Immunology Exam D

Question 1

1.) A 12-year-old girl presented to her physician with a sore throat, lymphadenopathy, and fatigue. Her laboratory results were 5,000 lymphocytes/microliter with 10% atypical lymphocytes, cytomegalovirus antibody negative, and heterophile antibody screen negative. These laboratory results:

a. suggest a diagnosis of infectious mononucleosis but should be followed by a test for IgM anti-VCA to strengthen the diagnosis.
b. indicate that the diagnosis is not infectious mononucleosis because the heterophile antibody screen is negative.
c. uggest a diagnosis of infectious mononucleosis but should be followed by a heterophile antibody titer to strengthen the diagnosis.
d. confirm a diagnosis of infectious mononucleosis.

Answer 1

a. suggest a diagnosis of infectious mononucleosis but should be followed by a test for IgM anti-VCA to strengthen the diagnosis.

Question 2

2.) A 14-year-old boy presents to the physician complaining of sore throat, fatigue, and fever for the past week. A monotest is performed and is reported as positive. It is likely that this boy has:

a. a common cold.
b. infectious mononucleosis.
c. streptococcal pharyngitis.
d. acute glomerulonephritis.

Answer 2

b. infectious mononucleosis.

Question 3

3.) A 17-year-old female with suspected mononucleosis tested negative for heterophile antibody using the slide agglutination monotest. Her serum was sent to a reference laboratory, and the following results were obtained: negative for IgM anti-VCA, positive for antibody to EA-D. What do these results suggest?

a. Mononucleosis has been reactivated
b. She is a healthy carrier of the virus
c. She does not have mononucleosis
d. She is in the early stages of the disease.

Answer 3

d. She is in the early stages of the disease.

Question 4

4.) A laboratory test that is used to confirm syphilis and detects specific treponemal antibodies is:

a. VDRL
b. RPR
c. FTA-ABS.
d. Monospot

Answer 4

c. FTA-ABS.

Question 5

5.) A patient has an antibody profile for Epstein-Barr virus (EBV) performed, with the following results: EB-VCA IgM = pos; EB-VCA IgG = pos; EBV-EBNA = neg; EBV-EA-D = neg. This patient has which of the following?

a. Acute EBV infection
b. Convalescent EBV
c. Lack of EBV infection
d. Past exposure to EBV

Answer 5

a. Acute EBV infection

Question 6

6.) A patient has detectable levels of IgG and IgM against the viral capsid antigens of Epstein-Barr virus (EBV). This patient has:

a. never had EBV.
b. an infection with HIV, too.
c. a current infection with EBV.
d. been infected with EBV in the past.

Answer 6

c. a current infection with EBV.

Question 7

7.) A patient has fever, chills, muscle aches and headache. On his arms and legs, he has three skin lesions that looks like a red bullseye. Two weeks ago, he went on a hunting trip in the woods of Vermont, and he also traveled to Germany a month ago. The physician believes the patient has Lyme disease. A serum sample reacted positively in the ELISA, but the western blot was negative. What should be considered?

a. The patient has another disease, such as syphilis
b. The sample was taken too early
c. The patient is infected with a Borrelia sp. other than B. burgdorferi
d. Need to test sample for infectious mononucleosis

Answer 7

c. The patient is infected with a Borrelia sp. other than B. burgdorferi

Question 8

8.) A patient has the following Epstein-Barr virus (EBV) antibody profile: EB-VCA IgM = neg; EB-VCA IgG = pos; EBV-EA-R IgG = pos; EBV-EBNA IgG = pos. Which of the following is the correct interpretation of these data?

a. Never infected with EBV
b. Acute infection with EBV
c. Reactivation of past infection with EBV
d. Recent convalescence from EBV

Answer 8

c. Reactivation of past infection with EBV

Question 9

9.) A patient is suspected of having latent syphilis. Which set of test results for RPR, TP-PA, and CSF-VDRL best confirms this diagnosis?

a. RPR = nonreactive; FTA-ABS = nonreactive; VDRL = nonreactive
b. RPR = nonreactive; FTA-ABS = reactive; VDRL = nonreactive
c. RPR = reactive 1:8; FTA-ABS = reactive; VDRL = reactive 1:4
d. RPR = reactive 1:2; FTA-ABS = nonreactive; VDRL = nonreactive

Answer 9

b. RPR = nonreactive; FTA-ABS = reactive; VDRL = nonreactive

Question 10

10.) A patient presents with a painless genital ulcer. The patient is then diagnosed as having syphilis. In what stage of syphilis is the patient?

a. Latent
b. Tertiary
c. Primary
d. Secondary

Answer 10

Primary

Question 11

11.) A patient with infectious mononucleosis would have what outstanding feature in the hematology evaluation?

a. Presence of atypical lymphocytes
b. Absence of neutrophils
c. Decreased total white blood cells
d. Increased percentage of eosinophils

Answer 11

a. Presence of atypical lymphocytes

Question 12

12.) A physician suspects that his patient has infectious mononucleosis. Heterophile antibody tests are negative. Serological testing for Epstein-Barr virus (EBV) was performed, with the following results obtained: EBV VCA IgM = neg; EBV VCA IgG = neg; EBV-EA = neg; EBV-NA = neg. What is this person’s status with regard to EBV?

a. Never infected with EBV
b. Acute EBV
c. Convalescent EBV
d. Past exposure to EBV

Answer 12

a. Never infected with EBV

Question 13

13.) A physician wants to know if his patient, who currently has a rash and fever, has an active rubeola virus infection. IgG against rubeola virus is detected. IgM against rubeola virus is not detected. What do these results mean?

a. The patient has never had either measles or chickenpox.
b. The patient has had a previous exposure to measles, either through natural infection or vaccination.
c. The patient has a current measles infection.
d. The patient has a current chickenpox infection

Answer 13

b. The patient has had a previous exposure to measles, either through natural infection or vaccination.

Question 14

14.) A positive rubella titer in a healthy, nonpregnant 22-year-old female most likely indicates which of the following?

a. No immunity
b. Immunity after administration of the vaccine
c. Current presence of the disease
d. Possibility of congenital rubella

Answer 14

b. Immunity after administration of the vaccine

Question 15

15.) A primary disadvantage of using serology in the diagnosis of an infection is:

a. sensitivity.
b. delayed appearance of antibodies after onset of infection.
c. biologic hazard to laboratory personnel.
d. Cost

Answer 15

b. delayed appearance of antibodies after onset of infection.

Question 16

16.) A new technologist is busy one night and has to perform an RPR on a serum sample. He does not calibrate the needle delivering the antigen, and the needle is delivering a larger volume of antigen than it is supposed to. What kind of error can this produce?
a. Biological false negative
b. Biological false positive
c. Laboratory-induced false negative resulting from postzone
d. Laboratory-induced false positive resulting from postzone

Answer 16

c. Laboratory-induced false negative resulting from postzone

Question 17

17.) A newborn suspected of having a congenital viral infection should be tested for viral-specific antibody of which class(es)?
a. IgG
b. IgA
c. All antibody classes
d. IgM

Answer 17

IgM

Question 18

18.) Acute glomerulonephritis can be a sequela of infection by:

a. Streptococcus pyogenes.
b. Mycoplasma pneumoniae.
c. Helicobacter pylori.
d. Rickettsia rickettsii.

Answer 18

a. Streptococcus pyogenes.

Question 19

19.) An antibody titer is defined as the reciprocal of the:

a. first serial dilution tube in which a negative reaction is achieved.
b. solvent multiplied by the diluent
c. diluent divided by the solvent.
d. last serial dilution tube in which a positive reaction is still visible.

Answer 19

d. last serial dilution tube in which a positive reaction is still visible.

Question 20

20.) If complement interferes with test results, the serum sample should be:

a. centrifuged at 3,000 g for 30 minutes.
b. heated to 56°C for 30 minutes.
c. treated with an anticoagulant.
d. frozen and thawed before testing

Answer 20

b. heated to 56°C for 30 minutes.

Question 21

21.) In infectious mononucleosis, which of the following would be detectable earliest in the infection, thereby indicating a current infection?

a. Anti-EA-IgG
b. Anti-EBNA
c. Anti-VCA-IgM

Answer 21

c. Anti-VCA-IgM

Question 22

22.) Laboratory results for a patient indicated a positive RPR and a negative FTA. The patient had no obvious sore, rash, or other symptoms. What is the most likely cause of these results?

a. Another disease, such as mononucleosis
b. Tertiary syphilis
c. Primary syphilis
d. Secondary syphilisAnti-VCA-IgG

Answer 22

a. Another disease, such as mononucleosis

Question 23

23.) Patient serum is mixed with gel particles that have been sensitized with Treponema pallidum antigens as well as with unsensitized gel particles in a separate well. Agglutination was observed in the well with sensitized gel particles but not in the well with unsensitized gel particles. What is the interpretation of these results?

a. Positive for anti–T pallidum antibodies
b. Negative for anti–T pallidum antibodies
c. Negative for anticardiolipin antibodies
d. Positive for heterophile antibodies

Answer 23

a. Positive for anti–T pallidum antibodies

Question 24

24.) RPR stands for

a. reactive phosphate reagent.
b. Rapid plasma reagin.
c. reagin plasma reactive.
d. random positive reagin.

Answer 24

b. Rapid plasma reagin.

Question 25

25.) Rubeola virus causes:

a. Shingles
b. Mumps
c. Measles
d. Chickenpox

Answer 25

Measles

Question 26

26.) Serology is performed on a patient with a rash and fever. Results are: rubella IgM = positive; rubella IgG = positive; measles IgM = negative; measles IgG = positive; varicella-zoster IgM = negative; varicella-zoster IgG = negative. What is the interpretation of these results?

a. Acute infection with measles virus
b. Acute infection with rubella virus
c. Not immune to measles or rubella viruses
d. Immune to varicella-zoster virus only

Answer 26

b. Acute infection with rubella virus

Question 27

27.) Swollen parotid glands are key diagnostic indicators of:
a. Varicella
b. Rubella
c. Mumps
d. Measles

