A1 individual Newborn
A2 individual Approximately 4% of individuals with A2 blood type will have Anti-A1 antibodies in their serum. Individuals with some rarer A subgroups may also have Anti-A1 in their serum. Agglutination will occur if the serum from any of these individuals is mixed with A1 red cells. An A1B or an A1 individual would not be expected to produce anti-A1. A newborn would not typically have yet formed any naturally occurring ABO antibodies.
What are the possible ABO genotypes of offspring of parents whose genotype is AA and BB? AB AO BO OO
AB In this case, the only blood type inheritance possible is AB, as one parent (AA) has given the A gene, and the other parent (BB) is giving the B gene. There isn't an "O" available from either parent, so none of the other genotypes are possible.
Which of the following describes the main function of hemoglobin? Hemostasis Fight infection Carry oxygen Support bone marrow stroma
Carry oxygen One of the main functions of hemoglobin is to carry oxygen that can be released in tissue. Hemostasis is an important function of platelets. Many white blood cells function to fight infections. Fibroblasts of the bone marrow help support the bone marrow stroma.
Which of the following blood components contains the most factor VIII concentration relative to the unit volume? Whole Blood Cryoprecipitated AHF Fresh Frozen Plasma Platelet Concentrate
Cryoprecipitated AHF Cryoprecipitated AHF is the cold-insoluble portion of plasma that remains after Fresh Frozen Plasma has been thawed at 1 - 6oC. It is rich in von Willebrand factor, fibrinogen, factor VIII, fibronectin, and factor XII. Since many components are made from whole blood, factor VIII is present in this component, but concentration would be low relative to unit volume. Fresh Frozen Plasma contains all the coagulation factors, >but the concentration of factor VIII would be low relative to unit volume. While a small amount of plasma is present in platelets, the amount of factor VIII present would be negligible.
A ficin (enzyme) treated panel can be a useful tool for determining the identity of an antibody. On a ficin-treated panel, reactions with which system would be enhanced? Rh Duffy MNS Kell
Rh Ficin treatment alters the surface of red blood cells such that interactions with Rh, Lewis and Kidd system antibodies are enhanced. Reactions with MNS (s is variably affected) and Duffy system (Fya and Fyb) antibodies are destroyed. Reactions with Kell system antibodies are unaffected.
The term used to describe patients with absence of Rh antigens is: Rhmod Rhnull Partial D Del
Rhnull In rare cases, individuals do not express any Rh antigens on their red blood cells. The term used to describe these individuals is Rhnull. Individuals that are Rhnull have mild compensated anemia, reticulocytosis, stomatocytosis, low hemoglobin and hematocrit, an increase in hemoglobin F, decreased serum haptoglobin, and in some cases, increased bilirubin. If a transfusion is needed, these patients would require blood from another Rhnull individual. Another set of individuals who are rare are those that have greatly reduced expression of Rh antigens due to suppression of the RH gene. Rhmod individuals have symptoms similar to those listed above, but in general the symptoms are less severe and not as significant clinically. Partial D is a mechanism in which the expression of D is weakened due to one or more D epitopes missing. These individuals are at risk for making an anti-D specific for the epitope that they are lacking. Expression of the other Rh antigens is normal in partial D. Del is a phenotype with very low D expression. Expression is so low in these patients that most anti-D will not detect the D antigen. Adsorption and elution methods can be used to detect the presence of D. Expression of the other Rh antigens is normal in Del.
What is the shelf-life of whole blood collected in CPDA-1? 21 days 28 days 35 days 48 days
35 days Whole blood collected with CPDA-1, or citrate-phosphate-dextrose-adenine, has a storage (shelf) life of 35 days from the date of collection. Whole blood collected with CPD (citrate-phosphate-dextrose), CP2D (citrate-phosphate-dextrose-dextrose), or ACD (acid-citrate-dextrose) has a storage (shelf) life of 21 days from the date of collection.
What is the maximum number of white blood cells allowed in a leukocyte-reduced unit of red blood cells? 5 x 10^6 1 x 10^10 5.5 x 10^10 3 x 10^11
5 x 10^6 A unit of leukocyte-reduced red blood cells cannot contain more than 5.0 x 10^6 white blood cells. A unit of apheresis granulocytes must contain at least 1.0 x 10^10 white blood cells. A unit of platelets must contain at least 5.5 x 10^10 platelets. Leukocyte-reduced apheresis platelets must contain at least 3.0 x 10^11 platelets in at least 90% of the units tested.
