Red cell distribution width and neutrophil-lymphocyte ratio as inflammatory markers in patients with rheumatoid arthritis.

Introduction: The aim was to study the red cell distribution width (RDW) and neutrophil-lymphocyte ratio (NLR) as inflammatory markers and their correlation with clinical disease activity parameters in patients with rheumatoid arthritis (RA).

Material and methods: This observational cross-sectional study included 100 randomly selected patients with RA. Disease Activity Score with 28-joint counts and erythrocyte sedimentation rate (DAS28-ESR) was taken as a marker of disease activity. The diagnostic value of NLR and RDW in RA was assessed.

Results: The majority (51%) of cases showed mild disease activity. The mean NLR in cases was 3.88 ±2.59. Mean RDW was 16.25 ±2.49%. Neutrophil-lymphocyte ratio significantly correlated with ESR (p = 0.026), severity of pain (p = 0.013), osteoporosis (p = 0.014) and radiographic joint erosions (p = 0.048), but not with DAS28-ESR (p > 0.05) and C-reactive protein (CRP) (p > 0.05). Red cell distribution width showed a significant correlation only with NLR (p = 0.009). The positive predictive values of NLR and RDW for disease activity were 93.3% and 90% and the negative predictive values were 20% and 16.7% respectively. For NLR, the area under the curve (AUC) was 0.78 (p = 0.001) and at a cut-off value of 1.63, the diagnostic sensitivity was 97.7% and specificity 50%. For RDW, the AUC was 0.43 (p = 0.40) and at a cut-off value of 14.52, the diagnostic sensitivity was 70.5% and specificity 41.7%. The sensitivity and specificity of NLR were higher than those of RDW. A significant difference was seen between the AUC of NLR and RDW (p = 0.02).

Conclusions: Neutrophil-lymphocyte ratio is a valuable inflammatory marker in patients with RA, but RDW is not useful in this regard.