Medical Lab Science Review: Virus Testing, Tumor Markers, and Blood Bank Procedures

MEDICAL LABORATORY SCIENCE 9. SUMMATIVE EXAM REVIEW QUESTIONS #04 + ANSWERS & RATIONALIZATIONS 1. 2. 3. 4. 5. 6. 7. 8. Blood products are tested for which virus before being transfused to newborns? a. EBV b. Human T-lymphotropic virus II (HTLV-II) c. Cytomegalovirus (CMV) d. Hepatitis D virus Interpret the following results for EBV infection: IgG and IgM antibodies to viral capsid antigen (VCA) are positive. a. Infection in the past b. Infection with a mutual enhancer virus such as HIV c. Current infection d. Impossible to interpret; need more information In general, in which of the following situations is the analysis of a tumor marker most useful? a. Testing for recurrence → via immunoassay b. Prognosis c. Screening d. Diagnosis What is the primary clinical utility of measuring CEA? a. Diagnosis of liver cancer b. Diagnosis of colorectal cancer c. Screening for cancers of endodermal origin d. Monitoring for recurrence of cancer Which type of cancer is associated with the highest level of AFP? a. Hepatoma b. Ovarian cancer c. Testicular cancer d. Breast cancer Which tumor marker is associated with cancer of the urinary bladder? a. CA-19-9 b. CA-72-4 c. Nuclear matrix protein d. Cathepsin-D A 55-year-old male with early stage prostate cancer diagnosed by biopsy had his prostate gland removed (simple prostatectomy). His PSA prior to surgery was 10.0 ng/mL. If the surgery was successful in completely removing the tumor cells, what would the PSA result be 1 month after surgery? a. Undetectable b. 1 to 3 ng/mL c. Less than 4 ng/mL d. Less than 10 ng/mL A patient has a prostate-specific antigen level of 60 ng/mL the day before surgery to remove a localized prostate tumor. One week following surgery, the serum PSA was determined to be 8 ng/mL by the same method. What is the most likely cause of these results? a. Incomplete removal of the malignancy b. Cross reactivity of the antibody with another tumor antigen c. Testing too soon after surgery → must be tested 3-4 weeks after surgery d. Hook effect with the PSA assay 10. 11. 12. 13. Which of the following statements regarding the Philadelphia chromosome is true? a. It is seen exclusively in chronic myelogenous leukemia b. It results from a translocation c. It appears as a short-arm deletion of chromosome 21 d. It is associated with a poor prognosis A major advantage of POCT is: a. Faster turnaround time b. Lower cost c. Better quality than traditional testing d. Both A and C → Major advantage of POCT is the rapidity of assay results; the major drawback is cost. The key structural difference that distinguishes immunoglobulin subclasses is the: a. Number of domains b. Stereometry of the hypervariable region c. The sequence of the constant regions d. Covalent linkage of the light chains lmmunoglobulin classes are differentiated according to the molecular structure of: a. Light chains b. Heavy chains c. Fab fragment d. Fc fragment → lg classes are differentiated based on their amino acid sequences of the constant region of the heavy chains. A 54-year-old female previous smoker presents with a recent history of fever, swollen joints, and morning stiffness. Laboratory results indicate elevated C-reactive protein, positive cyclic citrullinated peptide of 205 units (cut-off: 20 units), speckled ANA pattern (titer 1:320), and negative rheumatoid factor. What is the most likely diagnosis? a. Reactive arthritis b. Rheumatoid arthritis c. Systemic sclerosis d. Sjogren syndrome 14. Which of the following is used for the confirmation of infection with HIV-1? a. Western blot (immunoblot) assay b. ELISA c. Complement fixation d. p24 Antigen testing 15. Which technique is used for the confirmation of infection with HIV-1 and HIV-2? a. Western blot (immunoblot) assay b. ELISA c. FDA-approved NAT d. p24 Antigen testing 16. Clinical assays for tumor markers are most important for: a. Screening for the presence of cancer b. Monitoring the course of a known cancer c. Confirming the absence of disease d. Identifying patients at risk for cancer 1 17. In general, in which of the following situations is the analysis of a tumor marker most useful? a. Testing for recurrence b. Prognosis c. Screening d. Diagnosis 18. The chemical composition of an antibody is: a. Protein b. Lipid c. Carbohydrate d. Glycoprotein 19. What is the most common clinical incident that results in alloantibody production? a. Viral infection b. Solid tumor c. Red cell transfusion d. Autoimmune disease 20. What antibodies are present in polyspecific AHG reagent? a. Anti-IgG b. Anti-IgM and anti-IgG c. Anti-IgG and anti-C3d d. Anti-C3d 21. Which of the following medications is most likely to cause production of autoantibodies? a. Penicillin b. Cephalosporin c. Methyldopa d. Tetracycline → Medications associated with immunity 22. 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 23. The procedure that removes intact antibodies from the red cell membranes is: a. Autoadsorption b. Enzyme pretreatment c. Neutralization d. Elution → Adsorption vs Elution ▪ Adsorption - Removing the antibody from the serum ▪ Elution - Cells that are coated with antibody are treated in such a manner as to disrupt the bonds between the antigen and antibody Mechanism to free the antibody may be: • Physical (heating, shaking) • Chemical (ether, acid) 24. A 56-year-old female with cold agglutinin disease has a positive direct antiglobulin test (DAT). When the DAT is repeated using monospecific antiglobulin sera, which of the following is most likely to be detected? a. lgM b. lgG c. C3d d. C4a 25. A crossmatch is positive at AHG phase with polyspecific AHG reagent but is negative with monospecific anti-IgG AHG reagent. This may indicate the antibody: a. Is a weak anti-D b. Is a clinically insignificant Lewis antibody → cold-reacting c. Can cause decreased survival of transfused RBCs d. Is a Duffy antibody → Interpretation with AHG Reagent 26. 