AIM To determine the association of circulating mi R-125 a/b expression with the risk and disease severity of Crohn’s disease(CD), and with inflammatory cytokines.METHODS Plasma samples were collected from patients with active CD(A-CD), or CD in remission(R-CD) and from healthy controls(HCs). The levels of the inflammatory cytokines interleukin-17(IL-17), tumour necrosis factor-α(TNF-α), and interferon-γ(IFN-γ) were measured by enzyme-linked immunosorbent assay. The expression of mi R-125 a/b was assessed by quantitative polymerase chain reaction(q PCR).RESULTS Twenty-nine A-CD patients, 37 R-CD patients, and 37 HCs were included in the study. Plasma mi R-125 a expression was decreased in A-CD patients comparedwith that in R-CD patients(P < 0.001) and HCs(P < 0.001). mi R-125 a expression levels enabled the differentiation of A-CD from R-CD patients [area under curve(AUC) = 0.854] and from HCs(AUC = 0.780), whereas mi R-125 b expression did not. mi R-125 a was negatively correlated 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) in A-CD patients. Furthermore, mi R-125 a was negatively associated with CRP(P = 0.038) and CDAI(P = 0.021) in R-CD patients. Regarding mi R-125 b, no association with CRP, CDAI, IL-17, TNF-α, or IFN-γ was found in A-CD or in R-CD patients. mi R-125 a levels gradually increased in A-CD patients who achieved clinical remission(P = 0.009) after 3-mo treatment, whereas they remained unchanged among patients who failed to achieve remission. No changes in mi R-125 b expression were detected in remission or non-remission patients after treatment. CONCLUSION Circulating mi R-125 a but not mi R-125 b is decreased in patients with active disease status and negatively correlates with disease severity and inflammatory cytokines in patients with CD. AIM To determine the association of circulating mi R-125 a / b expression with the risk and disease severity of Crohn’s disease (CD), and with inflammatory cytokines. METHODS Plasma samples were collected from patients with active CD (A-CD), or CD in remission (R-CD) and from healthy controls (HCs). The levels of the inflammatory cytokines interleukin-17 (IL- 17), tumor necrosis factor- alpha (TNF- alpha), and interferon- gamma ) were measured by enzyme-linked immunosorbent assay. The expression of mi R-125 a / b was assessed by quantitative polymerase chain reaction (q PCR) .RESULTS Twenty-nine A-CD patients, 37 R-CD patients, and 37 HCs Plasma mi R-125 a expression was decreased in A-CD patients compared with that in R-CD patients (P <0.001) and HCs (P <0.001). mi R-125 a expression levels enabled the differentiation of A-CD from R-CD patients [area under curve (AUC) = 0.854] and from HCs (AUC = 0.780), while mi R- 125 b expression did not. mi R-125 a was negatively correlated (P = 0.017), erythrocyte sedimentation rate (ESR), Crohn’s disease activity index (CDAI) (P = 0.003), IL-17 (P = 0.004) in A-CD patients. Furthermore, mi R-125 a was negatively associated with CRP (P = 0.038) and CDAI no association with CRP, CDAI, IL-17, TNF-α, or IFN-γ was found in A-CD or in R-CD patients. mi R-125 a levels gradually increased in A-CD patients who achieved clinical remission ( P = 0.009) after 3-mo treatment, but they remained unchanged among patients who failed to achieve remission. No changes in mi R-125 b expression were detected in remission or non-remission patients after treatment. CONCLUSION Circulating mi R-125 a but not mi R-125 b is decreased in patients with active disease status and negatively correlates with disease severity and inflammatory cytokines in patients with CD.