Certified Clinical Transplant Nurse (CCTN) 2025 – 400 Free Practice Questions to Pass the Exam

The significance of HLA (Human Leukocyte Antigen) groups, including HLA-A, HLA-B, and HLA-DR, lies in their crucial role in determining organ transplant compatibility. HLA molecules are proteins found on the surface of most cells in the body and are vital for the immune system's ability to recognize which cells belong in the body and which do not. This recognition is essential in organ transplantation because the recipient's immune system must accept the transplanted organ as "self" rather than attacking it as a foreign invader.

HLA typing is performed to compare the HLA antigens of potential organ donors and recipients. The closer the match between the donor's and recipient's HLA antigens, the lower the chance of organ rejection. If the HLA compatibility is poor, the recipient’s immune system is more likely to recognize the transplant as foreign, leading to complications such as acute rejection or chronic graft failure.

In contrast, HLA groups are not related to metabolic processes, identification of viral infections, or the control of body temperature. The other choices do not accurately reflect the primary function of HLA antigens within the context of transplantation, highlighting that their main significance is indeed in transplant compatibility.