Circulating endothelial cells in patients with chronic lymphocytic leukemia.
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.
Go
Ronald S
RS
Center for Cancer and Blood Disorders, Gundersen Lutheran Health System, 1900 South Avenue, Mail Stop: EB2-001, 54601 La Crosse, WI, USA. rsgo@gundluth.org
Jobe
Dean A
DA
Asp
Krista E
KE
Callister
Steven M
SM
Mathiason
Michelle A
MA
Meyer
Lori A
LA
Bottner
Wayne A
WA
Cole
Craig E
CE
Farnen
John P
JP
Frisby
Kathleen A
KA
D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D051929:CD146 Antigen; D016022:Case-Control Studies; D042783:Endothelial Cells / Q000166:cytology*; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000097:blood; D005434:Flow Cytometry; D006801:Humans; D015448:Leukemia, B-Cell / Q000097:blood*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood*; D017493:Leukocyte Common Antigens; D008297:Male; D008875:Middle Aged; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011446:Prospective Studies; D019700:Thrombospondin 1 / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
D051929:CD146 Antigen; C497902:MCAM protein, human; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D019700:Thrombospondin 1; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; D017493:Leukocyte Common Antigens