Human fetal liver and spleen (Cell composition)

Cell composition has been studied in hepatic reprints of 76 human fetuses between 6-27 weeks of development. Erythropoiesis predominates during the whole period of hepatic hemopoiesis. During 6-7 weeks primary erythroblasts make 25% of all erythroid cells, and by the 22d-27^th weeks their content does not even reach 1,5%. Content of neutrophilic leucocytes is 1 - 1,5%. Nondifferentiated blast cells make 2,9±0,5 - 5,1±0,1%. Their greatest amount is observed between 6-8 and 18 and more weeks. The cell composition of the fetal spleen has been studied in 10 fetuses 19-25-week-old. Lymphoid forms make 85% of all cells of the organ’s hemopoietic tissue, of them 2,9±0,4% are lymphoblasts, 0,3±0,1% - nondifferentiated blasts. The investigations studying colonyforming properties of the hematopoietic cells confirmed that the highest content of myeloid precursors in the fetal liver and spleen is noted between 9-21 weeks of age. Therefore, it is possible to expect the greatest effect of these organ's transplantation during this time.