Medical Lab Science Review: Complement to Flow Cytometry

MEDICAL LABORATORY SCIENCE 9. SUMMATIVE EXAM REVIEW QUESTIONS #02 + ANSWERS & RATIONALIZATIONS 1. 2. 3. 4. 5. 6. 7. 8. Most plasma complement proteins are synthesized in the liver with the exception of: a. C1 and Factor B b. C1 and Factor D c. C3 and Factor B d. C3 and Factor D → Most plasma complement proteins are synthesized in the liver with the exception of C1 components; these are mainly produced by intestinal epithelial cells and Factor D, which is made in adipose tissue. Which complement component is present in the greatest quantity in plasma? a. 2 b. 3 c. 4 d. 8 The three complement activation pathways converge at the point of cleavage of complement component: a. C3 b. C5 c. C7 d. C8 Which of the following releases histamine and other mediators from basophils? a. C3a b. Properdin factor B c. C1q d. C4 Which of the following complement components is a strong chemotactic factor as well as a strong anaphylatoxin? a. C3a b. C3b c. C5a d. C4a Which of the following activities is associated with C3b? a. Opsonization b. Anaphylaxis c. Vasoconstriction d. Chemotaxis Mannose-binding protein in the lectin pathway is most similar to which classical pathway component? a. C3 b. C1rs c. C1q d. C4 Complement can be inactivated in human serum by heating to ___° C. a. 25 b. 37 c. 45 d. 56 → Complement can be inactivated by heating to 56° C for 30 minutes or, after 4 hours, reinactivated by heating for 10 minutes. 10. 11. 12. 13. 14. 15. 16. 17. A specimen should be reinactivated when more than ____ hour(s) has (have) elapsed since inactivation. a. 1 b. 2 c. 4 d. 8 Which outcome indicates a negative result in a complement fixation test? a. Hemagglutination b. Absence of hemagglutination c. Hemolysis d. Absence of hemolysis → A positive complement fixation test produces no hemolysis What is a general definition for autoimmunity? a. Increase of tolerance to self-antigens b. Loss of tolerance to self-antigens c. Increase in clonal deletion of mutant cells d. Manifestation of immunosuppression Laboratory features of SLE include: a. The presence of ANAs b. Circulating anticoagulant and immune complexes c. Decreased levels of complement d. All of the above What disease is indicated by a high titer of anti-Sm (anti-Smith) antibody? a. Mixed connective tissue disease (MCTD) b. RA c. SLE d. Scleroderma Which immunofluorescence pattern indicates the need for ENA testing by Ouchterlony immunodiffusion, Multiplex, or ELISA assays? a. Homogeneous or solid b. Peripheral or rim c. Speckled d. Nucleolar Rheumatoid factor is most often of which of the following classes: a. IgE b. IgA c. IgM d. IgG Rheumatoid factor consists of antibodies that bind the: a. Fc portion of IgG molecule b. Fab portion of IgG molecule c. Fc portion of IgM molecule d. Fab portion of IgM molecule A patient with joint swelling and pain tested negative for serum RF by both latex agglutination and ELISA methods. What other test would help establish a diagnosis of RA in this patient? a. Anti-CCP → specific for RA b. ANA testing c. Flow cytometry d. Complement levels 1 18. A laboratory is evaluating an enzyme-linked immunosorbent assay (ELISA) for detecting an antibody to cyclic citrullinated peptide (CCP), which is a marker for rheumatoid arthritis. The laboratory includes serum from healthy volunteers and patients with other connective tissue diseases in the evaluation. These specimens determine which factor of the assay? a. Sensitivity b. Precision c. Bias d. Specificity 19. In primary biliary cirrhosis, which of the following antibodies is seen in high titers? a. Antimitochondrial b. Anti-smooth muscle c. Anti-DNA d. Anti-parietal cell 20. Which disease might be indicated by antibodies to smooth muscle? a. Atrophic gastritis b. Autoimmune hepatitis c. Myasthenia gravis d. Sjögren’s syndrome 21. Antibodies to thyroid peroxidase can be detected by using agglutination assays. Which of the following diseases may show positive results with this type of assay? a. Graves’ disease and Hashimoto’s thyroiditis b. Myasthenia gravis c. Granulomatous thyroid disease d. Addison’s disease 22. In Grave’s disease, one of the main autoantibodies is: a. Anti-CCP b. Antibody to islet cells of pancreas c. Antibody to thyroid-stimulating hormone receptor d. Anti-dsDNA 23. HLA-B8 antigen has been associated with which of the following pairs of diseases? a. Ankylosing spondylitis and myasthenia gravis b. Myasthenia gravis and celiac disease c. Celiac disease and akylosing spondylitis d. Reiter disease and multiple sclerosis 24. Which immunologic mechanism is usually involved in Bronchial Asthma? a. Immediate hypersensitivity b. Immune complex c. Antibody mediated cytotoxicity d. Delayed hypersensitivity 25. After a penicillin injection, a patient rapidly develops respiratory distress, vomiting and hives. This reaction is primarily mediated by: a. IgG b. IgA c. IgM d. IgE 26. In skin tests, wheal-and-flare development is indicative: a. Immediate hypersensitivity b. Anergy c. Delayed hypersensitivity d. Arthus reaction 27. Which test would measure the coating of red cells by antibody as occurs in hemolytic transfusion reactions? a. Indirect antiglobulin test (IAT) b. Direct antiglobulin test (DAT) → for HDN, HTR, AIHA, drug-induced HA c. ELISA d. Hemagglutination → HTR DAT = (+) / (-) / mf 28. Which of the following conditions will most likely result in a false-negative DAT test? a. Insufficient washing of RBCs b. Use of heavy chain–specific