BB Exam 3
An antibody that causes in vitro hemolysis and reacts with the red cells of 3 our of 10 AHG-crossmatched donor units is most likely: a.) anti-Lea b.) anti-s c.) anti-k d.) anti-E
a.) anti-Lea Lewis antibodies may bind complement and fresh serum that contain anti-Lea may hemolyze Le(a+) red cells in vitro. Approximately 22% of the population is Le(a+).
a.) paroxysmal cold hemoglobinuria (PCH) The Donath-Landsteiner test is diagnostic PCH. The antibody is IgG and biphasic: hemolysis occurs when the antibody is incubated with cells and cold temps and then incubated at 37C. Often the antibody demonstrates specificity towards the high-incidence antigen P (not to be confused with P1). The antibody screen is usually negative and the pt's red cells are coated with complement
A 10 y/o girl was hospitalized because her urine had a distinct red color. The patient had recently recovered from an upper respiratory infection and appeared very pale and lethargic. Tests were performed with the following results: The patient probably has: a.) paroxysmal cold hemoglobinuria (PCH) b.) paroxysmal nocturnal hemoglobinuria (PNH) c.) warm autoimmune hemolytic anemia d.) hereditary erythroblastic multinuclearity with a positive acidified serum test (HEMPAS)
b.) anti-c and anti-E Anti-K and anti-P1 can be ruled out in cell 1 since there is no agglutination of it with pt's sample. Anti-M and anti-Jka can be eliminated on cell 2, which has a double-dose antigen expression of both M and Jka.
A 25 y/o Caucasian woman, gravida 3, para 2, required 2 units of RBCs. The antibody screen was positive and the results of the antibody panel are shown below: Which of the following antibodies may be the cause of the positive antibody screen? a.) anti-M and anti-K b.) anti-c and anti-E c.) anti-Jka and anti-c d.) anti-P1 and anti-c
d.) perform a warmutoadsorption Since the auto control is pos after the AHG phase and no reactivity was detected at IS, the serology is most consistent with a warm autoantibody. An adsorption with autologous cells to remove the antibody and subsequent testing of the adsorped plasma or serum for alloantibody detection is the next step.
A 26 y/o female is admitted with anemia of undetermined origin. Bloof origin samples are received with a crossmatch request for 1 unit of RBCs. The patient is group A, Rh-neg and has no history of transfusion or pregnancy. The following results were obtained in pretransfusion testing: The next step to continue this investigation would be: a.) do an antibody identification panel b.) use the saline replacement technique c.) use the pre-warm technique d.) perform a warmutoadsorption
b.) McLeod syndrome The McLeod phenotype demonstrates weakened Kell system antigens and the antigens Km and Kx are absent. McLeod syndrome is an X-linked disease state associated with acanthocytosis, muscular, neurologic, and psychiatric symptoms. Many also gave chronic granulomatous disease and recurrent infections.
A 5 y/o with chronic upper respiratory infections arrives in the Emergency Room with chronic anemia. The antibody screen and antibody identification panel are all strongly reactive when tested by solid phase automation. The DAT is negative, and the patient's phenotype is shown below. With these initial findings, what is suspected? a.) PCH b.) McLeod syndrome c.) WAIHA d.) CHD
c.) B Secretor studies demonstrate the presence of a substance by the observation of neutralization of the corresponding antibody. Nonreactivity with B and O cells indicates B and H substances are present in the saliva, so the red cells from this person are group B.
A person's saliva incubated with the following antibodies and tested with the appropriate A2, O, and B indicator cells, gives the following test results: The person's red cells ABO phenotype is: a.) A b.) AB c.) B d.) O
b.) may cause HDFN Anti-Fya may cause mild to rarely severe hemolytic disease of the fetus and newborn.
A pregnant woman has a positive antibody screen and the panel results are given below: What is the association of the antibody(ies) with HDFN? a.) usually fatal HDFN b.) may cause HDFN c.) is not associated with HDFN d.) HDFN cannot be determined
c.) Doluichos biflorus Dolichos biflorus plant seed extract forms complexes with N-aceylgalactosamine. When properly diluted, it can distinguish between A1 donor cells and all other subgroups of A.
A sample gives the following results: Which lectin should be used first to resolve this discrepancy? a.) Ulex europaeus b.) Arachis hypogaea c.) Doluichos biflorus d.)Vicia graminea
a.) 1 Antibodies to antigens on cells 2, 3, 4, and 5 can be ruled out in tubes II and III, in which there was no reaction between patient serum and cells.
An antibody identification study is performed with the 5-cell panel shown below: An antibody against which of the following antigens could not be excluded? a.) 1 b.) 2 c.) 3 d.) 4
c.) repeat ABO red cells typing and include a control When results with anti-A, anti-B, and anti-D are all pos, there is no way to determine the accuracy of the results. Repeat testing with an inert control verified as neg, is the only way to confirm the accuracy of these results.
Based on the results below, what is the next step in determination of the patient's ABO/Rh type? a.) interpret AB, D-pos b.) interpret at AsubB, D-pos c.) repeat ABO red cells typing and include a control d.) add room temp incubation with ABO red cell typing
a.) A1 Reaction with anti-A1 indicates groups A. Reaction with anti-A1 (Dolichos biflorus) and nonreactivity with anti-H (Ulex europaeus) verifies the reaction pattern as A1.
Based on these reactions, what is the patient's ABO type? a.) A1 b.) A2 c.) Amod d.) Ax
c.) cold autoantibody Presence of agglutination with A1 cells, screening cells and autocontrol at IS and RT is indicative of a cold autoantibody.
Consider the following ABO typing results: Additional testing was performed using patient serum: What is the most likely cause of this discrepancy? a.) A2 with anti-A1 b.) cold alloantibody c.) cold autoantibody d.) acquired-A phenomenon
b.) wash patient's RBCs and repeat testing Pts may have antibodies to components of reagents. Washing the pt's cells prior to testing to remove their plasma from the cell suspension will resolve the reactivity with anti-B.
