Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers, Exams of Medical Sciences

Download Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers and more Exams Medical Sciences in PDF only on Docsity! Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers What type of serological testing does the blood bank technologist perform when determining the blood group of a patient? A. Genotyping B. Phenotyping C. Both genotyping and phenotyping D. Polymerase chain reaction - correct answer B Phenotyping, or the physical expression of a genotype, is the type of testing routinely performed in the blood bank. An individual, for example, may have the AO genotype but phenotypes as group A. If anti-K reacts 3+ with a donor cell with a genotype KK and 2+ with a Kk cell, the antibody is demonstrating: A. Dosage B. Linkage disequilibrium Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers C. Homozygosity D. Heterozygosity - correct answer A Dosage is defined as an antibody reacting stronger with homozygous cells (such as KK) than with heterozygous cells (such as Kk). In addition to Kell, dosage effect is seen commonly with antigens M, N, S, s, Fya, Fyb, Jka, Jkb, and the antigens of the Rh system. Carla expresses the blood group antigens Fya, Fyb, and Xga. James shows expressions of none of these antigens. What factor(s) may account for the absence of these antigens in James? A. Gender B. Race C. Gender and race D. Medication - correct answer C The frequency of Duffy antigens Fya and Fyb varies with race. The Fy(a−b−) phenotype occurs in almost 70% of African Americans and is very rare in Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers type is expressed by the genotype hh. Bombays produce naturally occurring anti-H, and their serum agglutinates group O red cells in addition to red cells from groups A, B, and AB persons. Meiosis in cell division is limited to the ova and sperm producing four gametes containing what complement of DNA? A. 1N B. 2N C. 3N D. 4N - correct answer A Meiosis involves two nuclear divisions in succession resulting in four gametocytes each containing half the number of chromosomes found in somatic cells or 1N. A cell that is not actively dividing is said to be in: Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. Interphase B. Prophase C. Anaphase D. Telophase - correct answer A Interphase is the stage in between cell divisions. The cell is engaged in metabolic activity. Chromosomes are not clearly discerned; however, nucleoli may be visible. Which of the following describes the expression of most blood group antigens? A. Dominant B. Recessive C. Codominant Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. Corecessive - correct answer C The inheritance of most blood group genes is codominant, meaning that no gene or allele is dominant over another. For example, a person who is group AB expresses both the A and B antigen on his or her red cells. What blood type is not possible for an offspring of an AO and BO mating? A. AB B. A or B C. O D. All are possible - correct answer D A mating between AO and BO persons can result in an offspring with a blood type of A, B, AB, or O. The alleged father of a child in a disputed case of paternity is blood group AB. The mother is group O and the child is group O. What type of exclusion is this? Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers In this type of inheritance, the father carries the trait on his X chromosome. He has no sons with the trait because he passed his Y chromosome to his sons; however, all his daughters will express the trait. A. Autosomal dominant B. Autosomal recessive C. X-linked dominant D. X-linked recessive - correct answer C In X-linked dominant inheritance, there is absence of male-to-male transmission because a male passes his Y chromosome to all of his sons and his single X chromosome to all his daughters. All daughters who inherit the affected gene will express the trait. An example of this type of inheritance is the Xga blood group. Why do IgM antibodies, such as those formed against the ABO antigens, have the ability to directly agglutinate red blood cells (RBCs) and cause visible agglutination? Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. IgM antibodies are larger molecules and have the ability to bind more antigen B. IgM antibodies tend to clump together more readily to bind more antigen C. IgM antibodies are found in greater concentrations than IgG antibodies D. IgM antibodies are not limited by subclass specificity - correct answer A An IgM molecule has the potential to bind up to 10 antigens, as compared to a molecule of IgG, which can bind only two. Which of the following enhancement mediums decreases the zeta potential, allowing antibody and antigen to come closer together? A. LISS B. Polyethylene glycol C. Polybrene Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. ZZAP - correct answer A LISS contains a reduced concentration of NaCl (0.2%) and results in a reduction in charged ions within the ionic cloud, decreasing the zeta potential and facilitating antigen and antibody interaction. This type of antibody response is analogous to an anamnestic antibody reaction. A. Primary B. Secondary C. Tertiary D. Anaphylactic - correct answer B An anamnestic response is a secondary immune response in which memory lymphocytes respond rapidly to foreign antigen in producing specific antibody. The antibodies are IgG and are produced at lower doses of antigen than in the primary response. