Aim: We aimed to measure sensitivity, specificity, and to determine the cut-off value (COV) ratio of neutrophil-to-lymphocyte (NLR) in patients with active systemic lupus erythematosus (SLE).
Methods: A cross sectional study was conducted using the retrospective data from Hasan Sadikin Lupus Registry (HSLR). The inclusion criteria were SLE patients aged 18 years or older who had documented data of neutrophil, lymphocyte, and SLE disease activity index (SLEDAI). Patients with infections, malignancies, and other inflammatory diseases recorded in registry were excluded. SLEDAI with a score of ≤ 4 is considered inactive and score of > 4 is considered active. The neutrophil-to-lymphocyte ratio was calculated by dividing the absolute number of neutrophils by the absoulte number of lymphocytes. Receiver Operating Characteristic (ROC) curve was used to analyze and determine optimal COV of NLR.
Results: The total sample in this study were 112 subjects with a dominant of female (95.54%) and the mean age of 34.45 ± 9.40 years. The median of SLEDAI was 4.5 with a range from 0 to 16, while the median of NLR was 2.68 with a range of 0.59 to 19.02. The ROC analysis showed the optimal cut-off in this study was 2.94 with sensitivity and specificity as high as 60.71% and 76.79%, respectively.
Conclusion: Neutrophil-to-lymphocyte ratio with cut off value of 2.94 can be used to determine active disease of systemic lupus eythematousus.
Keywords: Neutrophil-to-lymphocyte ratio; disease activity; systemic lupus erythematosus.