What risk does the presence of allograft rejection pose?

The presence of allograft rejection poses a significant risk because transplanted tissue can be attacked by the recipient's immune system. When a tissue from a donor is introduced into a recipient's body, the immune system identifies the donor tissue as foreign due to differences in genetic markers. This recognition triggers an immune response aimed at destroying the perceived invader, which can lead to the failure of the transplant.

In the context of tissue banking, understanding this risk is crucial for managing transplant outcomes. Measures such as immunosuppressive therapy may be employed to help mitigate this rejection, but the fundamental issue remains that without proper compatibility and immune suppression, the likelihood of rejection increases markedly, threatening the success of the procedure and the health of the recipient.

Other options presented in the question do not directly address the primary concern of immune response related to allograft rejection, making the understanding of the immune attack as the key risk in this scenario clear and essential for tissue bank specialists.