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
Avian immune system The cause is believed to be high exposure to UV rays. Additionally, a cancer of the connective tissue, known as fibrosarcoma, is often seen in the leg or wing. This occurs in many parrot species, cockatiels, macaws and budgerigars. Treatment options include amputation and surgery. Avian immune system The avian immune system refers to the system of biological structures and cellular processes that protects birds from disease. The avian immune system resembles that of mammals since both evolved from a common reptilian ancestor and have inherited many commonalities. They have also developed a number of different strategies that are unique