Of the following, what is the recommended routine testing to be performed on a newborn of a group B Rh positive female? ABO and Rh testing would routinely be performed in this scenario. ABO, Rh and DAT would routinely be performed in this scenario. ABO, Rh and antibody screening would routinely be performed in this scenario. ABO/Rh, DAT and/or antibody screening are NOT routinely performed in this scenario.
ABO/Rh, DAT and/or antibody screening are NOT routinely performed in this scenario. Hemolytic Disease of the Fetus and Newborn caused by antibodies in the ABO system is typically caused by anti-A, anti-B, and/or anti-A,B from a group O mother who gives birth to a non-O newborn. Therefore, it is acceptable practice NOT to test newborns of Rh-positive women with blood types other than group O. However, laboratories choosing this protocol typically retain cord blood for a period should it be needed. If signs of anemia present in a newborn of a non-group O, Rh-positive mother, it would be appropriate to test the newborn for ABO/Rh; a DAT would be indicated if the newborn is ABO-incompatible with the mother. An antibody screening is only necessary if the newborn is to be transfused.
A false-negative reaction while performing the DAT technique may be the result of: Red cell/AHG tube is over centrifuged Blood collected in tube containing silicone gel Saline used for wash stored in glass or metal container AHG addition delayed for 40 or more minutes
AHG addition delayed for 40 or more minutes AHG must be added immediately after washing to prevent the possibility of a false negative; a false negative can occur in this situation because previously bound globulins may dissociate from red cells, leaving insufficient antibody coating on the red cells to produce a reaction, or free antibody may directly neutralize antiglobulin reagent. Overcentrifugation, use of tubes containing silicone gel, and use of saline stored in glass or metal container can all result in false-positive results.
When would unexpected positive reactions be encountered during ABO forward typing? A or B subgroups Antigen depression due to leukemia Hypogammaglobulinemia Acquired B antigen
Acquired B antigen The acquired B antigen phenomenon can cause an unexpected positive reaction during ABO forward typing. It is usually found in group A individuals with intestinal diseases, where certain bacteria produce a deacetylating enzyme that can alter the A antigen to resemble the B antigen. A and B subgroups, and antigen depression due to leukemia may cause unexpected negative reactions during forward typing. Hypogammaglobulinemia may cause an unexpected negative reaction during reverse typing.
Which one of the following may cause a FALSE-NEGATIVE result with antiglobulin techniques? Dust or dirt is present in the glass tubes used for antiglobulin testing. Patient or donor blood specimen was collected in silicone gel tubes. Patient or donor blood specimen has a positive DAT. Addition of AHG reagent is delayed for 40 minutes or more after final saline wash.
Addition of AHG reagent is delayed for 40 minutes or more after final saline wash. The AHG reagent must be added to the cells immediately following washing. Antibodies may elute from the cells if the cells are allowed to sit in saline without the addition of the AHG reagent. The AHG reagent can be neutralized by the presence of the antibodies now present in the saline, causing a false negative result, or too little IgG antibody remains attached to the cells for detection by the AHG reagent. False-positive reactions can result from dust or dirt in the glassware used for testing (clumping could occur that is mistaken for agglutination). False-positive reactions can result from the use of samples collected in silicone gel tubes due to complement attachment. If the patient or donor has a positive DAT, antibody coating the patient or donor RBCs can interfere with antiglobulin testing, for instance, phenotyping with antisera requiring an antiglobulin phase of testing.
Which of the following groups of antibodies generally reacts most strongly at room temperature or 4oC? Anti-P1, anti-Leb, anti-M Anti-K, anti-Lua, anti-Fya Anti-S, anti-Jkb, anti-Leb Anti-K, anti-Lub, anti-s
Anti-P1, anti-Leb, anti-M Anti-P1, anti-Leb, and anti-M all react best at 4oC as they are predominantly IgM antibodies. The other antibody group choices above include IgG antibodies such as anti-K, anti-s, anti-S, anti-Fya, anti-Lub, and anti-Jkb, which react best at 37oC.
Which of the following individuals is a candidate to receive RhIg? An Rh positive mother upon delivery of her 3rd child. An Rh negative mother upon delivery of her first child. An Rh negative mother who had previously developed anti-D. An Rh positive mother who miscarried after 2 months.
An Rh negative mother upon delivery of her first child. Rh-negative mothers are candidates to receive RhIg to prevent the formation of immune anti-D. Administration of RhIg should be done both antepartum and post-partum of first and all subsequent pregnancies. Rh-negative individuals who have already produced immune anti-D are not candidates to receive RhIg. Rh-positive individuals are not candidates to receive RhIg.
Evaluate the panel shown above. Which antibody is most likely causing these reactions? Note: Use the reaction patterns to identify the most likely antibody. There may be additional antibodies present that cannot be ruled out. Anti-c Anti-D Anti-K Anti-Fya
Anti-D Panel cells that give negative reactions are used to rule out antibodies. Begin with the first negative panel cell reaction, place a line through the antigen specificity that is positive (+) on the panel. Continue with all the other negative reactions. If an antigen-antibody reaction did not occur, the antibody did not react with the antigen on the panel cell and it can be eliminated as a possible antibody. The answer for this panel is anti-D. The pattern of reactivity exactly matches the expression on the panel cells. Anti-D occurs most commonly in Rh negative mothers who have been exposed to the D antigen through the birth of Rh positive children. Anti-D can also be present due to the administration of RhIg (Rh immune globulin).
Which one of the following antibodies has been implicated in hemolytic disease of the fetus and newborn (HDFN)? Anti-I Anti-K Anti-Lea Anti-Leb
Anti-K Only IgG antibody can cross the placental barrier and enter the fetal circulation to attach to the specific antigen on the fetal red cells resulting in HDFN. IgM antibodies, which are larger than IgG, do not cross the placenta and therefore would not be implicated in HDFN. Of the non-Rh system antibodies, anti-K is considered the most clinically significant in its ability to cause HDFN. Anti-I is a common autoantibody, a saline-reactive IgM agglutinin, and is not associated with in vivo red blood cell destruction. Lewis antibodies (Anti-Lea and Anti-Leb) are generally IgM and do not cross the placenta.
Below are results of a mini-panel chosen to confirm anti-D and exclude other antibodies in an Rh negative woman at delivery who received antenatal RhIg and who has a positive antibody screen consistent with passive anti-D. Assuming that cell #7 is positive due to the passive immunization of anti-D in the mother, what is the most likely candidate for the other antibody(ies) present? Anti-K Anti-S Anti-E Anti-Fya
Anti-K There are guidelines for the interpretation of an antibody identification panel. One guideline is for ruling out. For negative reactions, if no reaction was observed, the antibody to the antigen on the panel probably was not present. The only cells that showed positive results were cells #1, #4, and #7. Since we are assuming that #7 was showing a positive result due to the passive anti-D and #1 and #4 cells that are positive for K, then the most likely antibody based on this panel would be anti-K. Anti-S would not be possible because there weren't positive reactions for cells #3, #5, and #6. Anti-E would not be possible because there weren't positive reactions for cells #5 and #6. Anti-Fya would not be possible because there weren't positive reactions for cells #3 and #6.
A technologist performing an antibody identification in the blood bank has recorded the following results found in the worksheet below. Which antibody(ies) are MOST LIKELY the cause of the agglutination reactions? Only anti-Jkb Anti-k and anti-Jkb Only Anti-Leb Anti-Jka and anti-E
Anti-k and anti-Jkb After evaluating the panel results, the antibodies that are most likely present and causing the agglutination pattern observed are Anti-E and Anti-Jka. There is a variation in strength seen (reaction strength is 2+ to 4+) suggesting multiple antibodies are present. When looking at anti-Jkb, Anti-k, and Anti-Leb,each are either ruled out and/or do not match the agglutination pattern present.
During routine inspection, a unit of unexpired blood was noticed to have a black color with numerous small clots. What is the likely cause for this observation? The unit was frozen Donor had DIC Viral contamination Bacterial contamination
Bacterial contamination Bacterial contamination can manifest itself in several ways including: the presence of clots, darker purple-black color of blood unit, unit can appear cloudy, hemolysis may be present. A unit that was frozen inadvertently should be discarded and would be hemolyzed upon returning to normal storage temperature. A donor with DIC would not have been in adequate health to be an acceptable donor. Viral contamination of a unit would likely not demonstrate visible signs of compromise.
Which of the following is the most common reagent source for anti-A1? Group A1 plasma Dolichos biflorous seed extracts (lectins) Bandeiraea simplicifolia seed extracts (lectins) Ulex europaeus seed extracts (lectins)
Dolichos biflorous seed extracts (lectins) Lectins are seed extracts that can be utilized in the laboratory to agglutinate red blood cells. The lectin from the seeds of Dolichos biflorus is commonly used as a source of anti-A1. The use of this lectin allows the blood bank laboratory to differentiate A1 individuals from A2 individuals. This is important because some A2 individuals can make anti-A1, causing an ABO discrepancy when doing reverse grouping (forward looks like group A, but reverse looks like group O). The use of Dolichos biflorus assists the blood banking laboratory in resolving this discrepancy so that the patient's ABO grouping can be determined. If the patient's red blood cells do not agglutinate with the lectin the patient may in fact be group A2 making an anti-A1. Group A1 individuals do not make anti-A1. See extracts from Bandeiraea simplicifolia serve as a source of Anti-B Seed extracts from Ulex europaeus serve as a source of anti-H.
