Expression of interleukin-22 in Sjögren's syndrome: significant correlation with disease parameters.

Sjögren's syndrome (SS) is an autoimmune disease targeting the exocrine glands resulting in xerostomia/keratoconjunctivitis sicca. Presently, we examined the levels and clinical correlations of IL-22 in SS. Patients with SS together with normal controls were randomly selected. IL-22 was detected at significantly higher levels in sera of patients with SS. The levels of IL-22 present in sera showed statistically significant direct correlations with hyposalivation, anti-SSB, anti-SSA/SSB combined, hypergammaglobulinemia and rheumatoid factor. IL-22 showed a direct correlation with major clinical parameters. The data suggest that IL-22 plays a critical role in the development of SS, and further study is needed to examine its function in human SS.