Sun CM, et al. - Researchers carried out this study to ascertain the association of circulating miR-125a/b expression with the risk and disease severity of Crohn’s disease (CD), and with inflammatory cytokines. In patients with active disease status, circulating miR-125a was decreased. However, this was not observed with miR-125b. In patients with CD, circulating miR-125a was negatively correlated with disease severity and inflammatory cytokines.

Methods

• The researchers collected plasma samples from patients with active CD (A-CD), or CD in remission (R-CD) and from healthy controls (HCs).
• They measured the levels of the inflammatory cytokines interleukin-17 (IL-17), tumour necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) by enzyme-linked immunosorbent assay.
• They evaluated the expression of miR-125a/b by quantitative polymerase chain reaction (qPCR).

Results

• The researchers included 29 A-CD patients, 37 R-CD patients, and 37 HCs in the study.
• In A-CD patients, plasma miR-125a expression was decreased compared with that in R-CD patients (P < 0.001) and HCs (P < 0.001).
• The differentiation of A-CD from R-CD patients [area under curve (AUC) = 0.854] and from HCs (AUC = 0.780) was enabled by miR-125a expression, while this was not noted with miR-125b expression.
• In A-CD patients, miR-125a was negatively associated with C-reaction protein (CRP) (P=0.017), erythrocyte sedimentation rate (ESR) (P=0.026), Crohn’s disease activity index (CDAI) (P=0.003), IL-17 (P=0.015), and TNF-α (P=0.004).
• Furthermore, in R-CD patients, miR-125a was negatively correlated with CRP (P=0.038) and CDAI (P=0.021).
• No association with CRP, CDAI, IL-17, TNF-α, or IFN-γ was found in A-CD or in R-CD patients regarding miR-125b.
• In A-CD patients who achieved clinical remission (P=0.009) after 3-mo treatment, miR-125a levels gradually increased, while they remained unchanged among patients who failed to achieve remission.
• In remission or non-remission patients, no changes in miR-125b expression were detected after treatment.