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
Adaptive immune system immune system is provided by immune network theory. This theory, which builds on established concepts of clonal selection, is being applied in the search for an HIV vaccine. Acquired immunity is triggered in vertebrates when a pathogen evades the innate immune system and (1) generates a threshold level of antigen and (2) generates "stranger" or "danger" signals activating dendritic cells. The major functions of the acquired immune system include: The cells of the acquired immune system are T and B lymphocytes; lymphocytes are a subset of leukocyte. B cells and T cells are the major types of lymphocytes. The human