CD7 expression by CD34+ cells in CML patients, of prognostic significance?
The purpose of the study was to identify a unique immunophenotype of normal or Philadelphia chromosome positive (Ph+) CD34+ cells that might be used to purify normal CD34+ cells from chronic myelogenous leukemia (CML) patients. An immunophenotypical study of CD34+ bone marrow cells of 20 patients with CML at diagnosis and during hydroxyurea treatment, and 39 controls were performed. All patients were Ph+, two patients had variant translocations and three patients displayed cytogenetic signs of clonal evolution. The immature progenitor cell compartment (CD34+ HLA-DR- and CD34+ CD38- cells) was comparable. The CD34+ AC133+ progenitor cell compartment was decreased in CML patients. We found no difference for any of the adhesion molecules examined except for CD62L, where the percentage of CD34+ CD62L+ cells was decreased in CML patients. The number of myeloid progenitors (CD34+ CD33+) was increased at the expense of B-lymphoid progenitors (CD34+ CD10+ and CD34+ CD19+) in CML patients indicating that B-lymphopoiesis is inhibited in CML. The megakaryocytic (CD34+ CD61+) and erythroid (CD34+ CD71+) progenitors were increased in CML patients. The number of CD34+ CD7+ cells was also significantly increased (mean 25.3% vs. 4.9%). However, the level of CD7 expression was quite heterogeneous, and the patients could be separated into two populations according to CD7 expression (more or less than 20% CD7+ CD34+ cells). The Sokal and Hasford risk scores did not differ between CD34+ CD7- CML and CD34+ CD7+ CML, but all patients with signs of disease progression clustered in the CD34+ CD7+ population indicating that the level of CD7 expression on CD34+ cells may be of prognostic importance in CML.
Normann
Are P
AP
Institute of Immunology, Rikshospitalet University Hospital, Oslo, Norway. a.p.normann@labmed.uio.no
Egeland
Torstein
T
Madshus
Inger H
IH
Heim
Sverre
S
Tjønnfjord
Geir E
GE
D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000096:biosynthesis*; D019011:Antigens, CD7 / Q000096:biosynthesis*; D002448:Cell Adhesion; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D019041:L-Selectin / Q000096:biosynthesis; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013234:Stem Cells / Q000166:cytology; D013997:Time Factors; D014407:Tumor Cells, Cultured
D018952:Antigens, CD34; D019011:Antigens, CD7; D019041:L-Selectin; D006918:Hydroxyurea