Circulating Angiogenic T Cells and Their Subpopulations in Patients with Systemic Lupus Erythematosus

OBJECTIVE Systemic lupus erythematosus (SLE) is associated with accelerated atherosclerosis and increased cardiovascular risk. Angiogenic T cells (Tang), a specific T cell subset, have been identified and involved in the repair of damaged endothelium. This study aimed to analyze the Tang cell subsets in relation to disease specific features from SLE patients. METHODS Tang cell subsets were assessed in peripheral blood samples from 41 SLE patients and 22 healthy controls (HC) by flow cytometry on the basis of CD31 and CXCR4 expression on CD3+, CD4+, and CD8+ T cells. RESULTS The percentage of circulating CD8+CD31+CXCR4+ T cells (CD8+ Tang), but not CD3+CD31+CXCR4+ T cells (Tang) and CD4+CD31+CXCR4+ T cells (CD4+ Tang), in SLE was higher than HC. The percentages of Tang cell subsets in anti-dsDNA-positive SLE patients were significantly increased as compared to their negative counterparts and HC. Additionally, the levels of circulating Tang cell subsets were negatively correlated with age at sampling and at diagnosis, but not disease duration or disease activity. CONCLUSION Anti-dsDNA-positivity may identify a group of SLE patients with increased Tang cell subsets and circulating CD8+ Tang cells may be viewed as a potentially useful biomarker of endothelial damage and cardiovascular risk in SLE.