CD7 expression by CD34+ cells in CML patients, of prognostic significance?

• Published in: European journal of haematology Vol. 71; no. 4; pp. 266 - 275
• Main Authors: Normann, Are P., Egeland, Torstein, Madshus, Inger H., Heim, Sverre, Tjønnfjord, Geir E.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Munksgaard International Publishers 01.10.2003; Blackwell
• Subjects: Adult; Aged; Antigens, CD34 - biosynthesis; Antigens, CD7 - biosynthesis; Biological and medical sciences; CD34+ cells; CD7; Cell Adhesion; chronic myelogenous leukemia; Female; Flow Cytometry; flowcytometry; Hematologic and hematopoietic diseases; Humans; Hydroxyurea - pharmacology; Immunophenotyping; In Situ Hybridization, Fluorescence; L-Selectin - biosynthesis; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - diagnosis; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - immunology; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Male; Medical sciences; Middle Aged; progenitor cells; Prognosis; Stem Cells - cytology; Time Factors; Tumor Cells, Cultured; Human; Flow cytometry; flowcytometry; Prognosis; Precursor cell; Hematopoietic cell; Clinical form; chronic myelogenous leukemia; progenitor cells; Malignant hemopathy; Myeloproliferative syndrome; Chronic; Fluorescence in situ hybridization; Chronic myelocytic leukemia; CD7; Cytogenetics; Genetics; Molecular biology; CD34+ cells
• ISSN: 0902-4441; 1600-0609
• DOI: 10.1034/j.1600-0609.2003.00133.x

:  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.