AB0204 A NEW INFLAMMATORY MARKER ASSOCIATED WITH DISEASE ACTIVITY IN PATIENTS WITH RHEUMATOID ARTHRITIS: PLATELET TO ALBUMIN RATIO

Abstract

Background:Rheumatoid arthritis (RA) is an inflammatory autoimmune disease characterized by disordered immunity and dysregulated cytokine. Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) have been defined as inflammatory markers to evaluate disease activity of RA. Recently, platelet to albumin ratio (PAR) was reported as a new prognostic index in patients with cancer. However, similar studies have not been displayed in RA.Objectives:This study was to explore the role of PAR in RA and its association with disease activity.Methods:This retrospective study enrolled 136 RA patients and 87 age- and gender-matched healthy controls. Neutrophil, lymphocyte, monocyte, platelet, hemoglobin, albumin, NLR, neutrophil to hemoglobin ratio (NHR), neutrophil to albumin ratio (NAR), monocyte to lymphocyte ratio (MLR), monocyte to hemoglobin ratio(MHR), monocyte to albumin ratio(MAR), PLR, platelet to hemoglobin ratio (PHR), PAR, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and Disease Activity Score of 28 joints - ESR (DAS28-ESR) were detected. Receiver operation characteristic (ROC) curve was used to discriminate RA patients from healthy individuals. Relationships between PAR and DAS28-ESR as well as other laboratory data were measured by the Spearman’s correlations analysis.Results:RA patients showed higher levels of NLR, NHR, NAR, MLR, MHR, MAR, PLR, PHR PAR and lower levels of albumin than healthy controls. PAR and other inflammatory parameters were also raised along with increased disease activity in RA patients (P < 0.05) except NHR (P = 0.098). Similarly, albumin was decreased in RA patients as the disease activity increased (P = 0.001). ROC showed that area under curve (AUC) of PAR (0.887, 95%CI: 0.843-0.931) was higher than NLR (0.818, 95%CI: 0.762-0.874), NHR(0.839, 95%CI: 0.787-0.890), NAR(0.829, 95%CI: 0.776-0.882), MLR (0.794, 95%CI: 0.734-0.854), MHR(0.817, 95%CI: 0.760-0.874), MAR(0.814, 95%CI: 0.757-0.872), PLR (0.832, 95%CI: 0.779-0.886), PHR(0.884, 95%CI: 0.838-0.930) and albumin(0.860, 95%CI: 0.813-0.908). Besides, PAR was positively correlated with DAS28-ESR (r = 0.429, P < 0.001), CRP (r = 0.540, P < 0.001) and ESR (r = 0.492, P < 0.001), yielding a highest relevance than other inflammatory indexes.Conclusion:This study demonstrated that PAR was elevated in RA patients and increased with the disease activity. PAR may be a novel marker to assess the disease activity of RA patients.