Cellular and Molecular Biology


Human megakaryocyte ploidy

Y. Kobayashi and M. Kondo

First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kamigyo-ku Kyoto, Japan

Offprint requests to: Dr. Yutaka Kobayashi, First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajiicho 465, Kamigyo-ku, Kyoto, Japan. Fax: +81-75-252-3721. e-mail: kobataka@koto.kpu-m.ac.jp


Summary. We reviewed the literature concerning the history of determination of the ploidy of human mega-karyocytes and its relationship with diseases. The ploidy of rabbit megakaryocytes was analyzed by microspectro-photometry in 1964, and the analysis of the ploidy in human megakaryocytes was first performed in 1968. Presently, microphotometry and flow cytometry are the primary methods for the evaluation of the ploidy, but they have their merits and demerits. In the ploidy of human megakaryocytes, a peak has often been reported at 16N in healthy individuals, and the next peaks have been observed at 32N and 8N. The results of ploidy analyses have been reported by many investigators to be comparable between patients with idiopathic thrombo-cytopenic purpura and normal subjects, but various shifts of the peaks have also been documented. The ploidy is often reported to shift to a larger ploidy class in poly-cythemia vera and essential thrombocythemia, but it has invariably been reported to shift to a smaller class in chronic myelogenous leukemia. In reactive thrombo-cytosis, the ploidy pattern was reported to be the same as that in normal individuals by some investigators but to shift to a larger ploidy by others. These differences are considered to be due to heterogeneity of the subjects. In myelodysplastic syndrome, the ploidy shifts mostly to a smaller class, but it may show various patterns. We also reviewed the ploidy in other rare hematological disorders, the relationships of the ploidy with diabetes mellitus and atherosclerotic disorders, and its changes in the ontogeny. Details of the mechanism of polyploidi-zation and its biological significance remain unknown, and further advances in the studies of these topics are anticipated. Histol. Histopathol. 14, 1223-1229 (1999)

Key words: Megakaryocyte ploidy, Microfluorometry, Thrombocytopenia, Thrombocytosis

DOI: 10.14670/HH-14.1223