SAT0379 C-REACTIVE PROTEIN TO ALBUMIN RATIO IS ASSOCIATED WITH DISEASE ACTIVITY IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS
Authors: Z. Zhong, Y. Huang, Q. Huang, T. LI
Journal: Annals of the Rheumatic Diseases (2020)

Background: C-reactive protein to albumin ratio (CAR) has emerged as a significant biomarker to evaluate and predict systemic inflammation[1]. However, the role of CAR in patients with axial spondyloarthritis (axSpA) remains unknown. Objectives: The aim of this study was to investigate the relationship between CAR and disease activity of axSpA. Methods: A total of 241 patients and 61 healthy controls from Guangdong Second Provincial General Hospital from December 2015 to August 2019 were retrospectively recruited in this study. Patients were divided into two groups, with 176 patients in remission group (BASDAI&lt;4) and 65 patients in active group (BASDAI≥4). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), albumin (ALB), CAR, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and monocyte-lymphocyte ratio (MLR) were detected. The correlations between CAR, NLR, PLR, MLR and disease activity were analyzed by the Spearman’s correlations analysis. Receiver operation characteristic (ROC) curves were performed to evaluate the discriminative utility of these parameters for disease activity of axSpA. Furthermore, the evaluation of the risk factors of axSpA was conducted using binary logistic regression analysis. Results: CAR, ESR, CRP, NLR, PLR and MLR in axSpA patients were significantly higher than those in the control group (p&lt;0.05 for each), while ALB was significantly lower (p&lt;0.001). Similarly, CAR in remission group was higher than that in control group (p&lt;0.001) and was lower than that in active group (p&lt;0.001). Besides, there were significantly positive correlations between CAR and ESR (r=0.702, P&lt;0.001), CRP (r=0.996, P&lt;0.001), BASDAI (r=0.329, p&lt;0.001) and BASFI (r=0.328, P&lt;0.001). Furthermore, ROC suggested that the area under the curve (AUC) of CAR was 0.701, which was the highest. The optimal cutoff point of CAR was 0.3644, with sensitivity and specificity of 58.5% and 79.0%. Logistic analysis results revealed that elevated CAR and MLR were independent risk factors for axSpA (EXP (B) =15.546, 95%CI: 5.898-40.979, P&lt;0.001; EXP (B) =2.206, 95%CI: 1.077-4.519, P=0.031, respectively). Conclusion: CAR was increased in axSpA patients especially in active group, and significantly correlated with disease activity. CAR may serve as a novel inflammatory marker of monitoring disease activity in patients with axSpA. References: [1]He, Y., et al., Correlation between albumin to fibrinogen ratio, C-reactive protein to albumin ratio and Th17 cells in patients with rheumatoid arthritis. Clin Chim Acta, 2020. 500: p. 149-154. Fig 1. ROC curve analysis of the discriminative values of the parameters for disease activity of axSpA Table 1. Discriminative values of the parameters for disease activity of axSpA AUC 95% CI Optimal cutoff point Specificity Sensitivity CAR 0.701 0.623-0.778 0.3644 79.0% 58.5% NLR 0.450 0.365-0.534 3.165 84.1% 18.5% PLR 0.528 0.448-0.608 127.385 42.6% 69.2% MLR 0.468 0.384-0.553 0.385 92.6% 16.9% ESR 0.685 0.612-0.758 15.5 52.3% 76.9% CRP 0.691 0.614-0.769 10.85 71.6% 63.1% CAR, C-reactive protein to albumin ratio; NLR, neutrophil-lymphocyte ratio; PLR, platelet-lymphocyte ratio; MLR, monocyte-lymphocyte ratio; CRP, C reactive protein; ESR, erythrocyte sedimentation rate; AUC, areas under the ROC curve Disclosure of Interests: None declared