Immunocompatibility

Immunocompatibility refers to the degree to which a material or tissue is accepted by the immune system of a host organism. It is a critical consideration in fields such as transplantation, where donor organs or tissues must be compatible with the recipient's immune system to avoid rejection. In biomedical engineering, immunocompatibility is paramount when designing implants, prosthetics, or drug delivery systems, as a foreign material can trigger an immune response that leads to inflammation, scarring, or failure of the device.

The immune system identifies foreign substances through various mechanisms, primarily involving the recognition of antigens. Major histocompatibility complex (MHC) molecules, also known as human leukocyte antigens (HLA) in humans, play a crucial role in this recognition. Differences in MHC/HLA between donor and recipient are a primary driver of transplant rejection. Beyond MHC/HLA, other factors such as surface properties of materials, the presence of microbial contamination, and the body's inflammatory state can influence immunocompatibility.

Achieving good immunocompatibility often involves strategies to minimize the immune response. In transplantation, this includes tissue typing and immunosuppressive drug therapy. For biomaterials, approaches involve modifying their surfaces to reduce antigenicity, using biocompatible materials that elicit minimal inflammatory reactions, or creating materials that can actively modulate immune responses to promote acceptance. Understanding and engineering immunocompatibility is essential for the successful integration of foreign biological material or artificial devices within the host.