In a prenatal workup, the following results were obtained: ABO discrepancy was thought to be due to an antibody directed against a component of the typing sera. Which test would resolve this discrepancy? a.) A1 lectin b.) wash patient's RBCs and repeat testing c.) anti-A, anti-B, and extend incubation of the reverse group d.) repeat reverse group using A2 cells
d.) collect a new sample and repeat the tests Results of ABO and Rh testing on a current specimen must always be compared to that of a previous transfusion record. Errors in typing or patient identification may be detected when discrepancies are found. Collection of a new sample allows determination of which sample was incorrectly collected.
Samples from the same patient were received on 2 consecutive days test results are summarized below: How should the request for crossmatch be handled? a.) crossmatch A, Rh-pos units with sample from day1 b.) crossmatch B, Rh-pos units with sample from day 2 c.) crossmatch AB, Rh-pos units with both samples d.) collect a new sample and repeat the tests
a.) anti-C Rh antibodies demonstrate enhanced reactivity with enzyme-pretreated cells. Antibodies in the Kell system do not have enhanced reactivity with enzyme-pretreated cells. Anti-E and -D are ruled out on cell 3 and anti-K is ruled out on cell 7.
Refer to the following cell panel: Based on the results, which of the following antibodies is most likely present? a.) anti-C b.) anti-E c.) anti-D d.) anti-K
b.) warm autoimmune hemolytic anemia Reaction with anti-IgG in the DAT and with both screening cells and autocontrol at the AHG phase is indicative of a warm antibody
Refer to the following data: Which clinical condition is consistent with the lab results shown above? a.) cold hemagglutinin disease b.) warm autoimmune hemolytic anemia c.) penicillin-induced hemolytic anemia d.) delayed hemolytic transfusion reaction
b.) anti-E, anti-Jka, and anti-K Reactivity at 35C and AHG indicarte the presence of an IgG antibody. Anti-M, although usually IgM, may be partyl or wholly IgG. Anti-M is ruled out on cell 4. Anti-Leb is usually IgM and can be ruled out on cells 4 and 8. This leaves anti-E, anti-Jka, and anti-K.
Refer to the following panel: Based on the results of the above panel, the most likely antibody are: a.) anti-M and anti-K b.) anti-E, anti-Jka, and anti-K c.) anti-Jka and anti-M d.) anti-E and anti-Leb
a.) proteolytic enzyme treatment Enzymes treatment would allow for differentiation of the remaining antibodies after rule out. The Fya antigen would be denatured, allowing determination of whether anti-Jka and -K are present, and to confirm anti-E.
Refer to the following panel: Based on the results of the above panel, which technique would be most helpful in determining antibody specificity? a.) proteolytic enzyme treatment b.) urine neutralzation c.) autoadsorption d.) saliva inhibition
c.) Black 20% of persons of African ethnicity are Group B compared to only 11% of those of European ethnicity. For the Rh phenotype results, 44% of black compared to 4% of whites will demonstrate the Dce phenotype.
The following blood typing results were noted on a patient's sample: What is the patient's likely ethnicity? a.) Asian b.) Hispanic c.) Black d.) White
c.) multiple myeloma Pts w/ multiple myeloma demonstrate rouleaux formation. If the cells are washed to remove residual plasma, and tests repeated, an accurate red cell typing is obtained. By performing a saline replacement with the reverse typing, true agglutination will remain when the cell buttons of the reverse cells are resuspended in saline.
The following reactions were obtained: The technologist washed the patient's cells with saline, and repeated the forward typing. A saline replacement technique was used with the reverse typing. The following results were obtained: Based on these results, a likely diagnosis for the patient may be: a.) acquired immunodeficiency disease b.) Bruton agammaglobulinemia c.) multiple myeloma d.) acquired "B" antigen
b.) a warm autoantibody Presence of agglutination at AHG phase with both screening cells and autocontrol is indicative of warm autoantibody
The following results were obtained in pretransfusion testing: The most probable cause of these results is: a.) rouleaux b.) a warm autoantibody c.) a cold autoantibody d.) multiple alloantibodies
d.) perform antibody screening procedure at immediate spin and AHG using group O cells Unexpected reactivity with reverse cells should include a test with screen cells at immediate spin to determine if alloantibodies are present. Resolution of the ABO discrepancy can be performed with group B cells that lack the corresponding antigen for the identified alloantibody
The following results were obtained on a patient's blood sample during routine ABO and Rh testing: Select the course of action to resolve this problem: a.) enzyme treat the patient's red cells and repeat the forward blood typing b.) test the patient's serum with A2 cells and the patient's red cells with anti-A1 lectin c.) repeat the ABO antigen grouping using 3x washed saline-suspended cells d.) perform antibody screening procedure at immediate spin and AHG using group O cells
d.) weak subgroup of A Some subgroups of A are only recognized because of their lack of anti-A in the reverse typing. Often, the donors are confirmed as subgroups of A by an adsorption-elution technique.
The following results were obtained when testing a sample from a 20 y/o, first-time blood donor: What is the most likely cause of this ABO discrepancy? a.) loss of antigen due to disease b.) acquired B c.) phenotype Oh "Bombay" d.) weak subgroup of A
b.) autoantibody Reactivity of the patient's serum and eluate with all cells and the DAT results indicate the presence of warm autoantibody.
The patient's results are listed below. What is the most likely specificity based on the reaction pattern? a.) high incidence antibody b.) autoantibody c.) multiple alloantibodies d.) cold reactive antibody
d.) anti-E Antibodies to C, Leb, and Jka can be eliminated due to the lack of agglutination with panel cells 1 and 2. Panel cells 1 and 2 possessed the C, Leb, and Jka antigens. Only anti-E remains.
