Inflammation-associated biomarkers may predict respiratory failure in patients with myasthenia gravis (MG), according to a study recently published in the Annals of Clinical and Translational Neurology.

“The systemic inflammation markers expressed abnormally in [patients with MG], in which platelet to lymphocyte ratio may be an independent predictor of respiratory failure, and high systemic immune inflammation index and generalized MG were predictive risk factors for poor outcomes in [patients with MG],” the authors wrote.

This retrospective study included 117 patients previously diagnosed with MG from a single center in China and 120 controls. Mean age was 58 years for the MG cohort and 54 years for healthy controls. Most patients (73%) had late-onset MG, and only 31.62% also had a thymoma. 

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The researchers compared a total of 4 immunological markers between the MG and control groups, including neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio, and systemic immune inflammation index (SII). 

Of all biomarkers, only 3,NLR, PLR, and SII, were consistently higher in patients with MG compared to the control group, which further correlated with the Myasthenia Gravis Foundation of America classification.

A subsequent adjusted logistic regression demonstrated that PLR could independently predict respiratory failure among patients with MG, with favorable sensitivity and specificity values for diagnosing MG with respiratory failure. 

Moreover, a Kaplan-Meier curve identified 7 different variables that act as risk factors for worse outcomes in patients with MG, including increased levels in the same 3 immune-related biomarkers, which included NLR, PLR, and SII.

Respiratory failure, generalized MG, positive acetylcholine receptor antibodies, and intravenous immune globulin exposure played similar roles. After a multivariate Cox regression model, only high SII and generalized MG remained risk factors for poor outcomes.

“In conclusion, our study demonstrated that these systemic inflammation markers [are] easily measurable, available, and cost-effective parameters expressed abnormally in [patients with MG],” the study concluded.

Reference

Huang X, Xu M, Wang Y, et al. The systemic inflammation markers as possible indices for predicting respiratory failure and outcome in patients with myasthenia gravis. Ann Clin Transl Neurol. Published online November 10, 2022. doi:10.1002/acn3.51706