Causes
By Mayo Clinic staffDoctors don't know what causes mixed connective tissue disease. The disease is part of a larger group of diseases known as autoimmune disorders. When you have an autoimmune disorder, your immune system — responsible for fighting off disease — mistakes normal, healthy cells for intruders. As a result, healthy tissue in your body is damaged, causing signs and symptoms of disease. In connective tissue diseases, your immune system mistakenly attacks healthy connective tissue.
It isn't clear what causes your immune system to attack your body. Doctors believe a complex mix of viruses, chemicals and genetic factors may be involved.
- Bennett RM. Clinical manifestations of mixed connective tissue disease. http://www.uptodate.com/home/index.html. Accessed Dec. 15, 2009.
- Mixed connective tissue disease (MCTD). The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/sec04/ch032/ch032c.html. Accessed Dec. 25, 2009.
- Hoffman RW, et al. Immune pathogenesis of mixed connective tissue disease: A short analytical review. Clinical Immunology. 2008;128:8.
- Bennett RM. Definition and diagnosis of mixed connective tissue disease. http://www.uptodate.com/home/index.html. Accessed Dec. 15, 2009.

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