In this study it was aimed to differentiate stem cell, lymphocyte and lymphocyte subgroups in umbilical cord blood according to antigenic phenotypes and to determine the relative and absolute counts of these cells. Umbilical cord blood samples were collected from a total of 33 term newborns, 16 female (48.5%) and 17 male (51.5%), all of whom were born by spontaneous vaginal route without any complication during gestation or delivery. Lymphocyte and lymphocyte subgroups and CD34 stem cell ratios were detected by flow cytometry. Umbilical cord blood samples were compared with peripheral venous blood of 33 healthy adults and with bone marrow samples of 23 healthy adults regarding lymphocyte and lymphocyte subgroups, and CD34 stem cell, respectively. In umbilical cord blood, ratios of T cell, cytotoxic T cell and large granular lymphocytes were lower, and total B cell and T helper/suppressor ratios were higher in comparison to peripheral venous blood samples of adults (p<0.05). Numbers of all lymphocyte subgroups except for large granular lymphocytes were higher than those of the healthy adult samples because of the high number of leukocytes in umbilical cord blood (p<0.001). Ratio of CD34 stem cells in umbilical cord blood samples was higher than that of the samples of adult bone marrow (p<0.05). Significant absolute and relative differences were detected between the lymphocyte and lymphocyte subgroups of umbilical cord blood and peripheral adult venous blood, and umbilical cord stem cells and adult bone marrow.
Keywords: CD34+ stem cell, cord blood, lymphocyte subgroups
