Antibodies to the Jo-1 autoantigen (or histidyl-tRNA synthetase) are found in approximately 25% of polymyositis patients. Also a high proportion of patients with interstitial lung disease, associated with polymyositis, are positive for this autoantibody.
Intended use
Enzyme immunoassay for the detection of autoantibodies IgG against Jo-1.
Background
Polymyositis (PM) and dermatomyositis (DM) are inflammatory, autoimmune mediated disorders of the connective tissue with unknown etiology. They primarily damage skin and/or muscles, but may also affect other organs as e. g. the lung. Without treatment (standard therapy is immune suppression), they tend to develop into a life-threatening state. Since immunosuppressive agents are known to cause considerable side effects, early diagnosis of PM/DM is essential, in order to keep their dosage as low as possible.
A striking feature of PM/DM is the occurrence of antibodies to aminoacyl-tRNA synthetases; functionally related but immunologically distinct enzymes. About 30 % of all myositis patients carry antibodies against histidyl-tRNA synthetase, a 100 kDa dimeric antigen, located in the cytoplasma and known as Jo-1.
Technical information
The EULISA Jo-1 IgG is intended for the quantitative or qualitative determination of IgG antibodies in human serum, directed against Jo-1. The antigen used is a highly purified preparation of human histidyl-tRNA synthetase, expressed by baculovirus infected insect cells. The test is fast (incubation time 30-30-30 minutes) and flexible (break apart wells, ready-to-use reagents). Six calibrators allow quantitative measurements; a negative and a positive control are used to check assay performance.
Kit components and storage of reagents
Contents of the kit
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1 microwell plate, coated with Jo-1 antigen and hermetically packed in a foil laminate pouch together with a desiccant bag.
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Sample buffer, 100 mL, ready-to-use, orange coloured.
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Wash buffer, 100 mL, 10 x-concentrate, blue coloured.
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6 calibrators, 2.0 mL each 0, 1.0, 3.0, 10, 30 and 100 U Jo-1 antibodies (IgG) / mL ready-to-use, gradually blue coloured.
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Negative and positive control, 2.0 mL each, ready-to-use, green and red coloured, respectively.
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Anti-human IgG HRP conjugate, 14 mL, ready-to-use, red coloured.
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Substrate solution, 14 mL, ready-to-use, colourless.
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Stop solution (0.5 M H2SO4), 14 mL, colourless, ready-to-use.
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Directions for use
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Lot-specific certificate of analysis
All kit components are stored at 2 - 8°C.
