Low circulating level of CD133+KDR+cells in patients with systemic sclerosis

Abstract

Background: Results of previous studies on the level of circulating endothelial progenitor cells (EPCs), which are involved in vascular repair, in scleroderma (SSc) patients have been controversial. Objectives: To enumerate circulating EPC subsets and to examine their relation with endothelial dysfunction, biochemical markers of endothelial injury and vascular outcome in SSc patients. Methods: Enumeration of circulating CD34+KDR+ and CD133+ KDR+ EPCs was performed by flow cytometry. Endothelium-dependent vasodilation was evaluated by changes in flow-mediated dilation (FMD%) in the brachial artery. Serum level of vascular endothelial growth factor (VEGF) was measured by enzyme linked immunosorbent assay. Results: SSc patients (n=52) were found to have significantly lower CD133+KDR+EPCs (3.0 vs. 7.0/μl, p<0.001) as well as FMD% (4.8% vs. 7.8%, p<0.001) compared with ageand sex-matched controls (n=52). Among patients who had no concomitant cardiovascular risk factors (n=28), CD133+KDR+ EPC level was significantly lower than controls (3.8 vs. 7.3/μl, p =0.001) and correlated modestly with FMD% (r=0.29, p=0.03). Disease duration was the only determining factor identified for circulating CD133+KDR+ EPCs (p=0.03) by logistic regression analysis. Levels of serum VEGF (p=0.92) and KDR expression were not different between patients who had early and intermediate/late disease. Circulating CD34+KDR+ EPCs was not different between SSc patients and controls and did not correlate with any clinical or biochemical parameter. Conclusion: Lower circulating CDI33 +KDR+ EPC subset was found in SSc patients and correlated with impaired endothelium-dependent vasodilation in patients without cardiovascular risk factors suggesting a potential role of deficient EPC recruitment contributing to endothelial dysfunction in this disease. © Copyright CLINICAL AND.