The Rh nomenclature which uses the letters DCE is found in which of the following genetic models? Wiener Shorthand Fisher -Race Rosenfield
Fisher -Race Numerous genetic models have been proposed to describe the inheritance of the antigens within the Rh blood group system. Fisher and Race first proposed the existence of the three closely linked genes, and used the DCE terminology to describe their theory. They postulated that each gene produced an antigen expressed on the RBC surface. Wiener postulated that there was one gene present which produced an agglutinogen containing at least three antigens. Rh-Hr terminology is used to describe the Wiener theory. Shorthand refers to terminology that is used to describe Rh antigens inherited on one chromosome or haplotype. The use of shorthand allows clinical laboratory scientists to verbally communicate Rh antigens easier. An example is R1 which is used to represent the presence of DCe on one chromosome. Rosenfield is an alphanumeric terminology that assigns a number to antigens within different blood group systems. It was initiated due to the difficultly in assigning names to new antigens. In the Rh system Rh1 is D, Rh2 is C, Rh3 is E, Rh4 is c and Rh5 is e.
Which blood component is the most commonly used component for the replacement of multiple coagulation factor deficiencies in bleeding patients? Fresh Frozen Plasma Red Blood Cells Cryoprecipitate Whole Blood
Fresh Frozen Plasma Fresh Frozen Plasma (FFP) is indicated for bleeding patients with multiple coagulation factor deficiencies due to inadequate production, as in liver disease; excessive consumption, as in disseminated intravascular coagulation (DIC); or dilution, as in massive transfusion, generally defined as the replacement of one or more blood volumes in a period of 24 hours or less. FFP is also indicated for non-bleeding patients with multiple deficiencies who are undergoing invasive procedures. FFP is also used to reverse warfarin therapy in bleeding patients and for patients with congenital factor deficiencies for which no concentrates are available. Cryoprecipitate contains concentrated sources of fibrinogen and Factor VIII but would not be indicated for multiple factor deficiencies. Red blood cells and whole blood do not contain coagulation factors.
Which blood product should be shipped on dry ice? Fresh frozen plasma Whole blood Leukocyte-reduced red blood cells Apheresis granulocytes
Fresh frozen plasma Fresh frozen plasma and other frozen units must be shipped on dry ice. Whole blood and other red blood cell products such as leukocyte-reduced red blood cells must be transported on wet ice to be maintained between 1-10° C. Apheresis granulocytes must be kept at 20-24° C.
Which of the following blood group antigens are most susceptible to destruction by the action of enzymes? D Jka Lea Fya
Fya Duffy, or Fya and Fyb antigens, are most sensitive to enzyme treatment since they will be destroyed during this process. Enzyme panels can be helpful when multiple antibodies, including Duffy, are present in a patient sample. With the Duffy antigens destroyed, the panel can be performed to identify the remaining antibodies present. Other antigens that are sensitive to enzyme treatment include those of the MNS system and Xga. D, Jka, and Lea are enhanced by enzymes (Rh, Kidd, Lewis, P1, I, and ABO).
Marcus had a transfusion of packed RBC's 8 months ago following a surgery after a car accident. He is fully recovered and is otherwise healthy. How soon can Marcus donate a unit of blood? He can never donate a unit of blood. He can donate in 12 months. He can donate in 4 months. He can donate today.
He can donate today. The correct answer is, "he can donate today". The total deferral time following a blood transfusion is 3 months, as long as the donor meets all of the other requirements. This has recently changed. The deferral period after having received a blood transfusion used to be 12 months. Given Marcus received his transfusion 8 months ago, he would need not need to wait any additional time before he would be eligible to donate a unit of blood.
