Anti‐Mi‐2 antibody titers and cutaneous manifestations in dermatomyositis

摘要

The anti‐Mi‐2 antibody is a dermatomyositis (DM)‐specific autoantibody. It is thought to be associated with photosensitivity in patients with DM because higher expression levels of Mi‐2 antigens have been found in UV‐irradiated cultured cells and because epidemiological studies have supported this association. This study aims to identify the relations between anti‐Mi‐2 antibody titers measured by ELISA and clinical characteristics in patients with DM. We focused on analyzing associations between anti‐Mi‐2 antibody titers and cutaneous manifestations. This retrospective analysis covered 160 adult DM patients. Anti‐Mi‐2 antibodies were detected by an in‐house ELISA, and anti‐Mi‐2 titers were measured by a manufactured ELISA. Twelve of the 160 (7.5%) patients were anti‐Mi‐2 positive. The anti‐Mi‐2‐positive patients showed extremely elevated muscle enzyme levels ( P ?0.0001), less frequent interstitial lung disease complication ( P =?0.031), and favorable survival rate (100%) ( P =?0.07). No correlations were found between anti‐Mi‐2 antibody titers and clinical characteristics or skin manifestations, including photosensitive rashes. Further investigation is necessary to elucidate the pathological significance of the anti‐Mi‐2 antibody in DM.