TPO and Crohn disease: Amrom et al (2014) published a case series describing four cases of patients with RE who went on to be diagnosed with comorbid autoimmune disorders (with systemic lupus erythematosus (SLE) (with elevated serum anti-double stranded deoxyribonuclease titre (anti-dsDNA)), Hashimoto thyroiditis (with positive serum antibodies to thyroglobulin and thyroperoxidase), Crohn’s disease, or ulcerative colitis found in each of the cases they reported).