Rheumatoid arthritis associated with ankylosing spondylitis defined by scintigraphic and CT abnormalities.

Rheumatoid arthritis and ankylosing spondylitis were detected in the same patient after a long period of observation of the disease. X-ray studies demonstrated the characteristic rheumatoid arthritis changes in peripheral joints. By contrast, few X-ray changes of ankylosing spondylitis were detected, during follow-up. Diagnostic approach through scintigraphic studies disclosed a symmetric uptake of the radionuclide in sacroiliac joints, and computed tomography revealed bilateral ankylosis. The combination of these tests was useful to define the presence of axial disease. This patient was both HLA B27 and DR4 positive. Rheumatoid arthritis occurred before ankylosing spondylitis, that interestingly was defined as a late onset disease.