Immunology Review Corner

Prepared by Thao N. Tran, M.D. and Irena Veksler, M.D, Stony Brook University Hospital- SUNY; Karla Lowe, M.D., Walter Reed Medical Center; and Todd Levin, M.D., Medical College of Georgia

Chapter 37: Laboratory Tests for Allergic and Immunodeficiency Diseases

1. Which of the following is correct about immunoglobulin E (IgE)?
a. There is an age-dependent increase of serum IgE levels after 45 years of age
b. IgE is elevated in patients with atopic dermatitis, with a mean around 1000 kU/L
c. Increased IgE levels are observed in chronic GVHD
d. The serum IgE level decreases progressively until the age of 10 years

2. Which of the following IgG subclasses is found in the greatest concentration in the peripheral blood?
a. IgG1
b. IgG2
c. IgG3
d. IgG4

3. After immunotherapy, which of the following IgG subclasses has been observed to block antigen-induced basophil histamine release in vitro?
a. IgG1
b. IgG2
c. IgG3
d. IgG4

4. After which of the following ages can the diagnosis of a primary or secondary immunodeficiency be made if the total serum IgG concentration is less than 30 percent of the individual’s age-adjusted normal range?
a. 1 year
b. 2 years
c. 3 years
d. 4 years

5. Which of the following laboratory techniques has the lowest analytic sensitivity?
a. Precipitation in gel
b. Nephelometry
c. Enzyme-linked immmunoassay
d. Flow Cytometry

6. In which of the following assay configurations is the amount of the unlabeled antigen (ligand) the rate-limiting component of the binding reaction?
a. Equilibrium dialysis assay
b. Two-site immunoenzymetric assay
c. Radioimmunoprecipitation assay
d. Precipitin-based assay

7. Which of the following statements is true regarding tests for IgG antibodies?
a. Specific IgG can be useful in monitoring the response to Hymenoptera immunotherapy
b. Specific IgG is useful in the diagnosis of food allergy
c. Radioimmunoprecipitation assay is a qualitative test used to measure non-specific IgG
d. Radioimmunoprecipitation assay is a superior test compared to solid-phase radioimmunoassay in detecting IgG antibodies

8. Which of the following is true regarding tryptase?
a. Beta tryptase is constitutively secreted by all mast cells
b. Beta tryptase levels are a measure of mast cell activation
c. Alpha tryptase levels peak at 10-30 minutes after a sting in venom anaphylaxis
d. Total serum tryptase greater than 5 ng/ml is indicative of systemic mastocytosis

9. Which of the following specimen types is the specimen of choice for measurement of cotinine levels?
a. Tears
b. Saliva
c. Urine
d. Serum

10. Which of the following statements is true regarding measurement of indoor aeroallergens?
a. The threshold for sensitization for cat allergen Fel d 1 is 10,000 ng per gram of fine dust
b. Molds produce the same variety of protein when indoor versus when they are outdoors
c. Amounts of Der p 1 greater than 2000 ng per gram of fine dust are associated with increased symptoms in sensitized patients
d. The thresholds for sensitization are similar for cockroaches and cats

11. Which of the following is an accurate match of the lymphocyte subpopulations and their cell surface markers?
a. B-cells: CD8, CD19
b. Cytotoxic suppressor T-cells: CD3, CD8, CD45
c. NK cells: CD20, CD56
d. Monocytes: CD2

12. In order to evaluate the NK cell population, which of the following monoclonal antibody panels would likely be utilized?
a. CD3, CD19, CD45
b. CD3, CD8, CD45
c. CD3, CD4, CD45
d. CD3, CD16, CD56

Answers:
1. b, page 611
2. a, page 612
3. d, page 612
4. b, page 612
5. a, pages 617-627
6. b, page 618
7. a, page 623
8. b, page 624
9. d, page 625
10. c, page 626
11. b, page 628
12. d, page 628