Yukiko Asami1, Hiroaki Ishiguro2, Atsuhisa Ueda3, Hideaki Nakajima3. 1. Department of Rheumatology, Yokosuka City Hospital; and Department of Haematology and Clinical Immunology, Yokohama City University School of Medicine, Japan. daiichinaika2005@yahoo.co.jp. 2. Department of Nephrology, Yokosuka City Hospital, Japan. 3. Department of Haematology and Clinical Immunology, Yokohama City University School of Medicine, Japan.