Highest chance of success in renal transplant is possible when the donor is: September 2007, 2010
**Core Concept**
The question is testing the concept of HLA matching in renal transplantation, which is crucial for graft survival and success. HLA (Human Leukocyte Antigen) matching refers to the compatibility between the donor and recipient's immune system, specifically the HLA antigens on white blood cells.
**Why the Correct Answer is Right**
The correct answer is based on the principle of matching the donor and recipient's HLA types to minimize the risk of graft rejection. When the HLA match is good, the recipient's immune system is less likely to recognize the donor's kidney as foreign and mount an immune response against it. This leads to a lower risk of acute rejection and better long-term graft survival. In renal transplantation, HLA matching is typically done using HLA-A, HLA-B, and HLA-DR typing.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because HLA matching is more important than ABO blood group matching in renal transplantation. While ABO matching is still crucial, HLA matching has a greater impact on graft survival.
* **Option B:** This option is incorrect because family members are not always HLA-matched, and even if they are, the match may not be perfect.
* **Option C:** This option is incorrect because unrelated donors may be HLA-matched, but the match may not be as good as a matched related donor.
**Clinical Pearl / High-Yield Fact**
In renal transplantation, a good HLA match is not the only factor that determines graft success. Other factors, such as the donor's age, the presence of any underlying medical conditions, and the recipient's overall health, also play a crucial role.
**Correct Answer: C. Sibling.**