What section of an immunoglobulin molecule is responsible for the differences between immunoglobulin classes? Fc Fab Heavy chains Light chains
Heavy chains Antibodies are differentiated based on their heavy chains; different heavy chains create different isotypes. Humans have five different isotypes of immunoglobulins. The portion of antibodies where the C terminal region of each glycoprotein chain is located, is called the Fc portion. FC stands for fragment crystallizable. The FC portion of the immunoglobulin molecule after enzyme, papain, cleavage has structural identity and can be crystallized. The Fc portion has a constant amino acid sequence that defines the class and subclass of each antibody. The Fc portion is responsible for the biological activity of the antibody. Depending on the class of antibody, some of the functional activities of the Fc portion of antibodies include activating the complement pathway and binding to natural killer cells. Fab stands for fragment antigen binding and indicates the fragment after enzyme, papain, cleavage. The Fab section of an immunoglobulin molecule is the antigen-specific region. It has two light chains and portions of two heavy chains. It is a variable region that has two antigen-combining sites at the N-terminal ends. Light chains are small chains that are common to all immunoglobulin classes. L chains are of two subtypes: Kappa and lambda, which have different amino acid sequences and are antigenically different. Free light chains (FLCs)are incorporated into immunoglobulin molecules during B-lymphocyte development and expressed initially on the surface of immature B lymphocytes. In normal individuals, serum FLCs are rapidly cleared and metabolized by the kidneys depending on their molecular size.
The Major Histocompatibility Complex (MHC) codes for which antigens? ABO Kell Rhesus Human Leukocyte Antigens
Human Leukocyte Antigens The MHC, located on chromosome 6, codes for the human leukocyte antigens (HLA). ABO antigens are coded by the ABO locus on chromosome 9. The Kell blood group system gene is KEL, located on chromosome 7. Rhesus antigens are encoded by two closely-linked genes, known as RHD and RHCE, on chromosome 1.
The most significant blood group antibodies belong to which immunoglobulin classes? IgA and IgD IgA and IgM IgE and IgD IgG and IgM
IgG and IgM The most significant immunoglobulins in transfusion medicine are IgG and IgM. Most clinically important antibodies react at body temperature (37oC), are IgG, and can cause immune destruction of transfused red cells possessing the corresponding antigen. IgM antibodies react best at room temperature (20-22oC) or lower (to 4oC) and are usually not implicated in the destruction of transfused red cells. The important exception are the antibodies to ABO antigens. These antibodies are of the IgM class and react in vivo at room temperature and in vivo at body temperature. The transfusion of the wrong ABO blood group (antigen) would effectively activate the complement system and cause hemolysis of the transfused cells.
How does hydroxyurea aid in the treatment of sickle cell disease? Acts as an analgesic in pain management. Prevents sickle cells from clumping together. Induces increased production of HbF. Reduces the number of sickle cells that form.
Induces increased production of HbF. Hydroxyurea induces increased production of HbF. Most sickle cell patients who have increased levels of HbF experience milder forms of the disease than do patients with normal or low levels of HbF. Therefore, the focus of molecular treatments for sickle cell disease is to increase fetal hemoglobin (HbF). Anti-inflammatory agents are given to serve as an analgesic in pain management for sickle cell patients. Nitric oxide treatment prevents sickle cells from clumping together. Clotrimazole is an over-the-counter antifungal medication. This drug prevents water loss from the red blood cells, which helps prevent the formation of sickle cells.
What red blood cell component is indicated for patients who receive directed donations from immediate family members to prevent transfusion-associated graft versus host disease (TA-GVHD)? Irradiated Red Blood Cells Washed Red Blood Cells Leukocyte-reduced Red Blood Cells HLA matched Red Blood Cells
Irradiated Red Blood Cells Gamma-irradiation of blood components containing viable lymphocytes is very effective in preventing TA-GVHD. Irradiation is recommended for all Whole Blood, Red Blood Cell, Platelets, and Granulocyte transfusions to patients at risk. Patients at risk include neonates less than 4 months, patients with an acquired or congenital immunodeficiency, or patients receiving a directed donation from a family member. Irradiation prevents the proliferation of donor lymphocytes with a required dose of 25 Gy to the midplane of the blood container and a minimum of 15 Gy elsewhere. Washed components remove plasma proteins and are recommended for patients with allergies to plasma components, recipients with an IgA deficiency, maternal direct donations with an antibody to HLA to a neonate, complement removal to a patient with Post-transfusion purpura. Leukocyte-reduced components remove>99.9% of leukocytes and prevent the accumulation of cytokines during storage. They reduce the risk of febrile transfusion reactions, the risk of HLA alloimmunization, and the transmission of cytomegalovirus. Leukocyte reduction does not eliminate the risk of TA-GVHD.HLA testing is important for solid-organ and HPC transplantation. HLA-matched platelets are provided to patients with alloantibodies to HLA-A and HLA-B antigens.
