Analysis of progenitor cell involvement in B-CLL by simultaneous immunophenotypic and genotypic analysis at the single cell level.
B-cell chronic lymphocytic leukaemia (B-CLL) results from the clonal expansion of mature B lymphocytes. The detection of leukaemia-associated genetic markers in CD34-positive progenitor cells in a subset of B-CLL patients suggests that malignant transformation in B-CLL occurs in an immature progenitor cell compartment. To further quantify the percentage of B-CLL patients with genetically aberrant progenitor cells we have investigated CD34+ bone marrow cells in 11 B-CLL patients at the single cell level by simultaneous genetic and immunophenotypic analysis (FICTION). In five patients with trisomy 12, CD34+ haemopoietic progenitor cells were detectable on bone marrow smears. In one patient with trisomy 12, CD34+ progenitor cells were isolated by FACS sorting. In all six patients trisomy 12 was not found in the CD34+ cells. Progenitor cells were also analysed in three patients with Rb-deletion and in two patients with deletion of p53. In all patients the genetic marker was not detected in the CD34+ cells. In conclusion, we did not find genetically aberrant progenitor cells in this group of B-CLL patients. These results suggest that the subset of B-CLL patients with genetically aberrant CD34+ cells may be very small. This is of significance for our understanding of B-CLL biology and for future strategies using autologous stem cell transplantation.
Gahn
B
B
Department of Haematology and Oncology, University of Göttingen, Germany.
Wendenburg
B
B
Troff
C
C
Neef
J
J
Grove
D
D
Haferlach
T
T
Hiddemann
W
W
Wörmann
B
B
D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000473:pathology*; D014314:Trisomy
D018952:Antigens, CD34