Erythroid blast crisis in chronic myelogenous leukemia.

Blood or bone marrow specimens from 22 patients with chronic myelogenous leukemia in blast crisis were studied for the surface expression of glycophorin-A, a marker for early erythroid differentiation. The leukemic blasts were stained with rabbit anti-glycophorin-A antiserum. The glycophorin-A molecules detected by the rabbit antiserum were identified by polyacrylamide slab gel electrophoresis of the immunoprecipitates from the membrane lysates of surface-labeled blasts. Blasts expressing surface glycophorin-A were found in 9 of the 22 patients. In 4 patients, almost all blasts were glycophorin-A positive, and in 5 patients, less than half of the blast population expressed glycophorin-A. The present study shows that when glycophorin-A is used as a marker for erythroid blasts, involvement of the erythroid lineage during blast crisis of chronic myelogenous leukemia seems to occur more frequently than previously recognized.