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. Residual patient serum inactivated the AHG reagent c. Centrifuge speed was set too high d. Laboratorian did not add enough check cells 27. Autoantibodies demonstrating blood group specificity in warm autoimmune hemolytic anemia are associated more often with which blood group system? a. Rh → warm AIHA - common b. I c. P d. Fy 28. Which antibody is frequently seen in patients with warm autoimmune hemolytic anemia? a. Anti-Jka b. Anti-e → Rh ab c. Anti-K d. Anti-Fyb 29. Many enhancement media used in the blood bank promote hemagglutination in the presence of lgG antibodies by reducing which of the following? a. Hydrophilic forces b. Low ionic potential c. van der Waals forces d. Zeta potential 30. Low ionic strength saline (LISS) acts as an enhancement medium and facilitates antibody uptake by: a. Activating complement b. Increasing flexibility in hinge region c. Removing water molecules d. Reducing zeta potential 31. Which antibody would not be detected by group O screening cells? a. Anti-N b. Anti-A1 c. Anti-Dia d. Anti-k 2 32. Screening cells, major crossmatch, and patient autocontrol are positive in all phases. Identify the problem. a. Specific cold alloantibody b. Specific cold autoantibody c. Abnormal protein or nonspecific autoantibody d. Cold and warm alloantibody mixture 33. What corrective action should be taken when rouleaux causes positive test results? a. Perform a saline replacement technique b. Perform an autoabsorption c. Run a panel d. Perform an elution 34. Screening cells and major crossmatch are positive on IS only, and the autocontrol is negative. Identify the problem. a. Cold alloantibody → (+) IS = cold ab b. Cold autoantibody c. Abnormal protein d. Antibody mixture 35. Which of the following describes the expression of most blood group inheritance? a. Dominant b. Sex-linked c. Recessive d. Codominant 36. Which genotype(s) will give rise to the Bombay phenotype? a. HH only b. HH and Hh c. Hh and hh d. hh only 37. What should be done if all forward and reverse ABO results as well as the autocontrol are positive? a. Wash the cells with warm saline, autoadsorb the serum at 4°C b. Retype the sample using a different lot number of reagents c. Use polyclonal typing reagents d. Report the sample as group AB 38. A patient types as AB positive. Two units of blood have been ordered by the physician. Currently, the inventory shows no AB units, 10 A-positive units, 1 Anegative unit, 5 B-positive units, and 20 O-positive units. Which should be set up for the major crossmatch? a. A-positive units b. O-positive units c. B-positive units d. Call another blood supplier for type-specific blood e. Order of priority of blood types to be transfused with patient with AB blood: AB > A > B > O 39. A physician orders 2 units of leukocyte-reduced red blood cells. The patient is a 55-year-old male with anemia. He types as an AB negative, and his antibody screen is negative. There is only 1 unit of AB negative in inventory. What is the next blood type that should be given? a. AB positive (patient is male) b. A negative c. B negative d. O negative 40. In an emergency situation, Rh-negative red cells are transfused into an Rh-positive person of the genotype CDe/CDe. The first antibody most likely to develop is: a. Anti-c b. Anti-d c. Anti-e d. Anti-E 41. What antibodies could an R1R1 make if exposed to R2R2 blood? a. Anti-e and anti-C b. Anti-E and anti-c c. Anti-E and anti-C d. Anti-e and anti-c → Note: ▪ R1R1 = DCe/DCe ▪ R2R2 = DcE/DcE 42. 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 43. RhIg (Rhogam) is indicated for: a. Mothers who have anti-D b. Infants who are Rh-negative c. Infants who have anti-D d. Mothers who are Rh-negative → Criteria For Administering RhIg ▪ Mother must be D-negative; D-negative, Du positive patients are not usually given RhIg. ▪ Mother must have no detectable anti-D in her serum. ▪ Infant must be D-positive. ▪ The DAT on the cord blood must be negative. 44. RhIG should be administered within how many hours of delivery? a. 4 b. 48 c. 72 d. 96 45. Which of the following antigens is poorly expressed on cord blood cells? a. K b. M c. Leb → newborns are Le (a-b-) d. D 46. Which of the following is characteristic of anti-i? a. Often associated with hemolytic disease of the newborn b. Reacts best at 37ºC c. Reacts best at room temperature or 4ºC d. Is usually IgG 47. Paroxysmal Cold Hemoglobinuria (PCH) is associated with antibody specificity toward which of the following? a. Kell system antigens b. Duffy system antigens c. P antigen d. I antigen 48. In the Donath-Landsteiner Test, patient’s serum are incubated at various temperatures with: a. Group O RBCs that express the P antigen b. Group O RBCs that express the P1 antigen c. Group AB RBCs that express the P antigen d. Group AB RBCs that express the P1 antigen 3 49. Excluding ABO, is rated second only to D in immunogenicity. a. Kell b. Cellano c. Duffy d. Kidd 50. The K (KEL1) antigen is: a. Absent from the red cells of neonates b. Strongly immunogenic c. Destroyed by enzymes d. Has a frequency of 50% in the random population → K (KEL1) antigen is present in 10% of caucasians 4