The levels of IL-1β and soluble IL-1 receptors in patients with IgG4-related periaortitis/periarteritis

Purpose: IgG4-related disease (IgG4-RD) is a chronic fibrotic inflammatory and an immune-mediated disease characterized by high serum IgG4 concentration and IgG4-bearing plasma cell infiltration in affected organs. IgG4-related periaortitis/periarteritis is a recently identified disease entity in IgG4-RD that affects the cardio-vascular system, and its pathogenesis and characteristics remain unclear.The inflammatory cytokine IL-18 is involved in a variety of cellular activities including inflammation, fibrosis, and angiogenesis. The present study compared the levels of the inflammatory cytokine IL-18 and two soluble IL-1 receptors, IL-1R1 and IL-1R2, between IgG4-RD patients with and without IgG4-related periaortitis/periarteritis. Methods: The patients with IgG4-related periaortitis/periarteritis (n = 38), those without (n = 66) and healthy (n = 33) were recruited to measure cytokines of IL-18 and soluble receptors (sIL-1R1 and sIL-1R2) in sera by ELISA assay.Results: Serum IgG4 was significantly higher in patients with periaortitis/periarteritis compared to non-periaortitis/periarteritis (p = 0.0074), while serum IL-18 was significantly lower in patients with periaortitis/ periarteritis (p = 0.00037).The three groups did not show significant difference in sIL1-R1, while sIL-1R2 in the periaortitis/periarteritis and healthy group was higher than in the group without periaortitis/periarteritis (p = 0.00001).Conclusions: The characteristic changes in IL-18, sIL-1R1, and sIL-1R2 levels in IgG4-RD patients with and without IgG4-related periaortitis/periarteritis may indicate an active phase of the inflammatory process in these diseases.