Cytogenetic studies in 45 patients with acute lymphocytic leukemia

The chromosomes of bone marrow and peripheral blood were studied in 45 unselected patients with acute lymphocytic leukemia. Eighteen had no detectable chromosome abnormality in either leukemic or somatic cells. Five of these had detectable Philadelphia chromosome-positive cells after receiving leukocyte transfusions from chronic myelocytic leukemia donors. Six others, who had no abnormalities of their cells, were studied only in remission. Three patients had congenital cytogenetic abnormalities. Five had a wide range of chromosome distribution associated with intensive chemotherapy. These chromosome abnormalities readily reverted in 2 of these 5 patients with cessation of therapy. Thirteen subjects had cytogenetic abnormalities in their leukemic cells. These consisted of aneuploid cell lines found more frequently during the final 2 months of the patient's life than during the initial 6 weeks of illness. In these individuals, there was no apparent relationship between chromosome abnormalities and therapy. Once these abnormalities appeared, they tended to persist. None of these patients had the same chromosomal abnormalities; therefore, no unique chromosomal abnormalities were found in acute lymphocytic leukemia. These aneuploid cell lines probably represent selected outgrowth of abnormal cells during the disease. In all our patients, including those on intensive chemotherapy, the incidence of minor and major chromosome aberrations was not significant.