Comparison of Chromosome Constitution in Chronic Myelocytic Leukemia and Other Myeloproliferative Disorders

Abstract

The frequency of the Ph1 chromosome in freshly aspirated marrow cells of 14 patients with typical chronic myelocytic leukemia processed by a "direct technic" without resort to culture or colchicine was significantly higher (> 75 per cent) than that observed in the cultured blood cells (< 35 per cent) of the same subjects. The karyotypic abnormally of the abbreviated G-group chromosome would appear not to be related to therapy, since the frequency with which it occurred was not materially affected by treatment (including radiation). The Ph1 chromosome was not observed in any of the metaphases of blood or marrow of 12 subjects who had developed a leukemia-like picture complicating either myelofibrosis, polycythemia vera or myeloid metaplasia. A new chromosome abnormality—a shortened D-group chromosome—was observed with about the same frequency in the blood and marrow metaphases of a female patient with treated chronic myelocytic leukemia. This new karyotypic abnormality was associated with the highest frequency of the Ph1 chromosome in cultured blood cells in the group studied. The Ph1 chromosome was observed in the metaphases of a patient with the blastic phase of chronic myelocytic leukemia. The variations of the morphology of the Ph1 chromosome are discussed and illustrated, especially in relation to the Y-chromosome. In four patients with an atypical picture of CML, the Ph1 chromosome was not observed either in the marrow or cultured blood.

Coexistent Lymphosarcoma and Chronic Granulocytic Leukemia.

“…Finally, there exists the possibility of a relationship between the radiotherapy for the lymphosarcoma and tlie later development of leukemia, hardly a new concept in the pathogenesis of leukemia. Of interest in this rep r d are reports from Englandlg and the United Statess, 15 which stress the high incidence of prior radiotherapy in Phl chromosome negative cases of chronic granulocytic leukemia and, indeed, our case seems to represent another example of this correlation.…”

An Improved Method of Processing Bone Marrow for Chromosomes

“…(Tjio & Wang 1962). Sandberg et al (1962) did not use any. We found that while there was no appreciable difference between colchicine and colcemid, a high concentration of either yielded fewer mitotic figures as well as overcontracted chromosomes.…”

Chromosomal Differences Among the Acute Leukemias*

“…Similar obesrvations have been described for the incidence of the Phl chromosome in C M L before and after therapy. 2 The fuzzy and ill-defined appearance of acute leukemic chromosomes often makes it possible to identify the leukemic metaphases in marrow with great ease. This appearance contrasts with the well-defined cells of the marrow.…”