Correlation of platelet–lymphocyte ratio, systemic immune-inflammation index, and mean platelet volume with disease activity in rheumatoid arthritis: A monocentric and retrospective study

This study analyzes the platelet-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and mean platelet volume (MPV) in the evaluation of disease activity in patients with rheumatoid arthritis (RA). The clinical data of patients with RA and healthy controls, including complete blood count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), anti-cyclic citrullinated peptide antibody (anti-CCP antibody), and rheumatoid factor (RF), were retrospectively analyzed. The SII, PLR, and MPV were collected and calculated for the RA. Pearson correlation analysis was used to estimate the correlation between hematological indices and DAS28-ESR. Receiver-operating characteristic (ROC) curve analysis was performed to assess the value of these indices in differentiating active RA from RA remission. The results revealed that SII and PLR were elevated and MPV was markedly decreased in patients with RA compared to healthy controls (all P < .05). Statistical significance was observed in SII and MPV, but not in PLR, between the active RA patients and the remission RA group. SII and PLR were positively correlated with DAS28-ESR and DAS28-CRP, whereas MPV was negatively correlated with DAS28-CRP but not with DAS28-ESR. The ROC curve showed that the SII and MPV were helpful in assessing disease activity in RA. SII and MPV were correlated with the DAS28 score and may be used as complementary tools to evaluate disease activity in patients with RA.