The immunologically sensitised renal transplant recipient: the impact of advances in technology on organ allocation and transplant outcome

Abstract

S ince its inception in the 196Os, the lymphocytotoxic crossmatch test has remained pivotal for the detection ofdonor-specific immunological sensitisation. The prerequisite of avoiding transplantation ofdonor kidneys into specifically sensitised recipients by ensuring a negative crossmatch has virtually eliminated classical hyperacute rejection. Indeed, many contemporary transplantation clinicians have only read about such events in textbooks. Despite this fact, studies continue to report inferior transplantation outcomes in sensitised recipients. For many highly sensitised patients (those with immunoglobulin G&G] human leucocyte antigen lJIIA]-specific antibodies reactive with >85% of potential donors), successful transplantation is further complicated by the difliculties of finding a suitable crossmatchnegative donor. As a result, sensitised patients accumulate on waiting lists and constitute an everincreasing proportion of potential recipients. In addition, in recent years, a major reason for acceptance onto transplant waiting lists is the failure of a previous transplant, which is commonly associated with high levels of immunological sensitisation. Indeed, a review of the United Kingdom kidney transplant’s 19961997 waiting list found that 18% of new patients registered were waiting for a regraft. Furthermore, 35% of patients awaiting their first transplant and 81% of patients awaiting a repeat transplant were sensitised.* Refinements in the complement-dependent cytotoxicity (CDC) test, with increased sensitivity and improved discrimination between harmful and nondamaging antibodies, has facilitated successful transplantation of many sensitised patients. Furthermore,