Synovial fluid monocyte-to-lymphocyte ratio in knee osteoarthritis patients predicts patient response to conservative treatment: a retrospective cohort study

• Published in: BMC musculoskeletal disorders Vol. 25; no. 1; p. 379
• Main Authors: Lee, Jong Min, Lim, Sumin, Kang, Gunoo, Chung, Jun Young, Yun, Hee-Woong, Jin, Yong Jun, Park, Do Young, Park, Jae-Young
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 14.05.2024; BioMed Central; BMC
• Subjects: Aged; Analysis; Biological markers; Biomarker; Biomarkers; Biomarkers - analysis; Biomarkers - blood; Blood; Body mass index; Care and treatment; Cohort analysis; Conservative Treatment - methods; Decision-making; Diagnosis; Effusion; Evidence-based medicine; Female; Health aspects; Hematology; Humans; Injections, Intra-Articular; Joint replacement surgery; Knee; Leukocyte Count; Leukocytes (neutrophilic); Lymphocytes; Male; Medical examination; Methods; Middle Aged; Monocyte; Monocyte to lymphocyte ratio; Monocytes; Neutrophils; Osteoarthritis; Osteoarthritis, Knee - diagnosis; Osteoarthritis, Knee - therapy; Outpatient care facilities; Pathophysiology; Patients; Predictive Value of Tests; Proteins; Ratios; Retrospective Studies; Rheumatoid arthritis; Steroids; Synovial fluid; Synovial Fluid - cytology; Treatment Outcome; Tumor necrosis factor-TNF; South Korea; United States > US; Biomarker; Monocyte to lymphocyte ratio; Monocyte; Osteoarthritis
• ISSN: 1471-2474; 1471-2474
• DOI: 10.1186/s12891-024-07475-1

Biomarkers that predict the treatment response in patients with knee osteoarthritis are scarce. This study aimed to investigate the potential role of synovial fluid cell counts and their ratios as biomarkers of primary knee osteoarthritis. This retrospective study investigated 96 consecutive knee osteoarthritis patients with knee effusion who underwent joint fluid aspiration analysis and received concomitant intra-articular corticosteroid injections and blood tests. The monocyte-to-lymphocyte ratio (MLR) and neutrophil-to-lymphocyte ratio (NLR) were calculated. After 6 months of treatment, patients were divided into two groups: the responder group showing symptom resolution, defined by a visual analog scale (VAS) score of ≤ 3, without additional treatment, and the non-responder group showing residual symptoms, defined by a VAS score of > 3 and requiring further intervention, such as additional medication, repeated injections, or surgical treatment. Unpaired t-tests and univariate and multivariate logistic regression analyses were conducted between the two groups to predict treatment response after conservative treatment. The predictive value was calculated using the area under the receiver operating characteristic curve, and the optimal cutoff value was determined. Synovial fluid MLR was significantly higher in the non-responder group compared to the responder group (1.86 ± 1.64 vs. 1.11 ± 1.37, respectively; p = 0.02). After accounting for confounding variables, odds ratio of non-responder due to increased MLR were 1.63 (95% confidence interval: 1.11-2.39). The optimal MLR cutoff value for predicting patient response to conservative treatment was 0.941. MLR may be a potential biomarker for predicting the response to conservative treatment in patients with primary knee osteoarthritis.