Acute transfusion reactions are divided into categories based on all of the following symptoms EXCEPT: Fever Liver failure Allergic reaction Pulmonary involvement
Liver failure Acute transfusion reactions breakdown into three groups based on the presenting key clinical symptom: fever, allergic, or pulmonary. Liver failure is not indicated as a symptom in acute transfusion reactions. Fever is indicated in transfusion-associated sepsis (TAS), febrile nonhemolytic transfusion reaction (FNHTR), and acute hemolytic transfusion reaction (AHTR). Allergic (or allergy-mediated) transfusion reactions may be mild or severe. Pulmonary involvement is indicated in transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI).
Which of the following is responsible for causing transfusion associated graft-versus-host disease? Platelets Granulocytes Monocytes Lymphocytes
Lymphocytes Transfusion associated graft-versus-host reactions are caused by the engrafting of immunocompetent T lymphocytes into a severely immunosuppressed recipient. They can be prevented by gamma irradiation of cellular blood components. Platelets, monocytes, and granulocytes are not involved in transfusion associated graft-versus-host disease.
How does RhIg prevent anti-D production? Mainly by suppressing the immune response after exposure to D positive cells. Mainly by clearing antibody sensitized D negative RBCs from maternal circulation. Mainly by clearing IgG fetal antibodies from maternal circulation. Mainly by clearing maternal IgM antibodies from fetal circulation.
Mainly by suppressing the immune response after exposure to D positive cells. RhIg suppresses the immune response after exposure to D positive fetal cells and prevents the mother from producing anti-D. The mechanism is not clearly understood, but it may involve the removal of D-positive cells by macrophages, causing the release of cytokines that suppress the immune system response. Since it is the D positive cells that will stimulate the production of anti-D, the D negative cells are not a concern. Also, it is the fetal cells that cause the sensitization, not fetal immunoglobulins. The production of IgG antibodies is considered significant because they cross the placenta. Therefore, maternal IgM antibodies are not of concern.
Which of the following viruses or diseases is screened for in blood donors only using questions asked during the donor screening and selection process? Hepatitis B West Nile Virus Malaria HIV
Malaria Currently, there is no FDA-approved test available to screen donors for malarial infections. Donors are screened solely by questioning about travel to or residence in malaria-endemic areas. Blood donors are screened for Hepatitis B and HIV through both questioning and testing. Potential blood donors are asked questions about high-risk behaviors that are linked to hepatitis and/or HIV infection. Enzyme immunosorbent assays, chemiluminescent immunoassays, and NAT are methods used for donor screening for hepatitis and HIV. Blood donors are screened for West Nile Virus using NAT but are not asked any questions related to this virus during the donor selection and screening process.
Which of the following situations warrants postpartum administration of Rh immune globulin (RhIg)? Mother: D positive; Cord: D negative Mother: D negative; Cord: D negative Mother: D negative; Cord: D positive Mother: D positive; Cord: D positive
Mother: D negative; Cord: D positive A non-immunized D negative woman who delivers a D positive infant should receive a full dose of RhIg within 72 hours of delivery. RhIg prevents alloimmunization in D negative mothers exposed to D positive cells. Therefore, it is not needed if the mother is D positive or when the mother and baby are both D negative.
Which blood group antibody(ies) would you find in a group AB individual? Anti-A Anti-B Anti-A, Anti-B None
None Group AB individuals will have both the A antigens and B antigens on their red blood cells. These patients will NOT have anti-A or anti-B in their serum because those antibodies will go against their own red blood cell antigens. Group B patients will not have A antigens but, will have B antigens on their cells. They will have anti-A in their serum, but they will not have anti-B in their serum, which will give positive results with A cells and negative results B cells. Group A patients will have A antigens, but not B antigens on their cells. They will not have anti-A in their serum, but they will have anti-B. Group O patients will not have A or B antigens on their cells and they will have anti-A and anti-B in their serum.
What are the possible ABO genotypes of offspring from parents whose genotypes are OO and AB: AB and OO OA and OB AB OO
OA and OB The only possible genotypes in this case would be OA and OB. This is solved by utilizing a simple Punnett square. This leaves a 50% chance of an inherited OA type and a 50% chance of an inherited OB type.
A2B is suspected when a patient's ABO typing has the following results: Patient's red cells forward types as AB with anti-A1 present in the patient's serum. Patient's red cells forward types as A with anti-A1 and anti-B present in the patient's serum. Patient's red cells do not react with either Anti-A nor Anti-B, and anti-A1 and anti-B are present in the patient's serum. Patient's red cells forward types as A with a mixed field reaction of the patient's red cells with Anti-A, and anti-B detected in the patient's serum.
