title: Colony formation by megakaryocyte progenitors in myelodysplatic syndromes.
abstract: In vitro megakaryocytic colony formation by progenitors from the bone marrow was studied in 40 myelodysplastic syndrome patients. Megakaryocytic colonies were decreased in number or absent in 30 patients; only 10 showed normal colony growth. The growth correlated to some extent with the FAB-class. Patients with normal colony formation had either RA or RARS, but also in these two FAB-types half of the patients showed reduced megakaryocytic colony formation. Only 1 out of 15 patients with RAEB or RAEBt had normal megakaryocyte growth. The patients with CMML did not show any megakaryocytic colonies. The growth of erythroid colonies was normal in 3 patients and reduced or absent in the others. All 3 with normal erythroid colony formation also showed normal megakaryocyte growth, and all patients with normal megakaryocyte colony formation also had normal granulocyte-macrophage colony growth. Granulocyte-macrophage colony and cluster formation was normal in 17 patients. Defective formation of megakaryocytic, erythroid, and granulocyte-macrophage colonies was seen in 22 patients, compatible with a defect in a pluripotent stem cell. Megakaryocytic colony formation had no obvious correlation with any specific chromosome abnormality, and the distribution of the growth patterns was almost similar in patients with a normal and those with an abnormal karyotype.
authors.affiliation: Third Department of Medicine, University of Helsinki, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Juvonen
authors.forename: S
authors.initials: S
authors.lastname: Partanen
authors.forename: S
authors.initials: S
authors.lastname: Knuutila
authors.forename: T
authors.initials: T
authors.lastname: Ruutu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000753:Anemia, Refractory / Q000473:pathology; D000754:Anemia, Refractory, with Excess of Blasts / Q000473:pathology; D000756:Anemia, Sideroblastic / Q000473:pathology; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D003114:Colony-Forming Units Assay; D005260:Female; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006801:Humans; D007621:Karyotyping; D015477:Leukemia, Myelomonocytic, Chronic / Q000473:pathology; D008297:Male; D008533:Megakaryocytes / Q000473:pathology*; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000235:genetics / Q000473:pathology*; D010976:Platelet Count