SSA Autoantibody ELISA
The Calbiotech, Inc. (CBI) SSA IgG ELISA Kit is intended for the detection of IgG antibody to SSA in human serum or plasma.
Systemic autoimmune disease is characterized by the presence of circulating auto-antibodies directed to a wide variety of cellular antigens. Systemic lupus erythematosis (SLE), commonly referred to as Lupus is the best known of these diseases. Other possible connective tissue diseases include mixed connective tissue disease (MCTD), Sjogren syndrome, sclerodema, and polymyositis/dermatomyositis. The majority can be diagnosed by clinical presentation and their antibody profiles to the various antigens involved, which include dsDNA, SM, RNP, SSA, SSB, Scl-70, Jo1 and Histones. Therefore, immunoassays for autoantibodies are useful for diagnostic and prognostic evaluations of autoimmune disease. SSA (Ro) antigen (60kd) and 52 kd polypeptides complexed with Ro RNAs are detected in about 75% of primary and secondary Sjögren syndrome, In >90% of subacute cutaneous lupus and in the vasculitis-associated Sjögren syndrome, SS-A autoantibodies are present and are accompanied in ~50% by SS-B/La autoantibodies. The coexistence of SSA and SSB autoantibodies probably reflects the presence of these polypeptides on the same particle and the spreading among autoimmunity to these self antigens.
Diluted patient serum is added to wells coated with purified antigen. IgG specific antibody, if present, binds to the antigen. All unbound materials are washed away and the enzyme conjugate is added to bind to the antibody-antigen complex, if present. Excess enzyme conjugate is washed off and substrate is added. The plate is incubated to allow the hydrolysis of the substrate by the enzyme. The intensity of the color generated is proportional to the amount of IgG specific antibody in the sample.
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