The sample from a 45 y/o Asian woman, gravida 2, para 2 demonstrated a positive antibody screen. The results of the antibody panel are shown below: Which common antibody has not been ruled out by the panel? a.) anti-C b.) anti-Leb c.) anti-Jka d.) anti-E
d.) cold autoadsorption Unexpected ABO serum reactions due to cold reactive antibody can be dispersed with testing at 37C or by performing a cold autoadsorption and using that autoadsorbed serum to repeat the reverse ABO typing.
What method may be used to resolve the patient's ABO serum typing? a.) DTT-treat patient's red cells b.) warm saline wash patient's red cells c.) enzyme treat patient's red cells d.) cold autoadsorption
d.) anti-P1 cannot be confirmed due to the results of the negative control For neutralization studies to be valid, the saline dilutional control must be reactive. Since neutralization studies involve adding a substance to the pt's plasma, nonreactivity in test tube may be due to simple dilution. The saline control acts as the dilutional control and must be reactive. When the saline control is reactive, then if the tube with the substance is nonreactive, the interpretation that neutralization has occurred is made. If it is reactive, neutralization did not occur.
To confirm a serum antibody specificity identify as anti-P1, a neutralization study was performed and the following results obtained: What conclusion can be made from these results? a.) anti-P1 is confirmed b.) anti-P1 is ruled out c.) a second antibody is suspected due to the results of the negative control d.) anti-P1 cannot be confirmed due to the results of the negative control
b.) anti-Leb is confirmed because the tubes with Lewis substance are negative Anti-Leb is confirmed because the tubes with Lewis substance are neg. Nonreacticiy of the serum with Le(b+) cells indicates the anti-Leb in the serum was neutralized by the Lewis substance. The test is valid since the pt's serum with saline rather than substance added is still able to react with the Le(b+) cells.
To confirm the specificity of anti-Leb, an inhibition study using Lewis substance was performed with the following results: What conclusion can be made from these results? a.) second antibody is suspected due to the positive control b.) anti-Leb is confirmed because the tubes with Leiws substance are negative c.) anti-Leb is not confirmed because the tubes with Lewis substance are negative d.) anti-Leb cannot be confirmed because the saline positive is control
c.) R2r These red cells are negative for the C antigen. Therefore, the most likely Rh genotype is R2r
Using the antigen typing results below, what is the patient's likely phenotype? a.) R1R1 b.) R2R2 c.) R2r d.) R1R2
a.) result A An anamnestic response is a secondary response from memory cells. There will be an increase in antibody titer upon exposure; the antibody sensitizes incompatible cells circulating in the patient. The DAT appears MF since the patient's own cells are not sensitized.
Which direct antiglobulin test results are associated with an anamnestic antibody response in a recently transfused patient? a.) result A b.) result B c.) result C d.) result D
d.) group O secretor Reactivity with anti-H is no longer demonstrable, which indicates H substance is present. There is no A or B substance in the saliva as evidenced by the ability of anti-A and anti-B reacting with respective cells. People with H substance and no A or B substance are group O secretors.
Which of the following is the correct interpretation of this saliva neutralization testing? a.) group A secretor b.) group B secretor c.) group AB secretor d.) group O secretor
A patient is a subgroup of A (Asub), Rh-pos with anti-A1 in their serum. How many units would you have to screen to find 1 unit that is compatible with the patient's anti-A1? a.) 5 b.) 10 c.) 15 d.) 20
a.) 5 20% of the population is A1 negative. To find one unit that is A1 negative, 5 units would have to be screened. 20/100 = 1/x 20x = 100 x = 100/20 x = 5 units
A patient is group A2B, Rh-pos, and has an antiglobulin- reacting anti-A1 in his serum. He is in the operating room bleeding profusely and group A2B RBCs are not available. Which of the following blood types is first choice for crossmatching? a.) B, Rh-pos b.) B, Rh-neg c.) A1B, Rh-pos d.) O, Rh-neg
a.) B, Rh-pos This patient has an anti-A1, which eliminates A1B cells immediately. Rh-neg units should be conserved for Rh-neg patients when Rh-pos units are available. Selection of group B units compatible units quickly.
Which of the following blood bank chemicals produce Kell null cells? a.) DTT b.) ficin c.) formaldehyde d.) chloroquine diphosphate
a.) DTT Sulfhydral reagents (DTT, AET or 2-ME) may be used to eliminate certain blood groups system antigens. These antigens include those in the Kell, Dombrock, Cartwright, Lw and Knops systems. The use of DTT would eliminate Kell blood group system antigens from red cells, thus reacting Kell null cells.
Indications for an autologous hematopoietic progenitor cell (HPC) transplant include patients who have: a.) Hodgkin lymphoma with high-dose chemotherapy b.) congenital hemoglobinopathies c.) congenital immunodeficiency disorders d.) inborn errors of metabolism
a.) Hodgkin lymphoma with high-dose chemotherapy Autologous HPC transplants are used to restore hematopoietic rescue after high-dose chemotherapy. All the other clinical situations are treated with allogeneic HPC transplant.
A patient has a variable reacting anti-P1 pattern in antibody identification studies. What test can be used to verify the specificity of anti-P1? a.) P1 neutralization b.) PEG-AHG c.) cloroquine-AHG d.) DTT-AHG
a.) P1 neutralization Anti-P1 can be verified by P1 neutralization with hydatid cyst fluid or p1 substance from pigeon eggs. Enzymes may also be used to enhance the reactions of anti-p1.
Autoantibodies demonstrating blood group specificity in warm autoimmune hemolytic anemia are associated more often with which blood group system? a.) Rh b.) I c.) P d.) Duffy
a.) Rh Warm antibodies often exhibit Rh epiciicity.
