SBA — Single Best Answer · Review
Question 625
Immunology → General
Classification
Question
SSBAQuestion Header
Which of the following is identified as a factor determining the antigenicity of a substance?
Question Stem
Select the single best answer.
Options
A
Previous exposure to the antigen is essential
B
The substance must be a bacterial protein
C
It must resist all tissue enzymes
D
Foreignness to the host
E
It must be an immunoglobulin
Explanation
Antigenicity is influenced by factors including molecular size, chemical nature, foreignness, susceptibility to tissue enzymes and specificity.
Option Validity
A) Recognition of foreign antigen is not dependent on previous exposure.
B) Antigens are not restricted to bacterial proteins; proteins and polypeptides are commonly antigenic and large carbohydrates may also be antigenic.
C) Susceptibility to tissue enzymes influences antigenicity; complete resistance to all tissue enzymes is not stated as a requirement.
E) Immunoglobulin is not a requirement for a substance to be antigenic.
Further Reading
Saxena MRCOG-1 Basic Sciences — Immunology: Immunogenetics and Principles of Antigen Recognition, printed page 212 before Immunoglobulins.