ATI TEAS (Test of Essential Academic Skills) Version 7ScienceMedium
A patient presents with symptoms indicating a possible autoimmune disorder where the immune system mistakenly attacks healthy cells. Which type of immunity is primarily responsible for this destructive response?
- APassive immunity
- BHumoral immunity
- CInnate immunity
- DCell-mediated immunity
Show answer & explanationAnswer & explanation
Correct answer: D. Cell-mediated immunity
Autoimmune disorders often involve the immune system attacking self-antigens. Cell-mediated immunity, primarily driven by T lymphocytes, is responsible for directly attacking infected or abnormal cells, including self-cells in autoimmune conditions. While humoral immunity (antibodies) can also be involved, direct attack on cells is characteristic of cell-mediated responses.
Why the other options are wrong
- A. Passive immunity involves receiving antibodies from an outside source and is not about the body's own immune attack.
- B. Humoral immunity involves B cells producing antibodies, which tag pathogens for destruction but typically do not directly destroy cells themselves in the same way T cells do.
- C. Innate immunity is the body's first, non-specific line of defense and does not typically target specific self-cells in an autoimmune manner.
Cell-Mediated Immunity
An immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
- Primarily involves T lymphocytes (T cells).
- Targets infected cells, cancer cells, and foreign tissue (e.g., transplant rejection).
- Can be a major contributor to autoimmune diseases by attacking self-cells.
Memory trick: CHAMPS: Cell-mediated, Humoral, Antibodies, Memory, Protection, Specificity.