Superior survival of blood and marrow stem cell recipients given maternal grafts over recipients given paternal grafts

During the reproductive period, mothers and offspring exchange hematopoieti c cells and develop a form of immunological tolerance bidirectionally. To e xamine whether previous experience of such communication has any remote eff ect when maternal hematopoietic cells are later transplanted to the childre n, we retrospectively compared the outcomes of blood and marrow stem cell t ransplantation from maternal donors (n = 46) to those from paternal donors (n = 50) by using the database of the Japanese nationwide surveys for adult hematopoietic cell transplants between 1990 and 1998. At 5 years, recipien ts of maternal hematopoietic cells had a significantly higher overall survi val than patients receiving paternal grafts (60% vs 32%, P = 0.006). Althou gh no significant difference was observed in the occurrence of severe acute GVHD (grade greater than or equal to III) and the relapse of malignant dis eases between two groups, the probability of non-relapse treatment-related mortality was significantly lower after maternal donor transplants. Further more, multivariate analysis revealed that parental donor type was the only factor significantly associated with overall survival. In conclusion, our a nalysis indicates superior survival of maternally donated recipients in hem atopoietic stem-cell transplantations from biological parents. This finding has important implications in the selection of alternative familial donors , and warrants further prospective analysis of parental donor transplantati ons.