A New Biomarker for RA?

Elevated 14-3-3eta Serum Protein Levels Increase RA Confirmation in Recent-Onset Polyarthritis Patients

The diagnostic properties of 14-3-3eta were presented at the CRA by Dr. Gilles Boire.

14-3-3 is a family of intracellular proteins that seem to be acting as adaptors that modulate the activities of other intracellular proteins. There are 7 isoforms of this protein and about 10 years ago it was found that the “eta" form occurs in both the synovial fluid and the serum of patients with rheumatoid arthritis.

When cells are subjected to increased extracellular levels of 14-3-3eta, an increase in the production of pro-inflammatory cytokines is observed.

The objective of this study was to determine if the presence of 14-3-3eta is helpful in the diagnosis of rheumatoid arthritis.

331 patients with recent-onset polyarthritis from the Sherbrooke EUPA cohort were included in this study. Each patient had completed at least 5 years of follow-up within the cohort to ensure the study population reflected patients with persistent arthritis. The patients in the cohort were treated intensively to achieve a clinical remission defined as 0 out of 66 swollen joints.

At baseline, the patients were predminantly female (62%), mean age 60, median disease duration 3 months, mean DAS28-CRP 5.1, and mean SDAI 30.1. Over 90% of these patients were treated early with DMARDs.

14-3-3eta was observed in 46.2% of patients, RF in 44.1%, anti-CCP2 in 40.2%, and anti-Sa in 22.1%.

When grouped, 51.4% of patients were positive for at least one of RF, anti-CCP, or anti-Sa. When 14-3-3eta was also considered, the percentage of patients with at least one positive autoantibody increased to 58.6%.

The presence of 14-3-3eta increased the diagnostic sensitivity of currently available RA-associated antibodies. These data support measuring 14-3-3eta in patients with early arthritis to help with disease stratification.

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