Progenitor cells and circulating endothelial cells are associated with disease activity and damage in systemic lupus erythematosus patients

Abstract Background: Despite treatment advances, systemic lupus erythematosus (SLE) patients frequently experience disease flares, which can lead to organ damage and premature death. Therefore, assessing disease activity in SLE patients is crucial for adjusting treatment and preventing further organ damage. The aim of this study was to investigate progenitor cells and circulating endothelial cells levels in relation to SLE activity and accumulate organ damage. Methodos: A case-control study was conducted. CD34 + CD45 low/- progenitor cells, CD34 + CD45 low/- CD133 + progenitor, Endothelial Progenitor cells (EPC) and Circulating Endothelial cells (CEC) levels in peripheral blood were assessed by flow cytometry. Results: Thirty-two SLE patients and 28 matched controls were included. SLE patients had lower levels of CD34 + CD45 low/- progenitor cells (p=0.001), CD34 + CD45 low/- CD133 + progenitor cells (p=0.016), EPC (p=0.018) and CEC (p<0.001) compared to controls. In addition, cell subpopulations studied correlate with SLE activity biomarkers. CD34 + CD45 low/- progenitor cells showed a moderate negative correlation with levels of both C3 and C4. We also found significantly higher levels of CD34 + CD45 low/- progenitor cells, CD34 + CD45 low/- CD133 + progenitor cells, EPC and CEC in patients with SLE with SDI scores ≥1 versus those without organ damage (p=0.0073, p=0.018, p=0.018 and p=0.020, respectively). Conclusion: We found that CD34 + CD45 low/- progenitor cells, CD34 + CD45 low/- CD133 + progenitor cells, CPE and CEC were significantly reduced in patients with SLE as well as associated with disease activity and organ damage. Our observations suggest that CD34 + CD45 low/- progenitor cells could serve as a potential biomarker for disease activity and organ damage in SLE patients. It should be confirmed in a prospective study.