Immuno Set 8

Question 1

Which of the following is typically NOT associated with T cell immunodeficiencies?

A. Cancer

B. Viral infections

C. Autoimmunity

D. Infection with intracellular microbes

E. Infections with pyogenic bacteria

Answer 1

E. Infections with pyogenic bacteria

Question 2

In which of the following conditions would you be LEAST likely to see a robust delayed-type hypersensitivity (DTH) response to a Candida antigen skin challenge?

A. X-linked agammaglobulinemia

B. DiGeorge syndrome

C. Selective IgA deficiency

D. Common variable immunodeficiency

E. Chronic granulomatous disease

Answer 2

B. DiGeorge syndrome

Question 3

A 7-month-old boy is evaluated in the clinic for recurrent bacterial infections. His tonsils are not visible of physical examination. Serum IgA and IgG levels are markedly decreased and serum IgM levels are slightly above normal. Patient’s presentation is consistent with which of the following disorder?

A. X-linked agammaglobulinemia

B. X-linked severe combined immunodeficiency disease

C. Common variable immunodeficiency

D. X-linked hyper-IgM syndrome

E. ADA deficiency

Answer 3

D. X-linked hyper-IgM syndrome

Question 4

A 6-month-old infant presents with oral candidiasis (thrush). Laboratory blood analysis revealed normal numbers of B cells and very few CD3+ cells. In addition, maternally-derived T cells, as determined by HLA typing, are found. The infant’s mother reports that two of her brothers died as young children. This presentation consistent with which of the following of infection disorder?

A. X-linked agammaglobulinemia

B. X-linked severe combined immunodeficiency disease

C. Common variable immunodeficiency

D. X-linked hyper-IgM syndrome

E. ADA deficiency

Answer 4

B. X-linked severe combined immunodeficiency disease

Question 5

A 6-month-old infant presents with oral candidiasis (thrush). Laboratory blood analysis revealed normal numbers of B cells and very few CD3+ cells. In addition, maternally-derived T cells, as determined by HLA typing, are found. The infant’s mother reports that two of her brothers died as young children.

Based on the family’s history and clinical presentation above, a mutation in which of the following genes is most likely to be found in this patient?

A. Jak3 kinase

B. Adenosine deaminase

C. Common cytokine receptor y chain

D. RAG2

E. Purine nucleoside phosphatase

Answer 5

C. Common cytokine receptor y chain

Question 6

A 6-month-old infant presents with oral candidiasis (thrush). Laboratory blood analysis revealed normal numbers of B cells and very few CD3+ cells. In addition, maternally-derived T cells, as determined by HLA typing, are found. The infant’s mother reports that two of her brothers died as young children.

This infant should NOT be given the measles-mumps-rubella (MMR) vaccination because which of the following?

A. The vaccine would have no effect because he is not susceptible to infection with measles, mumps, or rubella.

B. The vaccine would have no effect because he cannot mount an appropriate humoral response.

C. The vaccine could not be dangerous because he is predisposed to development of allergic reactions to the MMR vaccine.

D. The vaccine could be dangerous because vaccination with MMR would put him as risk for developing a fatal infection.

E. Vaccination with MMR is not contraindicated in his case and should be performed to prevent future infections.

Answer 6

D. The vaccine could be dangerous because vaccination with MMR would put him as risk for developing a fatal infection.

Question 7

A lymph node biopsy from a young boy with X-linked agammaglobulinemia is expected to show which of the following?

A. Marked perivascular lymphocytic infiltrate

B. Abundant polymorphonuclear infiltration

C. Reduced follicles and germinal centers

D. Nearly absent parafollicular cortical regions

E. Enlarged follicles

Answer 7

C. Reduced follicles and germinal centers

Question 8

Which of the following is the most common known primary immunodeficiency with a prevalence of 1 in 700 white individuals?

