Semi-direct alloantigen presentation detected in human liver but not kidney transplant recipients: Implications for the future.

Abstract

Two papers in recent issues of AJT, from the labs of Sanchez-Fuyeo (1) and Thomson (2) address the profound interest of transplanters in "cross-dressed" (XD) leukocytes. These words indicate host cells that have acquired membrane proteins from the transplant donor. Typically, this process occurs as follows: after organ transplantation, the allograft donor passenger leukocytes and/or parenchymal cells release vast amounts of small extracellular vesicles (sEV) including exosomes (30-150 nm in diameter).