The Significance of Blood Index and Biochemistry Index in Patients with Rheumatoid Arthritis

Background: The aim of this study is to demonstrate the clinical significance of the platelet-to-lymphocyte ratio (PLR) and the ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) in patients with rheumatoid arthritis (RA). Methods: A total of 215 patients with RA, 115 patients with osteoarthritis (OA), and 303 healthy controls (HCs) were included in this study. Data on the AST and ALT levels were collected from liver function test reports, and data on the number of platelets and lymphocytes were obtained from a routine blood analysis. Moreover, all the laboratory parameters of patients with RA, patients with OA, and HCs were retrospectively analyzed. Results: The results obtained in this study showed that patients with RA had the highest PLR and AST/ALT ratio, whereas HCs had the lowest ratios (p < 0.05). Receiver operating characteristic (ROC) analysis showed that PLR + AST/ALT can produce high sensitivity and moderate specificity, distinguishing patients with RA from HCs, with a sensitivity of 91.1%, specificity of 75.3%, and area under the ROC curve (AUC) of 0.907. Spearman's analysis showed the PLR is negatively correlated with the erythrocyte sedimentation rate and C-reactive protein levels (p < 0.005). Conclusions: Combined detection of PLR and AST/ALT is better than each indicator individually and can improve the diagnostic efficiency of RA.