Disease, mixed connective tissue: A mixture of three diseases of connective tissue (the framework of the cells of the body) -- systemic lupus erythematosus, scleroderma, and polymyositis.

Patients with mixed connective tissue disease typically have features of each of the three component diseases. They also typically have very high quantities of antinuclear antibodies (ANAs) and antibodies to ribonucleoprotein (anti-RNP) detectable in their blood. The symptoms eventually become dominated by features of one of three component illnesses, most commonly scleroderma.

Patients can have overlap syndromes that involve any combination of the connective tissue diseases. Therefore, patients can have a combination, for example, of rheumatoid arthritis and systemic lupus erythematosus (hence, the coined name "rhupus").

The treatment of mixed connective tissue disease depends on which features are causing symptoms. Treatment is often directed at suppressing the inflammation in the tissues by using anti-inflammatory and immunosuppressive medications. These medications include nonsteroidal anti-inflammatory drugs (NSAIDs), cortisone drugs/steroids (such as prednisone), and cytotoxic drugs (such as methotrexate, azathioprine, and cyclophosphamide). Organ damage, such as in the kidneys, can require additional treatment directed at high blood pressure, etc.

The abbreviation for mixed connective tissue disease is MCTD.