Objective To detect the correlation of serum circASH2L and miR-129-5p expressions and disease severity in patients with rheumatoid arthritis (RA).

Methods A total of 98 patients with RA were adopted in the RA group, and 98 patients who were matched for gender and age during the same period were iadopted in the control group.According to the DAS28 score, RA patients were divided into 35 cases in stable stage (DAS28≤2.6) and 63 cases in active stage (DAS28>2.6), then the active RA patients were further divided into the mild (2.6 < DAS28≤3.2), moderate (3.2 < DAS28≤5.1) and severe (DAS28>5.1) activity groups.Fluorescence quantitative PCR was used to detect the expression levels of serum circASH2L and miR-129-5p, the serum levels of circASH2L and miR-129-5p in RA patients with different disease activity were analyzed and compared with those in the control group.The expression levels of serum circASH2L and miR-129-5p, their correlation with biochemical indexes and DAS28 scores were analyzed by Pearson method.Multiple linear regression was used to analyze the influencing factors of DAS28 score in RA patients.

Results Compared with the control group, the levels of serum circASH2L in RA patients were obviously higher (P < 0.01), and miR-129-5p were obviously lower (P < 0.01).Compared with the stable stage, the levels of serum circASH2L in patients with active RA were obviously higher (P < 0.01).The levels of circASH2L in the mild, moderate and severe activity groups were increased sequentially, while the levels of miR-129-5p were decreased sequentially (P < 0.05 to P < 0.01).Serum circASH2L in RA patients was negatively correlated with miR-129-5p (r=-0.680, P < 0.05), and positively correlated with CRP, RF-IgM and DAS-28 scores (r=0.587, 0.523, 0.637, P < 0.05).Serum miR-129-5p was negatively correlated with CRP, RF-IgM, and DAS-28 scores (r=-0.546, -0.557, -0.592, P < 0.05).Multiple linear regression analysis showed that after controlling for CRP, RF-IgM, age, ESR and anti-CCP antibody, the variation value of miR-129-5p independently explained the DAS28 scores in RA patients was increased by 7.9% (P < 0.01);after controlling for CRP, RF-IgM, age, ESR, anti-CCP antibody and miR-129-5p, the variation value of circASH2L independently explained the DAS28 scores in RA patients was increased by 8.8% (P < 0.01).

Conclusions The levels of serum circASH2L in RA patients are higher, and the levels of miR-129-5p are lower.Both of circASH2L and miR-129-5p are associated with patients′ CRP, RF-IgM and DAS28 scores, which can be used as a reference index for determining RA disease activity.