TY - JOUR T1 - The Interleukin 33/ST2 Axis in Patients with Primary Sjögren Syndrome: Expression in Serum and Salivary Glands, and the Clinical Association JF - The Journal of Rheumatology JO - J Rheumatol DO - 10.3899/jrheum.140234 SP - jrheum.140234 AU - Seung Min Jung AU - Jaeseon Lee AU - Seung Ye Baek AU - Jae Ho Lee AU - Jennifer Lee AU - Kyung-Su Park AU - Sung-Hwan Park AU - Ho-Youn Kim AU - Seung-Ki Kwok Y1 - 2014/12/15 UR - http://www.jrheum.org/content/early/2014/12/10/jrheum.140234.abstract N2 - Objective To evaluate the expression of interleukin 33 (IL-33) and its receptor in sera and salivary tissues of patients with primary Sjögren syndrome (pSS), and to investigate the association with clinical profiles. Methods Serum IL-33 and soluble ST2 (sST2) of 55 patients with pSS and 48 controls were determined by ELISA and assessed for clinical correlation. The expression of IL-33/ST2 in salivary tissues was investigated by immunohistochemical staining and was further characterized by confocal microscopy. We also measured IL-33 production in salivary glandular epithelial cells by proinflammatory stimuli. Results Serum levels of IL-33 and sST2 were higher in patients with pSS compared to those in controls (p = 0.018 and p < 0.0001, respectively). Among patients with pSS, sST2 concentration was associated with thrombocytopenia (p = 0.029) and correlated with disease duration (p = 0.013) and the European League Against Rheumatism Sjögren Syndrome Disease Activity Index (p = 0.042). The expression of IL-33 and ST2 was elevated in salivary glands of patients with pSS with grade 2 inflammation, and diminished in advanced inflammation. In patients with pSS, IL-33 was mainly observed in epithelial and endothelial cells of glandular tissue. The production of IL-33 mRNA by salivary gland epithelial cell line increased under stimulation with interferon-γ. Conclusion The expression of IL-33 and its receptor was elevated in sera and salivary tissues of patients with pSS. These results suggest that the IL-33/ST2 axis might have a role in the pathogenesis of pSS. ER -