polyclonal anti-human Ig c. Use of excessive centrifugal force d. Use of a sample obtained by finger puncture 29. Type III reactions are exemplified by all the following except: a. Arthus reaction b. Serum sickness c. Glomerulonephritis d. Shingles 30. Which test is used to evaluate the cellular immune system in a patient? a. Skin test for commonly encountered antigens b. Determination of isohemagglutinin titer c. Immunoelectrophoresis of serum d. Lymphocyte proliferation to mitogen/antigen 31. What immune elements are involved in a positive skin test for tuberculosis? a. IgE antibodies b. T cells and macrophages c. NK cells and IgG antibody d. B cells and IgM antibody → Mantoux test - skin test for tuberculosis 32. How can interfering cold agglutinins be removed from a test sample? a. Centrifuge the serum and remove the top layer b. Incubate the clot at 1 to 4°C for several hours, then remove serum c. Incubate the serum at 56°C in a water bath for 30 minutes d. Use an anticoagulated sample 33. All positive cold agglutinin tubes remain positive after 37°C incubation except the positive control. What is the most likely explanation for this situation? a. High titer cold agglutinins b. Contamination of the test system c. Antibody other than cold agglutinins d. Faulty water bath 34. What is the “M” component in monoclonal gammopathies? a. IgM produced in excess b. μ Heavy chain produced in excess c. Malignant proliferation of B cells d. Monoclonal antibody or cell line 35. The most common application of IEP of serum is for the: a. Diagnosis of monoclonal gammopathy b. Diagnosis of polyclonal gammopathy c. Diagnosis of autoimmune hemolysis d. Demonstration of Bence Jones (BJ) protein 2 36. The most important application of IEP of urine is: a. Diagnosis of monoclonal gammopathy b. Diagnosis of polyclonal gammopathy c. Diagnosis of autoimmune hemolysis d. Demonstration of Bence Jones (BJ) protein 37. Patients with Waldenström’s macroglobulinemia exhibit abnormally large amounts of: a. IgM b. IgG c. IgE d. IgA 38. The interaction between an individual antigen and antibody molecule depends upon several types of bonds such as ionic bonds, hydrogen bonds, hydrophobic bonds, and van der Waals forces. How is the strength of this attraction characterized? a. Avidity b. Affinity c. Reactivity d. Valency 39. Which of the following type(s) of bonding is (are) involved in antigen-antibody reactions? a. Hydrophobic b. Hydrogen c. Van der Waals d. All of the above 40. Bonding of antigen to antibody exists exclusively as: a. Hydrogen bonding b. Van der Waals forces c. Electrostatic forces d. Noncovalent bonding → The four types of noncovalent bonds involved in antigen antibody reactions are: ▪ Hydrophobic bonds ▪ Hydrogen bonds ▪ Van der Waals forces ▪ Electrostatic forces → The bonding of antigen to antibody is exclusively noncovalent. 41. Which of the following describes an antigen antibody reaction? a. The reaction is reversible b. The reaction is the same as a chemical reaction c. A lattice is formed at prozone d. A lattice is formed at postzone 42. When soluble antigens diffuse in a gel that contains antibody, in which zone does optimum precipitation occur? a. Prozone → antibody excess; remedy: serum dilution b. Zone of equivalence c. Postzone → antigen excess remedy: repeat test after a week d. Prezone 43. A soluble antigen and soluble antibody reacting to form an insoluble product describes a. Agglutination reactions → particulate/cellular ag + ab = larger complexes b. Heterophile reactions c. Labeled reactions d. Precipitation reactions → soluble ag + ab = insoluble complexes 44. Which of the following is the most common application of Immunoelectrophoresis (IEP)? a. Identification of the absence of a normal serum protein b. Structural abnormalities of proteins c. Screening for circulating immune complexes d. Diagnosis of monoclonal gammopathies 45. In FPIA, labeled antigens compete with unlabeled antigen in the patient sample for a limited number of antibody binding sites. The more antigen that is present in the patient sample: a. Less fluorescence b. Greater fluorescence c. Less fluorescence polarization d. Greater fluorescence polarization 46. Major systems in a flow cytometer include all of the following except: a. Fluidics b. Optics c. Computerized electronics d. Gating → Hydrodynamic Focusing - Cells in suspension move through sheath fluid in a single-file line, allowing each to individually pass through a laser light → Gating - Electronic boundaries created to separate a specific population of interest → Fluorescently Tagged Antibodies - Used to determine cell lineage and aid in characterizing patient immunophenotype 47. Flow cytometry characterizes cells on the basis of which of the following? a. Forward and 90-degree side scatter of an interrupted beam of light b. Front-angle scatter only of an interrupted light beam c. Absorbance of light by different types of cells d. Transmittance of light by cells in solution 48. What effect does selecting the wrong gate have on the results when cells are counted by flow cytometry? a. No effect b. Failure to count the desired cell population c. Falsely elevated results d. Impossible to determine 49. What is the immunologic method utilized in the flow cytometer? a. Latex agglutination b. Immunofluorescence c. Enzyme linked immunoassay d. Radioimmunoassay 50. What temperature is used to achieve DNA denaturation to a single strand? a. 74 °C b. 92 °C c. 94 °C d. 102 °C → PCR Temperatures 3