Clonal Diseases of the Myeloid Stem Cell Systems
The structure and kinetics of the hematopoietic stem cell compartment have long been the subject of considerable speculation. Based on morphologic observations of normal and abnormal human marrow and of a perturbed system in experimental animals, primarily the rabbit, in 1938, Downey  concluded there was a stem cell capable of giving rise to all hematopoietic tissue. He believed this cell in turn gave rise to a lymphoid stem cell and to a myeloid stem cell. The myeloid stem cell could give rise directly to erythroid, megakaryocytic and monocytic cell lines and in turn produced a tertiary stem cell which could generate neutrophils, eosinophils and basophils. With the development of functional assays for clonal cell growth in vivo and in vitro and through the use of chromosome marked clones this suggested structure has proved to be correct in substance although certain minor variations are indicated. Most definitive studies of the structure of the stem cell compartment are in mice  but, in general, the data generated in human diseases suggest that the human stem cell structure is the same as that of the mouse. In Fig. 1, one current “best guess” is shown. There seems little doubt that at least 3 concatenated precursor compartments exist for all myeloid cells. Whether there are still more intermediate stages and whether or not most cells forming colonies in vitro are stem cells (i.e. capable of self-replication) remain open question.
KeywordsAgar Leukemia Anemia Gall Neutropenia
Unable to display preview. Download preview PDF.
- 1.Downey, H. (ed.): Handbook of Hematology. Vol. 3. p. 2025. New York: Hafner Publishing 1938Google Scholar
- 8.Whang-Peng, J.: Cytogenetic studies on acute myelocytic leukemia. Blood 34,448 (1970)Google Scholar
- 9.Boggs, D. R.: Hematopoietic stem cell theory in relation to possible lymphoblastic conversion of chronic myeloid leukemia. Blood 44,499 (1974)Google Scholar
- 11.Fialkow. P. J.: Human myeloproliferative disorders: clonal origin in pluripotent stem cells. Proc. 5th Cold Spring Harbor Symposium (in press)Google Scholar
- 13.Wintrobe, M.M., Lee, R.E., Boggs, D.R., Bithel, T., Athens, J.W., Foerster, J.: Clinical Hematology (7th edition). Philadelphia: Lea and Febiger 1974Google Scholar