Background The role of the endothelium as an active player rather than a passive victim of inflammation has received considerable interest in systemic vasculitis ¹. Local vascular inflammation can have distant effects on the systemic vascular system, leading to widespread endothelial cell dysfunction ². Damage to endothelial cells and developed vascular endothelial dysfunction are crucial events during the pathogenesis of vasculitis. The mechanisms that drive such endothelial dysfunction are unclear but factors such as adhesion molecules, chemokines, inflammatory cells, and different cytokines may play a role. One of the adaptive responses to this injury is the migration of hemopoetic stem cells from the bone marrow to sites of endothelial injury under the control of serum cytokines and growth factors³.

Objectives The objectives of the study were to examine some serum markers of inflammation (adhesion molecules – sICAM-1, sPECAM; cytokines - IL-10, IL-8, TNFα) and activated T helpers and hemopoetic stem cells in patients with active vasculitis and healthy controls.

Methods We performed a longitudinal study of 32 patients with vasculitis and 30 healthy age-matched controls. The group of vasculitis consisted of 18 patients with ANCA negative vasculitis, developed in the course of systemic connective tissue disease and 14 patients with ANCA-associated vasculitis. The vasculitis subtype was classified using the Chapel Hill Consensus Conference (CHCC) criteria and/or the American College of Rheumatology (ACR) classification criteria. Serum levels of sICAM-1, sPECAM, IL-10, IL-8, TNFα were measured by sandwich enzyme-linked immunosorbent assay (ELISA). For the detection of activated T helpers (CD3+CD4+CD69) and hemopoetic CD45+CD34+ stem cells we used flow cytometry. Statistical analyses were performed with SPSS 19.0, it was used unpaired and paired two sample Students's t-test.

Results Levels of sPECAM and IL-8 were significantly higher in patients with vasculitis than in healthy controls (p=0.028, respectively p=0.002). We also found statistically significant increased percentage of CD3+CD4+CD69+ T helper cells in patients (p<0.001). No significant difference was found between both groups for TNFα, IL-10 and sICAM levels. The percentage of CD45+CD34+ hemopoetic stem cells was higher in healthy controls than in patients, as the difference was no significantly (p>0.05).

Conclusions We have demonstrated changes in some biomarkers of inflammation in patients with active vasculitis. The study of different biomarkers provides an opportunity to investigate the pathogenesis of vascular inflammation, which could be used for clinical monitoring of vasculitis.

References

1. Bacon P. Endothelial cell dysfunction in systemic vasculitis: new developments and therapeutic prospects. Curr Opin Rheum 2005, 17: 49-55.

2. Buckley C. Endothelail cells, fibroblast and vasculitis. Rheumatology 2005, 44: 860-863.

3. Clarke L et al. Endothelail injury and repair in systemic vasculitis of the young. Arth Rheum 2010, 62: 1770-1780.

Disclosure of Interest None declared