1 Department of Nephrology and Rheumatology, The First Department of Internal Medicine, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan. riektomo@ks.kyorin-u.ac.jp.
2 Department of Nephrology and Rheumatology, The First Department of Internal Medicine, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.