GpA measurement in erythroblasts.

Representative flow cytometry of GpA expression levels measured via a PE-conjugated antiserum in bone marrow erythroblasts purified from marrows of MM patients with active disease and severe anemia (group A) or with preserved erythropoiesis (group B). Group A patients display a preponderance of immature (GpA^+dim) erythroblasts, with a lack of mature (GpA^+bright) erythroblasts, as compared to the considerable peak of mature cells in both group B patients. Pt indicates patient.