Immunohematology (Questions)

***Which of the following is most helpful to confirm a weak ABO subgroup? A. adsorption-elution B. neutralization C. testing with A1 lectin D. use of anti-A,B

A. Adsorption and elution techniques are used to detect ABO antigens that are not detectable by direct agglutination. The cells are incubated with the antibody (anti-A or anti-B) to the antigen expected on the red blood cells. An elution method is performed and the antibody in the eluate is tested for recovering anti-A (or anti-B depending on the specificity that was used in the adsorption).

**The most appropriate laboratory test for early detection of acute posttransfusion hemolysis is: A. a visual inspection for free plasma hemoglobin B. plasma haptoglobin concentration C. examination for hematuria D. serum bilirubin concentration

A. Free hemoglobin released from destruction of transfused donor red cells will impart a distinct pink or red color in the posttransfusion sample plasma.

***Which of the following transfusion reactions is characterized by high fever, shock, hemoglobinuria, DIC and renal failure? A. bacterial contamination B. circulatory overload C. febrile D. anaphylactic

A. In septic transfusion reactions, patients experience fever >101F (38.3C), shaking chills, and hypotension. In severe reactions, patients develop shock, renal failure, hemoglobinuria, and DIC.

*All of the following apply to a double red cell unit apheresis collection EXCEPT: A. The hematocrit must be at least 38% B. The weight for a female is at least 150 lb C. The height for a male is at least 5 ft 1 in. D. The deferral period following collection is 16 weeks

A. The minimum hematocrit for a double red cell donation is 40%.

***For apheresis donors who donate platelets more frequently than every 4 weeks, a platelet count must be performed prior to the procedure and be at least: A. 150 x 10^3/uL B. 200 x 10^3/uL C. 250 x 10^3/uL D. 300 x 10^3/uL

A. The minimum platelet count required for frequent repeat donors is 150 x 10^3/uL. A platelet count is not required prior to the first donation or if the interval between donations is at least 4 weeks.

***In a cold autoadsorption 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. Treating autologous cells with a proteolytic enzyme such as ficin enhances the adsorption of the cold reactive antibody.

***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 adsorption 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. ZZAP is a reagent to remove IgG from the patient's own cells to allow better adsorption of IgG autoantibody from the patient's plasma onto the cells. The intent of the autoadsorption is to remove autoantibody to look for alloantibodies prior to transfusion.

*What type RBCs can be transfused to an A2 person with anti-A1? A. A only B. A or O C. B D. AB

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.

***A patient received about 15 mL of compatible blood and developed severe shock, but no fever. If the patient needs another transfusion, what kind of red blood cell component should be given? A. RBCs B. RBCs, washed C. RBCs, irradiated D. RBCs, leukocyte-reduced

B. Anaphylactic transfusion reactions are distinguished from other types of reactions by 1) the absence of fever, and 2) the reactions are sudden in onset after infusion of only a few mL of blood. Since the reaction is due to anti-IgA, washing the donor red blood cells to remove all plasma protein is indicated. Alternatively, blood products from IgA-deficient donors may be used.

***The main purpose of performing antibody titers on serum from prenatal immunized women is to: A. determine the identity of the antibody B. identify candidates for amniocentesis or percutaneous umbilical blood sampling C. decide if the baby needs an intrauterine transfusion D. determine if early induction of labor is indicated

B. Antibody titers do not themselves predict the severity of HDFN or the treatment needed. Instead, titers above a critical level, usually 16-32, identify candidates for amniocentesis or PUBS to monitor the fetus and determine the course of treatment.

***In a delayed hemolytic transfusion reaction, the direct antiglobulin test is typically: A. negative B. mixed-field positive C. positive due to complement D. negative when the antibody screen is negative

B. Delayed hemolytic transfusion reactions are associated with extravascular hemolysis, rather than intravascular. alloantibody coats the transfused antigen-positive donor cells in the recipient's circulation, producing a mixed-field positive reaction in the DAT.

***A 42-year-old male of average body mass has a history of chronic anemia requiring transfusion support. Two units of RBCs are transfused. If the pretransfusion hemoglobin was 7.0 g/dL, the expected post transfusion hemoglobin concentration should be: A. 8.0 g/dL B. 9.0 g/dL C. 10.0 g/dL D. 11.0 g/dL

B. Each unit of BCs is expected to increase the hemoglobin level by 1-1.5 g/dL.

***How many units of RBCs are required to raise the hematocrit of a 70 kg nonbleeding man from 24% to 30%? A. 1 B. 2 C. 3 D. 4

B. Each unit of RBCs is expected to increase the hematocrit level by 3%-5%, so it would take 2 units to raise the level 6%.

*FFP can be transfused without regard for: A. ABO type B. Rh type C. Antibody in product D. All of these options

B. FFP can be transfused without regard for Rh type because FFP is not a cellular product.

***Which of the following blood components must be prepared within 8 hours after phlebotomy? A. red blood cells B. fresh frozen plasma C. red blood cells, frozen D. cryoprecipitated AHF

B. Fresh Frozen Plasma (FFP) must be separated and frozen within 8 hours of Whole Blood collection.

***HLA antibodies are: A. naturally occurring B. indicated by multiple transfusions C. directed against granulocyte antigens only D. frequently cause hemolytic transfusion reactions

B. HLA antibodies are formed in response to pregnancy, transfusion or transplantation and are therefore not naturally occurring. They are associated with febrile nonhemolytic transfusion reactions and TRALI. They are directed against antigens found on granulocytes and other cells such as platelets.

