Mixed Lymphocyte Reaction (MLR) is an immunological laboratory test conducted to assess the compatibility and degree of immune response between two or more individuals. MLR is commonly employed in transplantation medicine and immunogenetics research to determine the level of histocompatibility between donors and potential recipients.
During an MLR, lymphocytes from one individual, known as the "responder," are mixed with lymphocytes from another individual referred to as the "stimulator" or "alloantigen." These two sets of lymphocytes are then co-cultivated in a specialized medium. The purpose of this test is to observe and measure the degree of T-cell proliferation or transformation that occurs.
The reaction measures the response of the responder's lymphocytes to foreign antigens derived from the stimulator's lymphocytes. If the responder's lymphocytes recognize the stimulator's antigens as foreign, they activate and undergo clonal expansion, leading to the production of immune mediators such as cytokines and effector cells.
The result of an MLR is typically quantified by assessing the level of lymphocyte proliferation, represented by the amount of DNA synthesis, radioisotope incorporation, or fluorescence labeling. A positive MLR suggests a significant immune response, indicating incompatibility and increasing the risk of graft rejection in transplantation scenarios.
Overall, Mixed Lymphocyte Reaction provides crucial information regarding the compatibility between donors and recipients, helping in the selection of appropriate donors, development of personalized immunosuppressive therapies, and improvement of transplantation outcomes.
