Mixed connective tissue disease connective tissue disease is not necessarily associated with serum antibodies directed against the U1-RNP, and MCTD is associated with a more clearly defined set of signs/symptoms. MCTD combines features of scleroderma, myositis, systemic lupus erythematosus, and rheumatoid arthritis (with some sources adding polymyositis, dermatomyositis, and inclusion body myositis) and is thus considered an overlap syndrome. MCTD commonly causes: It has been associated with HLA-DR4. Distinguishing laboratory characteristics are a positive, speckled anti-nuclear antibody and an anti-U1-RNP antibody. The prognosis of mixed connective tissue disease is in one third of cases worse than that of systemic lupus erythematosus (SLE). In spite
Connective tissue disease Connective tissue disease A connective tissue disease is any disease that has the connective tissues of the body as a target of pathology. Connective tissue is any type of biological tissue with an extensive extracellular matrix that supports, binds together, and protects organs. These tissues form a framework, or matrix, for the body, and are composed of two major structural protein molecules: collagen and elastin. There are many different types of collagen protein in each of the body's tissues. Elastin has the capability of stretching and returning to its original length—like a spring or rubber band. Elastin is the major