An antibody screen performed using solid phase technology revealed a diffuse layer of RBCs on the bottom of the well. These results indicate: a.) a positive reaction b.) a negative reaction c.) serum was not added d.) red cells have a positive DFAT
a.) a positive reaction In the solid phase technology, the antibody screening cells are bound to the surface of the well. Antibody specific for antigen on the RBC attaches, resulting in a diffuse pattern of RBCs in the well. A neg reaction would have manifested as a pellet of RBCs in the bottom of the well.
What ABO type is found in group A1 individuals following deacetylation of their A antigens? a.) acquired B b.) B (A) c.) Amod d.) Aint
a.) acquired B In a group A patient, Acquired B should be suspected when the patient initially types as group AB but with a weaker expression of the B antigenic the ABO red cell testing. To resolve Acquired B one needs to repeat the typing with a second source of antibody or acidified human anti-B.
A patient's serum reacted weakly positive (1+w) with 16 of 16 group O panel cells demonstrating no reactivity at the AHG phase. Which antibody is most likely responsible for these results? a.) anti-Ch b.) anti-k c.) anti-e d.) anti-Jsb
a.) anti-Ch The reactivity of anti-k and anti-Jsb with enzyme pretreated cells is unchanged and anti-e would show enhanced reactivity with enzyme treated cells. Chido antigens are sensitive to treatment with most enzymes and anti-Ch would therefore not react with enzyme pretreated cells. The Chido antigen is a high incidence antigen.
A patient's serum was reactive 2+ in the antiglobulin phase of testing with all cells on a routine panel including their own. Transfusion was performed 6 months previously. The optimal absorption method to remove the autoantibody is: a.) autoadsorption using the patient's ZZAP-treated red cells b.) autoadsorption using the patient's LISS-treated red cells c.) adsorption using enzyme treated red cells from a normal donor d.) adsorption using methyldopa-treated red cells
a.) autoadsorption using the patient's ZZAP-treated red cells ZZAP is a reagent to remove IgG from the pt's own cells to allow for better adsorption of IgG autoantibody from the pt's plasma to the cells. The intent of the autoadsorption is to remove autoantibody to look for alloantibodies prior to transfusion.
The autoantibody most often implicated in Paroxysmal Cold Hemoglobinuria (PCH) is: a.) cold-reactive, IgG, anti-P b.) cold reactive, IgM, anti-P c.) cold reactive, IgG, anti-I d.) cold reactive, IgM, anti-I
a.) cold-reactive, IgG, anti-P The causative antibody in PCH is unique in that it is a cold-reactive complement-binding, IgG antibody. The most common specificity is anti-P.
Some blood groups antibodies characteristically hemolyze appropriate antigen-pos red cells in the presence of: a.) complement b.) anticoagulant c.) preservatives d.) penicillin
a.) complement Some blood groups antibodies, in the presence of their corresponding antigen and complement, activate the complement cascade and demonstrate in-vitro hemolysis.
Which characteristics are true of all 3 of the following antibodies: anti-Fya, anti-Jka, and anti-k? a.) detected at IAT phase and may cause HDFN and transfusion reaction b.) not detected with enzymes treated cells; may cause delayed transfusion reactions c.) requires the IAT technique for detection; usually not responsible for causing HDFN d.) may show dosage effect; may cause severe hemolytic transfusion reactions
a.) detected at IAT phase and may cause HDFN and transfusion reaction All 3 antibodies can cause HDFN and delayed transfusion reactions. Anti-Jka is associated with showing dosage.
Which of the following tests is most commonly used to detect antibodies attached to a patient's RBCs in vivo? a.) direct antiglobulin b.) complement fixation c.) indirect antiglobulin d.) immunofluorescence
a.) direct antiglobulin The direct antiglobulin test (DAT) is used to identify RBCs that have been coated with antibody in vivo.
The mechanism that best explains hemolytic anemia due to penicillin is: a.) drug-dependent antibodies reacting with drug-treated cells b.) drug-dependent antibodies reacting in the presence of drug c.) drug-independent with autoantibody production d.) nonimmunologic protein adsorption with positive DAT
a.) drug-dependent antibodies reacting with drug-treated cells Detection of antibodies to penicillin requires treatment of test cells with penicillin and the subsequent testing of the patient's plasma and eluate. Test cells that have not been tested with penicillin do not react.
A patient's serum contains a mixture of antibodies. One of the antibodies is identified as anti-D. Anti-Jka, anti-Fya and possibly another antibody are present. What technique(s) may be helpful to identify the other antibody(ies)? a.) enzyme panel; select cell panel b.) thiol reagents c.) lowering the pH and increasing the incubation time d.) using albumin as an enhancement media in combination with selective adsorption
a.) enzyme panel; select cell panel Anti-Fya would not react with enzyme pretreated cells; a select cell panel would allow for individual reactivity of the remaining 2 antibodies. Thiol reagents would be used to disperse agglutination of IgM antibodies; the antibodies in question are IgG.
Ina cold adsorption procedure, pretreatment of the patient's red cells with which of the following reagents is helpful? a.) ficin b.) phosphate-buffered saline at pH 9.0 c.) low ionic strength saline (LISS) d.) albumin
a.) ficin Treating autologous cells with a proteolytic enzyme such as ficin enhances the adsorption of the cold reactive antibody.
