Persons with severe combined immunodeficiency has no

Options

A. interferons
B. macrophages
C. T or B cells
D. functioning lymph nodes

Answer

**Step-by-Step Solution:**

1. **Understanding Severe Combined Immunodeficiency (SCID):**
- SCID is a genetic disorder characterized by the absence of functional T cells and B cells, which are crucial components of the adaptive immune system.

2. **Identifying the Immune Cells Affected:**
- In individuals with SCID, both T cells and B cells are absent. This means that the body lacks the ability to mount an effective immune response against infections.

3. **Role of T Cells and B Cells:**
- T cells are responsible for cell-mediated immunity, helping to destroy infected host cells, activating other immune cells, and regulating immune responses.
- B cells are responsible for humoral immunity, producing antibodies that target pathogens.

4. **Consequences of Absence of T and B Cells:**
- The absence of these cells leads to severe immunodeficiency, making individuals highly susceptible to infections. Without a functioning immune system, even minor infections can become life-threatening.

5. **Natural Killer Cells:**
- In addition to T and B cells, natural killer (NK) cells may also be affected in some forms of SCID, contributing further to the immune deficiency.

6. **Conclusion:**
- Therefore, in persons with severe combined immunodeficiency, T cells and B cells are absent, leading to a severely compromised immune system.

**Final Answer:**
Persons with severe combined immunodeficiency have no T cells and B cells.

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