Overlap syndrome of ankylosing spondylitis and mixed connective tissue disease in female

Ankylosing spondylitis is a chronic inflammatory disease affecting the young men and less commonly women with a spectrum of manifestations including uveitis, arthritis, sacroiliitis, colitis and psoriasis (spondyloarthropathy). Mixed connective tissue disorder (MCTD) is a complex and heterogenous autoimmune disease that affects women in their childbearing age. It is characterized by circulating autoimmune antibodies that deposit in tissues, resulting in inflammatory response, causing irreparable tissue damage. Overlap and co-existence of these diseases are uncommon, as per literature evidence. The present study has reported the case of a 35-year-old female, who had HLA B27-positive spondyloarthropathy for 10 years and had been receiving sulfasalazine, and had neck swelling for 4 months. Screening conducted for TB in view of fever, weight loss and neck nodes, had reported negative results. She was found to have Reynaud’s disease, arthritis, bilateral cervical lymphadenopathy and elevated autoantibody titers including ANA, U1SM/RNP and Coombs-positive hemolysis. The diagnosis was concluded as MCTD and she had responded well to the treatment. As per the available literature, this could be touted as the first case study of a female patient with ankylosing spondylitis and MCTD.