Question

Which of the following statements regarding TST is true?

a. Tests should be read 48hrs after the injection
b. The size of the TST reaction has nothing to do with erythema but is based solely on induration
c. It is a teyp V T-cell-mediated immune response
d. The diameter of the induration is measured in cm

Answer 1

The TST must be read 48-72 hours after injection, measures reaction based on induration, and is a type IV T-cell-mediated immune response.

Step-by-step explanation:

The Tuberculin Skin Test (TST) is an important diagnostic tool for tuberculosis (TB). The correct statements regarding TST include that the test should be read 48-72 hours after the injection. Moreover, the reaction size is indeed based solely on induration, not erythema, and the diameter of the induration is measured to quantify the response. TST is a Type IV T-cell-mediated immune response, also known as delayed-type hypersensitivity, which involves T-helper cells and macrophages.