Evaluation of serum level of miR-155 and TNF-α in rheumatoid arthritis patients

Background: MicroRNAs play a vital role in the regulation of immune response and rheumatoid arthritis (RA) pathogenesis as a potential biomarker for disease control. We hypothesis some roles as a marker for serum miR-155 in the prognosis and the diagnosis of RA and its correlation with including rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), and tumor necrosis factor-alpha (TNF-alpha). Methods: In this cross-sectional study on 40 patients and 12 individuals as control, serum samples of participants were collected, and miR-155 expression was measured by relative quantitative real-time polymerase chain reaction (qRT-PCR). Anti-CCP and TNF-alpha levels were detected by enzyme-linked immunosorbent assay. Data analysis was performed via SPSS version 25. Results: MiR-155 expression was 32.2% lower in RA patients compared to controls (Fold change = 0.678, Delta Delta Ct = 0.56), although there was no significance difference between the groups. (p = 0.379). Our results showed that Delta Ct of miR-155 is not correlated with RF (p= 0.621), anti-CCP (p = 0.560), TNF-alpha (p= 0.267) and DAS28 score (p= 0.333). Conclusion: We concluded that miR-155 might not be a suitable diagnostic marker in serum of RA patients. We suggest more sample size for the subsequent studies.