***Anti-I may cause a positive 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. 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.

***In a random population, 16% of the people are Rh-negative (rr). What percentage of the Rh-positive population is heterozygous for r? A. 36% B. 48% C. 57% D. 66%

B. The Hardy-Weinberg equation states p^2 + 2pq + q^2 = 1.0 or (p+q)^2 = 1.0 or p+q=1.0 In this example, p^2 = .16, so p = .04. 1.0 - .4 = .6 so q = .96. Fill in the equation: (.4)^2 + 2(.4)(.6) + (.6)^2 = 1.0 or (.16) + (.48) + (.36) = 1.0 p^2 = 16% homozygous for rr 2pq = 48% heterozygous for Rr q^2 = 36% homozygous for RR

***Anti-N is identified in a patient's serum. If random crossmatches are performed on 10 donor units, how many would be expected to be compatible? A. 0 B. 3 C. 7 D. 10

B. The N antigen is lacking in 30% of the Caucasian population.

***Crossmatch results at the antiglobulin phase were negative. When 1 drop of check cells was added, no agglutination was seen. The MOST likely explanation is that the: A. red cells were overwashed B. centrifuge speed was set too high C. residual patient serum inactivated the AHG reagent D. laboratorian did not add enough check cells

C. A negative reaction after the addition of check cells indicates AHG serum was not present. Inadequate washing of red cells may leave residual patient serum behind, which can neutralize AHG serum.

*Which of the following antibodies characteristically gives a refractile mixed-field appearance? A. Anti-K B. Anti-Dia C. Anti-Sda D. Anti-s

C. Anti-Sda characteristically gives a refractile mixed-field agglutination reaction in the IAT phase. The refractile characteristic is more evident under the microscope.

***One of the most effective methods for the elution of warm autoantibodies from RBCs utilizes: A. 10% sucrose B. LISS C. change in pH D. distilled water

C. Antibody-antigen complexes are dependent upon neutral pH. Extremes in pH causes dissociation. Both auto and alloantibodies are recovered in eluates prepared by reagent kits that alter the pH.

***Which apheresis platelets product should be irradiated? A. autologous unit collected prior to surgery B. random stick unit going to a patient with DIC C. a directed donation given by a mother for her son D. a directed donation given by an unrelated family friend

C. Blood products from blood relatives containing viable lymphocytes must be irradiated to inhibit the proliferation of T cells and subsequent GVHD.

*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

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.

***Which of the following medications is most likely to cause production of autoantibodies? A. penicillin B. cephalothin C. methyldopa D. tetracycline

C. Methyldopa is frequently listed as the prototype for drug-independent antibody mechanism where autoantibody is present on the red cells and may also be present in the plasma.

*Should an O-negative mother receive RhIg if a positive DAT on the newborn is caused by immune anti-A? A. No, the mother is not a candidate for RhIg because of the positive DAT B. Yes, if the baby's type is Rh negative C. Yes, if the baby's type is Rh positive D. No, the baby's problem is unrelated to Rh blood group antibodies

C. RhIg is immune anti-D and is given to Rh-negative mothers who give birth to Rh-positive babies and who do not have anti-D already formed from previous pregnancies or transfusion.

***The red cells of a nonsecretor (se/se) will most likely type as: A. Le(a-b-) B. Le(a+b+) C. Le(a+b-) D. Le(a-b+)

C. The Lewis antigens are developed by gene interaction. Both the Lewis and Secretor gene are required for red cells to type as Le(a-b+). If a person has a Lewis gene, but not secretor gene, then the cells type as Le(a+b-). The Le(a-b-) phenotype is derived when the Lewis gene is absent and the secretor gene may or may not be present. The Le(a+b-) phenotype occurs in 22% of the population, and Le(a-b-) occurs in 6% so, the most likely phenotype of a nonsecretor (se/se) is Le(a+b-).

*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 D. The patient is an A1 with anti-A2

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.

***The observed phenotypes in a particular population ar: Phenotype Number of persons Jk(a+b-) 122 Jk(a+b+) 194 Jk(a-b+) 84 What is the gene frequency of Jka in this population? A. 0.31 B. 0.45 C. 0.55 D. 0.60

C. Use the Hardy-Weinberg equation: p^2 + 2pq + q^2 = 1.0. In this example, p^2 is the homozygous population, Jk(a+b-). The square root of p^2 = p, which is the gene frequency of Jka in this population. Out of 400 people, 122, or 30% are homozygous. The square root of 0.30 is 0.55.

*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? A. Direct/primary/first order B. Probability C. Random D. Indirect/secondary/second order

D. An indirect/secondary/second order exclusion occurs when a genetic marker is absent in the child but should have been transmitted by the alleged father. In this case, either A or B should be present in the child.

*What techniques are necessary for weak D testing? A. Saline + 22°C incubation B. Albumin or LISS + 37°C incubation C. Saline + 37°C incubation D. 37°C incubation + IAT

D. Weak D testing requires both 37°C incubation and the IAT procedure. Anti-D is an IgG antibody, and attachment of the D antigen is optimized at warmer temperatures. Antihuman globulin in the IAT phase facilitates lattice formation by binding to the antigen-antibody complexes.

**A 24 year old A negative female was transfused with approximately 65 cc o an A positive RBC unit. How many vials of Rh Immune globulin should this woman receive? A. 0, she is not an RhIg candidate B. 2 C. 3 D. 4 E. 5

E. The female is of childbearing age and is an Rh immune globulin candidate. RhIg is expected to counteract 15 cc of RBCs. 65/15 cc = 4.3. Round down to 4 (round down if the decimal is less than .5 and add 1 (safety factor) for a total of 5. (Remember, in a fetal-maternal bleed the number of cc is divided by 30.)

