Objective: Contradictory results have been reported regarding vasculogenesis in systemic sclerosis (SSc). Our aim was to investigate bone marrow-derived circulating endothelial precursors (EPCs) and activated circulating endothelial cells (CECs) in SSc patients.
Methods: Peripheral blood from consecutive patients with SSc hospitalised for systemic follow-up was analysed and compared with blood from patients with active refractory rheumatoid arthritis (RA) and osteoarthritis (OA). EPCs were quantified by cell sorting and flow cytometry and were identified as circulating CD34+CD133+ cells. Activated CECs were defined as CD105+CD62+CD105+CD102+CD105+CD106+ cells.
Results: Patients with SSc had higher putative EPC levels than OA patients, but lower levels than RA patients. In SSc patients, EPC levels increased with European disease activity score. Activated CEC levels were high in SSc patients and RA patients, but not correlated with EPC levels.
Conclusion: These results together and previous data suggest that EPCs may be recruited during active vascular disease but that the sustained ischaemic conditions of SSc may eventually lead to EPCs depletion.