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. The patient may have developed alloantibodies - correct answer C Bombay is the only ABO phenotype incompatible with O cells. The red cells of a Bombay show a negative reaction to anti-H because the cells contain no H substance. What antibodies are formed by a Bombay individual? A. Anti-A and anti-B B. Anti-H C. Anti-A,B D. Anti-A, B, and H - correct answer D A Bombay individual does not express A, B, or H antigens; therefore anti-A, B, and H are formed. Because a Bombay individual has three antibodies, the only compatible blood must be from another Bombay donor. Acquired B antigens have been found in: Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. Bombay individuals B. Group O persons C. All blood groups D. Group A persons - correct answer D The acquired B phenomenon is only seen in group A persons. Blood is crossmatched on an A positive person with a negative antibody screen. The patient received a transfusion of A positive RBCs 3 years ago. The donors chosen for crossmatch were A positive. The crossmatch was run on the Ortho Provue and yielded 3+ incompatibility. How can these results be explained? A. The patient has an antibody to a low-frequency antigen B. The patient has an antibody to a high-frequency antigen C. The patient is an A2 with anti-A1 Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. The patient is an A1 with anti-A2 - correct answer C The patient is likely an A2 with anti-A1 which is causing reactivity in the crossmatch. A negative antibody screen rules out the possibility of an antibody to a high-frequency antigen, and two donor units incompatible rules out an antibody to a low-frequency antigen. A patient's red cells forward as group O, serum agglutinates B cells (4+) only. Your next step would be: A. Extend reverse typing for 15 minutes B. Perform an antibody screen including a room- temperature incubation C. Incubate washed red cells with anti-A1 and anti-A,B for 30 minutes at room temperature D. Test patient's red cells with Dolichos biflorus - correct answer C The strong 4+ reaction in reverse grouping suggests the discrepancy is in forward grouping. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers C. B D. AB - correct answer B A person in need of an RBC transfusion who is an A2 with anti-A1 can be transfused A or O cells because the anti-A1 is typically only reactive at room temperature. What should be done if all forward and reverse ABO results as well as the autocontrol are positive? A. Wash the cells with warm saline, autoadsorb the serum at 4°C B. Retype the sample using a different lot number of reagents C. Use polyclonal typing reagents D. Report the sample as group AB - correct answer A These results point to a cold autoantibody. Washing the cells with warm saline may elute the autoantibody, allowing a valid forward type to be performed. The serum should be adsorbed using Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers washed cells until the autocontrol is negative. Then the adsorbed serum should be used for reverse typing. What should be done if all forward and reverse ABO results are negative? A. Perform additional testing such as typing with anti-A1 lectin and anti-A,B B. Incubate at 22°C or 4°C to enhance weak expression C. Repeat the test with new reagents D. Run an antibody identification panel - correct answer B All negative results may be due to weakened antigens or antibodies. Room temperature or lower incubation temperature may enhance expression of weakened antigens or antibodies. N-acetyl-D-galactosamine is the immunodominant carbohydrate that reacts with: A. Arachis hypogaea Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. Salvia sclarea C. Dolichos biflorus D. Ulex europeaus - correct answer C The immunodominant sugar N-acetyl- galactosamine confers A antigen specificity when present at the terminus of the type 2 precursor chain on the RBC membrane. Therefore, its presence would cause RBCs to react with anti-A1 lectin, Dolichos biflorus. A stem cell transplant patient was retyped when she was transferred from another hospital. What is the most likely cause of the following results? Patient cells: Anti-A, neg Anti-B, 4+ Patient serum: A1 cells, neg B cells, neg A. Viral infection B. Alloantibodies Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B cells and O cells. An identification panel should be performed. An acquired B person or someone with hypogammaglobulinemia should not make antibody that would agglutinate O cells. Which condition would most likely be responsible for the following typing results? Patient cells: Anti-A, neg Anti-B, neg Patient serum: A1 cells, neg B cells, 4+ A. Immunodeficiency B. Masking of antigens by the presence of massive amounts of antibody C. Weak or excessive antigen(s) D. Impossible to determine - correct answer C Excessive A substance, such as may be found in some types of tumors, may be neutralizing the anti-A. Weak A subgroups may fail to react with anti-A Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers and require additional testing techniques (e.g., room- temperature incubation) before their expression is apparent. Which of the following results is most likely discrepant? Anti-A, neg Anti-B, 4+ A1 cells, neg B cells, neg A. Negative B cells B. Positive reaction with anti-B C. Negative A1 cells D. No problem with this typing - correct answer C The reverse typing should agree with the forward typing in this result. The 4+ reaction with anti-B indicates group B. A positive reaction is expected with A1 cells in the reverse group. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A 61-year-old male with a history of multiple myeloma had a stem cell transplant 3 years ago. The donor was O positive and the recipient was B positive. He is admitted to a community hospital for fatigue and nausea. Typing results reveal the following: Anti-A = 0 Anti-B =0 Anti-A,B = 0 Anti-D = 4+ A1 cells = 4+ B cells = 0 How would you report this type? A. O positive B. B positive C. A positive D. Undetermined - correct answer D In a transplant scenario, there are no methods to employ to solve the discrepancy. The technologist must rely on the patient history of donor type and recipient type, and the present serological picture. A B-positive recipient given an O-positive transplant constitutes a minor ABO mismatch. The forward type resembles the donor. The reverse type still Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers test would yield positive results independent of the presence or absence of the D antigen on the red cells. Which donor unit is selected for a recipient with anti-c? A. r ŕ B. R0R1 C. R2r ́ D. r ́ry - correct answer D The designation r ́ is dCe and r y is dCE, neither of which contains the c antigen. The other three Rh types contain the c antigen and could not be used in transfusion for a person with anti-c. Which genotype usually shows the strongest reaction with anti-D? A. DCE\DCE Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. Dce\dCe C. D-\D- D. -CE\-ce - correct answer C The phenotype that results from D-\D- is classified as enhanced D because it shows a stronger reaction than expected with anti-D. Such cells have a greater amount of D antigen than normal. This is thought to result from a larger quantity of precursors being available to the D genes because there is no competition from other Rh genes. Why is testing for Rh antigens and antibodies different from ABO testing? A. ABO reactions are primarily due to IgM antibodies and usually occur at room temperature; Rh antibodies are IgG and agglutination usually requires a 37°C incubation and enhancement media B. ABO antigens are attached to receptors on the outside of the red cell and do not require any special enhancement for testing; Rh antigens are loosely Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers attached to the red cell membrane and require enhancement for detection C. Both ABO and Rh antigens and antibodies have similar structures, but Rh antibodies are configured so that special techniques are needed to facilitate binding to Rh antigens D. There is no difference in ABO and Rh testing; both may be conducted at room temperature with no special enhancement needed for reaction - correct answer A Detection of ABO and Rh antigens and antibodies requires different reaction conditions. ABO antibodies are naturally occurring IgM molecules and react best at room temperature. Rh antibodies are generally immune IgG molecules that result from transfusion or pregnancy. Detection may require 37°C incubation and\or enhancement techniques. Testing reveals a weak D that reacts 1+ after indirect antiglobulin testing (IAT). How is this result classified? A. Rh-positive B. Rh-negative, Du positive Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. Most weak D individuals make anti-D C. The problem could be due to a disease state D. A D mosaic may make antibodies to missing antigen parts - correct answer D The D antigen is comprised of different parts designated as a mosaic. If an individual lacks parts of the antigen, he or she may make antibodies to the missing parts if exposed to the whole D antigen. Which offspring is not possible from a mother who is R1R2 and a father who is R1r? A. DcE\DcE B. Dce\DCe C. DcE\DCe D. Dce\dce - correct answer A DcE\DcE (R2R2) is not possible because Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers R2 can be inherited only from the mother and is not present in the father. Why is testing a pregnant woman for weak D not required? A. An Rh-negative fetus may yield false positive results in a fetal maternal bleed B. An Rh-positive fetus may yield false positive results in a fetal maternal bleed C. D antigen strength decreases during pregnancy D. D antigen strength increases during pregnancy - correct answer B If a weak D test is performed on a pregnant woman with no previous history, a false-positive weak D test may result from the presence of fetal blood if the fetus is Rh positive. A pregnant woman with weak D may be given Rh immune globulin without any harmful consequences. Therefore, weak D testing of pregnant women is not necessary. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers What antibodies could an R1R1 make if exposed to R2R2 blood? A. Anti-e and anti-C B. Anti-E and anti-c C. Anti-E and anti-C D. Anti-e and anti-c - correct answer B The R1R1 (DCe\DCe) individual does not have the E or c antigen, and could make anti-E and anti-c antibodies when exposed to R2R2 cells (DcE\DcE). What does the genotype —\— represent in the Rh system? A. Rh negative B. D mosaic C. Rhnull Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. The alleles are named R1, R2, R0, r, r ́, r ̋, Rz, and ry C. There are multiple alleles at a single complex locus that determine each Rh antigen D. The antigens are named D, C, E, c, and e - correct answer C Wiener proposed a single-locus theory for Rh, with multiple alleles determining surface molecules that embody numerous antigens. The Wiener nomenclature for the E antigen is: A. hr ́ B. hrv ́ C. rh ̋ D. Rh0 - correct answer C The Wiener designation for the E antigen is rh .