*What can be done if HDN is caused by maternal anti-K? A. Give Kell immune globulin B. Monitor the mother's antibody level C. Prevent formation of K-positive cells in the fetus D. Not a problem; anti-K is not known to cause HDN

B. Anti-D is the only antibody for which prevention of HDN is possible. If a pregnant woman develops anti-K, she will be monitored to determine if the antibody level and signs of fetal distress necessitate clinical intervention.

*Cord cells are washed six times with saline and the DAT and negative control are still positive. What should be done next? A. Obtain a heelstick sample B. Record the DAT as positive C. Obtain another cord sample D. Perform an elution on the cord cells

A. If the cord cells contain excessive Wharton's jelly, then further washing or obtaining another cord sample will not solve the problem. A heelstick sample will not contain Wharton's jelly and should give a valid DAT result.

***Which of the following red cell antigens are found on glycophorin-A? A. M, N B. Lea, Leb C. S, s D. P, P1, Pk

A. The M and N antigens are found on glycophorin A.

**The following reactions were obtained on testing maternal serum and infant cord cells: Maternal Sample: O negative (D weak - mixed field) D control: Negative Antibody Screen: Negative Infant Cord Cells: A positive DAT: Negative The most likely explanation for these results is a/an: A. ABO grouping error on infant B. Detection of anetenatal Rh immune globulin C. Fetal-maternal hemorrhage D. False negative DAT

C. A positive weak D test in a post partum patient is usually due to a fetal maternal hemorrhage in which the fetal D positive cells have entered the maternal circulation most often at delivery. Option A is incorrect as it is plausible for an O negative mother to have an A positive infant. Option B is incorrect since the maternal antibody screen is negative (RhIg = anti-D). Option D is incorrect since hemolytic disease of the newborn is not indicated.

*Currently, nucleic acid amplification testing (NAT) testing is performed to detect which viruses? A. HIV and HTLV-1 B. HTLV I/II C. HIV, HCV, and WNV D. HIV, HBV, and WNV

C. According to AABB standards, NAT testing is required for viruses HIV-1, HCV, and WNV.

***The enzyme responsible for conferring H activity on the red cell membrane is alpha: A. galactosyl transferase B. N-acetylgalactosaminyl transferase C. L-fucosyl transferase D. N-acetylglucosaminyl transferase

C. Fucose is the immunodominant sugar for H.

***Leukocyte-reduced red blood cells are ordered for a newly diagnosed bone marrow candidate. What is the best way to prepare this product? A. crossmatch only CMV-seronegative units B. irradiate the unit with 1,500 rads C. wash the unit with saline prior to infusion D. transfuse through a Log^3 leukocyte-removing filter

D. Newly diagnosed bone marrow candidates are at great risk for severe sequelae of CMV infections. Infection can best be reduced by using leukocyte-reduction filters. CMV-seronegative units are rarely used since leukocyte reducing via filtration is so effective. Washing does not remove as may leukocytes as filtering.

**How many units of platelet concentrates would be needed to raise the platelet count 150,000/mm3 in an average sized adult? A. 4 B. 8 C. 12 D. 15

D. One unit of platelets theoretically increases the platelet count in an average sized adult 5,000 - 10,000/mm3. 150,000/10,000 = 15 units of platelets. The count could actually be as high as 30 units if this patient responds on the lower end: 150,000/5,000 = 30 units of platelets.

***A 26-year-old feemale is admitted with anemia of undetermined origin. Blood samples are received with a crossmatch request for 6 units of RBCs. the patient is group A, Rh-negative and has no history of transfusion or pregnancy. The following results were obtained in pretransfusion testing: IS 37C IAT Cell I 0 0 3+ Cell II 0 0 3+ autocontrol 0 0 3+ all 6 donors 0 0 3+ The best way to find compatible blood is to: A. do an antibody identification panel B. use the saline replacement technique C. use the pre-warm technique D. perform a warm autoadsorption

D. Since the autocontrol is positive after the AHG phase and not reactivity was detected at immediate spin, the serology is most consistent with a warm autoantibody. An adsorption with autologous cells to remove the antibody to use the adsorbed plasma for alloantibody detection is the next step.

***A commonly used screening method for anti-HIV-1 detection is: A. latex agglutination B. radioimmunoassay (RIA) C. thin-layer-chromatography (TLC) D. enzyme-labeled immunosorbent assay (ELISA)

D. The enzyme-labeled immunosorbent assay (ELISA) method is a very sensitive method employed to screen donors for markers of transfusion-transmitted diseases.

***Which of the following Rh antigens has the highest frequency in Caucasians? A. D B. E C. c D. e

D. The overall incidence of the e antigen is 98%. The overall incidence of c is 80%, D is 85% and E is 30%.

***Anti-Sda is strongly suspected if: A. the patient has been previously transfuse B. the agglutinates are mixed-field and refractile C. the patient is group A or B D. only a small number of panel cells are reactive

B. Anti-Sda is an antibody to a high-prevalence antigen, which varies in strength from person to person. Most examples of anti-Sda characteristically present as small, mixed-field, refractile agglutinates that may have a shiny appearance when observed microscopically after the antiglobulin test.

***To qualify as a donor for autologous transfusion a patient's hemoglobin should be at least: A. 8 g/dL B. 11 g/dL C. 13 g/dL D. 15 g/dL

B. Autologous donors have less stringent criteria than allogeneic donors. Donations must be collected at least 72 hours prior to surgery.

*An anti-M reacts strongly through all phases of testing. Which of the following techniques would not contribute to removing this reactivity so that more clinically significant antibodies may be revealed? A. Acidifying the serum B. Prewarmed technique C. Adsorption with homozygous cells D. Testing with enzyme-treated red cells

A. Lowering the pH will actually enhance reactivity of anti-M. Prewarming (anti-M is a cold-reacting antibody), cold adsorption with homozygous M cells, and testing the serum with enzyme-treated red cells (destroys M antigens) are all techniques to remove reactivity of anti-M.

*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

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.

***The antibody in the Lutheran system that is best detected at lower temperatures is: A. anti-Lua B. anti-Lub C. anti-Lu3 D. anti-Luab

A. Most examples of anti-Lua agglutinate saline suspended cells. Most examples of anti-Lub are IgG and reacts at 37C. Anti-Lu3 usually reacts at the AHG phase as does anti-Luab.

***A 56-year-old female with cold agglutinin disease has a positive direct antiglobulin test. When the DAT is repeated using monospecific antiglobulin sera, which of the following is most likely to be detected? A. IgM B. IgG C. C3d D. C4a

C. 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 red blood cells.

**Four units of platelets were pooled and issued at 2:00 p.m. At 7:00 p.m. the ward called, said they had never transfused the platelets, and wanted to know if the platelet pool could still be used? A. No, they outdated at 6:00 p.m. B. No, the platelets weren't refrigerated on the ward C. Yes, they won't outdate until 8:00 p.m. D. Yes, they are good for 24 hours after pooling

A. Option B, C, and D are incorrect because none reflect the correct time or storage temperature for pooled platelets. Pooled platelets are good for 4 hours after pooling and should be maintained at room temperature.

***A unit of FFP was inadvertently thawed and then immediately refrigerated at 4C on Monday morning. On Tuesday evening this unit may still be transfused as a replacement for: A. all coagulation factors B. Factor V C. Factor VIII D. Factor IX

D. Factors V and VIII would be decreased but IX would not be decreased.

***According to AABB Standards, platelets prepared from whole blood shall have at least: A. 5.5 x 10^10 platelets per unit in at least 90% of the units tested B. 6.5 x 11^10 platelets per unit in 90% of the units tested C. 7.5 x 10^10 platelets per unit in 100% of the units tested D. 8.5 x 10^10 platelets per unit in 95% of the units tested

A. Per AABB standards, at least 90% of the platelet units prepared from whole blood that are sampled must contain at least 5.5 x 10^10 platelets.

*A blood supplier ships 3 units of pooled cryoprecipitate. Each pool consists of 5 units of cryoprecipitate. If one unit is thawed at 5:00 p.m., when must it be dispensed from the blood bank? A. Before 9:00 p.m. B. Before 11:00 p.m. C. Before 12:00 a.m. D. Before 5:00 p.m. the next day

A. Pooled cryoprecipitate is a closed system; however, it has an outdate of 4 hours once thawed.

*The following whole blood donors regularly give blood. Which donor may donate on September 10th? A. A 40-year-old woman who last donated on July 23rd B. A 28-year-old man who had plateletpheresis on August 24th C. A 52-year-old man who made an autologous donation 2 days ago D. A 23-year-old woman who donated blood for her aunt on August 14th

B. A plateletpheresis donor must wait at least 48 hours between donations. The waiting period following an autologous donation is at least 3 days. An 8-week interval must pass between all other types of donations.

***Anti-D and anti-C are identified in their serum of a transfused pregnant woman, gravida 2, para 1. Nine months previously she received Rh immune globulin (RhIG) after delivery. Tests of the patient, her husband, and the child revealed the following: Anti-D Anti-C Anti-E Anti-c Anti-e Patient 0 0 0 + + Father + 0 0 + + Child + 0 0 + + The most likely explanation for the presence of anti-C is that the antibody is: A. actually anti-Cw B. from the RhIG dose C. actually anti-G D. naturally occurring

C. The G antigen is normally present on red cells possessing either C or D. Anti-G reacts with panel cells that are D+ or C+ and the antibodies appear to be anti-C and anti-D. The G antigen is expressed on the child's D+ red blood cells.

***Mixed leukocyte culture (MLC) is biological assay for detecting which of the following? A. HLA-A antigens B. HLA-B antigens C. HLA-D antigens D. immunoglobulins

C. The mixed lymphocyte culture (MLC) is used to detect genetic differences in the HLA D region antigens.

*SITUATION: An O-negative mother gave birth to a B-positive infant. The mother had no history of antibodies or transfusion. This was her first child. The baby was mildly jaundiced and the DAT weakly positive with polyspecific antisera. What could have caused the positive DAT? A. Anti-D from the mother coating the infant red cells B. An alloantibody, such as anti-K, coating the infant red cells C. Maternal anti-B coating the infant cells D. Maternal anti-A, B coating the infant cells

D. Anti-A,B is an IgG antibody and can cross the placenta and attach to infant cells. It is known as a single entity as opposed to separate antibodies. Anti-D would not be the cause because this is the first pregnancy. Anti-K is not the cause because there is no history of alloantibodies or past transfusions.

*All of the following are reasons for performing an adsorption, except: A. Separation of mixtures of antibodies B. Removal of interfering substances C. Confirmation of weak antigens on red cells D. Identification of antibodies causing a positive DAT

D. Antibodies causing a positive DAT would be coating red cells and would require an elution, not an adsorption, to identify them.

