Autoimmune myasthenia gravis and COVID-19. A case report-based review

Correlation Between the Prevalence of Myasthenia Gravis and the Frequency of Class II Human Leucocyte Antigen Alleles in Various Geographical Locations Around the World

Myasthenia gravis (MG) is an autoimmune condition characterised by muscle weakness due to antibodies produced against post-synaptic receptors. The impact of MG can be significant, especially with an ageing population. Human leukocyte antigens (HLA) are polymorphic genes associated with autoimmune conditions. Establishing the HLA alleles associated with MG may aid in the diagnosis, screening and early management of individuals at risk of MG. This research aims to establish the class II HLA alleles associated with the prevalence of MG in various regions of the world and identify the alleles that could predispose to the condition. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow chart and various databases including, Scopus and PubMed as well as other sources were used to find appropriate papers on HLA class II alleles associated with MG and the prevalence of MG in various countries. The frequency of selected HLA alleles in selected regions were obtained from the website, allelefrequencies.net. From this, a correlation coefficient and p-value were calculated to investigate whether the frequency of MG and the prevalence of HLA alleles had a significant association.  The results highlighted two HLA alleles, DRB1*04:04 and DRB1*03, to have a significant positive association with the prevalence of MG. The frequency of the alleles showed regional variation, with European countries, particularly Northern Europe, exhibiting the highest frequencies. A significant positive correlation between HLA-DRB1*04:04 and DRB1*03 showed with the prevalence of MG, highlighting these alleles as a possible cause of the disease. Screening for these alleles, particularly in Northern Europe, may help identify individuals susceptible to MG.

Acute Respiratory Failure Due to Inaugural Myasthenia Crisis

Myasthenia gravis is a rare disease that can lead to a serious condition known as myasthenic crisis (MC). The diagnosis of MC is clinical and relies on the presence of typical symptoms that can be absent, emphasizing the importance of attracting the attention of emergency physicians to this rare cause of respiratory failure. We present the case of a 66-year-old woman presenting to the emergency department with a history of recent muscle fatigue and dehydration who developed acute respiratory failure requiring mechanical ventilation.

The Incidence of Myasthenia Gravis in the Province of Ferrara, Italy, in the Period of 2008-2022: An Update on a 40-Year Observation and the Influence of the COVID-19 Pandemic

Myasthenia gravis (MG) is the most common neuromuscular junction disorder. We evaluated the MG incidence rate in the province of Ferrara, Northern Italy, over two time frames (2008-2018 and 2019-2022, i.e., the COVID-19 pandemic) and considered early-onset (EOMG), late-onset (LOMG), and thymoma- and non-thymoma-associated MG. Moreover, in the second period, we assessed its possible relationship with SARS-CoV-2 infection or COVID-19 vaccination. We used a complete enumeration approach to estimate the MG incidence and its temporal trend. For the period of 2008-18, 106 new cases were identified (mean incidence rate 2.7/100,000 people). The highest rates were observed for the over-70 age group and in rural areas, with 17% of thymoma-associated MG. During the COVID-19 period, 29 new cases were identified (average incidence rate 2.1/100,000 people), showing a marked (though not statistically significant) decrease in the mean annual incidence compared to the previous period. Again, the highest rate was observed for the over-70 age group. The first period was in line with our previous observations for the period between 1985 and 2007, highlighting a rising incidence of LOMG and a marked decrease in EOMG. During the COVID-19 period, incidence rates were lower in the first years whereas, when the pandemic ended, the previous trend was confirmed.