1. Nephrology Center, Toranomon Hospital, Tokyo, Japan
2. Okinaka Memorial Institute for Medical Research, Tokyo, Japan
3. Department of Pathology, Toranomon Hospital, Tokyo, Japan
4. Departments of Medicine (Neurology and Rheumatology) and Pediatrics, Shinshu University School of Medicine, Matsumoto; and the National Center of Neurology and Psychiatry, Tokyo, Japan