A 50-year-old man presented to our hospital with bone pain for 2 years. One year before admission, he quit his job as a miner owing to exacerbating pain. Gradually, fatigue and weakness developed, and he became wheelchair dependent. He was diagnosed with lumbar disc herniation at local hospitals and received physical therapy, but pain persisted. He was previously healthy, took no medications, and had stopped smoking and drinking alcohol since disease onset; he denied hepatitis B infection and other chronic diseases.