14-3-3η protein is associated with disease activity and osteoporosis in patients with rheumatoid arthritis.

Introduction: This study was designed to explore the potential association of serum 14-3-3η protein level with disease activity and bone mineral density (BMD) in Egyptian patients with rheumatoid arthritis (RA). Patients were recruited from the outpatient clinic at Mansoura University Hospital. Material and methods: One hundred eighty-eight patients with RA and 192 matched controls were enrolled. The rheumatoid arthritis activity parameters were evaluated in RA patients. Bone mineral density was measured. Serum levels of 14-3-3η protein and IL-6 were estimated for all participants by enzyme-linked immunosorbent assays (ELISA). Results: Rheumatoid arthritis patients had a significantly higher median serum 14-3-3η protein level compared to matched controls (p ≤ 0.05). Serum level of 14-3-3η protein was significantly correlated with DAS28-ESR (p ≤ 0.05) and serum IL-6 level (p ≤ 0.05). The rheumatoid arthritis-osteoporosis group had significantly higher serum 14-3-3η protein than the RA-osteopenia group and RA-control group. Similarly, the difference of the serum 14-3-3η protein between the RA-osteopenia group and the RA-control group was significant. In the linear regression analysis, the strongest factors that were associated with BMD in RA patients were the serum level of 14-3-3η protein (p ≤ 0.05), IL-6 (p ≤ 0.05) and DAS28-ESR (p ≤ 0.05). Conclusions: Serum level of 14-3-3η protein was significantly elevated in RA patients compared to controls and is significantly correlated with parameters of activity disease. The RA-osteoporosis group had significantly higher serum 14-3-3η protein than the RA-osteopenia group and RA-control group. Serum 14-3-3η protein can be a promising biomarker to reflect RA activity and predict presence of osteoporosis in RA patients.