Angiogenesis is increased in B-cell chronic lymphocytic leukemia (B-CLL). We wanted to quantify and characterize the circulating endothelial cells (CECs) in patients with B-CLL and correlate with plasma angiogenesis-related factors. Using a four-color flow cytometry, we prospectively analyzed the CEC in the whole blood of 20 healthy controls and 20 patients with B-CLL. We quantified (CD45-/CD31+/CD146+) and characterized the CECs according to whether they were apoptotic (annexin stain) or activated (CD106+). We also measured plasma levels of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and thrombospondin-1 (TSP-1). Most patients (90%) had Rai stages 0-2 at the time of diagnosis. As a group, B-CLL patients had higher number of CECs (median of 26.5 cells/ml) compared (P = 0.04) to healthy controls (18.5 cells/ml). However, only four (20%) patients had elevated CEC counts, defined as ≥2 SD of the control mean (≥53 cells/ml). The proportions of apoptotic (P = 0.83) and activated (P = 0.12) CECs were similar in both groups. B-CLL patients had higher FGF-2 (P < 0.001), lower TSP-1 (P = 0.004), and similar VEGF (P = 0.27) plasma levels. The number of CECs was not associated with Rai stage, absolute lymphocyte count, or levels of angiogenesis-related factors. CECs are increased in only a small fraction of B-CLL patients in our cohort with low rates of apoptosis and activation. While no correlation was found between CECs and clinical features, more studies in a larger patient sample size and advanced disease are necessary.
|Original language||English (US)|
|Number of pages||5|
|Journal||Annals of Hematology|
|State||Published - May 2008|
Bibliographical noteFunding Information:
Supported by the Gundersen Lutheran Center for Cancer and Blood Disorders and the Gundersen Lutheran Medical Foundation.
The Greater Richland Area Cancer Elimination (GRACE), Inc. and the Gundersen Lutheran Medical Foundation funded this study. R.S.Go(*).L.A.Meyer.W.A.Bottner.C.E.Cole. J. P. Farnen.K. A. Frisby Center for Cancer and Blood Disorders, Gundersen Lutheran Health System, 1900 South Avenue, Mail Stop: EB2-001, 54601 La Crosse, Wisconsin, USA e-mail: firstname.lastname@example.org