chapter 19

Delayed-type hypersensitivity skin tests are used to screen for:

cell-mediated immunodeficiencies

Defects in oxidative burst activity can be detected using flow cytometry by labeling patient neutrophils with:

dihydrorhodamine.

An inflammatory syndrome involving recurrent fevers is

hyper IgD.

Patients with recombinase activating gene 1 (RAG-1) or RAG-2 deficiencies have decreased numbers of:

lymphocytes.

A specific defect in innate immunity leading to bacterial infections could involve a deficiency in:

toll-like receptors.

A defective kinase needed for DNA repair and cell cycle control leads to involuntary muscle movements and dermal capillary swelling in which syndrome?

Ataxia telangiectasia

Which syndrome is characterized by defective apoptosis, leading to survival of lymphocytes that can react with self antigens?

Autoimmune lymphoproliferative

A 6-month-old baby has suffered from recurrent bacterial infections. Flow cytometry results indicate a lack of B cells but the presence of normally functioning T cells. Which is the most likely diagnosis?

Bruton's tyrosine kinase deficiency

A patient with hereditary angioedema will present with swelling in the tissues and has deficiencies in which of the following?

C1 inhibitor

The accumulation of immune complexes in renal glomeruli or joints (lupus-like syndromes) can be caused by a deficiency in the complement component:

C2

The most common complement component deficiency is:

C2

The most serious impairment of opsonization and antimicrobial defense is caused by a deficiency in complement component:

C3.

Leukocyte adhesion deficiency is caused by a defect in:

CD18.

A nitroblue tetrazolium test shows little color in cells observed under a microscope. What disease does this finding correlate with?

Chronic granulomatous disease

An autosomal-recessive disease characterized by the presence of abnormally large granules primarily affecting the function of lysosomes is known as:

Chédiak-Higashi syndrome.

A 2-week-old girl is evaluated by a specialist because her physical appearance is abnormal. She has been hospitalized since birth. Her CD3 level is reported as 15% (normal values: 60%-80%). Her CD4 is 10% (normal values: 30%-65%). Her CD8 is 5% (normal values: 10%-40%), and her CD19 is 84% (normal values: 5%-20%). Serum immunoglobulin levels are normal. Karyotyping reveals a deletion on chromosome 22. These laboratory results support a diagnosis of:

DiGeorge anomaly.

A 7-month-old boy is seen by a specialist because of hypocalcemia, viral pneumonia, a history significant for recurrent diarrhea, and oral candidiasis. An x-ray reveals the lack of a thymic shadow. A likely diagnosis for this boy is:

DiGeorge anomaly.

Decreased CD3-positive lymphocytes and a lack of responsiveness to phytohemagglutinin in the circulation are typically associated with:

DiGeorge anomaly.

A male baby who has suffered from persistent Candida fungal infections and several bouts of pneumonia before the age of 6 months is found to have some developmental problems as well as low-set ears. Laboratory testing reveals an absence of T cells. What is the most likely diagnosis?

DiGeorge syndrome

Which of the following diseases results in an acquired or secondary immunodeficiency?

HIV infection

A patient's total IgG is in the normal range, but he suffers from recurrent infections with encapsulated bacteria such as Streptococcus pneumoniae and Haemophilus influenza. T-cell functions are all normal. What is the most likely cause of the infections?

IgG subclass deficiency

Which of the following statements about severe combined immunodeficiency is true?

It may be associated with a signal transduction defect.

An autosomal-recessive form of severe combined immunodeficiency can be caused by a deficiency in:

JAK3

A child suspected of having an inherited humoral immunodeficiency disease is given a diphtheria/tetanus vaccine. Two weeks after the immunization, his level of antibody to the specific antigens is measured. Which result is expected for this patient if he does have this deficiency?

No change in the level of specific antibody

Which is true of selective IgA deficiency?

Patients may develop an anti-IgA antibody.

Which enzyme deficiency causes moderate to severe impairment of cell-mediated immunity, with little or no effect on humoral immunity?

Purine-nucleoside phosphorylase

Which of the following is associated with DiGeorge syndrome?

Small or missing thymus

Which of the following statements best describes common variable immunodeficiency?

There is a deficiency of IgA, IgG, or both.

A 9-month-old infant is seen by a physician because of a persistent skin infection. His white and red blood cell counts are normal. However, immunofixation electrophoresis indicates a low level of IgG. When the infant returns to the physician for a follow-up visit in a month, his IgG level has increased. What condition do these results indicate?

Transient hypogammaglobulinemia

A 1-year-old boy is evaluated for a suspected immune deficiency. He has a history since birth of eczema, recurrent rashes, and diarrhea. His white blood cell count (WBC) count is 6.75/uL (normal values: 5.0-10.8 × 103 uL) with a normal differential. Platelet count is 35,000 (normal values: 150,000-350,000/uL), and the platelets are small. His IgG is 750 mg/dL (normal values: 600-1,500 mg/dL). IgM is 30 mg/dL (normal values; 75-150 mg/dL). IgA is 475 mg/dL (normal values: 50-125 mg/dL). IgE is 750 mg/dL (10-50 mg/dL). The boy's blood is typed as O-positive, and he does not have anti-A or anti-B antibodies. Flow cytometry performed on his blood shows 11% CD19 (normal values: 5%-20%) and 50% CD3 cells (normal values: 60%-80%) with a normal ratio of CD4:CD8. T-cell function tests are abnormal. This boy most likely has:

Wiskott-Aldrich syndrome.

A 9-month-old boy is suspected of having an immune deficiency because he had many recurrent infections with Streptococcus pneumoniae. Laboratory tests reveal a normal percentage of T cells and T-cell subsets but a lack of mature B cells and immunoglobulins. This boy most likely has:

X-linked agammaglobulinemia.

The most common form of severe combined immunodeficiency disease results from an X-linked mutation in the gene that codes for:

a receptor subunit involved in signaling for interleukins-2, -4, -7, and -9.

The buildup of toxic purine metabolites that impair B- and T-cell proliferation is the result of a mutation in the gene coding for:

adenosine deaminase.