The relationship between neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune-inflammation index, and halp score with disease activity in patients with rheumatoid arthritis

Aim: Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by persistent joint inflammation driven by dysregulated immune responses. Identifying reliable biomarkers of disease activity remains crucial for optimizing patient management. This study investigated whether inflammatory indices derived from routine complete blood count (CBC) parameters—namely, the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and hemoglobin–albumin–lymphocyte–platelet (HALP) score—are associated with RA disease activity. Materials and Methods: This single-center, cross-sectional study enrolled 72 patients with rheumatoid arthritis who fulfilled the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria. Disease activity was assessed using the Disease Activity Score in 28 joints with C-reactive protein (DAS28–CRP), with remission defined as ≤2.6 and active disease as >2.6. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and hemoglobin–albumin–lymphocyte–platelet (HALP) score were calculated from routine hematologic and biochemical data. Associations between these indices and disease activity were examined using correlation and comparative statistical analyses. Results: Among the 72 patients (73.6% female; mean age, 53.8 ± 11.3 years), disease activity was categorized according to DAS28–CRP (remission ≤2.6; active >2.6). Patients with active disease demonstrated significantly higher NLR, PLR, and SII values compared with those in remission. Disease activity showed a positive correlation with these indices, as well as with CRP, whereas the HALP score exhibited an inverse association with inflammatory markers. Conclusion: NLR, PLR, and SII appear to be practical, cost-effective biomarkers for evaluating disease activity in rheumatoid arthritis. The HALP score may provide additional value by reflecting both inflammatory and nutritional status.