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
Immune system to the nervous system. Dendritic cells serve as a link between the bodily tissues and the innate and adaptive immune systems, as they present antigens to T cells, one of the key cell types of the adaptive immune system. Mast cells reside in connective tissues and mucous membranes, and regulate the inflammatory response. They are most often associated with allergy and anaphylaxis. Basophils and eosinophils are related to neutrophils. They secrete chemical mediators that are involved in defending against parasites and play a role in allergic reactions, such as asthma. Natural killer (NK cells) cells are leukocytes that attack and