A male patient's sample demonstrates a pattern most consistent with anti-D. The patient is Rh-neg, and was transfused with Rh-pos blood emergently after a motor vehicle accident 2 years previously. The anti-D shows variable reactivity when tested with D-pos cells. What test would be appropriate to enhance the anti-D reactivity and verify specificity? a.) ficin-AHG b.) DTT-AHG c.) trypsin-AHG d.) albumin-AHG
a.) ficin-AHG Red cells treated with enzymes like ficin and papain are known to increase reactivity of some blood group antibodies. (Rh, P, I, Lewis and Kidd)
A group O, Rh-neg pregnant female has anti-Vel in her serum. If needed, how might blood be provided for her infant? a.) maternal donation b.) paternal donation c.) random ABO-identical unit d.) random group O, Rh-neg unit
a.) maternal donation Anti-Vel has been associated with transfusion reactions and rarely, HDFN. If blood is needed, maternal red cells, washed to remove the anti-Vel, can be a transfusion source for the infant. Paternal and random source units would likely be Vel positive since Vel is a high-incidence antigen.
Transfusion of Ch+ (Chido positive) red cells to a patient with anti-Ch has been reported to cause: a.) no clinically significant red cell destruction b.) clinically significant immune red cell destruction c.) decreased 51Cr red cell survivals d.) febrile transfusion reactions
a.) no clinically significant red cell destruction Chido antibodies are considered clinically insignificant.
A patient received 4 units of blood 2 years previously and how has multiple antibodies. He has not been transfused since that time. It would be most helpful to: a.) phenotype his cells to determine which additional alloantibodies may be produced b.) recommend the use of directed donors, which are more likely to be compatible c.) use proteolytic enzymes to destroy the "in vitro" activity of some of the antibodies d.) freeze the patient's serum to use for antigen typing of compatible units
a.) phenotype his cells to determine which additional alloantibodies may be produced Determining the patient's phenotype allows focusing identification procedures towards antibodies the patient can develop.
A drug-induced immune hemolytic anemia caused by a drug-independent antibody would have which of the following results? a.) pos DAT with IgG; pos antibody screen b.) pos DAT with IgG; neg eluate c.) pos DAT with C3d; neg antibody screen d.) neg DAT; pos antibody screen
a.) pos DAT with IgG; pos antibody screen The antibody detected in drug-independent immune hemolytic anemia is indistinguishable from warm autoantibodies. The DAT is positive with IgG, the eluate and the serum react with all cells tested. Drugs that are known to cause this are methyldopa and fludarabine.
A patient is typed as group O, Rh-pos and crossmatched with 6 units of blood. At the indirect antiglobulin (IAT) phase of testing, both antibody screening cells and 2 crossmatched units are incompatible. What is the most likely cause of the incompatibility? a.) recipient alloantibody b.) receipt autoantibody c.) donors have pos DATs d.) rouleaux
a.) recipient alloantibody Presence of agglutination of AHG phase with screening cells and 2 out of 6 donor units indicates antibody in patient serum to antigen(s) on screening cells and donor cells. The presence of an autoantibody would most likely react with all cells, including the autologous control or DAT.
A 29 y/o male is hemorrhaging severely. He is AB, Rh-neg. Six units of blood are required STAT. Of the following types available in the blood bank, which would be most preferable for crossmatch? a.) AB, Rh-pos b.) A, Rh-neg c.) A, Rh-pos d.) O, Rh-neg
b.) A, Rh-neg When group specific units of RBCs are not available, group compatible units are selected. Since the patient is AB, group A would be selected to conserve group O units for group O patients. Rh-neg patients should receive Rh-neg units of RBCs.
Anti-I cold agglutinin disease may cause a pos DAT because of: a.) anti-I agglutinating the cells b.) C3d bound to the red cells c.) T-activation d.) C3c remaining on the red cells after cleavage of C3b
b.) C3d bound to the red cells In cold agglutinin syndrome, anti-I acts as a complement binding antibody with a high titer and high thermal amplitude. The complement cascade is activated and C3d remains on the red cell membrane of circulating cells.
Which of the following antigens enhanced reactions with its corresponding antibody following treatment of the red cells with proteolytic enzymes? a.) Fya b.) E c.) S d.) M
b.) E Rh antibodies show enhanced reactivity with enzyme pretreated cells. Treatment of re3d cells with enzymes weakens reactivity with antibodies in the MNMS and Duffy systems.
Inheritance of the rare Mk gene results in the deletion of both GYPA and GYPB. Which of the following blood group antigens is not expressed on red cells in the presence of a Mk gene? a.) Kx b.) Ena c.) f d.) G
b.) Ena The rare Mk gene leads to a deletion of the GYPA and GYPB genes. These red cells have a normal morphology and phenotype as M-N-S-s-U-; En(a-); Wr(a-b-). MkMk is a null phenotype in the MNS system and is associated with reduced RBC sialic acid and increased glycosylation of Band 4.1 and Band 3.
Which of the following systems plays an important role in transfusion-related acute lung injury (TRALI), transfusion-associated graft versus host disease (TA-GVHD), platelet refractoriness, and febrile nonhemolytic transfusion reaction (FNHTR) as well as in hematopoietic stem and organ transplantation rejection? a.) Rh b.) HLA c.) Lewis d.) Diego
b.) HLA Human leukocyte antigens (HLA) are found on most nucleated body cells with some exceptions such as neurons. The antigens and antibodies of this system play a significant role in several different transfusion related reactions and in transplantation rejection.
Polyspecific reagents used in the direct antiglobulin test should have specificity for: a.) IgG and IgA b.) IgG and C3d c.) IgM and IgA d.) IgM and C3d
b.) IgG and C3d Polyspecific AHG contains anti-IgG and anti-C3d.
In a Group O individual with Le and Se genes, what ABH and Lewis antigens are present in their secretions? a.) Lea, Leb b.) Lea, Leb, H c.) Lea, H d.) Leb, H
b.) Lea, Leb, H When the genes Le and Se are inherited in a group O individuals, Lea, Leb, and H soluble antigens will be in the secretions. Leb will be expressed on the red cell.
Which of the following genes on chromosome 1 encodes for the 4 common antigen combinations ce, cE, Ce, and CE. a.) RHD b.) RHCE c.) RHD and RHCE d.) RHd andRHce
b.) RHCE RHD and RHCE are closely linked genes of chromosome 1. RHD codes for the D antigen. RHCD codes for CE antigens in the 4 combinations of ce, CE, cE, and Ce.
