Diagnostic Value of Combined Test of Anti-Cyclic Citrullinated Peptide Antibody, AKA Antibody, Carp Antibody, and Rheumatoid Factor for Rheumatoid Arthritis

Int J Rheum Dis. 2025 Jan;28(1):e70058. doi: 10.1111/1756-185X.70058.

Abstract

Objective: To analyze the diagnostic value of a combined test of anti-cyclic citrullinated peptide antibody (CCP), anti-keratin antibody (AKA), anti-carbamylated protein antibody (Carp antibody), and rheumatoid factor (RF) in the early diagnosis of rheumatoid arthritis (RA).

Methods: Sixty cases of RA admitted to our hospital from 2021 to 2022 (observation group) were selected, along with 50 cases of healthy physical examiners (control group). The results of CCP antibody, AKA antibody, Carp antibody, and rheumatoid factor in both groups were analyzed: the concentration of CCP antibody, AKA antibody, Carp antibody, and rheumatoid factor in each group at different levels; the comparison of various testing methods with the "gold standard" test; and the ROC curve analysis of CCP antibody, AKA antibody, Carp antibody, and rheumatoid factor in each group.

Results: The concentrations of CCP antibody, AKA antibody, Carp antibody, and rheumatoid factor were significantly higher in the observation group than in the control group (p < 0.05). Furthermore, there was a significant increase in the concentrations of CCP antibody, AKA antibody, Carp antibody, and rheumatoid factor from the mild to moderate group (p < 0.05), as well as from the moderate to severe group (p < 0.05). Additionally, when comparing the mild and severe groups, there was a significant elevation in the concentrations of CCP antibody, AKA antibody, Carp antibody (p < 0.05), and rheumatoid factor (p < 0.05).

Conclusion: Anti-cyclic citrullinated peptide antibody, AKA antibody, Carp antibody, and rheumatoid factor combined tests have high sensitivity and specificity in the diagnosis of RA.

Keywords: AKA antibody; CCP antibody; Carp antibody; RA; combined test; diagnostic value; rheumatoid arthritis.

MeSH terms

  • Adult
  • Aged
  • Anti-Citrullinated Protein Antibodies* / blood
  • Arthritis, Rheumatoid* / blood
  • Arthritis, Rheumatoid* / diagnosis
  • Arthritis, Rheumatoid* / immunology
  • Autoantibodies* / blood
  • Biomarkers* / blood
  • Case-Control Studies
  • Early Diagnosis
  • Female
  • Humans
  • Keratins / analysis
  • Keratins / immunology
  • Male
  • Middle Aged
  • Peptides, Cyclic / immunology
  • Predictive Value of Tests*
  • Protein Carbamylation / immunology
  • Reproducibility of Results
  • Rheumatoid Factor* / blood

Substances

  • Rheumatoid Factor
  • Anti-Citrullinated Protein Antibodies
  • Autoantibodies
  • Biomarkers
  • Keratins
  • Peptides, Cyclic