Preleukemic Acute Human Leukemia

During the past three years we have had the unusual opportunity to observe 12 patients for as long as 27 months prior to the development of acute myelogenous or stem cell leukemia. During the preleukemic phase, the transitional phase to acute leukemia, as well as thereafter until death, their clinical courses were recorded, frequent complete peripheral blood cell counts were made, and serial biopsies of the bone marrow and, in some cases, biopsies of liver and spleen were obtained. Interest in the preleukemic phase of human acute leukemia has been heightened by recent studies in induced mouse leukemia. In both humans1and mice, the disease is usually rapidly fatal, with only short remissions sometimes produced by steroid or antifolic acid therapy. In the mouse, however, treatment with cortisone in the preleukemic phase of the disease has been shown to decrease the incidence of leukemia induced by x-ray2and