Mechanism of Transplant Rejection and Types of Transplant Rejection

This section includes: • Role of HLA in transplant rejection • Allorecognition • Role of innate immune system • Role of adaptive immune system • Acute and chronic cellular rejection • Acute and chronic Antibody Mediated rejection Transplant rejection is one of main reason of graft loss after organ transplant. Recipient immune system recognise donor HLA molecules and other proteins that are different then recipient as foreign antigens. Immune response involves both innate and adaptive immune response. Immune response can be Cell mediated response resulting in activation of parenchyma of transplanted organ or it can be Antibody mediated response. These antibodies are mainly against donor HLA molecules. These antibodies bind to donor HLA molecules in vascular endothelium and result in microvascular inflammation and larger vessels can also be involved. Chronic antibody mediated rejection is one of the main cause of graft loss.