The clinical case of a combination of ankylosing spondylitis, ulcerative colitis and rheumatoid arthritis in one patient: where is the intersection point?

We describe a clinical observation of a 64-year old Caucasian patient with a longstanding ankylosing spondylitis, who was admitted to the clinic for diarrhea and joint syndrome. Physical and X-ray examination showed that his musculoskeletal system disorder was represented by ankylosing spondylitis, symmetrical erosive polyarthritis of the metacarpophalangeal joints, and wrist joint ankylosis. Laboratory work-up identified that the patient was HLA-B27 positive, had high rheumatoid factor and anti-citrulline antibodies levels. At colonoscopy, there were signs of ulcerative colitis. After the differential diagnosis procedures, we were able to conclude that the patient had a combination of rheumatoid arthritis, ankylosing spondylitis, and ulcerative colitis as three independent but associated disorders. The first description of these three autoimmune diseases in one patient can be of interest for clinicians.