1. Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
2. Ito Hospital, Tokyo 150-8308, Japan
3. IM&CC Life Cycle Management, IVD, Roche Diagnostics K.K., Tokyo 105-0014, Japan
4. Department of Laboratory Medicine, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan