What is the difference between a bone marrow transplant and a stem cell transplant?

Source of stem cells: Originally, scientists thought that only the stem cells from the bone marrow compartment could be used to make new bone marrow. After we learned that bone marrow stem cells circulate throughout the body and also that we can increase their numbers in the blood stream, we moved to obtaining these stem cells from blood the same way we obtain platelets which is less invasive than marrow harvest.

Source of the cells: The terms are often used interchangeably. In a bone marrow transplant the cells are taken from the bone marrow. For a stem cell transplant the cells are taken from the blood.

Stem cell transplant: A bone marrow transplant is a type of stem cell transplant.

HSC Transplant: Hematopoietic Stem Cell Transplant includes both Bone Marrow Transplants (BMT) and Peripheral Blood Stem Cell (PBSC). The difference is whether the cells are collected directly from the donors bone marrow; or from the blood using an apheresis machine. These are the only types of stem cell transplant in regular practice. Researchers hope to develop stem cell transplants for other tissue types.