Mixed Connective Tissue Disease

**Definition:** A syndrome with overlapping clinical features of systemic lupus erythematosus, scleroderma, polymyositis, and Raynaud's phenomenon. The disease is differentially characterized by high serum titers of antibodies to ribonuclease-sensitive extractable (saline soluble) nuclear antigen and a speckled epidermal nuclear staining pattern on direct immunofluorescence.

**Tree numbers:** - C17.300.540

**Synonyms:** - MCTD - Connective Tissue Disease, Mixed - Sharp Syndrome