Systemic lupus erythematosus (SLE) is an autoimmune disease of multifactorial pathoaetiology. Different organs and blood vessels may be affected by chronic inflammation. A direct cause of the disease has not yet been found, so research is being carried out to this effect. The role of the recently identified helper T lymphocyte CD4+, described as Th17, and its dependent cytokines have been of particular interest. The aim of the study was to evaluate IL-17A, IL-17B, IL-17F and IL-23 in 60 SLE patients and 26 age-matched, healthy volunteers and also to investigate the correlation between levels of the investigated cytokines and VEGF, PIGF, as well as number of endothelial cells. IL-17A, IL-17B, IL-17BR and IL-17F levels were found to be higher in SLE patients than in the control group. However, only IL-17F levels showed a statistically significant correlation with the number of endothelial cells (aCEC) and disease activity. Correlations between levels of IL-17F and VEGF and PIGF as well as VEGF and IL-17A and IL-23 were statistically significant. Increased levels of the selected cytokines from the IL-17 family in SLE patients suggest a role for them not only in the inflammatory process but also in angiogenesis. This also highlights the role of IL-17F in activating vascular endothelial cells and consequently blood vessel formation, and in the relationship between the inflammatory reaction and angiogenesis in the development of SLE.
Keywords: IL-17A; IL-17B; IL-17F; SLE; circulating endothelial cells.