Carbonic anhydrase: a marker for the erythroid phenotype in acute nonlymphocytic leukemia.

Protein markers are often used to corroborate the morphological subtyping of hematopoietic malignancy. Most commonly, surface markers are used for the phenotyping of hematopoietic cells; however, internal proteins have also been used as markers. Glycophorin, hemoglobin A, hemoglobin F, and transferrin have all been used as markers for the erythroid phenotype. We have recently shown that carbonic anhydrase is constitutively and aberrantly expressed in two erythroleukemic cell lines. We here show that it is also present in high levels in primary erythroleukemic blasts and that it is a useful marker for the M6 phenotype when classifying acute nonlymphocytic leukemia.