High baseline neutrophil-to-lymphocyte ratio is associated with better adalimumab response in patients with rheumatoid arthritis

Objective To identify factors associated with adalimumab response in patients with rheumatoid arthritis, particularly focusing on the clinical characteristics and neutrophil-to-lymphocyte ratio. Methods This prospective study included 189 patients with rheumatoid arthritis. Associations between treatment response and various demographic, clinical, therapeutic, disease activity, and serological parameters were analyzed, including serum concentrations of proinflammatory cytokines. Treatment response was assessed using the Disease Activity Score in 28 joints at week 24. Results Baseline neutrophil-to-lymphocyte (odds ratio = 3.1, 95% confidence interval: 1.04–7.50, p = 0.019) was identified as an independent predictor of favorable response to adalimumab. Among good responders, neutrophil-to-lymphocyte levels decreased significantly following initiation of tumor necrosis factor inhibitor treatment (p < 0.001). Patients achieving Disease Activity Score in 28 joints-defined remission at week 24 had significantly higher baseline neutrophil-to-lymphocyte values than non-remitters (p < 0.001). A significantly greater proportion of patients in the high-neutrophil-to-lymphocyte group attained remission compared with the low-neutrophil-to-lymphocyte group (62.1% vs. 39.2%, p < 0.001). Conclusions A higher baseline neutrophil-to-lymphocyte is associated with improved response to adalimumab therapy in rheumatoid arthritis. These findings support the potential use of baseline neutrophil-to-lymphocyte as a clinically applicable biomarker for predicting therapeutic outcomes following adalimumab treatment.