Evaluation of engraftment kinetics following double unit umbilical cord blood transplantation in patients with life threatening haematological malignancy in whom stem cell transplant (SCT) offers the only prospect of cure.

The use of umbilical cord blood (CB) as a source of haemopoietic stem cells (HSC) for transplantation is increasing. Advantages of using CB compared to other sources of HSC include a reduction in search time and procurement, a low risk of transmission of viral disease and a reduced incidence of graft versus host disease. Delayed engraftment, due to the low cell number in CB grafts, has emerged as the limiting factor to more widespread use of CB as a source of HSC. Transplantation of multiple CB units is one approach to overcome low cell numbers and preliminary results are encouraging. In this study, patients with high risk haematological malignancy who require a HSC transplant but do not have a related or unrelated donor will receive a double unit CB transplant. The study hypothesis is that transplantation of two cord blood units is feasible and safe to administer.