Clinical Pathology(Immunology)

Front 1

All of the following are associated with diGeorge syndrome, except:
A. autosomal recessive inheritance pattern
B. defective T cell function
C. hypocalcemia
D. deletion of chromosome 22q11.2
E. depletion of lymph node paracortical areas

Back 1

A. autosomal recessive inheritance pattern.
Velocardiofacial, or diGeorge syndrome, is due to third and fourth pharyngeal pouch fusion and presents with neck, heart, and facial dysfunction/dysmorphia. Because of
the neck issues, both the thymus and parathyroids are hypoplastic, leading clinically to T cell defects and hypocalcemia, respectively. The syndrome is due to a sporadic
rather than inherited deletion of chromosome 22q11.2.
QCCP2, T cell defects

Front 2

What is the most frequent cause of severe combined immunodeficiency?
A. autosomal recessive Jak3 deficiency
B. autosomal recessive defect in adenosine deaminase
C. autosomal recessive purine nucleosidase phosphorylase deficiency
D. X-linked recessive defect in IL-2 receptor
E. autosomal recessive CD3 deficiency

Back 2

D. X-linked recessive defect in IL-2 receptor.
All of the choices presented are causes of SCID. However, the defects in the X-linked gene, IL-2 receptor, account for the majority of cases with ADA deficiency a close
second. All lead to severe defects in both humoral (B cell) and cellular (T cell) responses.
QCCP2, SCID

Front 3

The presenting symptoms/signs of Wiskott-Aldrich syndrome include all of the following, except:
A. microcytic anemia
B. eczema
C. small, uniform platelets
D. thrombocytopenia
E. immunodeficiency

Back 3

A. microcytic anemia.
The X-linked disorder, Wiskott-Aldrich syndrome (WAS), is characterized by all of the signs and symptoms presented in the question, with the exception of anemia. The
WAS gene product, WASP, has been implicated in the disorder. WAS is also one of the causes of platelet dense granule deficiency and bleeding.
QCCP2, Wiskott-Aldrich syndrome

Front 4

Which of the following disorders is characterized by cerebellar ataxia, telangiectasias, and recurrent infections?
A. Duncan disease
B. ataxia telangiectasia
C. chronic granulomatous disease
D. Bruton agammaglobulinemia
E. chronic mucocutaneous candidiasis

Back 4

B. ataxia telangiectasia.
Sometimes the obvious answer is correct! A defect in the DNA mismatch repair gene, ATM leads to a combined T cell and B cell disorder with ataxia and vascular
telangiectasias. Since the defect in humoral immunity is primarily IgA, there is usually a history of sinopulmonary infections. There is also a very high (~40%) risk of
malignancy, especially hematolymphoid.
QCCP2, ATM

Front 5

Duncan disease usually presents as a severe hemophagocytic response to this virus:
A. HIV
B. HHV8
C. HHV6
D. HTLV-I
E. EBV

Back 5

E. EBV.
There are several less severe prodromal signs associated with Duncan disease, but it is the intense response to EBV that defines the disorder. In addition, there are
usually subsequent B cell lymphoid malignancies and hepatic failure.
QCCP2, Duncan disease

Front 6

Which of the following is a suitable screening test for chronic granulomatous disease?
A. nitroblue tetrazolium test
B. NAD-coupled oxidation
C. catalase-positive bacterial provocative infection
D. sweat chloride test
E. Benedict's reagent assay

Back 6

A. nitroblue tetrazolium test.
Chronic granulomatous disease is due to defects in oxidative burst microbial killing, secondary to a defect in NADPH oxidase. As a result, catalase positive organisms
tend to cause severe granulomatous infections due to the immune system's inability to remove the organisms. Nitroblue tetrazolium is a direct assay of the respiratory
burst (see question 26 for more).
QCCP2, Chronic granulomatous disease

Front 7

Which of the following treatments can clear the Dohle bodies seen in May-Hegglin anomaly?
A. DNase
B. RNase
C. iron chelation
D. calcium phosphate precipitation
E. sodium dithionate treatment

Back 7

B. RNase.
Dohle bodies are large, pale blue inclusions composed of rough endoplasmic reticulum, and are seen in granulocytes and monocytes of the May-Hegglin anomaly.
Treatment of cells with ribonuclease can destroy these bodies. Remember that rough endoplasmic reticulum contains numerous ribosomes, which are mostly composed
of ribosomal RNA.
QCCP2, May-Hegglin anomaly

Front 8

Which of the following is/are associated with homozygous Pelger-Huet anomaly?
A. Dohle bodies
B. pince-nez cells
C. Jordan anomaly
D. Stodtmeister cells
E. giant platelets

Back 8

D. Stodtmeister cells.
Heterozygous Pelger-Huet is associated with the more familiar bilobed, or pince-nez, nuclei found in segmented neutrophils. With a homozygous case of Pelger-Huet,
monolobated, or Stodtmeister, cells are often seen.
QCCP2, Pelger-Huet anomaly

Front 9

What type of disorder usually follows defects in components of the classical pathway of complement activation?
A. recurrent gram-positive infections
B. hereditary angioedema
C. hematolymphoid neoplasms
D. autoimmune disease
E. recurrent systemic encapsulated organism infections

Back 9

D. autoimmune disease.
The vast set of disorders associated with deficiencies of complement proteins reflects the multifaceted role of complement in the body. All of the choices presented (with
the exception of hematolymphoid neoplasms) are due to defects in various complement proteins and activation pathways. Recurrent gram positive infections are seen
with deficiency of C2 and C3, hereditary angioedema is due to deficiency of C1q esterase inhibitor, autoimmune disease is due to defects in the classical pathway (C1q,
C2, and C4) and systemic encapsulated organism infections occur due to deficiencies of membrane attack complex (MAC) components (C5-C9).
QCCP2, Complement deficiency

Front 10

Which of the following cell types is used most commonly to screen for antinuclear antibody pattern staining?
A. Vero E6
B. Hep-2
C. HeLa
D. human diploid fibroblasts
E. primary monkey kidney

Back 10

B. Hep-2.
Diluted patient serum is added to Hep-2 cells in culture followed by detection with fluorescently-labeled anti-human globulin and a nuclear (DNA) counterstain. From this
assay, the classic staining patterns are interpreted.
QCCP2, Screening for anti-nuclear antigen with Hep-2