Objective To explore the correlations between the ratio of C-reactive protein to albumin (CRP/ALB), platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR) and disease activity index, 28-joint disease activity (DAS28) score of patients with rheumatoid arthritis (RA), and evaluate their value in the assessment of RA conditions.

Methods A total of 121 RA patients were selected, and divided into the remission group (15 cases), low activity group (25 cases), moderate activity group (52 cases) and high activity group (29 cases) according to the AS28-ESR score. Peripheral venous blood was collected from the patients to detected the levels of CRP/ALB, PLR, NLR, rheumatoid factor (RF) and erythrocyte sedimentation rate (ESR). The clinical significance of the indicators were evaluated through one-way analysis of variance, Spearman correlation analysis, multivariate logistic regression analysis and receiver operating characteristic (ROC) curve.

Results With the increase of disease activity, the levels of CRP/ALB, PLR, NLR, RF and ESR showed a gradually increasing trend (P ＜ 0.01). Spearman correlation analysis showed that the CRP/ALB, PLR and NLR were positively correlated with RF, ESR, and DAS28 scores (P ＜ 0.01). Multivariate logistic regression analysis indicated that the CRP/ALB (OR = 7.368), PLR (OR = 1.014) and NLR (OR = 2.625) were all independent risk factors of high activity in RA patients (P ＜ 0.01). ROC curve analysis showed that the area under the curve for the combined prediction of high activity in RA by the three was 0.878 (95%CI: 0.816–0.939), with a sensitivity of 79.00%, a specificity of 80.00% and a Youden index of 0.590.

Conclusions CRP/ALB, PLR, and NLR are closely related to the disease activity of RA, and effective indicators for evaluating the condition. The combined application of the three can significantly enhance the predictive value for moderate to high disease activity, and has important clinical reference significance.