Exam 12: Congenital and Acquired Immunodeficiencies

A 7-month-old boy is evaluated in the clinic for recurrent bacterial infections. His tonsils are not visible on physical examination. Serum immunoglobulin A (IgA) and IgG levels are markedly decreased, and serum IgM levels are slightly below normal. Based on the findings described, which one of the following should be excluded from the differential diagnosis?

A 36-year-old man with a history of a positive anti-HIV antibody test comes to the clinic with fever, sore throat, nonproductive cough, and weight loss. The patient has a high serum viral load, quantified by reverse transcriptase polymerase chain reaction (RT-PCR). This patient is LEAST likely to suffer from which of the following?

A 3-year-old boy is taken to the pediatrician because of a nosebleed (epistaxis). He has a history of severe, recurrent sinopulmonary infection. Physical examination is remarkable for dry, red patches of skin (eczema) and multiple petechiae (tiny hemorrhagic spots). Laboratory 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 7-month-old boy is evaluated in the clinic for recurrent bacterial infections. His tonsils are not visible on physical examination. Serum immunoglobulin A (IgA) and IgG levels are markedly decreased, and serum IgM levels are slightly below normal. The gene identified in this patient plays a critical role in receptor binding to all of the following ligands EXCEPT:

All of the following have a direct role in mediating human immunodeficiency virus (HIV) entry into susceptible cells EXCEPT:

An 18-month-old girl is brought to the pediatrician because of recurrent upper respiratory tract infections. She has a fever, labored breathing, and a dry cough. Diagnostic tests confirm infection with Pneumocystis jiroveci. Serum studies are remarkable for negligible levels of IgG and IgA in the presence of high concentrations of IgM. The family history is unremarkable; in particular, the patient's three older brothers are in excellent health. This patient most likely carries a mutation in which of the following molecules?

A 7-month-old boy is evaluated in the clinic for recurrent bacterial infections. His tonsils are not visible on physical examination. Serum immunoglobulin A (IgA) and IgG levels are markedly decreased, and serum IgM levels are slightly below normal. Careful examination of this infant reveals white plaques along the buccal mucosa, palate, and tongue, consistent with oral candidiasis (thrush). Analysis of blood cells reveals normal numbers of B cells and very few CD3⁺ cells. In addition, maternally-derived T cells, as determined by HLA typing, are detectable. The infant's mother reports that two of her three brothers died of infection as young children. Collectively, this presentation and history are most consistent with which of the following disorders?

A 7-month-old boy is evaluated in the clinic for recurrent bacterial infections. His tonsils are not visible on physical examination. Serum immunoglobulin A (IgA) and IgG levels are markedly decreased, and serum IgM levels are slightly below normal. Based on this family's history and clinical presentation, a mutation in which of the following genes is most likely to be found in this patient?

Which of the following strategies would be expected to be LEAST effective in the prevention and/or treatment of AIDS?

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

Which of the following patients is particularly susceptible to infection with Streptococcus pneumoniae, an encapsulated bacterium?

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

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

All of the following may result in an acquired immunodeficiency EXCEPT:

A 36-year-old man with a history of a positive anti-HIV antibody test comes to the clinic with fever, sore throat, nonproductive cough, and weight loss. This patient has had a partner for 8 years with whom he has frequently engaged in unprotected sexual intercourse. The partner is a healthy 29-year-old man who is HIV negative. The partner's relative "resistance" to HIV infection may be due to a loss-of-function mutation in which of the following proteins?

A 3-year-old boy is taken to the pediatrician because of a nosebleed (epistaxis). He has a history of severe, recurrent sinopulmonary infection. Physical examination is remarkable for dry, red patches of skin (eczema) and multiple petechiae (tiny hemorrhagic spots). Laboratory findings include thrombocytopenia and reduced IgM levels. The boy's maternal uncle died of bleeding complications after an emergency appendectomy. Which of the following represents a curative therapy currently available for this patient?

A 7-month-old boy is evaluated in the clinic for recurrent bacterial infections. His tonsils are not visible on physical examination. Serum immunoglobulin A (IgA) and IgG levels are markedly decreased, and serum IgM levels are slightly below normal. This infant should NOT be given the measles-mumps-rubella (MMR) vaccination because:

Human immunodeficiency virus (HIV) is NOT a: