Ankylosing spondylitis and systemic lupus erythematosus: a rare HLA combination

The condition of a 43-year-old man fulfilled the strict diagnostic criteria for both ankylosing spondylitis and systemic lupus erythematosus. To our knowledge, this is the fist verified report of the concurrence of these rheumatic diseases. An unusual combination of genetically determined markers seems to have caused an increased risk for the development of both disorders.