Potential of neutrophil to lymphocyte ratio in predicting sustained remission in rheumatoid arthritis compared to other immune activation markers

BACKGROUND & OBJECTIVES: Cells and cell proportions may indicate the equilibrium status of the immune system. The present study was conducted to evaluate the role of cytokines and the immunocompetent cells as biomarkers of remission in rheumatoid arthritis (RA) patients intended to withdraw or reduce disease-modifying anti-rheumatic drug (DMARD) treatment. METHODS: This prospective observational study involved newly diagnosed and treated RA patients who fulfilled 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria. The patients were classified based on disease activity score (DAS)28-C-reactive protein (CRP)(3) score into remission (≤2.6) and treatment-naïve/active (>2.6) groups. Remission patients were followed up for six months and were reclassified into those in sustained remission (≤2.6) and relapse (>2.6) based on the DAS28-CRP(3) score. Various cytokines and cell surface markers were quantitated using whole blood samples, and the CD3(+)/CD19(+) and FOXP3(+)/CD4(+) ratios were calculated. The clinical, demographic, cytokine and cellular phenotype characteristics were compared between remission and treatment-naïve groups. The factors associated with sustained remission were verified. RESULTS: Of the 72 patients, 52 were in remission and 20 were DMARD naïve and had active disease. Duration of illness, interleukin-6 (IL-6) and IL-10 were significantly different between remission and treatment naïve/active disease patients. Increased likelihood for achieving sustained remission was noted in RA patients with baseline NLR ≤2. Other demographic/clinical variables and cell phenotypes, namely age, gender, duration of illness, CD3(+), CD4(+), FOXP3(+), CD19(+), CD3(+)/CD19(+), FOXP3(+)/CD4(+) and cytokines - IL-6 and IL-10 were not associated with sustained remission. INTERPRETATION & CONCLUSIONS: The present preliminary study highlighted the potential of NLR in predicting sustained remission in RA patients with a cut-off <2. Further study with a large sample size should be done to confirm this finding.