A 57-year-old man was referred to us due to elevated serum C-reactive protein levels of unknown origin; he had experienced myocardial infarction 7 days earlier. He had a significant medical history of continuous lower back pain for four decades, which clinically corresponded to inflammatory back pain. His spinal movement was severely limited. Spinal radiography revealed a central radiodense streak, indicating the “dagger sign” (Picture 1). A lateral-view radiograph and computed tomography showed ossified supraspinous and interspinous ligaments (Picture 2). Vertebral body squaring and radiographic changes in his sacroiliac joints were observed; however, syndesmophytes were not significant. Based on the aforementioned findings and HLA-B27 positivity, a diagnosis of ankylosing spondylitis was made. He was subsequently treated with a tumor necrosis factor (TNF) inhibitor, which improved the pain but not the limited mobility. Sustained inflammation was presumed to have caused the myocardial infarction and irreversible spinal ossification, highlighting the importance of its early diagnosis and proper treatment.
Picture 1.
Picture 2.
Written informed consent for this case report was obtained from the patient.
The authors state that they have no Conflict of Interest (COI).
Financial Support
The publication of this article was partly supported by a research grant from UCB Japan.