Haematologica, Vol 89, Issue 1, 21-28
Copyright © 2004 by Ferrata Storti Foundation
Primitive hematopoietic stem cells shows a polyclonal pattern in myelodysplastic syndromes
F Guidetti,
S Grazioli,
F Capelli,
C Marini,
M Gallicchio,
D De Micheli,
L Castello,
PP Sainaghi,
GP Fra,
G Saglio,
and
GC Avanzi
Department of Medical Science, University of Piemonte Orientale Amedeo Avogadro Novara, Italy.
BACKGROUND AND OBJECTIVES: Clonal hematopoiesis is the hallmark of myelodysplastic syndromes, but the role played by pluripotent stem cells and progenitor cells in these disorders remains unclear. DESIGN AND METHODS: Eight female patients with myelodysplastic syndrome were studied. X-chromosome inactivation patterns were analyzed in peripheral blood granulocytes, T-lymphocytes, single colonies originating from bone marrow progenitors and pluripotent stem cells, using the human androgen receptor locus polymorphism assay. RESULTS: Granulocytes and progenitor cells were monoclonal in 7/8 cases. Immature stem cells showed a non-clonal pattern of X-inactivation and were detectable at diagnosis in the presence of clonal hematopoiesis. T-lymphocyte clonality was heterogeneous. INTERPRETATION AND CONCLUSIONS: In myelodysplastic syndromes, hematopoiesis may be dominated by a neoplastic clone by virtue of its biological advantage over a residual polyclonal, probably still normal, population of immature stem cells still able to grow in vitro.
