Clinical Evaluation of Plasma Decoy Receptor 3 Levels in Silicosis

Silicosis (SIL) is known to complicate various autoimmune diseases such as rheumatoid arthritis and systemic sclerosis (SSc). To investigate the immunological alterations in SIL, plasma decoy receptor 3 (DcR3) levels were measured. Additionally, correlation studies, multiple regression analysis, and factor analysis were performed using various clinical parameters including respiratory and exposure items, and immunological parameters such as cytokine levels and titers of various autoantibodies detected in SIL subjects. Although actual DcR3 values in SIL and SSc subjects were higher than those in HV, since age was the confounding factor, there were no significant differences. However, in terms of the role of DcR3 in SIL, positive correlations were found between DcR3 and TGF-β or soluble IL-2 receptor (sIL-2R). Multiple regression analysis showed a close and positive relation in SIL between DcR3 and G-CSF, and TGF-β and CENP-B antibodies. Finally, factor analysis indicated that DcR3 values were related to ANA and ANCA-antibodies, as well as G-CSF and IL-6. These data suggested that DcR3 could potentially be utilized as a representative marker of immunological dysfunction in SIL. Further studies are required to explore the cellular and molecular roles of DcR3, and to evaluate the clinical efficacy of utilizing DcR3 measurements for the early detection of complicated autoimmune diseases in SIL patients.