Lineage ambiguity in acute leukemia.

Two cases of acute nonlymphocytic leukemia that showed surface phenotypes characteristic of lymphoid cells are reported. The cases, both involving female patients were studied by a variety of methods including flow cytometry and karyotyping. In Case 1, the patient, a 10-year-old girl, had poorly differentiated myeloblasts (FAB M1), which were weakly positive for Sudan black B (SBB), but negative for alpha naphthyl acetate esterase (NAE) and naphthol ASD chloroacetate esterase (CAE). Myeloperoxidase was demonstrated ultrastructurally in some of the blasts. In Case 2, the 30-year-old patient had typical myelomonocytic leukemia (FAB M4), with SBB-, NAE-, and CAE-positive blasts. Both cases were negative for terminal deoxynucleotidyl transferase. Case 1 was negative for myeloid membrane markers, whereas Case 2 was strongly positive for My7 and My9. Surprisingly, both cases showed significant positivity for B-cell restricted antigens B1, B2, and B4. These findings suggest ambiguous or dual lineage, supporting the concepts that some leukemias could arise from a pluripotent hematopoietic progenitor cell (Case 1) or from cells that though differentiated in some respects, could still preserve some early antigens (Case 2).

Red blood cell distribution width index in some hematologic diseases.

The red blood cell distribution width index (RDW) was determined in a group of anemic male patients and normal male blood donors. Elevated mean RDW values were found in the anemic patients, with the highest value seen in sickle cell anemia, sickle cell-beta thalassemia, sickle cell trait, beta-thalassemia trait, and iron deficiency in decreasing order of magnitude. The mean RDW of the normal male subjects was 11.3. It was found that the RDW was proportional to the reticulocyte count, with the highest values in the patients with the highest reticulocyte count (sickle cell anemia). One clinical value of the RDW therefore may lie in its capacity for reflecting active erythropoiesis. For example, patients with normal or near-normal hemoglobin and with high RDWs may be suspected of having an elevated reticulocyte count that may indicate a hemoglobinopathy, such as sickle cell trait or thalassemia trait.