3.4 Autoimmune Diseases

Question 1

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

Answer 1

B. Loss of tolerance to self-antigens

Question 2

An ANA test is performed on a specimen from a 55-year-old woman who has unexplained joint pain. The IFA result shows a titer of 40 and a homogeneous pattern. The appropriate follow-up for this patient is:
A. Anti-DNA assay
B. Extractable nuclear antigen (ENA) testing
C. Retest ANA in 3 to 6 months
D. CH50 complement assay

Answer 2

C. Retest ANA in 3 to 6 months

Question 3

Which disease is likely to show a rim (peripheral) pattern in an immunofluorescence (IF) microscopy test for ANA?
A. Mixed connective tissue disease (MCTD)
B. RA
C. SLE
D. Scleroderma

Answer 3

C. SLE

Question 4

A patient’s specimen is strongly positive in an ANA ELISA. Which of the following would not be an appropriate follow-up to this result?
A. IFA on human epithelial type 2 (HEp-2) cells
B. Specific ENA ELISA tests
C. Specific anti-DNA ELISA
D. Rheumatoid factor (RF) assay

Answer 4

D. Rheumatoid factor (RF) assay

Question 5

What type of antibodies is represented by the homogeneous pattern in the IFA for ANAs?
A. Antihistone antibodies
B. Anticentromere antibodies
C. Anti-ENA (anti-Smith [anti-Sm] and anti-ribonucleoprotein [anti-RNP]) antibodies
D. Anti-RNA antibodies

Answer 5

A. Antihistone antibodies

Question 6

What disease is indicated by a high titer of anti-Sm antibody?
A. MCTD
B. RA
C. SLE
D. Scleroderma

Answer 6

C. SLE

Question 7

Which disease is least likely when a nucleolar pattern occurs in an IFA for ANAs?
A. MCTD
B. Sjögren syndrome
C. SLE
D. Scleroderma

Answer 7

A. MCTD

Question 8

What antibodies are represented by the nucleolar pattern in the IFA for ANAs?
A. Antihistone antibodies
B. Anti-dsDNA antibodies
C. Anti-ENA (anti-Sm and anti-RNP) antibodies
D. Anti-RNA antibodies

Answer 8

D. Anti-RNA antibodies

Question 9

Which test would best distinguish between SLE and MCTD?
A. Multiplex or ELISA test for anti-Sm and anti-RNP
B. IFA using Crithidia as substrate
C. Slide agglutination testing
D. Laboratory tests cannot distinguish between these disorders

Answer 9

A. Multiplex or ELISA test for anti-Sm and anti-RNP

Question 10

An ANA test on HEp-2 cells shows nucleolar staining in interphase cells and dense chromatin staining in mitotic cells. The most likely cause of this staining pattern is:
A. Antifibrillarin antibody
B. Anti–ribosomal P antibody
C. A serum with nucleolar and homogeneous patterns
D. Technical artifact

Answer 10

A. Antifibrillarin antibody

Question 11

Which immunofluorescence pattern indicates the need for ENA testing by multiplex, line blots, or ELISA assays?
A. Homogeneous or solid
B. Peripheral or rim
C. Speckled
D. Nucleolar

Answer 11

C. Speckled

Question 12

Which of the following is used in rapid slide tests for detection of RFs?
A. Whole IgM molecules
B. Fc portion of the IgG molecule
C. Fab portion of the IgG molecule
D. Fc portion of the IgM molecule

Answer 12

B. Fc portion of the IgG molecule

Question 13

Which of the following methods is least likely to give a definitive result for the diagnosis of RA?
A. Nephelometric measurement of anti-IgG
B. Agglutination testing for RF
C. Anti-CCP
D. IFA for ANAs

Answer 13

D. IFA for ANAs

Question 14

Which disease might be indicated by antibodies to smooth muscle?
A. Atrophic gastritis
B. Autoimmune hepatitis
C. Myasthenia gravis
D. Sjögren syndrome

Answer 14

B. Autoimmune hepatitis

Question 15

Antibodies to thyroid peroxidase may appear in which of the following diseases?
A. Graves disease and Hashimoto thyroiditis
B. Myasthenia gravis
C. Granulomatous thyroid disease
D. Addison disease

Answer 15

A. Graves disease and Hashimoto thyroiditis

Question 16

What is the main use of laboratory tests to detect antibodies to islet cells and insulin in cases of insulin-dependent diabetes mellitus (IDDM)?
A. To regulate levels of injected insulin
B. To diagnose IDDM
C. To rule out the presence of other autoimmune diseases
D. To screen susceptible individuals prior to destruction of β-cells

Answer 16

D. To screen susceptible individuals prior to destruction of β-cells

Question 17

A patient presents with clinical symptoms of celiac disease. Tests for anti-tissue transglutaminase and antigliadin antibodies are negative. Which of the following tests should be ordered?
A. IgG level
B. HLA DQ2 and DQ8 typing
C. HLA DR3 and DR7 typing
D. IgM level

Answer 17

B. HLA DQ2 and DQ8 typing

Question 18

A specimen appears to have a perinuclear staining pattern in an antineutrophil cytoplasmic antibody (ANCA) immunofluorescent assay using ethanol-fixed neutrophils, suggesting the possibility of a perinuclear ANCA (pANCA). On which of the following substrates would this specimen display cytoplasmic speckling?
A. Formalin-fixed neutrophils
B. Unfixed neutrophils
C. HEp-2 cells
D. Rabbit kidney tissue

Answer 18

A. Formalin-fixed neutrophils