Overlapping autoimmune syndromes include a number of different connective tissue disorders, thyroid conditions, and liver disorders with features of more than one condition. Unlike multiple autoimmune syndrome, overlapping conditions are difficult to diagnose because of their unique features, such as UI-RNP antibodies, which are seen in the autoimmune connective tissue disorder mixed connective tissue disease.

Because the prognosis and treatment of overlapping disorders differ from that of the individual disorders, a proper diagnosis is especially important.

8/18/2011