DETECTION OF OCCASIONAL AND CLONAL CHROMOSOME-ABERRATIONS IN PATIENTSWITH ACUTE NONLYMPHOCYTIC LEUKEMIA AFTER AUTOLOGOUS BONE-MARROW TRANSPLANTATION

Clonal chromosome aberrations observed in patients who have relapsed a fter autologous bone marrow transplantation (ABMT) are usually related to the cytogenetic abnormalities observed at diagnosis, In order to a ssess this relationship, we evaluated 30 acute non-lymphocytic leukemi a (ANLL) patients who underwent ABMT at our institution and had evalua ble serial cytogenetic studies before and after ABMT, Seventeen patien ts (57%) showed no chromosome aberrations after ABMT in any of the stu dies performed, while 13 patients (43%) carried abnormalities, In eigh t out of 30 patients (27%) the abnormal karyotype after ABMT was assoc iated with hematologic relapse, The cytogenetic abnormalities were: (1 ) the same as at diagnosis without additional abnormalities in five pa tients; (2) the same as at diagnosis but with additional abnormalities in three patients, In one patient a different karyotype from that of diagnosis was detected and a myelodysplastic syndrome was clinically e valuable, Furthermore, occasional and single cell chromosome abnormali ties were observed in four patients (13%), none of whom relapsed, The new and additional clonal cytogenetic abnormalities observed after ABM T were found in eight patients (27%), suggesting that this event may n ot be so frequent, that is presumably associated with the busulphan an d cyclophosphamide conditioning regimen, The re-appearance of the chro mosome aberrations after ABMT and the relationship with the risk of re lapse are discussed.