Human ACPA ELISA kit is a method intended for analysing in vitro quantitative levels of IgG antibodies against citrullinated protein (anti-citrullinated protein antibodies, ACPA) in human plasma and serum. This assay kit has a minimum analytical sensitivity limit of 1.0 U/ml.


Anti-citrullinated protein antibodies (ACPA) are autoantibodies that are usually present in majority of patients which have rheumatoid arthritis (RA) and are directed against proteins and peptides that are citrullinated. The first members of this autoantibody family were discovered in the 1970s, these were anti-perinuclear factor and anti-keratin antibodies. However, later studies have demonstrated that autoantibodies from RA patients have the ability to react with a number of different citrullinated antigens such as vimentin, fibrinogen and deiminated epstein-barr virus nuclear antigen 1.

This is a citrullinated protein which have been identified to be in rheumatoid synovial tissue of RA patients. Also, the titer of antibodies against vimentin in RA patients shows a direct correlation with the disease activity score. The primary diagnosis of RA in serological support and clinical manifestations has so far been restricted to the measurement of autoantibodies against rheumatoid factor (RF). This only has a moderate specificity of about 70% for RA, however, several recent studies have discovered that antibodies against citrullinated arginine residues which is present in filament proteins is found to occur in RF negative patients.


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: Bound by human anti-citrullinated protein antibodies.
  • Calibrator A-F: Concentrations 0, 20, 40, 100, 300, 1000 U/ml.
  • Control Positive and Control Negative: Human ACPA antibodies in a serum/buffer matrix.
  • Sample Buffer (5x).
  • Enzyme Conjugate: Anti-human IgG antibodies, HRP labelled.
  • TMB Substrate.
  • Stop Solution.
  • Wash Buffer (50x).
  • Instruction for Use.
  • Certificate of Analysis.


The minimum detection sensitivity level of human anti-citrullinated protein antibodies using current ACPA ELISA kit was 1.0 U/ml. The dynamic range for this assay is 20.0 – 1,000.0 U/ml.


– Anti-Citrullinated Protein Antibodies (ACPA): ELISA
– Measuring Range: 0 – 1000 U/ml
– Expected Values: In a normal range = Cut-off 20 U/ml, Negative = < 20 U/ml, Positive = ≥ 20 U/ml.
– Linearity: 85 – 109%
– Intra Assay Precision: 4.6 – 6.4%
– Inter Assay Precision: 5.3 – 9.2%
– Clinical Diagnosis: Sensitivity (81.2%), Specificity (98.0%), Overall agreement (91.4%).


  1. Genetics of ACPA positive rheumatoid arthritis: the beginning of the end? Ann Rheum Dis. (2011) 70 Suppl 1: i51-4. Review. de Vries R.R., et al.
  2. The lung in ACPA positive rheumatoid arthritis: an initiating site of injury? Rheumatology (Oxford). (2014) 53 (11): 1940-50. Review. Perry E., et al.
  3. The role of anti-citrullinated protein antibodies in the early stages of rheumatoid arthritis. Curr Opin Rheumatol. (2016) 28 (3): 275-81. Review. Dekkers J., et al.
  4. Anti-citrullinated peptide antibody: death of the rheumatoid factor? Med J Aust. (2009) 190 (12): 693-5. Review. Chatfield S.M., et al.


  • Full Name: ACPA ELISA Kit
  • Reactivity: Human
  • Sample Type: Serum, Plasma
  • Sensitivity: 1.0 U/ml



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