Which class of tissue graft is the least likely to be accepted by a patient's body?

• A. Xenograft
• B. Isograft
• C. Allograft
• D. Autograft

Answer: (A)

Verified step by step guidance

1. Understand the definitions of the four types of tissue grafts: Xenograft, Isograft, Allograft, and Autograft. A Xenograft is a tissue graft taken from a different species, an Isograft is from a genetically identical individual (e.g., identical twin), an Allograft is from a genetically different individual of the same species, and an Autograft is from the same individual.
2. Recall that the immune system plays a critical role in tissue graft acceptance. The more genetically similar the donor tissue is to the recipient, the less likely the immune system is to reject the graft.
3. Analyze the likelihood of rejection for each type of graft: Autografts are least likely to be rejected because the tissue comes from the same individual. Isografts are also unlikely to be rejected due to genetic identity. Allografts have a higher chance of rejection because they come from a genetically different individual of the same species. Xenografts are the most likely to be rejected because they come from a different species, which triggers a strong immune response.
4. Conclude that the class of tissue graft least likely to be accepted by a patient's body is the Xenograft, due to the significant genetic and species differences that provoke a strong immune rejection.
5. Review the importance of immunosuppressive therapy in cases where Allografts or Xenografts are used, as these treatments help reduce the likelihood of rejection by suppressing the immune response.