Selftissue

Selftissue refers to the tissues and cells that originate from and belong to an individual. It is contrasted with allogeneic tissue (from another person) or xenogeneic tissue (from another species). Examples include skin, muscle, fat, bone, cartilage, and organ tissue.

In normal physiology, selftissue expresses self-markers, including MHC antigens, and the immune system maintains tolerance to them, preventing attacks on the body's own tissues. Autoimmune diseases arise when this tolerance fails, leading to immune responses against selftissue.

Clinical applications include autologous tissue transplantation, which uses the patient's own selftissue for reconstruction or repair. Examples include autologous skin grafts, fat grafts, bone grafts, and tendon or ligament grafts. Because the tissue is selftissue, the risk of immune rejection is minimal and immunosuppression is usually unnecessary. Limitations include limited tissue availability and donor-site morbidity.

In regenerative medicine, selftissue approaches use the patient's cells and materials derived from their own body to promote healing and tissue restoration. Techniques include expanding autologous cells, employing decellularized autologous scaffolds, and three-dimensional bioprinting with the patient's own cells, aiming to reduce rejection risks and improve functional integration.

Research and diagnosis involving selftissue focus on understanding autoimmune processes, cancer biology, aging, and tissue degeneration. Diagnostic methods may compare affected selftissue with unaffected tissue from the same patient to identify pathologic changes and guide treatment decisions.