The test for weak D is performed by incubating patient's red cells with: a.) different dilutions of anti-D b.) anti-D antiserum c.) anti-Du antiserum d.) antiglobulin antiserum
b.) anti-D antiserum Although monoclonal anti-D react with most D-pos RBCs, cells with fewer antigen sites requires testing with an indirect antiglobulin test. The test is referred to as a test fir weak D.
In the process of identifying an antibody, the technologist observed 2+ reactions with 3 of the 10 cells in a panel after the immediate spin phase. The antibody most likely is: a.) anti-P1 b.) anti-Lea c.) anti-C d.) anti-Fya
b.) anti-Lea Lewis antibodies are usually IgM and agglutinate saline suspended cells. Approximately 22% of the population is Le(a+), which would account for 3 of 10 donor units being compatible.
In the process of identifying an antibody, the technologist observes 2+ reactions with 3 of 10 cells at immediate spin (IS) and room temperature (RT). There were no reactions at 37°C or AHG. What is the most likely antibody? a.) anti-Jkb b.) anti-Lea c.) anti-C d.) anti-Fya
b.) anti-Lea Most Lewis antibodies are reactive at IS and RT. They less often react at 37C and AHG phase of testing.
Which of the following is useful for removing IgG from RBCs with a pos DAT to perform a phenotype a.) bromelin b.) chloroquine c.) LISS d.)DTT
b.) chloroquine Two reagents used for removing IgG from RBCs are chloroquine diphosphate (CDP) and EDA glycine acid (EGA). Using either of these procedures is useful to reduce a pt's DAT and allow phenotyping with IAT reactive antisera.
Review the following schematic diagram: PATIENT SERUM + REAGENT GROUP "O" CELLS INCUBATE --> READ FOR AGGLUTINATION WASH --> ADD AHG --> AGGLUTINATION OBSERVED The next step would be to: a.) add "check cells" as a confirmatory measure b.) identify the cause of the agglutination c.) perform an elution techniqueque d.) perform a direct antiglobulin test
b.) identify the cause of the agglutination Agglutination at AHG phase indicates the presence of clinically significant antibody, indicating the need for antibody identification.
Results of a serum sample tested against a panel of reagent red cells gives presumptive evidence of an alloantibody directed against a high incidence antigen. Further investigation to confirm the specificity should include which of the following? a.) serum testing against red cells from random donors b.) serum testing against red cells known to lack high incidence antigens c.) serum testing against enzyme treated autologous red cells d.) testing of an eluate prepared from the patient's red cells
b.) serum testing against red cells known to lack high incidence antigens Lack of agglutination between patient serum and with cells that lack one of the high incidence antigens would confirm the specificity of the antibody.
Which of the following statements is correct about hematopoietic (HPC) transplantation? a.) successful allogenic transplantation requires that at least 5 out of 10 HLA loci match b.) sources for HPC collection include bone marrow, umbilical cord blood (UCB), and mobilized peripheral blood c.) bone marrow collection of HPC is preferred to apheresis collection because of fewer side effects d.) HPC products are infused into the patient over a period of at least 6 hours
b.) sources for HPC collection include bone marrow, umbilical cord blood (UCB), and mobilized peripheral blood Bone marrow, UCB and mobilized peripheral blood are the most common sources of HPCs. Success allogenic transplants require 8/10 or 10/10 HLA loci matches. Apheresis HPC collections have fewer adverse effects than bone marrow collection. HPC products are generally administered bycentral line infusiojn and as quickly as the patient can tolerate.
A group B, Rh-neg patient has a pos DAT. Which of the following situations would occur? a.) all major crossmatches would be incompatible b.) the weak D test and control would be positive c.) the antibody screening test would be positive d.) the forward and reserve ABO groupings would not agree
b.) the weak D test and control would be positive A pos DAT will interfere with weak D testing causing both the patient and control to demonstrate positive results. Any positive result in the control tub invalidates any results.
In what patient population may we observe the following results? anti-A anti-B anti-D A1C BC 4+ 0 4+ 0 1+ a.) labor and delivery patient b.) 30-year old GI bleed patient c.) 2-year old pre-surgical patient d.) 16-year old ACL repair surgery patient
c.) 2-year old pre-surgical patient ABO antibodies are not present at birth. ABO antibodies develop in response to the environment from3-6 months of age and continue to increaser in titer until achieving adult levels at 5-10 years of age.
Mixed field agglutination encountered in ABO grouping with no history of transfusion would most likely be due to: a.) Bombay phenotype (Oh) b.) T activation c.) A3 red cell d.) positive indirect antiglobulin test
c.) A3 red cell MF reactivity is a characteristic of the A3 subgroup. Transfusion history would be important to be sure it is not 2 cell populations.
A 56 y/o female with cold agglutinin disease has a positive DAT. When the DAT is repeated using monospecific antiglobulin sera, which of the following is most like to be detected? a.) IgM b.) IgG c.) C3d d.) C4a
c.) C3d Cold agglutinin disease is associated with cold reactive antibodies that typically activate complement. Cells that do not undergo lysis due to complement activation have C3d attached to the RBCs.
The most widely accepted QC test to measure probable Hematopoietic Progenitor Cell (HPC) engraftment is: a.) clonogenic assay b.) cell viability c.) CD34+ cell enumeration d.) manual differential
c.) CD34+ cell enumeration CD34+ enumeration is the most widely used and accepted, albeit surrogate, QC test to evaluate HPC engraftment.
