Two new inflammatory markers associated with Disease Activity Score-28 in patients with rheumatoid arthritis: neutrophil-lymphocyte ratio and platelet-lymphocyte ratio.

AIM: Rheumatoid arthritis (RA) is an inflammatory autoimmune disease with unknown etiology and systemic involvement. Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are two new inflammatory markers used in the assessment of systemic inflammation. The aim here is to study NLR and PLR in patients with RA to investigate their relation with Disease Activity Score of 28 joints (DAS-28).

METHODS: The study included 104 patients with RA and a control group of 51 age- and gender-matched healthy subjects. We divided the patients into two groups according to the DAS-28 score. Group 1 included patients with a score of lower than 2.6 by the DAS-28 (patients in remission) and Group 2 included patients with a score of 2.6 and higher (patients with active disease).

RESULTS: NLR was 2.12 ± 0.83 in the patient group and 1.58 ± 0.57 in the control group. PLR was 136.50 ± 53.52 in the patient group and 114.84 ± 29.41 in the control group. There was a statistically significant difference in NLR and PLR between the patient and control groups (P ≤ 0.0001 and P = 0.001, respectively). Patients in Group 1 had an NLR of 1.84 ± 0.61 and a PLR of 119.25 ± 41.77. Patients in Group 2 had an NLR of 2.29 ± 0.90 and a PLR of 147.28 ± 56.96. There was a statistically significant difference in NLR and PLR between the two groups (P = 0.003 and P = 0.005 respectively). A correlation was observed between NLR and PLR by DAS-28 (r = 0.345, P ≤ 0.0001 and r = 0.352, P ≤ 0.0001, respectively).

CONCLUSIONS: The present study showed us that NLR and PLR were two new inflammatory markers which could be used to assess disease activity in patients with RA.