Therapeutic Efficacy of Autologous Non-Mobilized Enriched Circulating Endothelial Progenitors in Patients With Critical Limb Ischemia　- The SCELTA Trial.

BACKGROUND: The therapeutic efficacy of bone marrow mononuclear cells (BM-MNC) autotransplantation in critical limb ischemia (CLI) has been reported. Variable proportions of circulating monocytes express low levels of CD34 (CD14+CD34lowcells) and behave in vitro as endothelial progenitor cells (EPCs). The aim of the present randomized clinical trial was to compare the safety and therapeutic effects of enriched circulating EPCs (ECEPCs) with BM-MNC administration.Methods and Results:ECEPCs (obtained from non-mobilized peripheral blood by immunomagnetic selection of CD14+and CD34+cells) or BM-MNC were injected into the gastrocnemius of the affected limb in 23 and 17 patients, respectively. After a mean of 25.2±18.6-month follow-up, both groups showed significant and progressive improvement in muscle perfusion (primary endpoint), rest pain, consumption of analgesics, pain-free walking distance, wound healing, quality of life, ankle-brachial index, toe-brachial index, and transcutaneous PO2. In ECEPC-treated patients, there was a positive correlation between injected CD14+CD34lowcell counts and the increase in muscle perfusion. The safety profile was comparable between the ECEPC and BM-MNC treatment arms. In both groups, the number of deaths and major amputations was lower compared with eligible untreated patients and historical reference patients. CONCLUSIONS: This study supports previous trials showing the efficacy of BM-MNC autotransplantation in CLI patients and demonstrates comparable therapeutic efficacy between BM-MNC and EPEPCs.

Endothelial Soluble Factors Mediate Differentiation of Circulating Endothelial Precursors.

Although endothelial progenitor cells have been used in clinical trials with promising preliminary results, the mechanism by which these cells interact with vascular wall cells and ischemic tissues remains unclear. We have previously reported that human coronary artery endothelial cells cocultured with peripheral blood mononuclear cell (PBMC) can stimulate their early differentiation toward a pre-endothelial phenotype. This study was aimed to assess possible soluble factors, released from the coculture, and involved in endothelial progenitor cell differentiation. Among cytokines and chemokines measured by means of Milliplex assay, interleukin (IL)-6, IL-8, endothelial growth factor, and CCL-2 were released in cocultures, and those levels were significantly higher than that found in human coronary artery endothelial cells or in PBMCs alone. To check their involvement in PBMC differentiation, blocking experiments with neutralizing antibodies were performed. Flow cytometry analysis confirmed an impairment of PBMC differentiation toward a pre-endothelial phenotype when IL-6, IL-8 and with a lesser extent CCL-2 were blocked. These data add a new insight into the mechanisms by which endothelial precursors interact with vascular wall, thus suggesting future directions in understanding and treating ischemic injury.

Hemodynamic 3D Infrared Thermal Stereoscopic Imaging (TSI) Investiga- tion in Chronic Vascular Leg Ulcers: A Feasibility Study.

UNLABELLED: Hemodynamic 3D infrared thermal stereoscopic imaging (TSI) was tested as a new non-invasive diagnostic method for studying chron- ic vascular leg ulcers. The aim was to test this new diagnostic approach in investigating mixed arterio-venous wounds. Duplex ultrasonography is the most useful test for investigating hemodynamic alterations in patients with vascular cutaneous ulcers; however, it fails to provide any information about microvascular dysfunctions, which could play a sig- nificant role in the development of skin wounds. The study of thermal patterns at the wound site represents a method of investigating cu- taneous microcirculation-temperature gradients indicating abnormal blood flow in the margins and bed of wounds with vascular disorders are well correlated with clinical findings. METHODS: In order to evaluate the predominance of the arterial or venous component in vascular mixed ulcers of the leg and to understand the underlying pathology of the ulcers, 3D thermography was tested in three different hemodynamic positions. A total of 20 physiological and 20 pathological patients were assessed standing, supine, or in a discharging position (legs raised above heart level). RESULTS: A relatively constant temperature trend was observed in healthy subjects, while a different reaction was recorded in those with ulcerated legs. Moreover, a different temperature trend was noted among the varying hemodynamic positions and a trend differ- ence was also observed between arterial and venous ulcers in clinical investigation tests. CONCLUSION: TSI appears to be a safe, user-friendly, rapid, and promising procedure for distinguishing both arterial and ve- nous involvement in mixed arterio-venous leg ulcers. .