Objective  To investigate clinical characteristics of patients with rheumatoid arthritis (RA) and positive thyroid peroxidase antibody (TPOAb), and to analyze the risk factors affecting the level of TPOAb.

  Methods  A total of 191 RA patients were selected as study objects and were divided into TPOAb negative group (TPOAb ≤ 34 IU/mL) and TPOAb positive group (TPOAb >34 IU/mL). The differences of clinical data, laboratory indexes and immunological indexes between the two groups were compared, and the risk factors of TPOAb level were determined by multivariate Logistic regression analysis.

  Results  Age and interleukin-10 (IL-10) in the TPOAb positive group were lower than those in the TPOAb negative group (P < 0.05), the level of interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) in the TPOAb positive group were higher than those in the TPOAb negative group (P < 0.05). Multivariate Logistic regression analysis showed the higher level of IL-17 (OR=1.395, 95%CI, 1.005 to 1.937, P=0.047) and higher level of TNF-α (OR=1.051, 95%CI, 1.013 to 1.090, P=0.008)and lower level of IL-10 (OR=0.795, 95%CI, 0.652 to 0.968, P=0.022) were independent influencing factors for positive TPOAb.

  Conclusion  In RA patients, the positive rate of TPOAb is 14.7%(correlated with to age). High levels of IL-17 and TNF-α and low level of IL-10 are high risk factors of TPOAb.