Which of the following statements is true about Class HLA antigens? a.) they are found on the surface of most nucleated cells b.) Bg antigens are part of HLA Class II c.) HLA-DR, HLA-DQ and HLA-DP are all Class II d.) they are only located on neurons and platelets
c.) HLA-DR, HLA-DQ and HLA-DP are all Class II HLA-DR, HLA-DQ and HLA-DP are Class II antigens which are only found on monocytes, macrophages, B lymphocytes, dendritic cells, early hematopoietic cells and intestinal epithelial cells
A patient's antibody identification panel demonstrated anti-M. The antibody was most reactive with homozygous M+ cells compared to heterozygous M+ cells. Which of the following cells would demonstrate the strongest reaction? a.) M-N+S-s+ b.) M+N+S+s+ c.) M+N-S-s+ d.) M+N+S-s-
c.) M+N-S-s+ The strength of reactions for some antibodies varies due to dosage. The strongest reactions are obtained on double-dose/homozygous red cell compared to a single-dose/heterozygous red cells.
The Rh-neg phenotype results from the complete deletion of what gene(s)? a.) RHD and RHce b.) RHCE c.) RHD d.) RHD and RHCE
c.) RHD The Rh-neg, or D-neg, phenotypes are most often due to the complete deletion of the RHD gene. The Rh-neg person expresses the RHCE gene only.
Plasma neutralization is best used to verify which of the following antibodies? a.) anti-Lub b.) anti-M c.) anti-Ch/Rg d.) anti-V
c.) anti-Ch/Rg Binding of Chido/Rodgers antibodies to red cells is readily inhibited by plasma from Ch/Rg-positive individuals.
Reagent antibody screening cells may not detect all antibodies. Which of the following antibodies is most likely to go undetected? a.) anti-Coa b.) anti-S c.) anti-Cw d.) anti-Xga
c.) anti-Cw Anti-Cw is an antibody to a low incidence antigen in the Rh blood group system. These antigens are present on the red cells of <1% of the population. Not all low incidence antigens are represented on the typical antibody screening cells.
A patient demonstrated 4+ reactivity with all red cells tested and the autocontrol is nonreactive. This high incidence antibody was suspected to be related to the P1PK blood group system as the patient is the rare p phenotype. What antibody specificity should be suspected? a.) anti-IP1 b.) anti-P2 c.) anti-PP1Pk d.) anti-P1
c.) anti-PP1Pk Anti-PP1Pk is the high incidence antibody made by the individuals with the p phenotype. This antibody has an association with early spontaneous abortion.
A patient serum reacts with 2 of the 3 antibody screening cells at the AHG phase. Eight of the 10 units crossmatched were incompatible at the AHG phase. All reactions are markedly enhanced by enzymes. These results are most consistent with: a.) anti-M b.) anti-E c.) anti-c d.)anti-Fya
c.) anti-c Rh antibodies show enhanced reactivity with enzyme pretreated cells. The Mc and Fya antigens are cleaved from enzyme pretreated cells and therefore there would be no reaction between enzyme pretreated cells and serum containing anti-M or anti-Fya. The incidence of the of the c antigen is 80%in whites and 96% in blacks. The incidence of the E antigen is 29% in whites and 22% in blacks. Increased reactivity with enzyme pretreated cells and incompatible results 8 of 10 donors units is most likely due to anti-c.
Use of EDTA plasma prevents activation of the classical complement pathway by: a.) causing rapid decay of complement components b.) chelating Mg++ ions, which prevents the assembly of C6 c.) chelating Ca++ ions, which prevents assembly of C1 d.) preventing chemotaxis
c.) chelating Ca++ ions, which prevents assembly of C1 EDTA chelates calcium preventing blood to clot. This chelation of calcium also will stop the complement cascade. Calcium ions are necessary for C1 to attach to IgG on the RBCs.
The following test results are noted for a unit blood labeled group A Rh-neg: Cells tested with: anti-A anti-B anti-D 4+ 0 3+ What should be done next? a.) transfused as a group A, Rh-neg b.) transfused as a group A, Rh-pos c.) notify the collecting facility d.) discard the unit
c.) notify the collecting facility A serological test to confirm the ABO on all RBC units and Rh on units labeled as Rh-negt be performed prior to transfusion. Any errors in labeling must be reported to the collection facility.
While performing an antibody screen, a test reaction is suspected to be rouleaux. A saline replacement test is performed and the reaction remains. What is the best interpretation? a.) original reaction of rouleaux is confirmed b.) replacement test is invalid and should be repeated c.) original reaction was due to true agglutination d.) antibody screen is negative
c.) original reaction was due to true agglutination Rouleaux will readily disperse in saline whereas true agglutination will remain after saline replacement.
A patient received 2 units of RBCs and had a delayed transfusion reaction. Pretransfusion antibody screening records indicate no agglutination except after the addition of IgG-sensitized cells. Repeat testing of the pretransfusion specimen detected an antibody at the antiglobulin phase. What is the most likely explanation for the original results? a.) red cells were overwashed b.) centrifugation time was prolonged c.) patient's serum was omitted from the original testing d.) antiglobulin reagent was neutralized
c.) patient's serum was omitted from the original testing Initial result was most likely a false-negative result due to the omission of patient serum. This would explain the initial negative results followed by the subsequent positive result.
During an emergency situation with no time to determine ABO group and Rh type on a current sample for transfusion, it is noted that previous records state the patient is known to be A, Rh-neg. The technologist should: a.) refuse to release any blood until the patient's sample has been typed b.) release A Rh-neg RBCs c.) release O Rh-neg RBCs d.) release O Rh-pos RBCs
c.) release O Rh-neg RBCs Emergent release of blood cannot use previous records. Blood typing must be performed on the current sample. In this case, group O, Rh-neg is the best choice since there is evidence the patient is Rh-neg.
The purpose of testing with anti-A,B is to detect: a.) anti-A1 b.) anti-A2 c.) subgroups of A d.) subgroups of O
c.) subgroups of A Ax cells react more strongly with anti-A,B than with anti-A. If anti-A is nonreactive, Ax cells may be detected with anti-A,B.
