Minimal residual disease after allogeneic bone marrow transplantation for chronic myeloid leukaemia: a metaphase-FISH study.
Metaphase-FISH was adopted for the detection of proliferating Philadelphia-positive (Ph+) residual leukaemic cells in 25 patients with chronic myeloid leukaemia treated with allogeneic bone marrow transplantation (BMT). Patients were followed up during their clinical remission for 4-50 months (median 17 months) after BMT. 80 bone marrow samples were studied. For most of the cases no fewer than 1000 metaphases were analysed. Six patients (24%) showed residual Ph+ cells during the first 6 months and two others by the end of the first year after BMT. Three patients relapsed during the study and in two of them residual Ph+ cells were detected during the first 6 months after BMT. In 17 patients no Ph+ cells were detected at any stage of follow-up and 16 (94.1%) of them continue in complete clinical and haematological remission. Our results indicate that metaphase-FISH is a reliable tool in the quantitation of proliferating residual leukaemic cells. We suggest that consecutive findings of equal amounts of residual leukaemic cells do not necessarily predict a relapse. However, their presence calls for follow-up at shorter intervals where an increasing number of these cells predicts an ensuing relapse.
el-Rifai
W
W
Department of Medical Genetics, University of Helsinki, Finland.
Ruutu
T
T
Vettenranta
K
K
Temtamy
S
S
Knuutila
S
S
D000293:Adolescent; D000328:Adult; D016026:Bone Marrow Transplantation; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics / Q000628:therapy*; D008297:Male; D008677:Metaphase; D008875:Middle Aged; D018365:Neoplasm, Residual; D010677:Philadelphia Chromosome; D011379:Prognosis