Primitive hematopoietic stem cells shows a polyclonal pattern in myelodysplastic syndromes.
OBJECTIVE
Clonal hematopoiesis is the hallmark of myelodysplastic syndromes, but the role played by pluripotent stem cells and progenitor cells in these disorders remains unclear.


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.


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.
Guidetti
Francesca
F
Department of Medical Science, University of Piemonte Orientale Amedeo Avogadro Novara, Italy.
Grazioli
Sandra
S
Capelli
Francesca
F
Marini
Claudia
C
Gallicchio
Margherita
M
De Micheli
Daniela
D
Castello
Luigi
L
Sainaghi
Pier Paolo
PP
Fra
Gian Paolo
GP
Saglio
Giuseppe
G
Avanzi
Gian Carlo
GC
D000368:Aged; D000369:Aged, 80 and over; D000753:Anemia, Refractory / Q000235:genetics / Q000473:pathology; D000754:Anemia, Refractory, with Excess of Blasts / Q000235:genetics / Q000473:pathology; D001854:Bone Marrow Cells / Q000473:pathology; D018929:Cell Culture Techniques; D041321:Chromosomes, Human, X / Q000235:genetics; D002999:Clone Cells / Q000473:pathology*; D019175:DNA Methylation; D004303:Dosage Compensation, Genetic; D005260:Female; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000473:pathology; D009190:Myelodysplastic Syndromes / Q000235:genetics / Q000473:pathology*; D009504:Neutrophils / Q000473:pathology; D010641:Phenotype; D039904:Pluripotent Stem Cells / Q000473:pathology; D013234:Stem Cells / Q000473:pathology