3.6 Immunoglobulins, Complement, and Cellular Testing

Question 1

Which of the following symptoms in a young child may indicate an immunodeficiency syndrome?

A. Anaphylactic reactions
B. Severe rashes and myalgia
C. Recurrent bacterial, fungal, and viral infections
D. Weight loss, rapid heartbeat, breathlessness

Answer 1

C. Recurrent bacterial, fungal, and viral infections

Question 2

What screening test should be performed first in a young patient suspected of having an immune dysfunction disorder?

A. Complete blood count (CBC) and WBC differential
B. Chemotaxis assay
C. Complement levels
D. Bone marrow biopsy

Answer 2

A. Complete blood count (CBC) and WBC differential

Question 3

Which test should be performed when a patient has a reaction to transfused plasma products?

A. Ig levels
B. T-cell count
C. Hemoglobin levels
D. RBC enzymes

Answer 3

A. Ig levels

Question 4

What is the “M” component in monoclonal gammopathies?

A. IgM produced in excess
B. Heavy chain produced in excess
C. Malignant proliferation of B cells
D. Monoclonal antibody or cell line

Answer 4

D. Monoclonal antibody or cell line

Question 5

A child suspected of having an inherited humoral immunodeficiency disease is given 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, indeed, has a humoral deficiency?

A. Increased levels of specific antibody
B. No change in the level of specific antibody
C. An increase in IgG-specific antibody but not IgM-specific antibody
D. Increased levels of nonspecific antibody

Answer 5

B. No change in the level of specific antibody

Question 6

Which disease may be expected to show an IgM spike on an electrophoretic pattern?

A. Hypogammaglobulinemia
B. Multicystic kidney disease
C. Waldenström macroglobulinemia
D. Wiskott-Aldrich syndrome

Answer 6

C. Waldenström macroglobulinemia

Question 7

In testing for DiGeorge syndrome, what type of laboratory analysis would be most helpful in determining the number of mature T cells?

A. CBC
B. Dihydrorhodamine reduction (DHR) test
C. T-cell mitogen assays
D. Flow cytometry

Answer 7

D. Flow cytometry

Question 8

Interpret the following description of an IFE assay of urine. Dense wide bands in both the κ- and λ-lanes. No bands present in the heavy-chain lanes.

A. Normal
B. Light-chain disease
C. Increased polyclonal Fab fragments
D. Multiple myeloma

Answer 8

C. Increased polyclonal Fab fragments

Question 9

Free monoclonal light chains are often present in the serum of patients with multiple myeloma and may be useful for disease monitoring. Which of the following assays would be recommended to detect the presence of free light chains in serum?

A. SPE
B. Urine immunofixation
C. Nephelometry
D. ELISA

Answer 9

C. Nephelometry

Question 10

What is measured in the CH50 assay?

A. RBC quantity needed to agglutinate 50% of antibody
B. Complement needed to lyse 50% of RBCs
C. Complement needed to lyse 50% of antibody-sensitized RBCs
D. Antibody and complement needed to sensitize 50% of RBCs

Answer 10

C. Complement needed to lyse 50% of antibody-sensitized RBCs

Question 11

What type of disorders would show a decrease in C3, C4, and CH50?

A. Autoimmune disorders, such as SLE and RA
B. Immunodeficiency disorders, such as common variable immunodeficiency
C. Tumors
D. Bacterial, viral, fungal, or parasitic infections

Answer 11

A. Autoimmune disorders, such as SLE and RA

Question 12

All of the following tests measure phagocyte function except:

A. Leukocyte adhesion molecule analysis
B. DHR assay
C. Nitro blue tetrazolium (NBT) test
D. IL-2 assay

Answer 12

D. IL-2 assay