title: Abnormal megakaryopoiesis in patients with myelodysplastic syndromes: analysis of cellular and humoral defects.
abstract: In 13 patients with myelodysplastic syndrome (MDS) mature and immature erythropoietic (CFU-E, BFU-E), granulopoietic (CFU-GM) and megakaryopoietic (CFU-Meg) colony formation from human bone marrow mononuclear cells was evaluated in a microagar culture system. All but three patients exhibited abnormal CFU-Meg. The defect of CFU-Meg paralleled the reduction of BFU-E, whereas CFU-GM number declined to a lesser extent. Not only the CFU-Meg number, but also the number of megakaryocytes (Mk) per colony was reduced suggesting an additional functional CFU-Meg defect. Megakaryocytic growth factor (Meg-CSF) abnormalities in MDS patients were detected using normal nonadherent T-lymphocyte depleted bone marrow cells as target cells for serum testing. Even for sera from patients with a reduction of platelets and bone marrow megakaryocytes Meg-CSF levels were not increased. No cellular or humoral inhibition could be detected in an MDS patient with a 5q- karyotype, who had an isolated defect of the megakaryocytic cell lineage at presentation. Some patients revealed a spontaneous formation of mixed erythrocytic, granulocytic and megakaryocytic clusters in the presence of fetal calf serum or autologous patient serum, probably representing autonomous proliferation of the malignant clone. In conclusion, both cellular and humoral factors can cause abnormalities of the megakaryocytic cell lineage in MDS patients.
authors.affiliation: Department of Internal Medicine, University of Innsbruck, Austria.
authors.forename: D
authors.initials: D
authors.lastname: Geissler
authors.forename: H
authors.initials: H
authors.lastname: Zwierzina
authors.forename: C
authors.initials: C
authors.lastname: Pechlaner
authors.forename: S
authors.initials: S
authors.lastname: Gaggl
authors.forename: F
authors.initials: F
authors.lastname: Schmalzl
authors.forename: G
authors.initials: G
authors.lastname: Konwalinka
authors.forename: H
authors.initials: H
authors.lastname: Braunsteiner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003114:Colony-Forming Units Assay; D005260:Female; D006133:Growth Substances / Q000097:blood; D006410:Hematopoiesis; D016298:Hematopoietic Cell Growth Factors; D006412:Hematopoietic Stem Cells / Q000473:pathology; D006801:Humans; D008297:Male; D008533:Megakaryocytes / Q000473:pathology*; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000097:blood / Q000473:pathology*; D013601:T-Lymphocytes / Q000502:physiology
chemical_list: D006133:Growth Substances; D016298:Hematopoietic Cell Growth Factors