Cell therapy is presently a treatment of choice for many types of haematological and metabolic diseases and is likely to become a therapeutic option for other severe human diseases and conditions in the near future. The success of cell transplantation depends on a variety of factors, including the degree of HLA match between the donor and the recipient, the infectious burden of the graft, cell dosage, age, general state of the recipient and other incompletely characterised features of the donor and the recipient. It is likely that the individual capacity for identification and repair of DNA damage and maintenance of genomic integrity may account, at least in part, for these elusive factors that modulate transplantation outcome in terms of success rate and both long and short term post-transplantation complications. This paper outlines the role of individual repair capacity of the donor and recipient in cell transplantations, summarising the little knowledge already accumulated in the field whilst analysing the known major issues of the use of different types of stem cells. Attention will be given to their capacity to maintain the integrity of their genome, the ability to renew their own population, differentiate into various cell types and in some cases, succumb to carcinogenic transformation. Analysis of the individual capacity may become a useful tool in the assessment of the suitability of a set of freshly collected stem cells or an in vitro propagated cell line for potential clinical applications.
