My approach to the immunogenetics of haematopoietic stem cell transplant matching.

Haematopoietic stem cell transplantation (HSCT) is now viewed as an effective treatment modality for a wide and varied number of diseases including both malignant and non-malignant haematological diseases, bone marrow failures, inherited immunodeficiencies and congenital metabolic disorders. This review will discuss the immunogenetic factors that play an influential role in the successful outcome of HSCT, most importantly the human leucocyte antigens (HLAs). Advances in HLA typing techniques enabling the definition of HLA types at the allele level have made it possible to investigate the impact of mismatching at individual HLA loci on HSCT outcome. Such studies have informed the strategy used for selection of both related and unrelated donors. This strategy, including the histocompatibility and immunogenetics laboratory testing required, is discussed in the context of published data, guidelines and recommendations.