With interest we read the article by Aksoy et al. about a 46 years old female with myasthenia gravis (MG) due to antibodies against the acetyl-choline receptor (AchR) being treated with 120mg pyridostigmine per day in whom MG exacerbated in the course of an infection with SARS-CoV-2 (COVID-19) [1]. It was concluded that early immune-modulatory therapy may be more effective in terms of preventing permanent lung damage than standard first-line treatments in patients with MG [1]. We have the following comments and concerns.

A shortcoming of the study is that AchR antibody titers were not determined during hospitalisation and were not compared with pre-hospitalisation titers. Knowing AchR antibody titers during hospitalisation would allow assessing if MG truly exacerbated. Missing in this respect are results of nerve conduction studies (NCSs), such as repetitive nerve stimulation or single-fiber EMG to document exacerbation of MG during the viral infection. Since clinical manifestations of COVID-19 may mimic clinical manifestations of MG, differentiation between deterioration due to the viral infection or due to MG is often not possible upon clinical investigations alone. The presented data are not convincing with regard to exacerbation of MG. Symptoms and signs could be simply explained by the severe SARS-CoV-2 infection. 

A dosage of 120mg/d pyridostigmine is very low according to the recommendations of international neurological societies for treating MG [2]. We should know the reason why the patient was treated with such a low dosage. Was this due to the low body weight of the patient or due to only mild symptoms during the last 4y since onset of MG?

Certain drugs may exacerbate MG, such as chloroquine [3] or azithromycin [4]. We should know why the patient nonetheless received these drugs on admission. Missing is the complete list of drugs the patient was regularly taking prior to admission.

We do not agree with the statement that corticosteroids should be used with caution in MG patients. Steroids are the mainstay of generalised MG treatment particularly before immune-suppressive treatment becomes effective or during exacerbations. Steroids may not only improve clinical manifestations of MG but may also lower AchR antibody titers [5]. 

According to a recent review of SARS-CoV-2 infected patients with MG [6], there is no increase in the prevalence of MG since the outbreak of the COVID-19 pandemic, MG not necessarily deteriorates in SARS-CoV-2-infected patients, there is no increase in the frequency of complications, and there is no general need to modify the anti-myasthenic treatment in asymptomatic SARS-CoV-2-positive MG patients [6]. In symptomatic SARS-CoV-2 infected MG patients, however, there may be a need to modify and adapt immune-modulating treatment depending on the clinical presentaiton and disease course.

Overall, this interesting study has a number of shortcomings which should be addressed before drawing final conclusions. There is a need for confirmation of MG exacerbation by non-clinical investigations, to differentiate between manifestations of MG and COVID-19. Immuno-suppression should be considered in all COVID-19 patients given the often severe immune-response with lymphocyte depletion and chemokine and cytokine elevation in these patients.