Bone marrow and peripheral blood transplantation has now been shown to be curative for a proportion of patients with life-threatening diseases including acute and chronic myeloid leukaemia (AML, CML), acute lymphoblastic leukaemia (ALL), myelodysplasia (MDS), chronic lymphatic leukaemia, Hodgkin’s (HD) and non-Hodgkin’s lymphoma (NHL), myeloma (MM), severe aplastic anaemia (AA), thalassaemia, severe combined immune deficiency and some other conditions (Atkinson, 1994; Forman et al., 1994). BMT has developed from being an experimental method to become an important treatment method for acute and chronic leukaemias (Alby, 1991).