Correlation between neutrophil-to-lymphocyte ratio and severity of myasthenia gravis in adults: A retrospective study

Background: The study aimed to explore the clinical value of neutrophil-to-lymphocyte (NLR) in evaluating myasthenia gravis (MG) severity and the correlation between NLR and the Quantitative Myasthenia Gravis Score (QMGS).Methods: This study included 128 patients with MG and 116 healthy controls. We completed Myasthenia Gravis Foundation of America (MGFA) classification for patients with MG, and defined MGFA I, II, and III as mild MG and MGFA IV and V as severe MG. The NLR of the patients were calculated, and statistical analysis was per-formed, with statistical significance set at P < 0.05. When pairwise comparisons between patients with mild MG, severe MG, and the healthy controls were performed, P < 0.017 was considered statistically significant under Bonferroni correction.Results: NLR was significantly higher in patients with severe MG than in those with mild MG [2.90(2.41-5.83) vs 1.72(1.38-2.51), P = 0.000] and in the healthy controls [2.90(2.41-5.83) vs 1.65(1.34-1.91), P = 0.000]. NLR was independently associated with severe MG. The cut-off value of NLR for differentiating mild MG from severe MG was 2.37, and the sensitivity and specificity were 0.900 and 0.815, respectively. The results of Spearman test showed that NLR was positively correlated with QMGS in mild MG. NLR tended to be correlated QMGS in pa-tients with severe MG, but the difference was not statistically significant.Conclusion: NLR may be a helpful marker for identifying patients with severe MG. NLR can also be used to further evaluate disease severity, especially for mild MG.