Assesment of relationship between IL-17 levels and oxidative stress in children with immunoglobulin a vasculitis

Introduction: Immunoglobulin A vasculitis (IgAV) is an IgA mediated small vessel vasculitis characterized by skin, gastrointestinal tract, kidney and joint involvement. Pathogenesis of IgAV is not clearly understood. Cytokines stimulate the production of chemokines by endothelial cells, attract inflammatory cells, induce the expression of cell adhesion molecules on endothelial cells and facilitate inflammatory cell adhesion to the vascular wall. In addition, activated cells of the immune system, could be responsible for tissue damage by producing reactive oxygen species. Aim: In this study, we aim to investigate the role of interleukin 17 (IL-17) and oxidative stress in the pathogenesis of IgAV and determine if there is a relationship between IL-17 and oxidative stress. Method: The patients, diagnosed with IgAV according to Ankara 2008 criteria were enrolled between July 2014 and August 2015. Patients who used steroid or nonsteroidal anti-inflammatory drugs in the last one month were excluded. Blood samples were obtained at active and remission phase of the disease and IL-17, malondialdehyde, 8-hydroxy deoxyguanine, 3-nitrotyrosine, total oxidant status and total antioxidant status (TAS) levels were measured via ELISA method. Results: Forty-four patients, including 25 (56.8%) males and 19 (43.2%) females, aged 1.91-15.41 years (mean: 7.71 years) were enrolled in this study. All patients had skin involvement, 39 (88.6%) had joint, 14 (31.8%) had gastrointestinal system and five (11.4%) had renal involvement. Levels of IL-17 and TAS were significantly higher in active phase of the disease compared to in remission phase (p: 0.007 and p: 0.01, respectively). A moderate positive correlation was observed between IL-17 and TAS levels in both active and remission phase of the disease (r: 0.33; p: 0.03 and r: 0.34; p: 0.02, respectively). Conclusion: These findings suggest that IL-17 might have a role in the pathogenesis of IgAV. Beside, higher TAS levels seen in active phase of the disease might be a compensatory response to oxidative stress, which is induced by inflammation. The positive correlation between IL-17 and TAS levels in both active and remission phase of the disease also supports this compensatory response.