Prospective identification of erythroid elements in cultured peripheral blood

We have developed a prospective approach to identify the generation of eryt hroid cells derived from cultured peripheral blood mononuclear cells (PBMC) by monitoring the expression of the cell surface protein CD48, Unpurified populations of PBMC obtained from the buffy coats of normal volunteers Here grown in suspension culture in the absence or presence of erythropoietin. A profile of surface CD48 expression permitted a now cytometric identificat ion of erythropoietin responsive populations at various stages of their mat uration. In the absence of erythropoietin (EPO) supplemented media, the CD- 48(-) cells represented <5% of the total population of PBMC remaining in cu lture, In cultures supplemented with 1 U/mL EPO, the mean percentage of CD4 8(-) cells increased to 33.7 + 14.9%, (p < 0.01) after 14 days in culture, Coordinated CD34 and CD71 (transferrin receptor) expression, morphology. ga mma-globin transcription, and colony formation in methyl-celluose were obse rved during the 14-day culture period. Flea cytometric monitoring of bulk c ultured PBMC provides a simple and reliable means for the prospective or re al-time study of human erythropoiesis. (C) 1999 International Society for E xperimental Hematology. Published by Elsevier Science Inc.