CONNECTIVE TISSUE DISEASES

The MESACUP-3 TEST Sm is semi-quantitative enzyme-linked immunosorbent assay (ELISA) for the detection of anti Sm antibodies in human serum.

Background:

Sm antibodies are ENA antibodies named after “Smith”, a patient who suffered from Systemic Lupus Erythematosus (SLE). Sm antibodies are frequently found with RNP antibodies. It is detected in 10-30% of SLE patients. At high levels, Sm antibody is indicative of SLE and is rarely detected in other diseases. It has been adopted as a marker for diagnosis of SLE by the American Rheumatism Association (ARA). Anti-Sm antibodies are observed at a high titer in the active period of SLE and at a low titer in the non-active period. Raynaud’s phenomena and nephropathy are reported more frequently in SLE patients testing positive for anti-Sm antibodies.

The MESACUP-3 TEST Sm measures with high sensitivity, anti-Sm antibodies present in the serum by ELISA.

Principle:

The MESACUP-3 TEST Sm measures anti-Sm antibodies present in the serum by ELISA. Calibrators and patient serum are added to microwell coated with Sm antigens, allowing anti-Sm antibodies to react with　the immobilized antigen (Sample incubation). After wash to remove any unbound serum proteins, horseradish peroxidase conjugated anti human IgG, IgA and IgM are added and incubated (Conjugate incubation). Following another washing step, the peroxidase substrate is added and incubated for an additional period of time (Substrate incubation). Acid solution is then added to each well to terminate the enzyme reaction and to stabilize the color development. The assay can be quantified by measuring the reaction photometrically and plotting the results.

Size: 96 wells

Method: ELISA

Antigen: native purified proteins