1. First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
2. Department of Respiratory Medicine, Japanese Red Cross Society Suwa Hospital, Suwa, Nagano, Japan
3. Department of Diagnostic Pathology, Ina Central Hospital, Ina, Nagano, Japan
4. Department of Hematology and Medical Oncology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan