Exploring the frequency of anemia in patients with Axial Spondyloarthritis: associations with inflammatory markers and response to Anti-Tumor Necrosis Factor (TNF)-α therapy

Background: Despite the well-established link between systemic inflammation and anemia in rheumatic diseases, the relationship between specific inflammatory markers and both anemia and therapeutic response in axial spondyloarthritis (axSpA) remains unclear. This study aimed to determine the frequency of anemia in patients with axSpA, assess its association with specific inflammatory markers such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) and evaluate the impact of anti-tumor necrosis factor (TNF)-α therapy on these parameters. Methods: This study included 102 patients with axSpA. Patient characteristics and laboratory parameters including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), hemoglobin (Hb), hematocrit (Hct) and mean corpuscular volume (MCV), and values of NLR, PLR and SII were evaluated at baseline and after 12 months of continuous anti-TNF-α therapy. Results: < 0.05). Multivariate analysis showed that changes in CRP, NLR, and SII were significantly associated with improvements in Hb. Conclusion: Anemia is a common comorbidity in axSpA and appears to be closely linked to systemic inflammation. Anti-TNF-α therapy was associated with significant improvements in Hb levels and inflammatory markers over one year. These findings support the value of simple hematologic indices to monitor inflammatory burden and treatment response in axSpA.