*Which immunization has the longest deferral period? A. HBIG B. Rubella vaccine C. Influenza vaccine D. Yellow fever vaccine

A. Deferral for HBIG injection is 12 months. Deferral for rubella vaccine is 4 weeks. The deferral period for influenza and yellow fever vaccines is 2 weeks.

***Which of the following would be the best source of platelets for transfusion in the case of alloimmune neonatal thrombocytopenia? A. father B. mother C. poole platelet-rich plasma D. polycythemic donor

B. When platelets are needed, maternal platelets are often prepared for use at cordocentesis or delivery. Platelets should be washed to remove maternal antibody.

*What percentage of red cells must be retained in leukocyte-reduced red cells? A. 75% B. 80% C. 85% D. 100%

C. A red cell unit that has been leukocyte reduced must retain 85% of original red cells.

***Which of the following phenotypes will react with anti-f? A. rr B. R1R1 C. R2R2 D. R1R2

A. Anti-f will react with cells that carry c and e on the same Rh polypeptide. No other listed genotypes produce an Rh polypeptide that carries both c and e.

*Why do Rh-negative women tend to have a positive antibody screen compared to Rh-positive women of childbearing age? A. They have formed active anti-D B. They have received RhIg C. They have formed anti-K D. They have a higher rate of transfusion

B. The most common reason an Rh-negative woman has a positive antibody screen is because of previously receiving RhIg or passive anti-D.

***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 survival D. febrile transfusion reactions

A. Chido antibodies are considered clinically insignificant.

***Cryoprecipitated AHF must be transfused within what period of time following thawing and pooling? A. 4 hours B. 8 hours C. 12 hours D. 24 hours

A. Cryoprecipitate must be transfused within 4 hours of pooling.

*All of the following statements regarding FFP are true, EXCEPT: A. FFP must be prepared within 24 hours of collection B. After thawing, FFP must be transfused within 24 hours C. Storage temperature for FFP with a 1-year shelf life is ≤−18°C D. When thawed, FFP must be stored between 1°C-6°C

A. FFP must be prepared within 8 hours after collection if the anticoagulant is citrate phosphate dextrose (CPD), citrate phosphate double dextrose (CP2D), or citrate phosphate dextrose adenine (CPDA-1); or within 6 hours if the anticoagulant is ACD.

*Red cells from a recently transfused patient were DAT positive when tested with anti-IgG. Screen cells and a panel performed on a patient's serum showed very weak reactions with inconclusive results. What procedure could help to identify the antibody? A. Elution followed by a panel on the eluate B. Adsorption followed by a panel on the adsorbed serum C. Enzyme panel D. Antigen typing the patient's red cells

A. If the red cells show a positive DAT, then IgG antibody has coated incompatible, antigen-positive red cells. If screening cells and panel cells show missing or weak reactions, most of the antibody is on the red cells and would need to be eluted before it can be detected. An elution procedure followed by a panel performed on the eluate would help to identify the antibody.

*Which of the following is acceptable according to AABB standards? A. Rejuvenated RBCs may be made within 3 days of outdate and transfused or frozen within 24 hours of rejuvenation B. Frozen RBCs must be prepared within 30 minutes of collection and may be used within 10 years C. Irradiated RBCs must be treated within 8 hours of collection and transfused within 6 hours D. Leukocyte-reduced RBCs must be prepared within 6 hours of collection and transfused within 6 hours of preparation

A. Rejuvenated RBCs may be prepared within 3 days of the outdate of the unit and washed and transfused or frozen within 24 hours. A unit of RBCs may be frozen within 6 days of collection. An RBC unit can be irradiated any time prior to expiration date; once irradiated, the unit must be transfused within 28 days of irradiation or the original outdate, whichever comes first. Leukocyte-reduced RBCs should be prepared within 6 hours of collection, but must be given within 24 hours, if prepared using an open system. Leukocyte-reduced RBCs prepared using a closed system may be kept until the original outdate.

*All of the following are advantages of using single donor platelets as opposed to random donor platelets, EXCEPT: A. Less preparation time B. Less antigen exposure for patients C. May be HLA matched D. No pooling is required

A. Single-donor platelets require more preparation time than random-donor platelets because they are prepared by apheresis, which may require 1-3 hours depending on the instrumentation used. Pooling random donor platelets in equivalent amounts may require only a few minutes.

*Which technology may report an Rh-weak D positive as Rh negative? A. Gel System B. Solid Phase C. Tube Testing D. None of these options

A. The Gel system cannot detect a weak D phenotype because there is no 37°C or AHG phase with the ABD card.

***A mother has the red cell phenotype D+C+E-c-e+ with anti-c (titer of 32 at AHG) in her serum. The father has the phenotype D+C+E-c+e+. The baby is Rh-negative and not affected with hemolytic disease of the newborn. What is the baby's most probable Rh genotype? A. r'r' B. r'r C. R1R1 D. R1r

A. The baby is Rh-negative and lacks c, since there is no evidence of HDFN. Inheritance of no D and no c is denoted as r'. the baby must have inherited this gene from both parents, and is homozygous r'r'.

