Value of combination of 25-(OH)-D3, IL-6, and cyclic peptide containing citrulline antibodies in different stages of rheumatoid arthritis.

ABSTRACT

OBJECTIVE: To determine the value of a combination of 25-hydroxyvitamin D3 (25-(OH)-D3), interleukin-6 (IL-6), and cyclic peptide containing citrulline (CCP) antibodies in the acute stage and remission stage of patients with rheumatoid arthritis (RA). METHODS: A retrospective analysis was made on 80 RA patients who received treatment in Wenjiang District People's Hospital of Chengdu from February 2017 to February 2020. According to their condition, they were identified as acute-stage patients (n=48) or remission-stage patients (n=32). In addition, 40 healthy individuals who received physical examination in our hospital during the same period were enrolled in a control group. Serum 25-(OH)-D3, IL-6, and CCP antibodies in all enrolled participants were quantified, and their levels were compared between RA patients at the acute stage and those at the remission stage before therapy, and also between patients with different efficacy after 3 months of therapy. The correlations of serum 25-(OH)-D3, IL-6, and CCP antibodies with disease activity score in 28 joints (DAS-28) were analyzed. A corresponding joint receiver operating characteristic (ROC) curve was drawn to analyze the diagnostic value of the combination of 25-(OH)-D3, IL-6, and CCP antibodies in the staging of RA patients, and logistic regression was used to establish an efficacy risk model. RESULTS: The highest serum 25-(OH)-D3 level was found in the control group, followed by the remission-stage patients and then acute-stage patients from high to low (all P<0.05), and the lowest levels of serum IL-6 and CCP antibodies were also found in the control group, followed by the remission-stage patients and then the acute-stage patients from low to high (all P<0.05). The Pearson's test revealed a negative correlation of 25-(OH)-D3 with DAS-28 and a positive correlation of IL-6 and CCP antibodies with DAS-28. According to ROC curve-based analysis, the area under the joint curve of 25-(OH)-D3, IL-6, and CCP antibodies was >0.9. After therapy, patients showed an increase in 25-(OH)-D3 and decreases in IL-6 and CCP antibodies (all P<0.05). The logistic model confirmed that the area under the ROC curve of RA affecting the efficacy on patients was >0.8. CONCLUSION: A combination of 25-(OH)-D3, IL-6, and CCP antibodies can be adopted as a diagnostic indicator in acute and remission stages of RA. A risk factor model of clinical efficacy in RA patients can help us effectively identify high-risk patients before therapy and take intervention measures early.