Background:
Rheumatoid arthritis (RA) is a common progressive chronic inflammatory
autoimmune disease which affects mostly small joints, causing pain, swelling, deformity, and
disability. Although progress has been made in exploring RA nature, still there is a lot to know
about the disease pathogenesis, diagnosis, and treatment.
Aim of the Work:
To investigate the role of serum anti-carbamylated protein antibodies and 14-3-3η in the diagnosis of RA compared to rheumatoid factor (RF), anti-CCP antibodies, and highfrequency
musculoskeletal ultrasound used to assess the disease activity and joint damage.
Methods:
Serum anti-carbamylated protein antibodies and 14-3-3η were measured using ELISA
in 61 RA patients and 26 normal controls. RA Disease Activity Score (DAS 28), X-ray and musculoskeletal
ultrasound (hands and feet), carotid ultrasound (Intima-Media Thickness IMT)
were used in assessing the RA disease.
Results:
Anti-carbamylated protein antibodies were significantly elevated in RA patients 4.5 (4.1-
8.9 U⁄ml) compared to the control 3.2(1.9- 4.3 U⁄ml) (p< 0.001) but 14-3-3η showed no significant
difference. There was a significant positive correlation between anti-carbamylated protein antibodies,
14-3-3η levels and disease activity score assessed by DAS 28, increased IMT measured by
carotid duplex, total synovitis and total erosion score were assessed by musculoskeletal ultrasound.
There was no correlation between RF and anti-CCP antibodies. Anti-carbamylated protein
antibodies were found to have 66.7% sensitivity and 85.2% specificity in RA diagnosis, while 14-
3-3η had 51.9% sensitivity and 72.1% specificity.
Conclusion:
Anti-carbamylated protein antibodies and 14-3-3η have a high sensitivity and specificity
in RA diagnosis and had a correlation with the disease activity and joint damage.
Elevated levels of IgM and IgA antibodies to Proteus mirabilis and IgM antibodies to Escherichia coli are associated with early rheumatoid factor (RF)-positive rheumatoid arthritis
