O papel da histocompatibilidade em transplantes de células-tronco hematopoiéticas: revisão da literatura

Abstract

Through the studies about transplants in liquid tissues, such as the bone marrow, the need for histocompatibility between donor and recipient was realized. Compatibility occurs through equivalence in human leukocyte antigens (HLA). These molecules are produced by the major histocompatibility complex - a dense genomic region with high polymorphism - and its main function is associated with the presentation of antigens to T lymphocytes. This allelic variability distributed in the population makes it difficult to find a match between individuals, such as observed in populations with high miscegenation, since some alleles are associated with ethnicities. Therefore, donor registries around the world are created and expanded with donor incentive campaigns so that you can increase the possibility of finding a donor have a match with a patient. Hematopoietic stem cell transplantation is a curative therapeutic method for several neoplastic and non-neoplastic diseases. The origin of the cells used may be the patient's own (autologous), a donor related or not (allogeneic) or coming from an identical twin (syngeneic). Bone marrow is not the only source of extraction to give rise to hematopoietic precursors, since umbilical cord blood as well as peripheral blood precursors are also used. However, prior to being submitted to the procedure, the patient is exposed to a conditioning regimen that exhibits toxicity, which may lead to complications, as well as incompatibility in HLA molecules also lead to clinical signs of graft rejection.