2017 年 40 巻 6 号 p. 467-470
A female in her sixties with slowly progressive type 1 diabetes mellitus (SPT1DM) and chronic thyroiditis was referred to our rheumatology department with swelling in her fingers. A prominent atherosclerotic lesion was revealed upon brain magnetic resonance imaging, and she was found to have mixed connective tissue disease (MCTD) positive for proteinase 3 (PR3)-antineutrophil cytoplasmic antibody (ANCA). This rare case of MCTD accompanying SPT1DM and PR3-ANCA suggested that a synergy between MCTD and PR3-ANCA triggers atherosclerosis.