Patient's red cells forward types as AB with anti-A1 present in the patient's serum. A2B individuals may produce anti-A1. 22-35% of A2B individuals have anti-A1 in their serum. A2B individuals forward type as AB, and may demonstrate anti-A1 in their serum. A2 individuals forward types as A, and may demonstrate anti-A1 in their serum. A2 individuals will have anti-B in their serum. 1-8% of A2 individuals have naturally occurring anti-A1 in their serum. A patient whose red cells do not react with either Anti-A nor Anti-B, and have anti-A1 and anti-B are present in the their serum is type O. The A3 subgroup RBCs will have a mixed field pattern of agglutination with anti-A reagents.
All of the following are required to be in a machine-readable format on a blood component label, EXCEPT: ABO & Rh of the donor Product code Collection facility Outdate
The correct answer is outdate. The outdate may be handwritten, but must be legible. 21 CFR 606.121 requires this information be machine-readable: A unique collection facility identifier Lot number relating to the donor Product code ABO and Rh of the donor
Bacterial contamination is MOST likely in which of the following blood products? Packed red blood cells Frozen red blood cells Platelets Fresh frozen plasma
The correct answer is platelets. Bacterial contamination of platelets is most likely because they are stored at room temperature. The estimated rate of bacterial contamination in platelets is around 10%. Bacterial contamination is possible in packed red blood cells stored in the refrigerator, but the estimated rate of bacterial contamination is only around 0.2% Frozen red blood cells are not likely to have bacterial contamination. Fresh frozen plasma is not likely to have bacterial contamination.
When a unit of packed RBC's is split using the open system, each portion of the unit must be issued: Within 24 hours Within 48 hours Within 30 days By the original expiration date
The correct answer is within 24 hours. If a unit is entered without using a sterile connection device (open system), it must be used within 24 hours of entry. Closed systems retain the same expiration date as the original whole blood unit.
Lewis Blood Group System is a human blood group unlike most others. The antigen is produced and secreted by exocrine glands, eventually adsorbing to the surface of red blood cells. Its expression is based on the genetic expression of the Lewis and Secretor genes. Based on the following genotype (Le) (Se), what would you predict the Lewis antigen phenotypic expression to be? Le(a- b-) Le(a+ b+) Le(a- b+) Le(a+ b-)
The correct answer is: Le(a- b+) A person with a functional Lewis gene (Le) and functional Secretor gene (Se) expresses the phenotype Le(a-b+). The key to answering this question and all others like it, is simply memorizing the following chart: Le(a+b-): Le / sese Le(a-b+): Le / Se Le(a-b-): lele / sese or Se Essentially, a functional Lewis gene codes for the enzyme fucosyltransferase 3, which adds fucose to an oligosaccharide precursor at the penultimate position. Meanwhile, a functional Secretor gene codes for the enzyme fucosyltransferase 2, which adds fucose to an oligosaccharide precursor at the terminal position. If a person has Le expression but is a nonsecretor (sese), he will express a phenotype of Le(a+b-). If a person has Le expression and is also a secretor (Se), he will express a phenotype of Le(a-b+). If a person does not have Le expression (lele), it does not matter if he is a Secretor (Se) or nonsecretor (sese), he will always express the phenotype Le(a-b-).
Following a motorcycle accident, a man sustains heavy bleeding and is given two units of blood by your blood bank. The patient does not demonstrate any antibodies prior to the transfusion and cross matching the unit did not demonstrate incompatibility. Unfortunately, seven days later he is still anemic and has now developed a fever and jaundice. Antibody screening of a new specimen from this patient seven days after the transfusion reveals the presence of an antibody. What antibody do you suspect based on the case history and antibody screening results above? Anti-D Anti-e Anti-Jka Anti-Lea
The correct answer is: anti-Jka. This case concerns the delayed development of an antibody that is now causing a hemolytic transfusion reaction. The patient received blood two years ago, before which he did not demonstrate any antibodies. After the first transfusion, he may have developed an antibody that decreased in titer until it was undetectable. Now, two years later, he has been transfused more blood, and his antibody production has ramped back up and is attacking the donor red cells, causing anemia and resulting in fever and jaundice. Antibodies implicated in delayed hemolytic transfusion reactions (DHTR) include, from most to least common, Kidd, Duffy, Kell, and MNS. Anti-Jka (Kidd system) is the only antibody not ruled out in the antibody panel above (given these choices) and also implicated in DHTR. Anti-D is ruled out on screen cell #3. Anti-e is not ruled out, but only screen cell #2 is positive for the e antigen and the patient's serum reacted equally with both screen cells #1 and #2. This does not allow one to rule it out, but it is less likely to be implicated given this information. Anti-Lea is typically an IgM antibody, but in this case all three screen cells lack the Lea antigen so an antibody directed against this antigen would not be detected by this set of screening cells.
Why is it dangerous to transfuse a blood group O person with a unit of blood group A? The patient will make antibodies to the type A blood. The group A blood may become the prominent blood group. The patient's Anti-O would destroy the donor's cells with severe consequences to the patient. The patient's anti-A would destroy the donor's cells with severe consequences to the patient.
The patient's anti-A would destroy the donor's cells with severe consequences to the patient. Group O individuals have naturally occurring anti-A, anti-B, and anti-A,B. These antibodies are "naturally occurring" because they are produced without being exposed to foreign red blood cells. Transfusing group A blood cells into a patient who is group O will result in a hemolytic transfusion reaction where the body would mount an immune response with anti-A against the foreign cells entering the body. The consequences of such a reaction can be very dangerous for the patient. The answer "The patient will make antibodies to the type A blood" is incorrect, because a person with blood type O already has anti-A and anti-B antibodies in his/her serum. Again, these are "naturally occurring" antibodies, the patient does not have to be exposed to type A, type B, or type AB blood to produce these antibodies. The group A red cells would be destroyed by the anti-A present in this group O patient so they would not change the patient's blood group. Lastly, there is no anti-O antibody. The O gene is an amorph, meaning is does not code for a transferase so there is no O antigen for an antibody to be made toward.
When giving a whole blood donation to a patient, what consideration must be made in regards to the ABO/Rh compatibility between the recipient and the donor? The recipient and the donor ABO or Rh compatibilities are not a concern. The recipient and donor ABO and Rh types must be compatible. The recipient and donor ABO and Rh types must be identical. The recipient and donor ABO types must be identical, but the Rh does not matter.
The recipient and donor ABO and Rh types must be identical. Because whole blood donations contain all blood products, including plasma and red blood cells, the donor and recipient ABO and RH must be identical to prevent a transfusion reaction or the development of Anti-D antibodies. ABO and Rh compatibilities are not typically a concern in platelet donations. However, donor and recipient ABO and Rh must be identical in whole blood donations since they contain all blood products. To not regard ABO and Rh compatibility would cause a transfusion reaction. Though ABO and Rh compatibility is safe for donated red blood cells, whole blood also contains plasma. Because of this, the ABO and Rh of donor and recipient must be identical to prevent a transfusion reaction. The Rh is a consideration because not matching a donor, and recipient Rh may cause the recipient to develop anti-D following the transfusion. Like with red cell donations, transfusing Rh-positive blood into Rh-negative recipients should only be done in specific circumstances and as a last option.
Which of the following noninfectious complications of blood transfusion is prevented by the irradiation of blood components? Anaphylactic reactions Febrile non-hemolytic reactions Transfusion-related acute lung injury (TRALI) Transfusion-associated graft versus host disease (TA-GVHD)
Transfusion-associated graft versus host disease (TA-GVHD) Irradiation prevents the proliferation of donor T lymphocytes in blood components. T lymphocytes in blood components may cause TA-GVHD in patients who are immunocompromised, who are receiving components from a blood relative, or who receive HLA-matched components. Washed components or components from IgA-deficient donors are indicated for patients at risk for anaphylactic reactions. The incidence of febrile non-hemolytic reactions has been reduced through the implementation of universal leukoreduction. One mitigation strategy to reduce the incidence of TRALI is to collect components from male donors, female donors who have never been pregnant, or female donors who have been tested since their last pregnancy and are negative for HLA antibodies.
When performing an anti-human globulin (AHG) test, it is important to completely wash the red cells because: Washing eliminates concentrations of unbound antigens. Washing prevents elution of cell-bound antibody. Washing promotes false positive effects of rouleaux. Washing prevents neutralization of the anti-human globulin (AHG) serum.
Washing prevents neutralization of the anti-human globulin (AHG) serum. In the AHG test procedure, the source of antigen for potential reaction comes from red blood cells. Washing procedures that remove red blood cells or antigen from the testing system would invalidate any testing results. In a positive AHG test, antibody is bound to antigen after the incubation stage. Washing should not remove cell-bound antibody, nor would it prevent bound antibody from eluting from the antigen. The effects of rouleaux may be noted in test systems in which the protein content is high. Washing removes protein from the test system, so rouleaux is not a cause of false positive reactions in AHG testing. Inadequate cell washing will lead to unbound antibody remaining in the red cell suspension. This residual unbound antibody would be available to neutralize the AHG (Coombs serum), so it will not react with red blood cells (antigen) bound with antibody.
