Correlations between concentrations of interleukin (IL)-17A, IL-17B and IL-17F, and endothelial cells and proangiogenic cytokines in systemic lupus erythematosus patients

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.