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Published on: September 15, 2016
[Diagnostic performance of anti-cyclic citrullinated antibodies and IgM rheumatoid factor in rheumatoid arthritis]
Ana Lemos1, Maria Piedade Ramos, Maria Jose Furtado
1Laboratório de Imunologia, Serviço de Patologia Clinica. amarialemos@hotmail.com
Unlabelled:
The presence of IgM class rheumatoid factor RF-M in the serum is one of the ACR criteria for the classification of rheumatoid arthritis RA .
Objectives:
To compare the sensitivity and specificity of two diagnostic markers for RA in Portuguese patients the 2nd generation anti-cyclic citrullinated peptide antibodies anti-CCP2 and the RF-M.
Methods:
Serum samples from 56 patients with established RA 44 women and 12 men mean disease duration 9 5 -8 5 years were evaluated for the presence of anti-CCP2 and RF-M. Results were compared with 93 samples from a control group with identical demographic characteristics 43 from patients with spondylarthropaties and 50 from healthy blood donors . The determination of anti-CCP2 antibodies was performed by enzymatic fluroimunoassay and RF-M was measured by microElisa.
Results:
Anti-CCP2 antibodies were positive in 40 patients with RA 71 4 at a mean antibody concentration of 350 5 UA ml range 11-1670 UA ml and negative in all controls. The RF-M was positive in 34 patients with RA 60 7 in 4 patients with spondylarthropaties 9 3 and in one blood donor 2 . The sensitivity specificity positive predictive value and negative predictive value for RF-M was 60 7 90 7 89 5 and 63 9 and for anti-CCP2 was 71 4 100 100 and 72 9 respectively.
Conclusions:
The anti-CCP2 assay showed an excellent specificity and a global performance superior to that of the RF-M test in this population with established RA.
Insights
Rheumatoid arthritis (RA) diagnosis is improved by anti-cyclic citrullinated peptide 2 (anti-CCP2) antibodies. This marker shows higher sensitivity and specificity than IgM rheumatoid factor (RF-M) in Portuguese RA patients.
Area of Science:
- Immunology
- Rheumatology
Background:
- IgM rheumatoid factor (RF-M) is an established classification criterion for rheumatoid arthritis (RA).
- The diagnostic utility of RF-M can be limited in certain patient populations.
Purpose of the Study:
- To compare the diagnostic performance of anti-cyclic citrullinated peptide 2 (anti-CCP2) antibodies and RF-M.
- To evaluate these markers in a cohort of Portuguese patients with established RA.
Main Methods:
- Serum samples from 56 established RA patients and 93 controls were analyzed.
- Anti-CCP2 antibodies were measured using enzymatic fluoroimmunoassay.
- RF-M was quantified using microElisa.
Main Results:
- Anti-CCP2 antibodies were positive in 71.4% of RA patients and 0% of controls.
- RF-M was positive in 60.7% of RA patients, with low positivity in controls (9.3% spondylarthropathies, 2% healthy donors).
- Anti-CCP2 demonstrated higher sensitivity (71.4% vs 60.7%) and perfect specificity (100% vs 90.7%) compared to RF-M.
Conclusions:
- Anti-CCP2 antibody testing offers superior diagnostic performance over RF-M in Portuguese patients with established RA.
- The high specificity of anti-CCP2 makes it a valuable tool for accurate RA diagnosis.
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