Immunology Review Corner

Immunology Review Corner: Chapter 61 of the 6th edition of Middleton’s Allergy Principles and Practice, edited by N. Franklin Adkinson, et al.

Prepared by Drs. Eric Chenworth, Mayo Clinic; Karla R. Davis, Walter Reed Medical Center; Anne K. Ellis, McMaster University; and Soo Kim-Delio, Walter Reed Army Medical Center.

Chapter 61: Human Immunodeficiency Virus and Allergic Disease

1. Which of the following is routinely used for the diagnosis of HIV-1 infection in children less than 18 months of age?

A. HIV enzyme immunoassay (EIA)
B. Western blot
C. Measurement of the p24 antigen
D. DNA polymerase chain reaction (PCR)

2. Worldwide, the predominant mode of HIV transmission is which of the following?

A. Vertical exposure
B. Homosexual intercourse
C. Heterosexual intercourse
D. Parenteral exposure

3. Which of the following conditions is considered a Category B in HIV infection? (Category B consists of symptomatic conditions in an HIV-infected adolescent or adult that are not included among conditions listed in Clinical Category C, and that meet at least one of the following criteria: (a) the conditions are attributed to HIV infection or are indicative of a defect in cell-mediated immunity, or (b) the conditions are considered by physicians to have a clinical course or to require management that is complicated by HIV infection.)

A. Bacillary angiomatosis
B. Invasive cervical cancer
C. Cryptococcosis, extrapulmonary
D. Kaposi’s sarcoma

4. Which of the following skin conditions is the most common type of drug-related eruption in HIV-1-infected patients?

A. Photodermatitis
B. Morbilliform rash
C. Erythema multiforme
D. Toxic epidermal necrolysis

5. Which of the following favors entry of lymphocytotrophic HIV-1 strains in CD4+ T cells?

A. MIP-1alpha
B. MIP-1beta
C. RANTES
D. IL-4

6. Which cell type is likely to be first infected by HIV-1?

A. CD4+ T cell
B. Macrophage
C. Dendritic cell
D. CD8+ T cell

7. A 3-year-old girl with mild persistent asthma and known HIV infection is found to have a CD4+ count of 60 cells/muL. The child is clinically stable. Pneumocystis cariniii Pneumonia prophylaxis has previously been addressed. Which of the following is the appropriate next step?

A. Initiate MAC prophylaxis with oral amoxicillin.
B. Initiate MAC prophylaxis with oral clarithromycin.
C. Initiate MAC treatment with intravenous ceftriaxone.
D. Monitor spirometry on a biweekly basis.

8. A 37-year-old, HIV-positive man on Highly Active Antiretroviral Therapy (HAART) develops a diffuse, erythematous, blanching, pruritic rash on the trunk and extremities while being treated with trimethoprim-sulfamethoxazole (TMP-SMX) for Pneumocystis cariniii Pneumonia prophylaxis. Which of the following is most consistent with TMP-SMX hypersensitivity in HIV patients?
A. A higher total lymphocyte count may be associated with increased incidence of TMP-SMX hypersensitivity.
B. A lower total lymphocyte count may be associated with increased incidence of TMP-SMX hypersensitivity.
C. There is no correlation between total lymphocyte count and incidence of TMP-SMX hypersensitivity.
D. TMP-SMX hypersensitivity is rarely seen in HIV infected patients.

9. Which portion of the HIV virion binds directly with the CD4 molecule?
A. gp41
B. p24
C. gp120
D. p17

10. Drug hypersensitivity is relatively common in HIV-1 infected individuals. The rate of reaction to trimethoprim-sulfamethoxazole (TMP-SMX) in HIV-1-infected individuals has been reported as ____________, compared to 3 percent for patients with either normal immunity or with another type of immunodeficiency disorder.

A. 13-20 percent
B. 23-40 percent
C. 43-65 percent
D. 73-80 percent

Answers
1. D, page 1073
2. C, page 1074
3. A, page 1075
4. B, page 1077
5. D, page 1081
6. B, page 1080
7. B, page 1076
8. A, page 1078
9. C, page 1079
10. C, page 1077