1. Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan, ROC
2. Central Region Laboratory, Center of Research and Diagnostics, Centers for Disease Control, Taichung, Taiwan, ROC
3. Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan, ROC
4. Institute of Respiratory Therapy, China Medical University, Taichung, Taiwan, ROC