Clinical significance of serum CXCL13 change in rheumatoid arthritis

Abstract

Objective To observe and follow up the changes of serum CXCL13 in rheumatoid arthritis (RA) patients and to investigate its significance on RA patients. Methods Blood samples were collected from 15 primary RA patients (RA group) and 21 healthy controls (HC group) who visited clinic in People’s Hospital of Zhengzhou University from June 2014 to June 2017. Fifteen primary RA patients were followed up, and their blood samples were collected before treatment and at 3, 6 and 12 months after treatment, respectively. Serum CXCL13 were detected by enzyme-linked immunosorbent assay. Information on clinical symptoms and the findings of physical examinations was collected including name, gender, age, tender and swollen joint count (28 joints), general assessment of disease activity by patient, general assessment of disease activity by doctor, and thus the disease activity score (DAS) in 28 joints with erythrocyte sedimentation rate (ESR)-based or C-reative protein (CRP)-based, simplified disease activity index (SDAI), and clinical disease activity index (CDAI) were calculated according to the above data. The level of serum CXCL13 in 15 cases of follow-up RA patients was analyzed. Results ① The CXCL13 level was (147.03±56.26) pg/ml before initial treatment, (86.55±61.39) pg/ml at 3 months after treatment, (63.81±32.68) pg/ml at 6 months after treatment, and (90.71±39.08) pg/ml at 12 months after treatment, which were all significantly higher than the level of HC group [(42.24±11.21)pg/ml], P<0.05. ② The tendency of DAS28(CRP), CDAI and SDAI were similar to DAS28(ESR). ③ CXCL13 level had entered in a downtrend at 3 and 6 months after treatment, which was similar to the tendency of DAS28(ESR), DAS28(CRP), CDAI, SDAI. CXCL13 level at 12 months after treatment was higher than that at 6 months, but DAS28(ESR), DAS28(CRP), CDAI, SDAI had a downtrend, which was different from tendency of serum CXCL 13. Conclusions Serum CXCL13 level is significantly higher in RA patients and its level is in a downtrend in the first few months and then increased, which suggests that serum CXCL13 level may serve as clinical markers of assessment on disease activity and treatment response, that is serum CXCL13 may contribute to the pathogenesis of RA. Key words: Rheumatoid arthritis; CXCL13; Disease activity