A. X-linked agammaglobulinemia

B. Selective IgA deficiency

C. Common variable immunodeficiency

D. Chronic granulomatous disease

E. Chediak-Higashi syndrome

Answer 8

B. Selective IgA deficiency

Question 9

An 18-month-old female presents with recurrent respiratory tract infections. She has a fever, labored breathing, and a dry cough. Laboratory investigations confirm infection with Pneumocystis jiroveci. The family history is unremarkable; the patient’s three older brothers are in excellent health. This patient most likely carries a mutation in which of the following molecules?

A. CD18

B. CD40L

C. ZAP-70

D. CD80

E. CD40

Answer 9

E. CD40

Question 10

A 3-year-old male presents with a nosebleed. The past medical history is remarkable for severe recurrent sinopulmonary infections. Physical examination revealed eczema and multiple tiny hemorrhagic spots. Laboratory blood findings include thrombocytopenia and reduced IgM levels. The boy’s maternal uncle died of bleeding complications after an emergency appendectomy. Which of the following is the most likely diagnosis?

A. X-linked hyper IgM syndrome

B. Wiskott-Aldrich syndrome (WAS)

C. Chediak-Higashi syndrome

D. Transient hypogammaglobulinemia of infancy

E. DiGeorge syndrome

Answer 10

B. Wiskott-Aldrich syndrome (WAS)

Question 11

A 2-month-old male infant presents with persistent diarrhea, signs and symptoms of Pneumocystis carinii pneumonia, and an oral fungal infection with Candida albicans. His weight is in the 10th percentile. Test results for HIV are negative by polymerase chain reaction. Which of the following is the most consistent with findings in this patient?

A. grossly reduced levels of B cells

B. an X-linked inheritance of HLA genes

C. defective isotype switching

D. defective T-cell function

E. selective lgA deficiency

Answer 11

D. defective T-cell function

Question 12

A 5-year-old girl has a small deletion in chromosome 22. She has impaired thymus development with a significant deficiency in the number of functional T cells. Which of the following is the most likely etiology of this patient clinical presentation?

A. Adenosine deaminase (ADA) deficiency

B. Chediak-Higashi syndrome

C. DiGeorge syndrome

D. Hereditary angioedema

E. Severe combined immunodeficiency (SCID)

Answer 12

C. DiGeorge syndrome

Question 13

A 3-year-old boy with an X-linked defect in the Bruton tyrosine kinase (BTK) gene is impaired in which of the following mechanisms?

A. Antibody-mediated bacterial clearance

B. Formation of the membrane attack complex

C. Inability to produce respiratory burst

D. IFN-y secretion by CD4 + T cells

E. T-cell precursor migration to the thymus

Answer 13

A. Antibody-mediated bacterial clearance

Question 14

A 6-month-old male infant has diarrhea, extensive fungal infections, and skin rashes and has failed to gain weight. He is deficient in both T- and B-cell function. The thymus is of normal size. Which of the following would be the most likely therapy for permanent restoration of immunity in this patient?

A. an antibiotic “cocktail” given at regular intervals

B. bone marrow transplantation

C. exogenous immunoglobulins administered periodically

D. isolation to an antiseptic environment

E. thymic hormones given throughout his life

Answer 14

B. bone marrow transplantation

Question 15

A female neonate has cardiac abnormalities and hypocalcemia in addition to the diminished cell- mediated and B-cell responses. Which of the following immune deficiencies should be included in the differential diagnosis of this patient?

A. Adenosine deaminase (ADA) deficiency

B. DiGeorge syndrome

C. Hereditary angioedema

D. Severe combined immunodeficiency disease (SCID)

E. Wiskott-Aldrich syndrome

Answer 15

B. DiGeorge syndrome

Question 16

A 21 -year-old woman has a history since childhood of recurrent episodes of swelling of the submucosal and subcutaneous tissue of the gastrointestinal and respiratory tracts. Her C1 inhibitor level is less than 5% of the reference value. These findings support a diagnosis of which of the following?

