Immunology Review Corner

Immunology Review Corner: Chapter 60 of the 6th edition of Middleton’s Allergy Principles and Practice, edited by N. Franklin Adkinson, et al.

Prepared by Dr. Thao N. Tran, Puget Sound Allergy, Asthma and Immunology, and Dr. Karla R. Davis, Walter Reed Medical Center.

Chapter 60: Approach to the Patient with Recurrent Infections

1. Recurrent septicemia is suggestive of which of the following defects?
a. Neutropenia
b. Phagocytic defect
c. Opsonic defect
d. Collagen defect

2. A young child presents to your clinic with a lupuslike rash with negative antinuclear antibody (ANA) titer. Which of the following complement components is most likely deficient.
a. C2
b. C6 & C7
c. C9
d. Factor H

3. The patient has recurrent infections, broad-based gait and telangiectasia. Which of the following lab values is most likely elevated?
a. IgA
b. CD4+ T cells
c. Alpha fetoprotein
d. ANA

4. You are obtaining a total hemolytic complement activity (CH50) on a patient. Which of the following is the appropriate method of handling the blood sample to ensure that the hemolytic activity does not get degraded?
a. Cool the sample to room temperature and do not serum separate it.
b. Place it on ice immediately, serum separated, and store at -70 degrees Celsius
c. Ensure that the sample remains warm at body temperature, serum separated, and analyzed immediately
d. Collect another blood sample and run an AH50 (alternate pathway function) for comparison

5. You suspect a patient with disseminated Candida albicans infection has myeloperoxidase deficiency. Which of the following lab tests is the easiest method to confirm your diagnosis?
a. Nitroblue tetrazolium dye
b. Flow cytometry with dihydrorhodamine dye
c. Automated differential white blood cell counters
d. Peripheral blood smear

6. Which of the following Severe Combined Immunodeficiency Diseases (SCID) has the following phenotype: T-B-NK-?
a. Omenn’s syndrome
b. ZAP-70 deficiency
c. Reticular dysgenesis
d. Purine Nucleoside Phosphorylase (PNP) deficiency

7. Patients with which of the following forms of SCID differ from most patients with SCID because they have palpable lymph nodes and a normal-sized thymus on radiography?
a. RAG1 deficiency
b. ZAP-70 deficiency
c. Reticular dysgenesis
d. X-linked SCID

8. The gene mutation identified in X-linked Immune Dysregulation, Polyendocrinopathy, Enteropathy Syndrome (IPEX) is:
a. Autoimmune regulator (AIRE)
b. Fas (CD95)
c. SH2D1A (encodes SLAM-associated protein)
d. FOXP3

9. Maintaining a serum IgG trough level greater than which of the following helps prevent severe acute bacterial infections and bronchiectasis in patients with XLA on IVIG replacement therapy?
a. 200mg/dl
b. 400mg/dl
c. 500mg/dl
d. 800mg/dl

10. In adults, deficiency of which of the following IgG subclasses is the most common?
a. IgG1
b. IgG2
c. IgG3
d. IgG4

11. Which of the following is the primary antibody response to Moraxella catarrhalis?
a. IgG1
b. IgG2
c. IgG3
d. IgG4

Answers
1. c, page 1043
2. a, pages 1046-47
3. c, page 1046
4. b, page 1048
5. c, page 1051
6. c, page 1053
7. b, page 1057
8. d, page 1060
9. c, page 1063
10. c, page 1065
11. c, page 1066