Start practicing

Pathology · single question

What type of hypersensitivity does a tuberculin (Mantoux) test measure?

  1. Type III (immune complex)
  2. Type IV (delayed, cell-mediated)
  3. Type II (cytotoxic)
  4. Type I (IgE-mediated)
Show answer and explanation

Correct answer: B. Type IV (delayed, cell-mediated)

  • A. Type III involves immune complex deposition and complement activation — not the T-cell mediated mechanism of the tuberculin test.
  • B. The tuberculin skin test (Mantoux/PPD) is a classic example of TYPE IV HYPERSENSITIVITY (delayed, cell-mediated). Sensitized CD4+ T-helper cells react to purified protein derivative (PPD) injected intradermally, releasing cytokines that recruit macrophages and cause a local induration at the injection site — appearing 48-72 hours later. This delayed cellular reaction is Type IV.
  • C. Type II involves antibody-mediated cytotoxicity — not T-cell mediated delayed reaction.
  • D. Type I is immediate, IgE-mediated — reactions occur within minutes. Tuberculin test induration takes 48-72 hours.

Practice Pathology questions Pathology study notes

More Pathology practice questions