A purified protein from Mycobacterium tuberculosis is injected into a person’s skin. A hardened, red area develops around the injection site within 3 days.

검증된 단계별 안내

Identify the type of immune response described: a purified protein from Mycobacterium tuberculosis is injected intradermally, and a localized hardened, red area develops within 3 days. This suggests a delayed-type hypersensitivity reaction.

Recall that the test described is the Tuberculin Skin Test (TST), also known as the Mantoux test, which is used to detect prior sensitization to Mycobacterium tuberculosis.

Understand that the reaction is mediated by T cells (specifically Th1 cells) that recognize the protein antigen and recruit macrophages, leading to inflammation and induration (hardening).

Name the test based on this immunological principle: it is called the Tuberculin Skin Test or Mantoux test.

Summarize that the observed reaction is a classic example of a Type IV hypersensitivity reaction, which is cell-mediated and typically appears 48-72 hours after antigen exposure.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Tuberculin Skin Test (Mantoux Test)

The tuberculin skin test involves injecting a purified protein derivative (PPD) from Mycobacterium tuberculosis into the skin to detect prior exposure. A localized immune reaction causing redness and induration within 48-72 hours indicates a positive test, reflecting a cell-mediated immune response.

Delayed-Type Hypersensitivity (Type IV Hypersensitivity)

This immune response is mediated by T cells rather than antibodies and occurs 24-72 hours after antigen exposure. In the tuberculin test, sensitized T cells recognize the injected protein, releasing cytokines that recruit macrophages and cause localized inflammation and tissue hardening.

Cell-Mediated Immunity in Tuberculosis

Cell-mediated immunity is crucial for controlling Mycobacterium tuberculosis infection. Sensitized T helper cells activate macrophages to contain the bacteria, and this immune memory is the basis for the skin test reaction, indicating prior sensitization to the pathogen.