̋ The Wiener designation hr ́ denotes c, hr ̋ denotes e, and Rh0 is D. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A physician orders 2 units of leukocyte-reduced red blood cells. The patient is a 55-year-old male with anemia. He types as an AB negative, and his antibody screen is negative. There is only 1 unit of AB negative in inventory. What is the next blood type that should be given? A. AB positive (patient is male) B. A negative C. B negative D. O negative - correct answer B While giving Rh-positive RBCs to an Rh- negative patient would not harm the patient in this case, because he is male, giving A negative would be the first choice. You should not expose a patient to the D antigen, if possible, and the residual anti-B in a unit of A-negative packed cells is less immunogenic than giving B or O red cells. Which technology may report an Rh-weak D positive as Rh negative? Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. Gel System B. Solid Phase C. Tube Testing D. None of these options - correct answer A The Gel system cannot detect a weak D phenotype because there is no 37°C or AHG phase with the ABD card. A patient has the Lewis phenotype Le(a−b−). An antibody panel reveals the presence of anti-Lea. Another patient with the phenotype Le(a−b+) has a positive antibody screen; however, a panel reveals no conclusive antibody. Should anti-Lea be considered as a possibility for the patient with the Le(a−b+) phenotype? A. Anti-Lea should be considered as a possible antibody B. Anti-Lea may be a possible antibody, but further studies are needed Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers Which of the following statements is true concerning the MN genotype? A. Antigens are destroyed using bleach-treated cells B. Dosage effect may be seen for both M and N antigens C. Both M and N antigens are impossible to detect because of cross-interference D. MN is a rare phenotype seldom found in routine antigen typing - correct answer B Dosage effect is the term used to describe the phenomenon of an antibody that reacts more strongly with homozygous cells than with heterozygous cells. Dosage effect is a characteristic of the genotype MN because the M and N antigens are both present on the same cell. This causes a weaker reaction than seen with RBCs of either the MM or NN genotype, which carry a greater amount of the corresponding antigen. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers Anti-M is sometimes found with reactivity detected at the immediate spin (IS) phase that persists in strength to the IAT phase. What is the main testing problem with a strong anti-M? A. Anti-M may not allow detection of a clinically significant antibody B. Compatible blood may not be found for the patient with a strongly reacting anti-M C. The anti-M cannot be removed from the serum D. The anti-M may react with the patient's own cells, causing a positive autocontrol - correct answer A While anti-M may not be clinically significant, a strongly reacting anti-M that persists through to the IAT phase may interfere with detection of a clinically significant antibody that reacts only at IAT. A patient is suspected of having paroxysmal cold hemoglobinuria (PCH). Which pattern of reactivity is characteristic of the Donath-Landsteiner antibody, which causes this condition? Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. The antibody attaches to RBCs at 4°C and causes hemolysis at 37°C B. The antibody attaches to RBCs at 37°C and causes agglutination at the IAT phase C. The antibody attaches to RBCs at 22°C and causes hemolysis at 37°C D. The antibody attaches to RBCs and causes agglutination at the IAT phase - correct answer A The Donath-Landsteiner antibody has anti-P specificity with biphasic activity. The antibody attaches to RBCs at 4°C and then causes the red cells to hemolyze when warmed to 37°C. How can interfering anti-P1 antibody be removed from a mixture of antibodies? A. Neutralization with saliva B. Agglutination with human milk Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. Anti-D, anti-e, anti-C C. Anti-M, anti-N D. Anti-Fya, anti-Fyb - correct answer C Antibodies to the M and N antigens are IgM antibodies commonly found as cold agglutinins. Which of the following antibodies characteristically gives a refractile mixed-field appearance? A. Anti-K B. Anti-Dia C. Anti-Sda D. Anti-s - correct answer C Anti-Sda characteristically gives a refractile mixed-field agglutination reaction in the IAT phase. The refractile characteristic is more evident under the microscope. