BACKGROUND: Mesenchymal stromal cells, MSCs, show expression of specific antigens on their surface. The aim of the study is to assess the phenotype of stem cells like isolated from the umbilical cord with respect to the presence of surface antigens CD34, CD90, and CD105 and differences in the expression of surface antigens in cells isolated from freshly sampled material in comparison with the phenotype of cells from in vitro culture.

MATERIAL AND METHODS: Stem cells collected from the umbilical cord from healthy patients and then cultured in vitro. To assess the phenotype of stem cells, cytometric analysis was carried out. To assess the phenotype of cells we used fluorescently labelled monoclonal antibodies: APC Mouse anti-human CD34, PC5 Mouse anti-human CD90 and PE Mouse anti-human CD105.

RESULTS: In the case of cells from the umbilical cord and then cultured in vitro for the period of 10–14 days CD34 expression is lower (69,5%) in comparison with the group of cells not cultured. Not cultured cells were demonstrated 37% of cells co-expression of antigens CD34 and CD105, over 21% of CD34/CD90 cells and over 24% of CD105/CD90. Cultured cells group was showed higher percentage of CD90, CD105, CD34/CD105, CD34/CD90, CD105/CD90 in comparison with not cultured cells.

CONCLUSIONS: Our reults suggested that adherent cells population from umbilical cord, demonstrate CD34 expression In vivo. Moreover, the phenotype of MSCs, mainly in the context of CD34 expression, may vary depending on the place of collection of cells and the length of growing the cell culture.

Keywords: Antigens, CD34, Antigens, Thy-1, mesenchymal stromal cells, Umbilical Cord