VIP and rheumatoid arthritis: On the other hand, when we analyzed serum VIP levels in different pathologies, we observed that they were significantly higher in psoriasis (p = 0.002), Graves’ disease (p = 0.007), and spondyloarthritis (p ≤ 0.0001), compared to controls, whereas RA patients showed similar VIP levels to healthy donors (Figure 1B).