Abstract:Objective To investigate the expressions and clinical significance of soluble CD14 subtype (sCD14-ST) and procalcitonin (PCT) in patients with rheumatoid arthritis(RA) and systemic bacterial infection. Methods A total of 136 patients diagnosed with RA in the Sixth Affiliated Hospital of Xinjiang Medical University from January 2018 to January 2019 were selected as the research objects. Crohn′s disease activity index (CDAI), Disease Activity Score 28 (DSA28) based on C-reactive protein (DSA28-CRP), DSA28 based on erythrocyte sedimentation rate (DSA28-ESR) were used to evaluate the disease activity of RA patients, and sequential organ failure assessment (SOFA) score was used to evaluate the infection severity of RA patients. The levels of PCT and sCD14-ST were respectively detected by electrochemiluminescence and ELISA. Results The sites of infection in RA patients were mainly pulmonary infection (63. 79%), and Gram-positive bacteria (56. 90%) were the main pathogens. The concentrations of sCD14-ST and PCT in infection group were significantly higher than those in non-infected group and healthy group(P<0.05). The sCD14-ST was positively correlated with CDAI, DAS28-CRP, DAS28-ESR and SOFA score (P<0.05). There was no significant correlation between PCT concentration and SOFA score (P>0.05). Both sCD14-ST and PCT have diagnostic value for infection in RA patients, and their cut-off values were 238 ng/L and 0.5 μg/L, respectively. Conclusion The changes of sCD14-ST and PCT levels have certain value in the diagnosis of bacterial infection in RA patients and can be used as an inflammatory marker for early infection of RA patients. 