**The transfusion component of choice for a bleeding patient with a prolonged bleeding time, increased APTT, decreased levels of Factor VIII antigen and impaired aggregation of platelets in response to ristocetin would be: A. Cryoprecipitate B. Factor VIII C. Fresh frozen plasma D. Platelets

A. These laboratory data suggest a patient with Von Willebrand Syndrome. Cryoprecipitate is the only component containing Von Willebrand factor (vWF) as well as factor VIII. Both of these are deficient in these patients. It is the vWF that is responsible for the platelet aggregating effect of ristocetin. Since the patient is bleeding, it is more likely a severe case which would warrant cryo. If the case was mild, DDAVP could be used instead. Option B is incorrect because plain Factor VIII does not contain vWF; you would need to use the Factor VIII concentrates known to have vWF. Option C lists FFP as a choice. FFP has cryo in it but has too much volume; you need to give the patient concentrated factors, not volume. Option D is incorrect because you don't need platelets, you need vWF.

***Which of the following is characteristic of Tn polyagglutinable red cells? A. if group O, they may appear to have acquired a group A antigen B. they show strong reactions when the cells are enzyme-treated C. they react with Arachis hypogaea lectin D. the polyagglutination is a transient condition

A. Tn is caused from a somatic mutation and the phenomenon is persistent. Resolution of the red cell typing can be performed with enzyme-treated patient cells, since Tn is denatured by enzymes. Although the reactivity with anti-A may be weak, testing with anti-A1 lectin gives strong reactivity, unlike subgroups of A, which are weakly reacting with anti-a and nonreactive with A1 lectin.

*How much anticoagulant would have to be removed from the collection bag given a donor who weighs 90 lb? A. 12 mL B. 15 mL C. 20 mL D. 23 mL

A. To determine the amount of anticoagulant to remove when the donor is less than 110 lb, divide weight by 110 lb and multiply by 450 mL; divide that number by 100 and multiply by 14 (this gives the anticoagulant volume needed); then subtract this from 63 mL, which is the standard volume of anticoagulant in a 450 mL bag. The result is the amount of anticoagulant to remove.

***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. Warm autoantibodies often exhibit Rh specificity.

*What is the expiration of cryoprecipitate once pooled? A. 4 hours B. 6 hours C. 8 hours D. 24 hours

A. When individual Cryo units are pooled in an open system, the expiration time is 4 hours; if Cryo is pooled using a sterile connecting device, the expiration time is 6 hours.

***A patient's serum reacted weakly positive (1+w) with 16 of 16 group O panel cells at the AHG test phase. The autocontrol was negative. Tests with ficin-treated panel cells demonstrated 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. 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.

*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

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.

***Which of the following antibodies is neutralizable by pooled human plasma? A. anti-Ka B. anti-Ch C. anti-Yka D. anti-Csa

B. Anti-Ch and anti-Rg react at IAT with trace amounts of C4 (a component of complement) present on normal RBCs. The Ch and Rg substance is found soluble in plasma. Neutralization studies with pooled plasma can help confirm the antibody reactivity in a patient's sample. If test procedures are used to coat cells with C4, a patient with anti-Ch or anti-Rg may agglutinate the cells directly.

**For which of the following blood groups is it NOT necessary to run an Rh control if you are using a monoclonal/polyclonal blend anti-D? A. A neg B. A pos C. AB neg D. AB pos

B. Option A and C are incorrect because an Rh control is needed for any weak D test so would be required for A neg and AB neg. Answer D is incorrect because a negative reaction with either the anti-A and/or anti-B reagent (as needed) shows that the patient cells are not spontaneously agglutinating and acts as the negative control. The AB positive has positive reactions with reagent anti-A and anti-B.

*Anti-E is detected in the serum of a woman in the first trimester of pregnancy. The first titer for anti-E is 32. Two weeks later, the antibody titer is 64 and then 128 after another 2 weeks. Clinically, there are beginning signs of fetal distress. What may be done? A. Induce labor for early delivery B. Perform plasmapheresis to remove anti-E from the mother C. Administer RhIg to the mother D. Perform an intrauterine transfusion using E-negative cells

B. Plasmapheresis removes excess anti-E from the mother and provides a temporary solution to the problem until the fetus is mature enough to be delivered. The procedure may need to be performed several times, depending upon how quickly and how high the levels of anti-E rise. Administration of RhIg would not contribute to solving this problem caused by anti-E. Intrauterine transfusion would not be performed before week 20, and would be considered only if there is evidence of severe hemolytic disease.

***The drug cephalosporin can cause a positive DAT with hemolysis by which of the following mechanisms? A. drug-dependent antibodies reacting with drug-treated cells B. drug-dependent antibodies reacting in the presence of a drug C. drug-independent with autoantibody production D. nonimmunologic protein adsorption with positive DAT

B. Second and third generation cephalosporins react when the drug is present in vitro. When serum, drug, and red cells are present, direct or indirect agglutination or lysis may be observed.

*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 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

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.

***The Liley method of predicting the severity of hemolytic disease of the newborn is based on the amniotic fluid: A. bilirubin concentration by standard methods B. change in optical density measured at 450 nm C. Rh determination D. ratio of lecithin to sphingomyelin

B. The change in optical density (absorbance) of amniotic fluid measured spectrophotometrically at 450 nm is calculated and plotted on the Liley graph according to the weeks gestation. The graph is divided into 3 zones, which predict the severity of HDFN and the need for intervention and treatment.

***Based upon the Kleihauer-Betke test results, which of the following formulas is used to determine the volume of fetomaternal hemorrhage expressed in mL of whole blood? A. % of fetal cells present x 30 B. % of fetal cells present x 50 C. % of maternal cells present x 30 D. % of maternal cells present x 50

B. The percentage is cells/100, the mother's volume is assumed to be 5,000 mL. The percentage must be multiplied by 50 to determine total volume.

*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 C. Allergic D. TRALI

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.

