Human Anti Scl-70 IgG ELISA KIT

Cat # 3300-140-SCG

Intended Use:

ADI's Anti-Scl-70 is an indirect solid phase enzyme immunoassay (ELISA) for thequantitative measurement of IgG class autoantibodies against Scl-70 in humanserum or plasma. The kit is intended for in vitro research use only (RUO) as anaid in the diagnosis of scleroderma.

INTRODUCTION

Rheumatoid autoimmune diseases are often associated with theoccurrence of autoanti-bodies against several nuclear or cytoplasmicantigens. Today the best investigated immunoreactive antigens aredouble-stranded DNA (dsDNA), single stranded DNA (ssDNA), Sm(Smith), sn-RNP (small nuclear ribonucleoprotein particles), the complexRNP/Sm which is stabilized by ribonuleic acid as well as SS-A (Ro) andSS-B (La). The antigen Scl 70, a 70 kD molecular weight protein, alsoknown as DNA-topoisomerase-1, is associated with scleroderma. AntiScl-70 antibodies (also called anti-topoisomerase I) is a type of anti-nuclear autoantibody seen mainly indiffuse systemic scleroderma, but is also seen the more limited form of systemic scleroderma calledCREST syndrome. Anti Scl-70 antibodies are associated with more severe scleroderma disease.Today the best investigated immunoreactive antigens are double-stranded DNA (dsDNA), singlestranded DNA (ssDNA), Sm (Smith), sn-RNP (small nuclear ribonucleoprotein particles), the complexRNP/Sm which is stabilized by ribonuleic acid as well as SS-A (Ro) and SS-B (La). The antigen Scl 70,a 70 kD molecular weight protein, also known as DNA-topoisomerase-1, is associated with scleroderma.In rheumatoid autoimmune diseases various profiles of autoantibodies to these antigens can bedetected. In a high incidence they are related to active and inactive systemic Lupus erythrematodes,mixed connective tissue diseases (Sharp Syndrome), rheumatoid arthritis, Sj?gren-Syndrome,Scleroderma, photosensitve dermatitis and drug-induced lupus. In Lupus patients typically anti-dsDNAantibodies can be detected. Patients without these antibodies very often show anti-ssDNA antibodies and anti-SS-A and anti-SS-B are present. A strong correlation between antibody concentration andseverety of the disease has been observed with higher antibody concentrations in active phases of thedisease. Thus quantitation is more informative compared to simple titering by immunoflourescence. Mostof these parameters are not specific for just one disease but they occur in various combinations. Thepattern of different antibody combinations and their concentration together with the whole clinical pictureof the patient are helpful diagnostic tools in the assessment of rheumatoid autoimmune diseases. Anti- Scl-70 is found in ~75% patients with the diffuse progressive form of scleroderma. The presence of anti- Scl-70 seems to exclude the presence of anti-centromere antibody, which is a marker for a subset ofpatients with scleroderma known as CREST (calcinosis, sclerodactyly, and telangiectasia) syndrome.

SPECIFICITY:

The microplate is coated with Scl-70 antigen highly purified by affinitychromatography. The Anti-Scl-70 test kit is specific only forautoantibodies directed to Scl-70. No cross reactivity to the other ENA- antigens have been observed.

Sensitivity:

The lower detection limit for Anti-Scl-70 has been determined at 1.0U/ml.

Species Reactivity:

This kit is designed to test human samples. It detects IgG class of anti- Scl70 antibodies with no or minimal detection of IgG, IgA or IgEantibodies.ADI has separate kits to detect slc70 antibodies in monkey, mouse or ratsamples.