Quantification of circulating endothelial cells in peripheral blood of systemic lupus erythematosus patients: a simple and reproducible method of assessing endothelial injury and repair.
BACKGROUND
Quantification of circulating endothelial cells (CECs) in peripheral blood is developing as a novel and reproducible method of assessing endothelial damage/dysfunction. Accordingly, elevated levels of CECs may be a marker of vascular injury in systemic lupus erythaematosus (SLE). This study was undertaken to assess the blood level of CECs in SLE and to correlate its level with the activity of the disease and to find out the possibility that the presence of increased numbers of CECs can be used as a marker of immune-mediated vessel damage.


METHODS
The study included 33 patients with SLE and 20 healthy controls. They were subjected to clinical examination together with laboratory investigations including complete blood count (CBC), erythrocyte sedimentation rate (ESR), urine analysis, renal function test, C3, C4, ANA, anti-ds DNA antibody, antiphospholipid (IgM and IgG) antibodies and quantification of CECs in blood. CECs were calculated using flow cytometry after staining with a mouse anti-human CD45 antibody (pan-leukocyte marker), mouse anti-human CD146 antibody (endothelial cell marker) and 7-amino-actinomycin D (7-AAD) viability marker. CECs were defined as the live cells with 7-AAD negative, CD45 negative and CD146 positive.


RESULTS
The number of CECs was significantly higher in patients with SLE compared with those in healthy control (mean +/- SD 38.6 +/- 21.2 versus 7.4 +/- 3.4). Furthermore, CECs were correlated positively with SLE disease activity index (SLEDAI) score, ESR and anti-ds DNA. CECs from patients with vasculitic skin lesions, renal and central nervous system (CNS) manifestation were significantly higher than patients free from the previous signs.


CONCLUSIONS
An increased number of CECs observed in patients with SLE was associated with the active phase of the disease and may represent a marker of widespread endothelial injury.
Elshal
Mohamed
M
Department of Molecular Biology, Genetic Engineering and Biotechnology Institute, Minoufiya University, Egypt.
Abdelaziz
Abeer
A
Abbas
Ayman
A
Mahmoud
Khaled
K
Fathy
Hanan
H
El Mongy
Shaimaa
S
El-Basyuoni
Shereif
S
Ahmed
Hamada
H
McCoy
Philip
P
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D015415:Biomarkers / Q000097:blood; D051929:CD146 Antigen / Q000097:blood; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000276:immunology / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014652:Vascular Diseases / Q000097:blood* / Q000209:etiology / Q000473:pathology*; D055815:Young Adult
D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D051929:CD146 Antigen