[Expression of early hematopoietic markers in cord blood and mobilized blood]

G-CSF mobilized peripheral blood and cord blood are major sources of hematopoietic progenitor cells. These cells are characterized by the expression of "early" antigens. We have evaluated the coexpression of hematopoietic cell markers CD34, CD133, CD90, CDCP1, CD117 and activation antigen CD38 using multicolor flow cytometry. We show that (1) cells being positive for every single antigen form a separate population. (2) Percentage of cells expressing each "early" antigen are twice more in the cord blood than in the mobilized blood. The content of cells with complex progenitor phenotype (CD34+/CD38-/CD117, CD133+/CD34+/CD38-, CDCP1+/CD34+/CD38- etc.) is equal in mobilized and cord blood. (3) There are strong positive correlations between the expression of CD34, CD133, CD117 and CDCP1 in both groups. Positive correlation exists for CD90 with CD34, CD133, CDCP1 and CD117 only in cord blood and is not significant in mobilized blood. The analyses of early antigens coexpression with activation marker CD38 revealed that hypothesis on sequential activation and loss of expression of the aforementioned antigens is not confirmed. We assume that there is global regulation of the expression of CD34, CD133, CDCP1 and CD117. Yet expression of CD38 could be reversibly abolished during maturation of the hemapoetic cells and CD117 could be expressed not only on myeloid cells.