*The reactivity of an unknown antibody could be anti-Jka, but the antibody identification panel does not fit this pattern conclusively. Which of the following would not be effective in determining if the specificity is anti-Jka? A. Testing with enzyme-treated cells B. Select panel of homozygous cells C. Testing with AET-treated cells D. Increased incubation

C. AET denatures Kell antigens and has no effect on Kidd antibodies. Because the detection of Kidd antibodies is subject to dosage effect, selection of cells homozygous for the Jka antigen (and longer incubation) would help to detect the presence of the corresponding antibody. Enzyme-treated red cells would also react more strongly in the presence of Kidd antibodies.

***Refer to the following data: Forward group anti-A: 4+ anti-B: 0 anti-A1 lectin: 4+ Reverse group A1 cells: 0 A2 cells: 2+ B cells: 4+ The above ABO discrepancy is most likely due to: A. anti-A1 B. rouleaux C. anti-H D. unexpected IgG antibody present

C. An ABO discrepancy in an A1 individual, manifested by agglutination in the serum grouping with A2 cells, is most likely due to anti-H. The greatest concentration of H substance is found on O cells, followed by A2 cells, the least amount of H substance if found on A1 and A1B 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

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 and require additional testing techniques (e.g., room-temperature incubation) before their expression is apparent.

***When the main objective of an exchange transfusion is to remove the infant's antibody-sensitized red blood cells and to control hyperbilirubinemia, the blood product of choice is ABO compatible: A. fresh whole blood b. washed RBCs C. RBCs suspended in FFP D. heparinized RBCs

C. For exchange transfusion, antigen-negative RBCs are typically resuspended in ABO-compatible thawed FFP.

*Which of the following is true regarding granulocyte concentrates? A. The product must contain a maximum of 1.0 × 1010 granulocytes B. The pH must be 6.0 C. The product must be crossmatched D. The product must be irradiated

C. Granulocyte concentrates contain a large amount of red cells and must be crossmatched with the recipient's serum.

*SITUATION: A transplant patient may receive only type A or AB platelets. There are only type O apheresis platelets available. What devices may be used to deplete the incompatible plasma and replace with sterile saline? A. Cytospin/irradiator B. Water bath/centrifuge C. Centrifuge/sterile connecting device D. Cell washer/heat sealer

C. In the event of an ABO mismatched stem cell transplant, special attention must be paid to the choice of transfused blood products. Type A or AB platelets may be given to a transplant in which the donor is A and the recipient is O; once the stem cells engraft, platelets/plasma must be compatible with type A cells. If only type O single-donor platelets are available, the product can be spun down using a centrifuge and plasma can be removed. Then, a sterile connecting device can be used to aseptically transfer sterile isotonic saline to the platelet product, replacing the incompatible plasma.

*A 56-year-old patient diagnosed with colon cancer demonstrates a positive antibody screen in all three screen cells at the antiglobulin phase. A panel study is done and shows 10 cells positive as well as the autocontrol at the antiglobulin phase. The reactions varied from 1+ to 3+. This patient had a history of receiving 2 units of blood approximately 1 month ago. What should be done next? A. Perform a DAT on the patient cells B. Perform an autoadsorption C. Perform an alloadsorption D. Issue O-negative cells

C. In this situation, an allogeneic adsorption must be performed to adsorb out the autoantibody and leave potential alloantibodies in the patient's serum that will need to be identified before transfusion of blood to the patient. An autoadsorption cannot be performed due to the fact that any alloantibodies would be absorbed by circulating donor cells from a month prior.

*An antibody identification panel reveals the presence of anti-Leb and a possible second specificity. Saliva from which person would best neutralize the Leb antibody? A. Le, H, sese B. Le, hh, Se C. Le, H, Se D. lele, hh, sese

C. Lewis antibodies are usually not clinically significant but may interfere with testing for clinically significant antibodies. Lewis antibodies are most easily removed by neutralizing them with soluble Lewis substance. The Lewis antigens are secreted into saliva and plasma and are adsorbed onto the red cells. Leb substance is made by adding an L-fucose to both the terminal and next to last sugar residue on the type 1 precursor chain. This requires the Le, H, and Se genes. Since some examples of anti-Leb react only with group O or A2 RBCs, neutralization is best achieved if the saliva comes from a person who is group O.

*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

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.

***According to AABB Standards, at least 90% of all apheresis platelets units tested shall contain a minimum of how many platelets? A. 5.5 x 10^10 B. 6.5 x 10^10 C. 3.0 x 10^11 D. 5.0 x 10^11

C. Per AABB standards, at least 90% of platelet pheresis units sampled must contain at least 3.0 x 10^11 platelets.

*What protocol is followed when screening whole blood donors for HIV-1 RNA? A. Pools of 10 are tested; if the pool is nonreactive, donors are accepted B. Pools of 20 are tested; if the pool is reactive, samples are tested individually C. Pools of up to 16 donors are tested; if pool is reactive, individual samples are screened D. All donors are screened individually; if samples are reactive, blood is discarded

C. Pools of up to 16 donors are tested by nucleic acid amplification technology. If the pool is reactive, samples from each individual donor are tested.

***In chronic granulomatous disease (CGD), granulocyte function is impaired. An association exists between this clinical condition and a depression of which of the following antigens? A. Rh B. P C. Kell d. Duffy

C. Red blood cells of individuals with the McLeod phenotype lack Kx and Km and have significant depression of other Kell antigens. The McLeod phenotype has been found in patients with chronic granulomatous disease (CGD).

