Twelve patients with chronic granulocytic leukemia were examined for the presence of the Ph1 chromosome abnormality at various stages of their disease. The abnormality was demonstrated either in the blood or marrow of all patients. Patients in relapse showed very high numbers of Ph1-positive mitoses in both blood and marrow; those in remission showed relatively few or no positives in the blood but sizeable numbers in the marrow. There was a positive correlation between the degrees of abnormality of blood and marrow on the one hand, and the percentage of Ph1-positive mitoses on the other. Direct examination of the marrow for the demonstration of the Ph1 appeared of particular value in the acute phase of chronic granulocytic leukemia.
It seemed likely that therapy depressed the number of abnormal (Ph1-positive) mitoses. There was, however, no evidence that these ever disappeared from the marrow, even in complete remission.
The findings presented and those in the literature did not make it possible to decide in what way the Ph1 chromosome abnormality is related to the onset of leukemia.