The Significance of Neutrophil Lymphocyte Ratio, Platelet Lymphocyte Ratio, and Red Cell Distribution Width in Osteoarthritis

Background: The neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and red cell distribution width (RDW) are routinely available inflammatory biomarkers. Their significance in osteoarthritis (OA) is poorly understood. This is a systematic review, and meta-analysis aimed to determine the association of these biomarkers with the presence and severity of OA. Methods: We searched MEDLINE, EMBASE, and Cochrane library for studies reporting on associations between NLR, PLR, and RDW with OA from October 1, 2022, to November 18, 2022. We generated pooled effect measures using random-effects inverse-variance modeling to compare biomarker levels in patients with OA against healthy controls. We generated pooled effect measures to compare patients with severe OA against mild/moderate OA as defined by the Kellgren-Lawrence grading scale, a classification of OA severity based on radiographic findings. We performed metaregression to explore between-study heterogeneity. Results: We included 20 studies involving 5,109 patients in this review. Both NLR and PLR were significantly elevated in OA. RDW was not significantly elevated with OA presence or severity. Only NLR demonstrated a significant elevation with OA severity. Conclusions: In this systematic review and meta-analysis, both NLR and PLR were associated with the presence of OA, whereas only NLR was associated with the severity of disease.