Essential concept of transplant immunology for clinical practice

Abstract

Our understanding of transplant immunology has advanced from gross allograft rejection to cellular response and to current molecular level. More sensitive assays have been developed to characterize patient sensitization and to detect pre-existing donor-specific antibodies (DSA) in pre-transplant crossmatch. After a transplant, pre-existing or de novo DSA are increasingly monitored to guide clinical management. Therefore, it is important for clinicians to understand the basic concepts and key components of transplant immunology as well as be familiarized with the modern immunological techniques used in kidney transplantation.

Keywords: Alloimmune response; Major histocompatibility complex; Human leukocyte antigens; Co-stimulation pathway; Panel reactive antibody; Donor specific antibody; Non-human leukocyte antigens antibody; Crossmatch

Core tip: The alloimmune response is initiated by T-cell recognition of alloantigens through direct or indirect pathways. Three signal models have been established during T-cell activation, which subsequently produces various effector T-cells and antibody production. Sensitive crossmatch is routinely performed before kidney transplant to detect any significant donor-specific antibodies, so that hyperacute rejection can be eliminated. Solid phase based Luminex assay can further characterize human leukocyte antigens antibodies before and after kidney transplant to guide our clinical practice.