A conditioning or preparative regimen is used to: A. target patients at risk for disease recurrence. B. shrink the primary tumor to improve the effectiveness of surgery. C. eliminate residual disease prior to stem cell transplantation D. prevent graft-versus-host disease.
The correct answer and explanation is:
Correct Answer:
C. Eliminate residual disease prior to stem cell transplantation
Explanation:
A conditioning or preparative regimen is a critical step before stem cell transplantation (SCT), whether autologous (using the patient’s own cells) or allogeneic (using donor cells). The primary purpose of this regimen is to eliminate any remaining disease, such as leukemia, lymphoma, or other hematologic malignancies, and to create space in the bone marrow for new stem cells to engraft and grow.
Key Objectives of a Conditioning Regimen
- Destroy Residual Malignant Cells:
- In patients with leukemia, lymphoma, or myelodysplastic syndromes, even after initial chemotherapy or radiation, microscopic levels of disease can persist. High-dose chemotherapy and/or total body irradiation (TBI) in the conditioning regimen aim to eradicate these remaining cancer cells.
- Suppress the Immune System:
- This is particularly important in allogeneic transplants, where the patient receives stem cells from a donor. The regimen weakens the patient’s immune system to prevent rejection of the donor cells and facilitate engraftment.
- Create Marrow Space for New Stem Cells:
- The high-dose chemotherapy or radiation helps wipe out existing bone marrow, ensuring that the transplanted stem cells can settle and start producing healthy blood cells.
Types of Conditioning Regimens
- Myeloablative Conditioning (MAC): Uses high-intensity chemotherapy and/or radiation to fully eradicate the bone marrow.
- Reduced-Intensity Conditioning (RIC): Uses lower doses to suppress the immune system while allowing some residual bone marrow function.
Conclusion
Conditioning regimens are crucial for the success of stem cell transplantation, ensuring that the new cells engraft properly while eliminating any remaining cancer cells that could cause relapse.
Now, I’ll generate an image related to stem cell transplantation and conditioning therapy.
Here is the medical illustration depicting the process of stem cell transplantation, focusing on the conditioning regimen. Let me know if you need any modifications or further details!
