Second allogeneic peripheral blood stem cell transplants with reduced-intensity conditioning.

In two institutions in México, twelve patients were given a second allogeneic stem cell transplantation, using the "Mexican" non-myeloablative preparative regimen. Eight had a malignant condition (six acute leukemias, one myelofibrosis and one myelodysplasia), eleven individuals were allografted twice from the same donor and in one case, cells from two different umbilical cords were used. The median time to conduct the second allograft after the first one was 6 months (range 1-41). The five patients who failed to engraft after the first transplant failed also to engraft after the second one; all of them had been heavily transfused. Only three patients were successfully rescued with the second transplant, two with acute leukemia and one with aplastic anemia. Seven patients are alive 10-41 months (median 35) after the second transplant, but only three (25%) remain disease-free. The 52-month overall survival (SV) of the patients is 58%, whereas the median overall SV has not been reached, being above 52 months. Conducting a second allograft may be useful to rescue some individuals relapsing after a first hematopoietic allotransplant.