*Which of the following is true regarding apheresis platelets? A. The minimum platelet count must be 3.0 × 10^11, pH must be ≥6.0 B. The minimum platelet count must be 3.0 × 10^10, pH must be ≤6.2 C. The minimum platelet count must be 3.0 × 10^11, pH must be ≥6.2 D. The minimum platelet count must be 5.5 × 10^10, pH must be ≤6.0

C. Single-donor platelets prepared by apheresis must contain a minimum of 3.0 × 1011 platelets and the pH must be 6.2 or higher throughout the shelf life of the product.

*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

C. TRALI is associated with antibodies to human leukocyte antigens or neutrophil antigens, which react with patient granulocytes and cause acute respiratory insufficiency.

*What method can be employed to detect bacteria in random donor platelets? A. pH B. Glucose C. Pan genera detection (PGD) assay D. Gram stain

C. The FDA has mandated that pH and glucose can no longer be used as a screening test for platelets. The Verax PGD assay has been FDA approved for both single-donor platelets and random-donor platelets for bacteria screening.

***In the direct antiglobulin test, the antiglobulin reagent is used to: A. mediate hemolysis of indicator red blood ells 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. Antiglobulin reagent is used to detect the presence of red cells, coated in vivo with IgG and/or C3d. Antiglobulin reagent may be polyspecific (contains an anti-IgG and anti-C3d) or monospecific (anti-IgG or anti-C3d).

*SITUATION: RhIg is requested on a 28-year-old woman with suspected abortion. When the nurse arrives in the blood bank to pick up the RhIg, she asks the medical laboratory scientist (MLS) if it is a minidose. The MLS replies that it is a full dose, not a minidose. The nurse then requests to take 50 mcg from the 300 mcg syringe to satisfy the physician's orders. What course of action should the MLS take? A. Let the nurse take the syringe of RhIg, so that she may withdraw 50 mcg B. Call a supervisor or pathologist C. Instruct the nurse that the blood bank does not stock minidoses of RhIg and manipulating the full dose will compromise the purity of the product D. Instruct the nurse that the blood bank does not stock minidoses of RhIg, and relay this information to the patient's physician

D. Blood banks operate by strict standard operating procedures. These include which products are supplied from the blood bank. While B may also be a solution, D is the best answer because the patient's physician can communicate with the pathologist once he or she receives this information from the nurse.

***Laboratory studies of maternal and cord blood yield the following results: Maternal Blood Cord Blood O, Rh-negative B, Rh-positive anti-E in serum DAT=2+ anti-E in eluate If exchange transfusion is necessary, the best choice of blood is: A. B, Rh-negative, E+ B. B, Rh-positive, E+ C. O, Rh-negative, E- D. O, Rh-positive, E-

D. Blood selected for exchange transfusion is usually crossmatched with the mother's blood, and should be ABO-compatible. It should be negative for the antigen that she has produced antibody against. Unless the HDFN is caused by anti-D, the baby's Rh type is selected. In this case, group O, baby's Rh type, E-, is the best choice for the exchange transfusion.

*A donor was found to contain anti-K using pilot tubes from the collection procedure. How would this affect the compatibility test? A. The AHG major crossmatch would be positive B. The IS (immediate spin) major crossmatch would be positive C. The recipient's antibody screen would be positive for anti-K D. Compatibility testing would not be affected

D. Compatibility testing would not be affected if the donor has anti-K in his or her serum. This is 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.

***Saliva from which of the following individuals would neutralize an auto anti-H in the serum of a group A, Le(a-b+) patient? A. group A, Le(a-b-) B. group A, Le(a+b-) C. group O, Le(a+b-) D. group O, Le(a-b+)

D. Group O have the most H substance in their saliva. The person must also be a secretor of ABH substances. due to gene interaction between the secretor gene and Lewis gene, people who are Le(a-b+) assures H in their saliva.

*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

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 resembles the recipient. The ABO type reported out does not fit a pattern resulting in an undetermined type.

***Which of the following explains an ABO discrepancy caused by problems with the patient's red blood cells? A. an unexpected antibody B. rouleaux C. agammaglobulinemia D. Tn activation

D. Most ABO discrepancies are due to problems in the reverse typing. Discrepancies stemning from the forward type or the patient's cells are usually due to Tn activation from a somatic mutation.

**A patient has experienced febrile reactions following 2 red cell transfusions. The best component to use if subsequent transfusions are needed would be: A. Neocytes B. Packed red cells C. Washed red cells D. Leukocyte-reduced red cells

D. Most febrile nonhemolytic (FNH) transfusion reactions are due to cytokines released from WBCs in the stored blood or to recipient antibodies to antigens on donor lymphocytes, granulocytes and platelets. Patients experiencing a FNH reaction for the first time do not always have a similar reaction with subsequent transfusions. Leukocyte-reduced products are recommended for patients who exhibit 2 or more FNH reactions. Option A and B could both still have WBC and/or cytokines. Option C is a viable option since washing would remove WBCs and cytokines but is too expensive and rarely used for this purpose since the development of leukoreduction filters. Pre-storage leukoreduction works the best since this prevents the buildup of cytokines during storage.

***The serum of a group O, Cde/Cde donor contains anti-D. In order to prepare a suitable anti-D reagent from this donor's serum, which of the following cells would be suitable for the adsorption? A. group O, cde/cde cells B. group O, Cde/cde cells C. group A2B, CDe/cde cells D. group A1B, cde/cde cells

D. The serum of a group O individual contains anti-A, anti-B and anti-A,B. To prepare a suitable reagent, the ABO antibodies must be removed and anti-D left in the serum. The serum would need to be adsorbed with the cells of the A1B, cde/cde phenotype