Certified Clinical Transplant Nurse (CCTN) Practice Exam 2026 - Free CCTN Practice Questions and Study Guide

A 12 of 12 match in HLA typing signifies that all major human leukocyte antigen (HLA) loci are identical between the donor and recipient. The HLA system plays a critical role in the body’s immune response, particularly in transplant surgery where the potential for organ rejection is primarily influenced by HLA compatibility. A perfect match can greatly reduce the risk of transplant rejection and enhance the recipient's chances of a successful outcome.

Given that matching at all HLA loci ensures that the recipient's immune system is less likely to recognize the donor organ as foreign, it optimizes the likelihood of long-term graft survival. In contrast, lesser matches (such as 10 of 12, 8 of 12, or 6 of 12) increase the risk of immune reactions and may require the recipient to take more immunosuppressive medications, which can have long-term health implications. Therefore, achieving a 12 of 12 match is the most favorable scenario in transplantation to ensure the best possible outcome for the recipient.