What are the three types of bone marrow transplants?

• A. Autologous, allogeneic, and synthetic
• B. Autologous, allergic, and syngeneic
• C. Autologous, allogeneic, and syngeneic
• D. None of the above

Answer: (C)

In bone marrow transplantation the main distinction is the source of the hematopoietic stem cells. Autologous transplants use the patient’s own cells, collected before high-dose chemotherapy and then returned to the patient. Allogeneic transplants come from a donor—often a related family member or an unrelated matched donor—whose cells repopulate the patient’s marrow. Syngeneic transplants come from an identical twin, providing near-perfect genetic compatibility and usually the lowest risk of graft-versus-host disease, though donor availability limits this option.

The other terms aren’t used to describe transplant types: synthetic implies artificial marrow, and allergic isn’t a transplant source.