TNFAIP6 and spondyloarthropathy: Kynurenic Acid Analog Attenuates the Production of Tumor Necrosis Factor-α, Calgranulins (S100A 8/9 and S100A 12), and the Secretion of HNP1–3, and Stimulates the Production of Tumor Necrosis Factor-Stimulated Gene-6 (TSG-6) but Does Not Alter IL-17 Levels in Whole-Blood Cultures of Patients with Spondyloarthritis