Relationship between neutrophil-lymphocyte, platelet-lymphocyte ratio and disease activity in rheumatoid arthritis treated with rituximab.

Background: Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) may be used as indicators of inflammatory markers and disease activity due to inflammatory changes in neutrophils, platelets and lymphocytes. Our aim is to investigate the relationship between NLR, PLR ratio and disease activity in RA patients treated with rituximab.

Methods: Thirty-eight patients (8 male, 30 female, mean age 56.8 ± 11.8 years) diagnosed with RA and 30 healthy controls were included in the study. Disease Activity Score of 28 joints - erythrocyte sedimentation rate (DAS28-ESR), lymphocyte, neutrophil, platelet counts, ESR, C-reactive protein (CRP), PLR, and NLR were evaluated before and after rituximab in RA patients. The relationship between all parameters was assessed by Pearson's correlation, Wilcoxon signed-rank, Mann-Whitney U and paired t tests.

Results: The levels of CRP, ESR, and DAS28-ESR decreased significantly at 6 months of rituximab treatment compared to pre-treatment. NLR and PLR ratios were higher in patients with RA than the control group. The median levels were 33.5 mm/hour, 5.7 mg/dL, and 3.7 respectively after 6 months of rituximab treatment. And, the levels were lower than baseline treatment. There was a significant correlation between the levels of DAS28-ESR and NLR, DAS28-ESR and PLR before and after treatment.

Conclusions: The NLR and PLR were higher than healthy controls and correlated with DAS28-ESR in patients with RA. These parameters which are indicative of disease activity decrease with rituximab and correlate with disease activity at 6 months. The NLR and PLR may be useful indices to evaluate RA disease activity treated with rituximab.