A case of ankylosing spondylitis from the excavations at Klcl Necropolis (Sinope, Northern Turkey) and its implications on the antiquity of the disease in Anatolia

Abstract

Ankylosing spondylitis (AS) is a chronic, inflammatory, and progressive rheumatic disease that is a member of a family of disease referred to as spondyloarthritis. Although the prevalence estimates of AS vary from 0.25% up to 4.5% in living human populations, the frequency of the disease in the past has not yet been determined. Some suspected AS cases have been reported only based on the vertebral ankyloses or fusions of sacroiliac joints dating from the Neolithic period to the Middle Ages among ancient Anatolian populations, but the AS diagnosis has not been definitively revealed in these cases. In this study, we aimed to identify an AS case that has AS-originated pathological changes on a relatively well-preserved middle-aged male skeleton, recovered from the archaeological excavation of Klcl Church, Sinope, Northern Turkey and dated to the 18-9th centuries. In addition, we made a differential diagnosis with other pathologies such as diffuse idiopathic skeletal hyperostosis, reactive arthritis, and psoriatic arthritis. In the specimen, there are four macroscopic features that are diagnostic of AS: (a) both sacroiliac joints were symmetrically obliterated, (b) spinal fusion was observed without skipping any vertebrae, (c) the spine has "bamboo spine" appearance, and (d) the vertebral syndesmophytes caused squaring of the vertebral bodies. We conclude that the Klcl skeleton, one of the few archaeological specimens showing all symptoms of AS disease, is the first convincing case in Anatolia.