A. DiGeorge syndrome

B. Hereditary angioedema

C. Malnutrition-based immunodeficiency

D. Paroxysmal nocturnal hemoglobinuria

E. Wiskott-Aldrich syndrome

Answer 16

B. Hereditary angioedema

Question 17

A 3-month-old male infant has recurrent infections and is found to have an impaired ability to kill microbes by the nitroblue tetrazolium test (which evaluates effectiveness of oxidase enzymes). Which of the following conditions is most likely responsible for the findings in this patient?

A. Chediak-Higashi syndrome

B. Chronic granulomatous disease

C. Hereditary angioedema

D. Common Variable Immune Deficiency

E. Common y chain deficiency

Answer 17

B. Chronic granulomatous disease

Question 18

A 4-year-old child is referred with the diagnosis of type 1 LAD. She has a history of recurrent bacterial infections, including pneumonias and skin abscesses. Radiography demonstrates granuloma-like lesions in her lungs and liver. However, the data in the following table suggest this condition has not been properly diagnosed. Which of the elements in the table is inconsistent with a diagnosis of type 1 LAD?

A. The CD2 value

B. The CD19 value

C. The CD11a value

D. The CD45 value

E. The CD3 value

Answer 18

C. The CD11a value

Question 19

A 3-month-old child presents with a history of persistent diarrhea and oral thrush beginning at age 3 weeks and has developed signs and symptoms consistent with Pneumocystis carinii pneumonia. Both he and his parents are HIV negative based on serological and polymerase chain reaction (PCR) testing. Complete blood counts demonstrate profound lymphopenia. Which of the following blood cell types should show normal numbers if this condition was caused by a Rag deficiency?

A. CD3+ cells with a CD4 coreceptor

B. CD19+ cells
C. Single-positive thymocytes
D. Memory B cells

E. NK cells

Answer 19

E. NK cells

Question 20

Measuring which of the following immune parameters would distinguish hyper-IgM syndrome from X-linked agammaglobulinemia?

A. IgG levels in the serum

B. CD19+ cells in the blood

C. IL-2 production by the patient’s lymphocytes in vitro

D. NK cell-mediated cytotoxicity in vitro

E. IgA levels in the saliva

Answer 20

B. CD19+ cells in the blood

Question 21

A 2-year-old boy is evaluated for a severe combined immunodeficiency disease. His bone marrow has normal cellularity. Radioactive tracer studies demonstrate a normal number of T-cell precursors entering the thymus, but no mature T lymphocytes are found in the blood or peripheral organs. Cells populating the thymus are found to lack CD3. Which of the following capabilities would his cells lack?

A. Ability to bind cell-bound peptides

B. Ability to express CD4/CD8 coreceptors

C. Ability to produce terminal deoxynucleotidyl transferase

D. Ability to proliferate in response to specific antigen

E. Ability to rearrange T-cell receptor gene segments

Answer 21

D. Ability to proliferate in response to specific antigen

Question 22

A young woman with acute myeloblastic leukemia is treated with intensive chemotherapy and achieves remission of her symptoms. Because the prognosis for relapse is relatively high, a bone marrow transplant is undertaken in her first remission. Which of the following cytokines administered with the bone marrow cells would have the beneficial result of stimulating lymphoid-cell development from the grafted stem cells?

A. IL-1

B. IL-2

C. IL-3

D. IL-6

E. IL-7

Answer 22

E. IL-7

Question 23

A lymph node biopsy of a 6-year-old boy shows markedly decreased numbers of lymphocytes in the paracortical areas. Analysis of his peripheral blood leukocytes is likely to show normal to elevated numbers of cells expressing which of the following surface marker?

A. CD2

B. CD3

C. CD4

D. CD8

E. CD19

Answer 23

E. CD19

Question 24

An 8-month-old baby has a history of repeated Gram-positive bacterial infections. Which of the following is most probable cause for this condition?

A. the mother did not confer sufficient immunity to the baby in utero

B. the baby suffers from erythroblastosis fetalis (hemolytic disease of the newborn)

C. the baby has a defect in the alternative complement pathway

D. the baby is allergic to the mother’s milk

E. none of the above

Answer 24

E. none of the above

Question 25

A 50-year-old worker at an atomic plant who previously had a sample of his own bone marrow cryopreserved was accidentally exposed to a minimal lethal dose of radiation. He was subsequently transplanted with his own bone marrow. Which of the following this patient can expect in the future?