A mother is Rh-neg and the father Rh-pos. Their baby is Rh-neg. It may be concluded that: a.) the father is homozygous for D b.) the mother is heterozygous for c.) the father is heterozygous d.) at least 1 of the 3 Rh typings must be incorrect
c.) the father is heterozygous Mom does not have the D gene. Father would have to have inherited one gene that produces D and another gene that does not produce D. The mom and dad both passed on genes that do not produce D to child.
During prenatal studies, a woman is noted to have a positive antibody screen and anti-Kpa is identified. What percentage of units will be compatible for this patient if transfusion is necessary? a.) <2% b.) 50% c.) 85% d.) >98%
d.) >98% Anti-Kpa is an antibody to a low-incidence antigen. The Kpa antigen is presnt in 2% of Caucasian population and <1% of black populations. Therefore more than 98% of random fono units should be compatible if transfusion is needed for this patient.
A patient's serum sample was reactive with all cells except the autocontrol when tested by PEG-AHG. The patient's phenotype was confirmed as C-E+c+e+; K-k+, Kp (a-b+), Js(a-b+); Fy(a-b+); Jk(a-b-); M+N+S+s+. Phenotypically similar cells were tested and found to be nonreactive. In what population of donors are we most likely to find a compatible donor for this patient? a.) African b.) Middle Eastern c.) South American d.) Tahitian
d.) Tahitian As high as 1 in 400 ppl of Polynesian ethnicity have a silent gene at the JK locus, leading to the Jk(a-b-) phenotype.
In the direct antiglobulin test, the antiglobulin reagent is used to: a.) mediate hemolysis of indicator red cells by providing complement b.) precipitate anti-erythrocyte antibodies c.) measure antibodies in a test serum by fixing complement d.) detect preexisting antibodies on erythrocytes
d.) detect preexisting antibodies on erythrocytes Antiglobulin reagent is used to detect the presence of red cells, coated in vivo with IgG and/or C3d. Antiglobulin reagent may be polyspecific or monospecific
Which of the following would most likely be responsible for an incompatible antiglobulin crossmatch? a.) recipient's red cells possess a low frequency antigen b.) anti-K antibody in donor serum c.) recipient's red cells are polyagglutinable d.) donor red cells have a positive DAT
d.) donor red cells have a positive DAT Since crossmatching is a test between the pt's plasma and donor's cells, any incompatibility is due to the donor's red cells.
The process of separation of antibody from its antigen is known as a.) diffusion b.) adsorption c.) neutralization d.) elution
d.) elution An elution is the process of removal of antibody from RBCs. The product of the elution method is an eluate. The eluate contains the antibody and can be used in antibody identification methods.
A 10% red cell suspension in saline is used in a compatibility test. Which of the following would most likely occur? a.) false-pos result due to antigen excess b.) false-pos result due to the prozone phenomenon c.) false-neg result due to the prozone phenomenon d.) false-neg result due to antigen excess
d.) false-neg result due to antigen excess The strength of agglutination is dependent upon optimal antigen to antibody ratio. Excessive amount of antigen does not allow maximal uptake of antibody per red cell and therefore agglutination is negatively affected leading to weaker or negative results.
A patient in the immediate post bone marrow transplant period has a hematocrit of 21%. The red cell product of choice for this patient would be: a.) packed b.) saline washed c.) microaggregate filtered d.) irradiated
d.) irradiated Bone marrow transplant pts are at risk for transfusion-associated graft-vs-host disease (TA-GVHD) and therefore should receive irradiated blood products.
A patient is group a, Rh-pos but is receiving a Group O, bone marrow transplant (BMT) on Friday. After the transplant, what hemagglutination pattern will the patient demonstrate when the patient's red cells are tested with anti-A a.) rouleaux b.) aggregation c.) polyagglutination d.) mixed-field
d.) mixed-field 2 cells populations may lead to a MF agglutination pattern. MF may occur from transfusion stem cell transplant or rare genetic chimera. A chimera is a person with a dual population of cells derived from more than one zygote.
The drug cephalosporin can cause a positive direct antiglobulin test due to modification of the RBC membrane by the drug which is independent of antibody production. This mechanism related to the drug cephalosporin is best described as: a.) drug-dependent b.) complement related drug-dependent c.) drug-autoantibody d.) nonimmunologic protein adsorption
d.) nonimmunologic protein adsorption Cephalosporins were originally associated with pos DAT and nonimmunologic protein adsorption (or membrane modification). Other drugs that cause nonimmunologic protein adsorption and a pos DAT include tazobactam, sulbactum, cisplatin, oxaliplatin, and diglycaldehyde.
The major crossmatch will detect a(n): a.) group A patient mistyped as group O b.) unexpected red cell antibody in the donor unit c.) Rh-neg donor unit mislabeled as Rh-pos d.) recipient antibody directed against antigens on the donor red cells
d.) recipient antibody directed against antigens on the donor red cells The major crossmatch tests the recipient's plasma with donor's cells. This would detect any antibody in the recipient that would react with antigens on the donor's RBCs.
Which of the following might cause a false-negative IAT? a.) over-reading b.) IgG-coated screening cells c.) addition of an extra drop of serum d.) too heavy a cell suspension
d.) too heavy a cell suspension Weak antibodies may be missed id there are excess RBC antigens as there may be too few antibodies to bind to red cell antigens.
Which of the following genes on chromosome 1 is made up of 2 exons, leading to the expression of the Duffy glycoprotein and its antigens? a.) DAF b.) FYAB c.) FY d.)ACKR1
d.)ACKR1 The ACKR1 (formerly DARC) gene encodes for the Duffy glycoprotein. ACKR1 stands for atypical chemokine receptor 1.