Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio as a marker of disease activity in patients with systemic lupus erythematosus

Background: Systemic lupus erythematosus (SLE) is a female predominant multiple system involving autoimmune inflammatory disorder. Considering the affordability and wide availability of the recently studied marker of inflammation neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR), this study was done to investigate the relationship between NLR and PLR with the disease activity in patients with SLE. Methods: In this hospital based cross sectional study done in Assam medical college and hospital, Dibrugarh done over one year period, newly diagnosed SLE patients above the age of 13 years were included. Patients with underlying disorders or on medications that may affect cell counts, drug induced lupus and recent history of blood transfusion were excluded. The disease activity was calculated using SLE disease activity index 2000 (SLEDAI-2K) and the patients were divided in two groups, group-A (SLEDAI-2K score <9) and group-B (SLEDAI-2K score >9) and correlation was sought with NLR and PLR. Results: In this study 49 patients were included, with a mean age of 26.33 years and a female predominance (98%). NLR was found to be higher in group-B (11.37 vs 8.05, p<0.001) and NLR positively correlated with SLEDAI-2K score (p<0.001), ESR (p<0.001) and CRP (p=0.212). PLR had a positive correlation with SLEDAI-2K score, CRP, and ESR, although it was the correlation with ESR that was statistically significant (p=0.029). Conclusions: NLR and PLR was found to have a positive correlation with SLEDAI-2K scores, CRP and ESR and therefore can serve as an inexpensive marker of disease activity in patients with SLE.