A. have recurrent bacterial infections

B. have serious fungal infections due to deficiency in cell-mediated immunity

C. make antibody responses to thymus-independent antigens only

D. all of the above

E. none of the above

Answer 25

E. none of the above

Question 26

Which of the following immune deficiency disorders is associated exclusively with an abnormality of the humoral immune response?

A. X-linked agammaglobulinemia (Bruton agammaglobulinemia)

B. DiGeorge syndrome

C. Wiskott–Aldrich syndrome

D. IL-7R alpha chain deficiency

E. Jak3 deficiency

Answer 26

A. X-linked agammaglobulinemia (Bruton agammaglobulinemia)

Question 27

A sharp increase in levels of IgG with a spike in the IgG region seen in the electrophoretic pattern of serum proteins would be consistent with which of the following?

A. IgA or IgM deficiency

B. plasma cell myeloma

C. macroglobulinemia

D. hypogammaglobulinemia

E. severe fungal infections

Answer 27

B. plasma cell myeloma

Question 28

Patients with DiGeorge syndrome may fail to produce IgG in response to immunization with T- dependent antigens. Which of the following would explain the result of immunization?

A. they have a decreased number of B cells that produce IgG

B. they have increased numbers of suppressor T cells

C. they have a decreased number of T helper cells

D. they have abnormal antigen-presenting cells

E. They cannot produce IgM during primary responses

Answer 28

C. they have a decreased number of T helper cells

Question 29

A 2-year-old child has had three episodes of pneumonia and two episodes of otitis media. All the infections were demonstrated to be pneumococcal. Which of the following disorders is most likely to be the cause?

A. an isolated transient T-cell deficiency

B. a combined T- and B-cell deficiency

C. a B-cell deficiency

D. transient anemia

E. AIDS

Answer 29

C. a B-cell deficiency

Question 30

An immunodeficiency disease can result from which of the following?

A. developmental defect of T lymphocytes

B. developmental defect of bone marrow stem cells

C. defect in phagocyte function

D. defect in complement function

E. all of the above

Answer 30

E. all of the above

Question 31

A 9-month-old baby was vaccinated against smallpox with attenuated smallpox virus. He developed a progressive necrotic lesion of the skin, muscles, and subcutaneous tissue at the site of inoculation. The vaccination reaction probably resulted from which of the following?

A. B-lymphocyte deficiency

B. reaction to the adjuvant

C. complement deficiency

D. T-cell deficiency

E. B- and T-lymphocyte deficiency

Answer 31

D. T-cell deficiency

Question 32

Which of the following is the most common clinical consequence of C3 deficiency?

A. increased incidence of tumors

B. increased susceptibility to viral infections
C. increased susceptibility to fungal infections

D. increased susceptibility to bacterial infections

E. all of the above

Answer 32

D. increased susceptibility to bacterial infections

Question 33

An adolescent with a history of childhood upper respiratory tract infections and diarrhea continues to have recurring sinusitis, which is attributed to Pseudomonas aeruginosa, a gram- negative bacterium. Laboratory tests over the past 5 years have repeatedly indicated that he has normal T cell numbers (based on CD3, CD4, and CD8), normal serum complement levels and activity, and normal serum IgM and IgG levels for his age. Neutrophil numbers and function (chemotaxis, phagocytosis, and respiratory burst) are all normal. His IgG antibody response to tetanus toxoid challenge is also within the normal range. He shows strong reactions in delayed hypersensitivity skin tests against several common fungal antigens. What therapy is appropriate for this patient?

A. Antibiotics only

B. Antibiotics and IVIG

C. Antibiotics, IVIG, and stem cell transplantation

D. Stem cell transplantation

E. Antibiotics and IFN-γ

Answer 33

A. Antibiotics only