During serial studies of serum muramidase activity (SMA) over a 4-year period on 168 patients with leukemia and myeloproliferative disorders (MPD) eight p a t i e n w n e with polycythemia Vera (PCV), one with agnogenic myeloid metaplasia, three with atypical myeloid metaplasia, and three with chronic myelogenous leukemia-developed acute myeloblastic or acute myelomonocytic leukemia (AMML). Onset of leukemia occurred early during the course of the disease and was associated with striking elevation of SMA in all six patients with AMML. Three patients studied in detail had significant hypokalemia possibly related to toxic effects of an excess of muramidase on renal tubules. Seven of the eight patients received therapy, consisting of splenic irradiation, alkylating agents, or both. R a p i d rise of SMA in patients with M P D may herald the onset of acute leukemic metamorphosis.
were carried out on 168 patients with leukemia and a variety of myeloproliferative disorders.20 Among the cases, there were three with chronic myelogenous leukemia, one with polycythemia Vera, and four with myeloid metaplasia in which transition to acute myeloblastic or acute myelomonocytic leukemia took place. Studies on these eight patients are presented with detailed serial observations in three cases terminating in acute myelomonocytic leukemia. Acute leukemic transition in the latter three cases was associated with striking elevation of SMA and marked muramidasuria.