LONG-TERM CRYOPRESERVATION - SUCCESSFUL TRILINEAGE ENGRAFTMENT AFTER AUTOLOGOUS BONE-MARROW TRANSPLANTATION WITH BONE-MARROW CRYOPRESERVED FOR 7 YEARS

Successful autologous bone marrow transplantation (ABMT) and periphera l blood stem cell transplantation depend on safe hematopoietic stem ce ll (HSC) cryopreservation and storage, Several successful methods for cryopreservation and storage have been established and are commonly us ed all over the world, However, little is known about the effects of l ong-term cryopreservation on the capacity to sustain a complete immuno hematopoietic engraftment, Several authors have investigated stem cell viability after cryopreservation and storage for more than 5 years an d reported preclinical good viabilities in terms of dye-exclusion or c olony-forming capability in vitro. Only two studies using BM cryoprese rved for more than 5 years for transplantation are reported, but they did not provide proof of trilineage engraftment. In February 1997 at o ur institution, a patient with relapsed non-Hodgkin's lymphoma underwe nt ABMT with BM harvested in February 1990, He achieved a granulocyte count >500 x 10(6)/L on day 21 and a self-supporting platelet count >2 0 x 10(9)/L on day 30, After day 29, his hemoglobin level was satisfac tory without need of transfusion support. This successful trilineage e ngraftment with cryopreserved BM that had been stored for 7 years sugg ests that HSC are able to maintain their capability to reconstitute he matopoiesis for a long time.