The role of 14.3.3 eta protein in the diagnosis of patients with early rheumatoid arthritis

Aim of the work: To evaluate the role of 14-3-3 eta protein in diagnosing early rheumatoid arthritis (RA), and its association with disease activity. Patients and methods: A total of 40 patients with early RA were enrolled, along with 20 controls with non-erosive arthritis (8 with systemic lupus erythematosus, 8 with osteoarthritis, and 4 with systemic sclerosis), and 20 healthy controls. The clinical disease activity index (CDAI) and simplified disease activity index (SDAI) were assessed. Measurement of rheumatoid factor (RF) titer, anti-cyclic citrullinated peptide (anti-CCP), and serum level of 14-3-3 eta was performed for all participants. Results: The mean age of RA patients was 32.02 +/- 8.31 years and they were 33 females and 7 males. Age and gender were comparable with non-erosive arthritis patients and control. Serum levels of 14-3-3 eta were significantly higher in RA patients (range 4.01-50.45, median 13.5 ng/ml) than in the non-erosive arthritis group (range 1.12-16.1, median 3.16 ng/ml) and the healthy control group (range0.88-3.44, median 1.7 ng/ml) (p < 0.001).14-3-3 eta serum levels showed significant correlations with CDAI (r = 0.979,p < 0.001) and SDAI (r = 0.975,p < 0.001). Serum 14-3-3 eta at a cut-off >5.03 ng/ml was able to diagnose early RA with a sensitivity of 97.5 % and specificity of 90 %. When combining the three markers together (RF, anti CCP, and 14-3-3 eta) sensitivity was enhanced to 98.9 % and specificity reached 100 %. Conclusion: 14-3-3 eta protein can serve as a potential diagnostic marker for early RA and when combined with RF and anti-CCP the sensitivity and specificity of diagnosis is enhanced.