Autoimmune joint diseases in Late Medieval skeletal sample from Croatia.

Analysis of 25 skeletons from Late Medieval cemetery Uzdolje-Grablje near Knin, Croatia, revealed three cases of systematic pathological changes to joints. Observed pathological lesions were examined macroscopically and radiologically and compared to the available paleopathological standards in order to formulate a differential diagnosis. In all three cases observed changes were most consistent with autoimmune joint diseases including ankylosing spondylitis, juvenile idiopathic arthritis and psoriatic arthritis. Based on published clinical studies, we suggest that the high prevalence of autoimmune diseases in our skeletal sample stems from the genetic basis of the autoimmunity, and that three individuals describe here are possibly closely related.