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers What does the 3+3 rule ascertain? A. An antibody is ruled in B. An antibody is ruled out C. 95% confidence that the correct antibody has been identified D. 95% confidence that the correct antibody has not been identified - correct answer C The 3+3 rule ascertains correct identification of antibody at a confidence level of 95%. For this level to be met, reagent red cells are found containing target antigen to suspected antibody that react in test phase; likewise, reagent red cells devoid of antigen will not react in test phase. The k (Cellano) antigen is a high-frequency antigen and is found on most red cells. How often would one expect to find the corresponding antibody? A. Often, because it is a high frequency antibody Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. Rarely, because most individuals have the antigen and therefore would not develop the antibody C. It depends upon the population, because certain racial and ethnic groups show a higher frequency of anti-k D. Impossible to determine without consulting regional blood group antigen charts - correct answer B The k antigen is found with a frequency of 99.8%; therefore, the k-negative person is rare. Because k-negative individuals are very rare, the occurrence of anti-k is also rare. Which procedure would help to distinguish between an anti-e and anti-Fya in an antibody mixture? A. Lower the pH of test serum B. Run an enzyme panel C. Use a thiol reagent Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A technologist performs an antibody study and finds 1+ and weak positive reactions for several of the panel cells. The reactions do not fit a pattern. Several selected panels and a patient phenotype do not reveal any additional information. The serum is diluted and retested, but the same reactions persist. What type of antibody may be causing these results? A. Antibody to a high-frequency antigen B. Antibody to a low-frequency antigen C. High titer low avidity (HTLA) D. Anti-HLA - correct answer C HTLA antibodies may persist in reaction strength, even when diluted. These antibodies are directed against high-frequency antigens (such as Cha). They are not clinically significant but, when present, are responsible for a high incidence of incompatible crossmatches. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers An antibody is detected in a pregnant woman and is suspected of being the cause of fetal distress. The antibody reacts at the IAT phase but does not react with DTT-treated cells. This antibody causes in vitro hemolysis. What is the most likely antibody specificity? A. Anti-Lea B. Anti-Lua C. Anti-Lub D. Anti-Xga - correct answer C Of the antibodies listed, only Lub is detected in the IAT phase, causes in vitro hemolysis, may cause HDN, and does not react with DTT-treated cells. What sample is best for detecting complement- dependent antibodies? A. Plasma stored at 4°C for no longer than 24 hours B. Serum stored at 4°C for no longer than 48 hours Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers C. Either serum or plasma stored at 20°C-24°C no longer than 6 hours D. Serum heated at 56°C for 30 minutes - correct answer B Serum stored at 4°C for no longer than 48 hours preserves complement activity. Plasma is inappropriate because most anticoagulants chelate calcium needed for activation of complement. Heating the serum to 56°C destroys complement. Which antibody would not be detected by group O screening cells? A. Anti-N B. Anti-A1 C. Anti-Dia D. Anti-k - correct answer B ABO antibodies are not detected by group O screening cells, because O cells contain no A or B antigens. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. Anti-Fyb Link to Panels (https://docs.google.com/document/d/1PTPii_JLOi- ow0MWtPPDn4NMQB-AGkN_mKYVj_A2xmg/edit? usp=sharing) - correct answer B To rule out an antibody, there should be a homozygous cell with the corresponding antigen that fails to react with the serum. Of the choices, anti-C was not ruled out on Panel 2. To rule this antibody out, a cell that is homozygous for C and negative for K (the other probable antibody) would be run against patient serum. A positive reaction supports the presence of anti-C, whereas a negative reaction would rule out anti-C. On Panel 2, which cells are homozygous for C? A. 1, 2, 3 B. 1, 2, 9 C. 3, 4, 7 D. 7, 8, 10 Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers Link to Panels (https://docs.google.com/document/d/1PTPii_JLOi- ow0MWtPPDn4NMQB-AGkN_mKYVj_A2xmg/edit? usp=sharing) - correct answer B On panel cells 1, 2, and 9, the C antigen is present and the c antigen is absent, rendering the cells homozygous for C. A 77-year-old female is admitted to a community hospital after a cardiac arrest. History includes an abdominal aortic aneurysm 2 years ago in which she received 6 units of packed cells. Her blood type is A positive and antibody screen is positive at AHG phase in screening cells II and III. A panel is performed using LISS. Referring to panel 3, which antibodies are likely implicated? A. C and K B. Jka and c C. E and c D. Fya and M Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers Link to Panels (https://docs.google.com/document/d/1PTPii_JLOi- ow0MWtPPDn4NMQB-AGkN_mKYVj_A2xmg/edit? usp=sharing) - correct answer C The antibodies evident in the panel are E and c. Every positive reaction at 37°C and IAT phases are positive for either the E antigen and\or for cells homozygous for c antigen. What observation is apparent with one of the antibodies present on Panel 3? A. One antibody is only reacting with heterozygous cells B. Both antibodies are only reacting with homozygous cells C. One antibody is only reacting with homozygous cells D. Both antibodies are exhibiting dosage Link to Panels (https://docs.google.com/document/d/1PTPii_JLOi- ow0MWtPPDn4NMQB-AGkN_mKYVj_A2xmg/edit? usp=sharing) - Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. High-frequency alloantibody or a mixture of alloantibodies C. A warm autoantibody D. A cold and warm alloantibody - correct answer B High-frequency alloantibodies or a mixture of alloantibodies may cause all three screening cells to be positive. A negative autocontrol would rule out autoantibodies. What does a minor crossmatch consist of? A. Recipient plasma and recipient red cells B. Recipient plasma and donor red cells C. Recipient red cells and donor plasma D. Donor plasma and donor red cells - correct answer C A minor crossmatch consists of recipient red cells and donor serum or plasma. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers Can crossmatching be performed on October 14th using a patient sample drawn on October 12th? A. Yes, a new sample would not be needed B. Yes, but only if the previous sample has no alloantibodies C. No, a new sample is needed because the 2-day limit has expired D. No, a new sample is needed for each testing - correct answer A Compatibility testing may be performed on a patient sample within 3 days of the scheduled transfusion; however, if the patient is pregnant or was transfused within 3 months, the sample must be less than 3 days old. A type and screen was performed on a 32-year-old woman, and the patient was typed as AB negative. There are no AB-negative units in the blood bank. What should be done? A. Order AB-negative units from a blood supplier Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. Check inventory of A-, B-, and O-negative units C. Ask the patient to make a preoperative autologous donation D. Nothing—the blood will probably not be used - correct answer B An AB person is the universal recipient and may receive any blood type; because only a type and screen were ordered and blood may not be used, check inventory for A-, B-, and O-negative units. What ABO types may donate to any other ABO type? A. A negative, B negative, AB negative, O negative B. O negative C. AB negative D. AB negative, A negative, B negative - correct answer B An O-negative individual has no A or B antigens and may donate red cells to any other ABO type. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers because the major crossmatch uses recipient serum and not donor serum. Other tests such as ABO, Rh, and antibody screen on the recipient also would not be affected. Which of the following is not a requirement for the electronic crossmatch? A. The computer system contains logic to prevent assignment and release of ABO incompatible blood B. There are concordant results of at least two determinations of the recipient's ABO type on record, one of which is from the current sample C. Critical elements of the system have been validated on site D. There are concordant results of at least one determination of the recipient's ABO type on file - correct answer D ABO determinations must be concordant on at least two occasions, including the current sample. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A patient showed positive results with screening cells and 4 donor units. The patient autocontrol was negative. What is the most likely antibody? A. Anti-H B. Anti-S C. Anti-Kpa D. Anti-k - correct answer D Anti-k (cellano) is a high-frequency alloantibody that would react with screening cells and most donor units. The negative autocontrol rules out autoantibodies. Anti-H and anti-S are cold antibodies and anti-Kpa is a low-frequency alloantibody. Screening cells and major crossmatch are positive on IS only, and the autocontrol is negative. Identify the problem. A. Cold alloantibody Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. Cold autoantibody C. Abnormal protein D. Antibody mixture - correct answer A A cold alloantibody would show a reaction with screening cells and donor units only at IS phase. The negative autocontrol rules out autoantibodies and abnormal protein. Six units are crossmatched. Five units are compatible, one unit is incompatible, and the recipient's antibody screen is negative. Identify the problem: A. Patient may have an alloantibody to a high-frequency antigen B. Patient may have an abnormal protein C. Donor unit may have a positive DAT D. Donor may have a high-frequency antigen - correct answer C The incompatible donor unit may have Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. Obtain a different enhancement medium for testing - correct answer B Antigen typing or phenotyping of the patient's cells confirms the antibody identification; antigen typing of donor cells helps ensure the crossmatch of compatible donor units. What is the disposition of a donor red blood cell unit that contains an antibody? A. The unit must be discarded B. Only the plasma may be used to make components C. The antibody must be adsorbed from the unit D. The unit may be labeled indicating it contains antibody and released into inventory - correct answer D The unit may be used in the general blood inventory, if it is properly labeled and only cellular elements are used. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers Given a situation where screening cells, major crossmatch, autocontrol, and DAT (anti-IgG) are all positive, what procedure should be performed next? A. Adsorption using rabbit stroma B. Antigen typing of patient cells C. Elution followed by a cell panel on the eluate D. Selected cell panel - correct answer C A positive DAT using anti-IgG indicates that antibodies are coating the patient cells. An eluate would be helpful to remove the antibody, followed by a cell panel in order to identify it. A major crossmatch and screening cells are 2+ at IS, 1+ at 37°C, and negative at the IAT phase. Identify the most likely problem. A. Combination of antibodies B. Cold alloantibody Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers C. Rouleaux D. Test error - correct answer B The reaction pattern fits that of a cold antibody reacting at the IS phase and of sufficient titer to persist at 37°C incubation. The reactions disappear in the IAT phase. What corrective action should be taken when rouleaux causes positive test results? A. Perform a saline replacement technique B. Perform an autoabsorption C. Run a panel D. Perform an elution - correct answer A Rouleaux may be dispersed or lessened by using the saline replacement technique. This involves recentrifuging the tube, then withdrawing serum and replacing it with 2 drops of saline. The tube is respun and examined for hemolysis. Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. ABO and Rh typing B. Type and screen C. Major crossmatch D. All of these options - correct answer A The only requirement for transfusing an autologous unit is a check of the ABO and Rh type. A patient types as AB positive. Two units of blood have been ordered by the physician. Currently, the inventory shows no AB units, 10 A-positive units, 1 A-negative unit, 5 B-positive units, and 20 O-positive units. Which should be set up for the major crossmatch? A. A-positive units B. O-positive units C. B-positive units Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. Call another blood supplier for type-specific blood - correct answer A The type chosen should be A-positive red cell units. Although all choices would be compatible, the first choice should be A-positive because this unit will contain residual plasma anti-B. Anti-B is less immunogenic than anti-A, which would be present, albeit in small amounts, in B-positive and O-positive units. Which of the following comprises an abbreviated crossmatch? A. ABO, Rh, and antibody screen B. ABO, Rh, antibody screen, IS crossmatch C. Type and screen D. ABO, Rh, IS crossmatch - correct answer B The abbreviated crossmatch usually consists of a type and screen and an immediate spin crossmatch. When may an IS crossmatch be performed? Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. When a patient is being massively transfused B. When there is no history of antibodies and the current antibody screen is negative C. When blood is being emergency released D. When a patient has not been transfused in the past 3 months - correct answer B The IS crossmatch may be performed when the patient has no history of antibodies and the current antibody screen is negative. A patient had a transfusion reaction to packed red blood cells. The medical laboratory scientist began the laboratory investigation of the transfusion reaction by assembling pre- and post-transfusion specimens and all paperwork and computer printouts. What should he do next? A. Perform a DAT on the post-transfusion sample B. Check for a clerical error(s) Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers example of a reaction caused by an antibody such as anti-Jka. What may be found in the serum of a person who is exhibiting signs of TRALI (transfusion-related acute lung injury)? A. Red blood cell alloantibody B. IgA antibody C. Antileukocyte antibody D. Allergen - correct answer C TRALI is associated with antibodies to human leukocyte antigens or neutrophil antigens, which react with patient granulocytes and cause acute respiratory insufficiency. Which type of transfusion reaction occurs in about 1% of all transfusions, results in a temperature rise of 1°C or higher, is associated with blood component transfusion, and is not related to the patient's medical condition? Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers A. Immediate hemolytic B. Delayed hemolytic C. Febrile nonhemolytic reaction D. Transfusion-related acute lung injury - correct answer C A febrile nonhemolytic transfusion reaction (FNHTR) is defined by a rise in temperature of 1°C or higher within 24 hours post-transfusion, and unexplained by other causes. The patient has formed antibodies to HLA, which react with donor cells and result in release of pyrogens. What would be the result of group A blood given to an O patient? A. Nonimmune transfusion reaction B. Immediate hemolytic transfusion reaction C. Delayed hemolytic transfusion reaction Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. Febrile nonhemolytic transfusion reaction - correct answer B Group A blood given to a group O patient would cause an immediate hemolytic transfusion reaction because a group O patient has anti-A and anti-B antibodies and would destroy A cells. Patient DB received 2 units of group A-positive red cells 2 days ago. Two days later, he developed a fever and appeared jaundiced. His blood type was A positive. A transfusion reaction workup was ordered. There were no clerical errors detected. A post-transfusion specimen was collected and a DAT performed. The DAT was positive with monospecific anti-IgG. The plasma was also hemolyzed. An antibody screen and panel studies revealed the presence of anti-Jkb (postspecimen). The antibody screen on the pretransfusion specimen was negative. Which of the following explain the positive DAT? A. The donor cells had a positive DAT B. The donor cells were polyagglutinable C. The donor cells were likely positive for the Jkb antigen Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers on the urinalysis, microscopic red cells were also found. Since intact RBCs are not caused by a transfusion reaction, the cause of hematuria was not likely transfusion related. A febrile nonhemolytic reaction is highly consistent with both symptoms and post- transfusion test results. A 92-year-old male diagnosed with anemia and episodes of frequent falling was typed as B negative and transfused 1 unit of packed red blood cells, also B negative. He was not recently transfused, and the antibody screen was negative. During the transfusion, his temperature rose from 36.2°C to 36.4°C, his pulse rose from 96 to 124, respirations from 18 to 20, and BP from 127\81 to 174\83. He was transfused with 205 mL before a reaction was called by the transfusionist. The postspecimen DAT was negative and clerical check acceptable. Urinalysis yielded 1+ blood with 5 RBCs microscopically. Other symptoms included tachycardia and flushing. What reaction had most likely taken place? A. Febrile nonhemolytic B. Acute hemolytic C. Anaphylactic Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers D. Volume overload - correct answer D The tachycardia, increased pulse, and volume transfused before a reaction was called are consistent with volume overload. The temperature change did not meet criteria for a febrile reaction, and evidence for a hemolytic reaction is lacking. A 76-year-old female diagnosed with urosepsis was transfused 2 units of packed red blood cells. Her type was AB positive with a negative antibody screen. The units transfused were AB positive. Upon receiving the second unit, the patient became hypoxic with tachypnea. The clerical check was acceptable and DAT negative. She received 269 mL from the second unit before a reaction was called. Her temperature fell from 38°C to 36.4°C, her pulse increased from 72 to 90, and respirations rose from 35 to 41. Her BP was 110\70. The patient expired approximately 12 hours from the time the reaction was called. What type of reaction was most likely present? A. Febrile B. Symptoms not related to transfusion Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers C. Allergic D. TRALI - correct answer B This case emphasizes the statistic that not all causes of death are related to transfusion. The temperature dropped ruling out a febrile reaction; there was no evidence of pulmonary edema or hypotension seen with TRALI (and plasma products are more associated with TRALI than red cells); and there was no sign of hives or itching, which are often associated with an allergic reaction. A 52-year-old male received 2 units of packed red blood cells as an outpatient in the IV therapy unit. He had a 20- year history of head trauma and was quadriplegic. He had recurrent pneumonia and hematuria due to removal of a Foley catheter. His blood type was A positive with a previously identified anti-Fya. There was an ABO discrepancy in that the A1 cells were positive. The technologist attributed the reaction to the Fya antigen being present on the A1 cells. The patient also had a cold autoantibody. Two units of A-positive packed cells were crossmatched that were Fya negative, and were compatible. One unit was transfused at 11:30 a.m. without incident. The second unit was transfused at 2:16 p.m., and stopped at 3:55 p.m. due to reddish brown- tinged urine discovered in his collection bag. A post- Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers g\dL before surgery. How many units of RBCs would most likely be required to accomplish this? A. 2 B. 3 C. 6 D. 8 - correct answer C One unit of RBCs will raise the hemoglobin level by approximately 1 to 1.5 g\dL, and the hematocrit by 3%-4%. Results vary depending upon the age of the blood, and the patient's blood volume and hydration status. Six units will raise the hemoglobin to at least 12 g\dL. Which of the following is not a viable method for removing leukocytes from red blood cells? A. Prestorage filtration B. Bedside filtration Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers C. Poststorage filtration D. Buffy coat removal - correct answer D Removal of the buffy coat, which contains both platelets and WBCs, is not an approved method for leukoreduction of red blood cells. The other methods can be employed to achieve a leukoreduction of <5x106. Four units of packed RBCs were brought to the nurses' station at 10:20 a.m. Two units were transfused immediately, and 1 unit was transfused at 10:40 a.m. The remaining unit was returned to the blood bank at 11:00 a.m. The units were not refrigerated after leaving the blood bank. What problem(s) is (are) present in this situation? A. The only problem is with the returned unit; the 30- minute limit has expired and the unit cannot be used Medical Laboratory Science Review - Harr - Blood Bank Questions And Answers B. The unit should not have been transfused at 10:40 a.m. because the time limit had expired; this unit and the remaining unit should have been returned to the blood bank C. The returned unit may be held for this patient for 48 hours but cannot be used for another patient D. No problems; all actions were performed within the allowable time limits - correct answer A There is a 30-minute time limit for a unit of RBCs that is not kept under proper storage conditions (1°C-6°C). A unit of whole blood is collected at 10:00 a.m. and stored at 20°C-24°C. What is the last hour platelet concentrates may be made from this unit? A. 4:00 p.m.