An optimal technology for cell cycle analysis would allow the concomitant measurement of apoptosis, G0, G1, S, G2 and M phases in combination with cell surface phenotyping. We have developed an easy method in flow cytometry allowing this discrimination in an only two-color fluorescent plot. It is based on the concomitant use of 7-amino-actinomycin D and the antibodies anti-Ki67 and anti-phospho(Ser10)-histone H3, both conjugated to Alexa Fluor®488 to discriminate G0 and M phases, respectively. The method is particularly valuable in a clinical setting as verified in our laboratory by analyzing human leukemic cells from marrow samples or after exposure to cell cycle modifiers.

Summary. Some patients unexpectedly fail to mobilize sufficient numbers of haematopoietic progenitor cells (HPCs) into the peripheral blood for autologous transplantation. Considering the important role of the chemokine stromal cell-derived factor 1 (SDF-1) in HPC homing, we investigated a possible relationship between SDF1 gene polymorphism and HPC mobilization capacity in 63 patients with malignancy. Some 67% of the good mobilizers ($ 50 CD34 1 cells/ml) and only 36% of the intermediate/poor mobilizers were SDF1-3 0 A allele carriers (P 0´032). In multivariate analysis, the presence of the SDF1-3 0 A allele was the only factor predictive of good CD341 cell mobilization (P 0´025). This is the first report showing the involvement of genetic factors for HPC mobilization in humans and suggests a significant role for SDF-1 in this process.

ClinicalTrials.gov; No.: NCT01995448; URL: www.clinicaltrials.gov.

Chronic lymphocytic leukemia cell (CLL) usually (95%) express B-phenotype and the CD5 antigen which is usually present on the surface of normal T cells. However, among B CLL, 7 to 20% do not express CD5. The significance of the lack of CD5 expression remains unclear. We reviewed 42 consecutive CD5- B CLL seen in three French medical centers from 1985 to 1991 and compared them with 79 CD5+ B CLL. Immunophenotype studies were performed using indirect immunofluorescence under light microscopy as well as flow cytometry after 1988. B CLL was considered to be CD5 negative when less than 5% of mononuclear cells expressed CD5 after subtraction of the number of T-cells. Cases with CD5- B CLL had isolated splenomegaly more frequently (p = 2.10(-7)). They frequently expressed a higher level of surface immunoglobulin (S-Ig) or the switch mu/delta phenotype (p = 4.7 10(-2)). The median survival time was not reached but no significant difference between CD5 negative and positive B CLL was observed at the time of our data analysis (p = 0.97). Clinical presentation of CD5- B CLL seems to be different from other forms of B CLL. Although, no conclusion can be reached in terms of prognosis, CLL with low expression of CD5 should be regarded as a subtype of CLL with a different clinical presentation than CD5+ CLL.