051. MOESIN EXPRESSION LEVEL OF MPO-ANCA ASSOCIATED-VASCULITIS MODEL MICE Free

Background: Myeloperoxidase-anti-neutrophil cytoplasmic autoantibody (MPO-ANCA) is used as a specific marker for the diagnosis and treatment of ANCA associated vasculitis (AAV). However, the titer of MPO-ANCA does not always correlate with disease activities and treatment responses. We previously reported anti-moesin antibody exists in the sera of patients with MPO-AAV and is associated with the severity of vasculitis via activation of neutrophils and endothelial cells (Suzuki et al., 2014). In this study, we examined mRNA expression levels of moesin and cytokines in various organs of SCG/Kj strain, which is a mouse model for MPO-ANCA-association vasculitis.

Methods: Sera and organs (kidney, lung, spleen, heart, and skin) were collected from 14-weeks-old female mice of C57BL/6 (healthy control) and SCG/Kj strains. The serum concentrations of anti-moesin antibody and 32 kinds of cytokines were evaluated by ELISA and BioPlex. The mRNA expression levels of moesin and various cytokines were measured by real-time PCR using the SYBR Green method.

Results: The serum anti-moesin autoantibody titers in SCG/Kj were higher than those in the healthy mice. The serum concentrations of most cytokines were also higher in SCG/Kj. On the other hand, mRNA expression levels of moesin and various cytokines were different among organs. In particular, IL-10, RANTES, and TNF-significantly higher in spleen, lung, and kidney of SCG/Kj. Furthermore, moesin mRNA expression levels were higher in the spleens and skins of SCG/Kj.

Conclusion: Based on the results of higher moesin expression levels in spleen and skin and higher anti-moesin antibody titer in sera of SCG/Kj than in those of C57BL/6, the anti-moesin antibody may be a useful marker for disease activity in AAV.

Disclosures: None