Simvastatin reduces endothelial activation and damage but is partially ineffective in inducing endothelial repair in systemic sclerosis.

OBJECTIVE: To investigate whether statins may improve endothelial function in systemic sclerosis (SSc) by evaluating the effects of simvastatin on vasculogenesis [indicated by the expansion of circulating endothelial progenitor cells (EPC)] and the markers of vascular injury in the peripheral blood of patients with SSc. METHODS: Twenty SSc patients with normal cholesterol concentrations and 20 hypercholesterolemic subjects were allocated to receive 20 mg/day simvastatin for 12 weeks. Peripheral blood samples were collected before and 12 weeks after initiation of treatment, and 4 weeks after discontinuation. Five-parameter, 3-color flow cytometry was performed with a FacScan to enumerate EPC and mature circulating endothelial cells (CEC). Levels of soluble E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, interleukin 6, and endothelin-1 were assessed by commercial ELISA. RESULTS: Simvastatin treatment significantly increased EPC in the hypercholesterolemic group, but failed to improve the EPC levels in the SSc patients, mainly in patients with late disease. Baseline levels of CEC were significantly higher in SSc patients compared with controls and at the end of the treatment they were significantly decreased. Regarding other markers of endothelial activation, we found that all the cytokine levels decreased in a statistically significant manner in the treated patients. CONCLUSION: Treatment with simvastatin results in rapid and significant improvement of measures of endothelial activation, suggesting a potential role of statins in the treatment of peripheral vascular disease in SSc. The lack of effect on increase of EPC confirms our previous findings of a defective endothelial stem cell recruitment in the bone marrow of SSc patients. This could indicate that the potential effectiveness of statins in SSc could mainly be ascribed to their effectiveness in modulating endothelial activation mechanisms.

Bone marrow endothelial progenitors are defective in systemic sclerosis.

OBJECTIVE: Vascular abnormalities represent the main component of the pathobiology of systemic sclerosis (SSc), progressing from structural derangements of the microcirculation with abortive neoangiogenesis to final vessel loss. Since circulating endothelial progenitor cells (EPCs) are important in the vascular repair process, we undertook this study to examine their numbers in the peripheral blood (PB) of SSc patients and to evaluate whether their status is related to impaired quantitative and/or qualitative aspects of the bone marrow (BM) microenvironment. METHODS: Circulating EPCs from 62 SSc patients were evaluated by flow cytometry and characterized as CD45 negative and CD133 positive. BM EPCs, identified as CD133 positive, were isolated from 14 SSc patients and grown to induce endothelial differentiation. In addition, progenitor numbers and functional properties of hematopoietic and stromal compartments were analyzed by various assays. RESULTS: We found that EPCs were detectable in the PB of patients with SSc, and their number was significantly increased in patients with early-stage disease but not in those with late-stage disease. All of the examined BM samples contained reduced numbers of EPCs and stromal cells, both of which were functionally impaired. Both endothelial and stromal progenitors expressed vascular endothelial growth factor receptor, indicating that BM is strongly induced to differentiate into the endothelial lineage; furthermore, only BM EPCs from patients with early disease led to endothelial differentiation in vitro. CONCLUSION: This study provides the first demonstration that in SSc, there is a complex impairment in the BM microenvironment involving both the endothelial and mesenchymal stem cell compartments and that this impairment might play a role in defective vasculogenesis in scleroderma.

Increased levels of circulating endothelial cells in chronic periaortitis as a marker of active disease.

BACKGROUND: The pathogenesis of chronic periaortitis (CP) has not been clarified. The histologic features and the association with autoimmune diseases suggest an immune-mediated disorder with marked inflammatory vascular and perivascular lesions. To clarify the role of vascular damage we looked for the presence and the surface phenotype of circulating endothelial cells (CECs) in the peripheral blood of patients with chronic periaortitis. METHODS: Eleven patients with CP were evaluated for the presence of CECs; 9 patients had active and 2 inactive disease. Three patients with active disease were also evaluated 3 months after therapy. Ten atherosclerotic patients, 10 patients with renal insufficiency of variable degree and etiology, and 40 healthy subjects were evaluated as controls. Five-parameter, 3-color flow cytometry was performed with a FACScan. CECs were defined as CD45 negative, CD31, P1H12, and CD36 positive, and activated CECs as CD45 negative and P1H12, CD62 positive. RESULTS: The median number of CECs in patients with CP (10(6) cells/mL) was significantly higher than in healthy controls (16 cells/mL, P= 0.0004) and atherosclerotic patients (25 cells/mL, P= 0.0005) Two patients with inactive disease had a CEC count comparable to that of normal subjects. In 2 of the 3 patients reevaluated, 3 months after therapy CEC numbers normalized. Almost all CECs were microvascular in origin and showed an activated phenotype. CONCLUSION: The presence of a high number of CECs in the active phase of chronic periaortitis and their normalization during inactive disease suggest that endothelial damage may play a role in the pathogenesis of the disease.

Circulating endothelial cells as a marker of ongoing vascular disease in systemic sclerosis.

OBJECTIVE: Circulating endothelial cells (CECs) have been described in different conditions involving vascular injury. Vascular abnormalities play a key role in the pathogenesis of systemic sclerosis (SSc). The aim of this study was to search for the presence of CECs in patients with SSc and to evaluate their clinical associations and possible pathogenic role. METHODS: The study cohort included 46 patients with SSc and 40 healthy controls. Five-parameter, 3-color flow cytometry was performed with a FACScan. CECs were defined as CD45 negative, CD34 positive, and P1H12 positive, and activated CECs were defined as CD45 negative and P1H12 positive, CD62 positive, or CD106 positive. Progenitors were identified as CD34 positive and CD133 positive. RESULTS: Total and activated CEC counts were significantly higher in SSc patients compared with healthy controls and were positively correlated with the disease activity score. With respect to visceral involvement, significant correlation was observed between the CEC number and the severity of pulmonary hypertension. High levels of endothelial progenitors were observed in patients with SSc, and the counts were higher in the early stages of disease. CONCLUSION: The presence of CECs in patients with SSc may represent direct evidence of endothelial disease and may be a promising new clinical marker for active SSc. Notably, the association between CECs and pulmonary hypertension and impaired carbon monoxide diffusing capacity was evident in patients with limited cutaneous SSc only, suggesting an important role for CECs in this disease subset with prominent vascular changes. Detection of circulating endothelial progenitors may represent a response to vascular ischemia in early SSc, as an attempt at revascularization.