Progenitor cell trafficking in physiologic conditions and in myeloproliferative diseases: quantification of CD34+ cells by polymerase chain reaction.
OBJECTIVE
Previous studies using flow cytometry have shown that CD34+ cell trafficking is increased in patients with chronic idiopathic myelofibrosis. Few data exist on physiologic CD34 + cell trafficking and the quantification of very low cell ranges requires reliable and sensitive measurement techniques. The aim of this study was to establish a quantitative polymerase chain reaction (PCR) technique for studying CD34+ cell trafficking in physiologic conditions, and in patients with myeloproliferative diseases.


METHODS
CD34+ cell trafficking was measured in 56 controls [(healthy controls (n=21), patients with ischemic cardiopathy (n=21), patients with secondary thrombocytosis or erythrocytosis (n=14)], and in 37 untreated patients with myeloproliferative diseases diagnosed according to the WHO-criteria [(essential thrombocythemia (n=10), polycythemia vera (n=14) and chronic idiopathic myelofibrosis (n=13)]. Quantitative PCR was used to determine CD34 mRNA expression in peripheral blood samples.


RESULTS
Physiologic CD34 mRNA expression ranges were determined in the healthy control group. Mean CD34 mRNA expression was within the physiologic range in patients with ischemic cardiopathy, secondary thrombocytosis or erythrocytosis, essential thrombocythemia and polycythemia vera (p=0.146), but was significantly increased in patients with chronic idiopathic myelofibrosis (p<0.001). When analyzed individually, 12/13 patients with chronic idiopathic myelofibrosis and 3/14 patients with polycythemia vera showed CD34 mRNA expression above the physiologic range.


CONCLUSIONS
This is a first report about CD34+ cell trafficking measured by quantitative PCR. Quantitative PCR is a reliable method suitable for the quantification of very low cell populations. Our study confirms the significant increase of CD34+ cell trafficking in patients with chronic idiopathic myelofibrosis, and in a subset of patients with polycythemia vera. Prospective studies are underway to characterize these circulating CD34+ cells and to investigate their role in the pathophysiology of myeloproliferative diseases.
Hematology Department, University Hospital Inselspital, CH-3010 Bern, Switzerland.
Elisabeth
E
Oppliger Leibundgut
Claudio
C
Brunold
Dorothee
D
Marti
Michael Peter
MP
Horn
Christian
C
Seiler
Verena
V
Schroeder
Jean-Paul
JP
Schmid
Andreas
A
Tobler
Caroline
C
Zwicky
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000096:biosynthesis*; D002469:Cell Separation / Q000379:methods*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000097:blood* / Q000175:diagnosis / Q000378:metabolism*; D011087:Polycythemia Vera / Q000097:blood / Q000175:diagnosis; D016133:Polymerase Chain Reaction / Q000379:methods*
D018952:Antigens, CD34