RNP/Sm Autoantibody ELISA
The Calbiotech, Inc. (CBI) RNP/Sm IgG ELISA Kit is intended for the detection of IgG antibody to RNP/Sm 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, Ro, La Scl- 70, Jo1 and Histones. Therefore, immunoassays for autoantibodies are useful for diagnostic and prognostic evaluations of autoimmune disease. RNP Abs target U1 RNA 70kD, A or C proteins and are present in most MCTD patients and in about 15% of SLE patients. The Sm or Smith Abs target B’/B or D proteins and are present in approximately 30% of patients with SLE . Sm is a very specific marker for SLE. Sm antibodies are very rare in other autoimmune diseases and normals.
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.
- Tan, E.M. 1982. Autoantibodies to Nuclear Antigens (ANA): Their Immunobiology and Medicine. Adv. Immunolo. 33 :167-240.Disposable pipette tips.
- Nakamura, R.M., and E.M. Tan. 1986. Recent Advances in Laboratory Tests and the Significance of Autoantibodies to Nuclear Antigens in Systemic Rheumatic Disease. Clin. Lab Med. 6:41-53.
- McCarty, G.A., D.W. Valencia, and M.J. Fritzler. 1984. Antinuclear Antibodies : Contemporary Techniques and Clinical Application to Connective Tissue Disease. In: Antinuclear Antibodies. Oxford Univ. Press, New York. pp 1-95.
- Kurki, P., M. Gripenberg, P. Parlanen, and T. Helve. 1987. Screening Test for Rheumatic Disease: A Combined Enzyme Immunoassay of Rheumatoid Factors and Autoantibodies to DNA and Extractable Nuclear Antigens. J. Clin. Pathol. 40 : 1475-1480.
- Geisler, C. and M. Hoier-Madsen. 1985. An Enzyme-Linked Immunosorbent Assay for Autoantibodies Against the Nuclear Protein Scl-70. J. Immuno. Methods. 80 : 211-219.