A neutrophil-to-lymphocyte ratio of more than 2.7 can differentiate severe myasthenia gravis from mild disease, according to a new study published in the Journal of Clinical Neuroscience. The neutrophil-to-lymphocyte ratio could, therefore, be a helpful marker to identify patients with severe disease and evaluate the severity of myasthenia gravis.

To explore the clinical value of the neutrophil-to-lymphocyte ratio in evaluating disease severity in myasthenia gravis, a team of researchers from China analyzed 128 patients with the disease and 116 healthy controls. The researchers also wanted to evaluate the correlation between the neutrophil-to-lymphocyte ratio and the Quantitative Myasthenia Gravis Score (QMGS).

They found that the neutrophil-to-lymphocyte ratio of patients with severe myasthenia gravis was significantly higher than that of patients with mild disease, with the ratio in those with severe disease being 2.9, while in those with mild disease, it was 1.72. Patients with Myasthenia Gravis Foundation of America scores of 1, 2, or 3 were classified as having mild disease, while those with a score of 4 or 5 were classified as having severe disease. The ratio in healthy controls was 1.65, which was also significantly lower than in patients with severe disease. 

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The researchers said that the neutrophil-to-lymphocyte ratio was independently associated with severe myasthenia gravis and reported that the cut-off value to differentiate between mild and severe disease was 2.37. 

They also reported that the neutrophil-to-lymphocyte ratio was positively correlated with QMGS in mild myasthenia gravis and that it also tended to be correlated with QMGS in severe disease. However, the difference was not statistically significant, they said. 

The neutrophil-to-lymphocyte ratio reflects the balance between systemic inflammation and immunity and is a prognostic biomarker used in many diseases.

Reference

Duan Z, Jia A, Cui W, Feng J. Correlation between neutrophil-to-lymphocyte ratio and severity of myasthenia gravis in adults: a retrospective study. J Clin Neurosci. Published online October 22, 2022. doi:10.1016/j.jocn.2022.10.017