RNP 70 Ab ELISA Kit (Ribonucleoprotein 70)

INTENDED USE

Human RNP 70 Ab ELISA kit is intended for measuring in-vitro quantitative levels of IgG autoantibodies to ribonucleoprotein 70 (RNP-70, anti-RNP 70, RNP-70 Ab) in human serum or plasma samples. This assay has a minimum analytical sensitivity limit of 1.0 U/ml.

BACKGROUND

Autoantibodies directed against ribonucleoprotein 70 (RNP-70) have been important for the serological detection of Sharp syndrome (MCTD – Mixed Connective Tissue Disease), it is essentially a 70kDa protein which is part of the U1-snRNP complex. The sensitivity of this is 100%, meaning that MCTD can be completely ruled out if the autoantibodies are absent. However, some patients with SLE and systemic sclerosis are also found to test positive for anti-RNP. In general, patients only displaying antinuclear antibodies against the this protein tend to have the classical MCTD, whereas, other SLE-typical autoantibodies (for example anti-Sm, dsDNA and anti-histone) are found this indicates transition into SLE. Anti-RNP are antinuclear antibodies which belong to the extractable nuclear antigen antibodies (ENA) subset and these are directed against the U1-ribonucleoprotein of the ribonucleoprotein multi-enzyme complex.

CONTENT

All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

• Divisible Microplate: Consisting of 12 modules of 8 wells, purified RNP-70 is bound to microwells.
• Calibrator A-F: Concentrations 0, 12.5, 25, 50, 100, 200 U/ml, made up from ribonucleoprotein 70.
• Control Positive and Control Negative: Containing human anti-RNP 70 antibodies in a serum/buffer matrix.
• Sample Buffer (5x).
• Enzyme Conjugate: Contains anti-human IgG antibodies, HRP labelled.
• Substrate: 3,3’, 5,5’- Tetramethylbenzidin (TMB).
• Stop Solution.
• Wash Buffer (50x).
• Certificate of Analysis.
• Instruction for Use.

SENSITIVITY

The minimum detection sensitivity level of human IgG antibody to ribonucleoprotein 70 (RNP-70 IgG, RNP 70 Ab) using current RNP-70 Ab ELISA kit was 1.0 U/ml. The dynamic range for this assay is 12.5 – 200.0 U/ml.

ASSAY CHARACTERISTICS

-> Limit Of Detection (LOD): Functional sensitivity was 1 U/ml.
-> Measuring Range: 0 – 200 U/ml
-> Linearity: 97 – 100%
-> Expected Values: Cut-off 25 U/ml.
-> Results Interpretation: Negative: < 25 U/ml, Positive: ≥ 25 U/ml.
-> Intra Assay Precision: 3.9 – 5.8%
-> Inter Assay Precision: 4.9 – 5.2%
-> Interference: None.
-> Clinical Diagnosis: Sensitivity (66.0%), Specificity (95.8%), Overall agreement (82.3%).

REFERENCES

1. Autoantibody recognition of distinctly modified forms of the U1-70-kd antigen is associated with different clinical disease manifestations. Arthritis Rheum. (2000) 43 (4): 881-8. Greidinger E.L., et al.
2. Identification of human Sm and (U1) RNP antigens by immunoblotting. J Immunol Methods. (1983) 64 (1-2): 45-59. Guldner H.H., et al.
3. Human autoantibodies against the 70-kd polypeptide of U1 small nuclear RNP are associated with HLA-DR4 among connective tissue disease patients. Arthritis Rheum. (1990) 33 (5): 666-73. Hoffman R.W., et al.
4. Anti-Sm and anti-RNP antibodies. Autoimmunity. (2005) 38 (1): 47-54. Review. Migliorini P., et al.
5. T cell vaccination therapy in an induced model of anti-RNP autoimmune glomerulonephritis. Clin Immunol. (2010) 137 (2): 281-7. Trivedi S., et al.

ADDITIONAL INFORMATION

• Full Name: RNP 70 Ab ELISA Kit (Ribonucleoprotein 70)
• Reactivity: Human
• Sample Type: Plasma, Serum
• Sensitivity: 1.0 U/ml

OTHER RELATED ELISA KITS

• RNP/Sm ELISA Kit
• Sm ELISA Kit
• Rib-P ELISA Kit

Contact Us