Serum 14-3-3 ETA levels in ankylosing spondylitis with pure axial involvement: Could it be a potential biomarker to assess disease activity?

Abstract

Aim: The 14-3-3η (eta) protein has been associated with the severity of the disease and joint destruction in patients with rheumatoid arthritis (RA). It has also been shown to be likely to be effective in inflammatory events. We aimed to investigate whether eta levels could be a potential biomarker in the diagnosis of ankylosing spondylitis (AS) and in the determination of disease activity in patients with AS.Methods: This study included 51 patients diagnosed with AS and 49 healthy controls aged 20-65 years. The routine hemogram, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels were measured and the neutrophil/lymphocyte ratio (NLR) was calculated in the patients. The serum eta levels were also measured in the patient and healthy control groups. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS) were used to assess disease activity. Sacroiliac joint radiographs of the patients were evaluated and the sacroiliitis was graded.Results: There was no statistically significant correlation between the degree of sacroiliitis, disease activity indices, and eta levels. There was no statistically significant correlation between eta levels and hematological parameters except for CRP. There was a negative, weak, and statistically significant relationship between the patients’ eta levels and CRP (r=-0.277; p=0.049). We could not find any correlation between the degree of sacroiliitis, disease activity indexes, and serum eta levels in AS patients.Conclusion: Serum eta levels are not a good biomarker for detecting disease activity in patients with ankylosing spondylitis. The 14-3-3η protein may play a more active role in rheumatic diseases where peripheral joint involvement is prominent.