1 Department of Rheumatic Diseases, Tokyo Metropolitan Tama Medical Center, Fuchu city, Tokyo, Japan. Electronic address: tanomoginaokiwind@yahoo.co.jp.
2 Department of Pathology, Keio University School of Medicine, Shinjyuku-ku, Tokyo, Japan.
3 Department of General Medicine, Shinshu University Hospital, Matsumoto, Nagano, Japan.