Preleukemia manifested by hemolytic anemia with pyruvate-kinase deficiency.

A 27-year-old patient manifested severe hemolytic anemia during a preleukemia phase. Low levels of adenosine triphosphate and decreased activity of pyruvate kinase were found. Acute myeloblastic leukemia developed in this patient 20 months later. The case suggests that acquired enzyme deficiency may play a role in the development of anemia in the preleukemic state.