Patients With Myasthenia Gravis With Acute Onset of Dyspnea: Predictors of Progression to Myasthenic Crisis and Prognosis

Yangyu Huang,Jingwen Yan,Yuzhou Guan,Ying Tan,Ke Li,Jiayu Shi

doi:10.3389/fneur.2021.767961

Abstract

Background: Life-threatening myasthenic crisis (MC) occurs in 10–20% of the patients with myasthenia gravis (MG). It is important to identify the predictors of progression to MC and prognosis in the patients with MG with acute exacerbations.Objective: This study aimed to explore the predictors of progression to MC in the patients with MG with acute onset of dyspnea and their short-term and long-term prognosis.Methods: This study is a retrospective cohort study. We collected and analyzed data on all the patients with MG with acute dyspnea over a 10-year period in a single center using the univariate and multivariate analysis.Results: Eighty-six patients with MG were included. In their first acute dyspnea episodes, 36 (41.9%) episodes eventually progressed to MC. A multivariate analysis showed that the early-onset MG (adjusted OR: 3.079, 95% CI 1.052–9.012) and respiratory infection as a trigger (adjusted OR: 3.926, 95% CI 1.141–13.510) were independent risk factors for the progression to MC, while intravenous immunoglobulin (IVIg) treatment prior to the mechanical ventilation (adjusted OR: 0.253, 95% CI 0.087–0.732) was a protective factor. The prognosis did not significantly differ between the patients with and without MC during the MG course, with a total of 45 (52.3%) patients reaching post-intervention status better than minimal manifestations at the last follow-up.Conclusion: When treating the patients with MG with acute dyspnea, the clinicians should be aware of the risk factors of progression to MC, such as early-onset MG and respiratory infection. IVIg is an effective treatment. With proper immunosuppressive therapy, this group of patients had an overall good long-term prognosis.

Highlights

Myasthenia gravis (MG) is an autoimmune disease caused by the autoantibodies that affect the structure of the post-synaptic membrane
Thirty-six (41.9%) dyspnea episodes eventually progressed to Myasthenic crisis (MC), and 32 patients received mechanical ventilation, 28 (87.5%) of which ended with invasive mechanical ventilation
By comparing the baseline characteristics between the MC group and non-MC group using the univariate analysis, we found that the variables with p < 0.10 included age of MG onset (p = 0.006), early-onset MG (p = 0.024), age at the dyspnea episode (p = 0.009), ocular muscle involvement when dyspnea episode occurred (p =0.025), TABLE 2 | The multivariable analysis for predictors of progression to MC

Summary

Introduction

Myasthenia gravis (MG) is an autoimmune disease caused by the autoantibodies that affect the structure of the post-synaptic membrane. Exploring the risk factors of progress to MC in the patients with acute onset of dyspnea will aid clinical decision-making and medical resource allocation, especially in the developing countries. The previous studies focused on the clinical characteristics of the patients with MC [4, 12, 13] or the risk factors of MC occurrence after thymectomy [14,15,16], very few studies aimed to investigate the predictors of progression to MC in the patients with MG with acute onset of dyspnea. This study aimed to explore the predictors of progression to MC in the patients with MG with acute onset of dyspnea and their short-term and longterm prognosis. Life-threatening myasthenic crisis (MC) occurs in 10–20% of the patients with myasthenia gravis (MG). It is important to identify the predictors of progression to MC and prognosis in the patients with MG with acute exacerbations

Methods

Results

Discussion

Conclusion