Preimplantation HLA typing and stem cell transplantation: report of International Meeting, Cyprus, 27-8 March, 2004

There has been progress in the application of stem cell transplantation for the treatment of an increasing number of severe congenital and acquired bone marrow disorders that are currently restricted by the availability of human leukocyte antigen(HLA)-matched related donors. Preimplantation HLA typing has recently been introduced to improve the access to stem cell therapy for inherited bone marrow failures, and its possible use for the treatment of common sporadic malignant and non-malignant bone marrow disorders has also been explored. This paper describes the current experience of preimplantation HLA typing, reviewed by the International Meeting on the subject, which includes preimplantation HLA typing in 147 cycles, 109 of which were carried out as part of preimplantation genetic diagnosis (PGD) for Fanconi anaemia, thalassaemia, Wiscott-Aldrich syndrome, hyperimmunoglobulin M syndrome, hypohidrotic ectodermal dysplasia with immune deficiency, and X-linked adrenoleukodystrophy, and 38 for the sole purpose of HLA typing for leukaemias and aplastic and Diamond-Blackfan anaemias. The applied method resulted in the accurate pre-selection and transfer of HLA-matched embryos, yielding 25 clinical pregnancies and the birth of 14 HLA-matched children to the siblings who required stem cell transplantation.