Answer 27

c. Mumps

Question 28

28.) Tests for specific treponemal antibody include which of the following?
a. VDRL
b. RIBI
c. FTA-ABS
d. RPR

Answer 28

c. FTA-ABS

Question 29

29.) The ability of an organism to cause disease is known as its:
a. pathogenicity
b. colonization
c. infectivity
d. resistance

Answer 29

a. pathogenicity

Question 30

30.) The antibody called reagin that is found in syphilis
a. is detected by the FTA-ABS test
b. reacts with cardiolipin
c. is specific for treponemal antigen
d. appears in all patients within 7 days after exposure to syphilis

Answer 30

b. reacts with cardiolipin

Question 31

31.) The causative agent of infectious mononucleosis is:
a. Staphylococcus aureus
b. Rubeola virus.
c. Streptococcus pyogenes.
d. Epstein-Barr virus.

Answer 31

d. Epstein-Barr virus.

Question 32

32.) The pathogen that causes Lyme disease is
a. transmitted by ticks
b. a cause of syphilis
c. an obligate intracellular pathogen
d. transmitted by sexual activity

Answer 32

a. transmitted by ticks

Question 33

33.) The pathogenesis of poststreptococcal glomerulonephritis involves:
a. bacterial-induced dehydration
b. destruction of glomeruli by streptolysin O.
c. invasion of the kidneys by Streptococcus pyogenes
d. deposition of immune complexes in the kidneys.

Answer 33

d. deposition of immune complexes in the kidneys.

Question 34

34.) The M protein of group A streptococci inhibits:
a. lymphocyte proliferation
b. antibody binding
c. phagocytosis
d. T-cell apoptosis

Answer 34

phagocytosis

Question 35

35.) The RPR and VDRL are similar in which of the following ways?
a. Both are read macroscopically.
b. Both are flocculation reactions.
c. Both are specific assays for syphilis.
d. Both are antigen detection assays.

Answer 35

b. Both are flocculation reactions.

Question 36

36.) The RPR and VDRL tests differ from each other in which of the following ways?
a. Specificity of antibody detected
b. Specificity of antigen detected
c. Method for reading or visualizing the reaction
d. Principle for detecting antigen–antibody complexes

Answer 36

c. Method for reading or visualizing the reaction

Question 37

37.) What is the most common routine diagnostic test for rubella virus infection in a young adult?
a. Antibody detection
b. Polymerase chain reaction
c. Antigen detection
d. Viral culture

Answer 37

a. Antibody detection

Question 38

38.) Which of the following illnesses is not caused by Streptococcus pyogenes directly, but rather by destructive host defense responses?
a. Scarlet fever
b. Pharyngitis
c. Acute rheumatic fever
d. Pyoderma (impetigo)

Answer 38

c. Acute rheumatic fever

Question 39

39.) Which of the following is a cause of a laboratory-induced false-negative result in the screening tests for syphilis?
a. Systemic lupus erythematosus
b. Alcohol ingestion prior to blood draw
c. Excess serum antibody
d. Temperature greater than 30°C

Answer 39

c. Excess serum antibody

Question 40

40.) Which of the following is the first reaction in a lateral flow immunochromatographic assay?
a. Antibody reacts with a labeled antigen.
b. Antigen is captured by antibody immobilized at a specific location on a membrane.
c. Antigen reacts with a labeled antibody.
d. Labeled antibody is captured by membrane-immobilized antibody.

Answer 40

c. Antigen reacts with a labeled antibody.

Question 41

41.) Which of the following markers is a reliable indicator of high infectivity and active disease?
a. HBeAg
b. anti-HBcAg IgG
c. HBcAg
d. HBsAg

Answer 41

HBeAg

Question 42

42.) Which of the following positive antibody tests may be an indication of recent rubella vaccination or early primary rubella infection in a patient with no clinical symptoms?
a. Only IgG positive
b. Both IgG and IgA antibodies positive
c. Only IgM positive
d. Fourfold rise in titer for IgG

Answer 42

c. Only IgM positive

Question 43

43.) Which of the following statements best describes how lateral flow assays demonstrate the presence of bacterial, fungal, and viral antigens?
a. Migration of labeled antigen to the capture zone produces a positive result.
b. During the assay, bacterial antigens present in a specimen are pretreated by coating them with colloidal gold prior to binding to an antibody.
c. A positive test results from the binding of the conjugated antibody and antigen to a fixed antibody directed against the antigen in the capture zone.
d. A positive test results from the precipitation of the antigen–antibody complex in the capture zone.

Answer 43

c. A positive test results from the binding of the conjugated antibody and antigen to a fixed antibody directed against the antigen in the capture zone.

Question 44

44.) Which types of hepatitis are transmitted primarily through fecal-oral route?
a. Hepatitis A and E
b. Hepatitis A, B, and C
c. Hepatitis C, D, and E
d. Hepatitis B, C, and D

Answer 44

a. Hepatitis A and E

Question 45

45.) Which virus is transmitted primarily by aerosolized respiratory droplets?
a. Epstein-Barr virus
b. Hepatitis E
c. Varicella-zoster virus
d. Human T-cell lymphotropic virus type I

Answer 45

c. Varicella-zoster virus