The impact of these symptoms can be observed across all aspects of patients’ lives, from physical activities and challenges at work to emotional well-being and social relationships.6
As of 2021, it is estimated that over 80,000 people are living with MG in the United States alone. Greater awareness and earlier diagnosis are among the potential reasons the epidemiology of MG is changing.1
gMG is a rare autoimmune neuromuscular disease characterized by fluctuating muscle weakness
In gMG, antibodies formed against the acetylcholine receptor (AChR), muscle-specific kinase (MuSK) or lipoprotein-receptor-related protein 4 (LRP4) can lead to damage of the postsynaptic membrane at the neuromuscular junction and can cause impaired neuromuscular signal transmission.2,3
MG can be categorized as generalized (85% of all cases) or ocular (15% of all cases).4 Generalized MG (gMG) affects multiple muscle groups throughout the body, while ocular MG is limited to muscles controlling eye movement and eyelid function.2
Among those with generalized MG (gMG), ~80% exhibit antibodies against AChR.5 In a subset of patients (10-15%), however, antibodies for AChR, MuSK, or LRP4 are not detected and may be considered seronegative.2,5
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NextHow gMG can affect patients
Though gMG is characterized by muscle weakness with fatigability, the symptoms of gMG are highly individualized and varied in nature. Common symptoms can include2,6:
Fatigue
(physical and mental)
(physical and mental)
Weakness of the arms, hands,
legs, and feet
legs, and feet
Trouble swallowing
Difficulty holding or grasping objects
Speech impairment
There are two measures of symptom impact used in treating MG: the patient-reported Myasthenia Gravis Activities of Daily Living (MG-ADL) scale and physician-administered Quantitative Myasthenia Gravis (QMG) scale.7
The MG-ADL is an 8-item, patient-reported scale that evaluates MG symptoms and their impact on patients’ function. The QMG is a 13-item clinician-reported assessment. The MG-ADL and QMG can be used to assess function related to both ocular and generalized symptoms.7
Potential role of inflammatory markers
A positive correlation has been demonstrated between elevated levels of pro-inflammatory cytokines/ chemokines and the presence of AChR antibodies. This suggests an association between underlying inflammation and gMG disease activity.3
In fact, studies have suggested that inflammation is present in as many as 80% of gMG cases.3 Inflammation and degradation of the neuromuscular junction contribute to gMG symptoms.8-10
Take another PASS
To uncover the impact of recurring symptoms on patients with gMG, ask:
Considering all the ways you are affected by [gMG], if you had to stay in your current state for the next months, would you say that your current disease state status is satisfactory?11,12
The Patient Acceptable Symptom State (PASS) evaluation is a single-question score that has been validated in several chronic inflammatory diseases.11,12
Diagnosis and treatment of gMG
As muscle weakness is a hallmark symptom of gMG, if this manifestation is present it is often prudent to perform serologic or electrodiagnostic tests to confirm suspected gMG in a patient.13
Therapies used to treat gMG as well as other forms of MG have evolved over time. From early treatments to the advanced therapies of today, progress toward treating gMG continues to be made.14
References: 1. Ye Y, Murdock DJ, Chen C, et al. Epidemiology of myasthenia gravis in the United States. Front Neurol. 2024;15:1-10. doi.org/10.3389/fneur.2024.1339167 2. Gilhus NE, Tzartos S, Evoli A, et al. Myasthenia gravis. Nat Rev Dis Primer. 2019;5(30):1-19. doi.org/10.1038/s41572-019-0079-y 3. Huda R. Inflammation and autoimmune myasthenia gravis. Front Immunol. 2023;14:1110499. doi:10.3389/fimmu.2023.1110499 4. Law N, Davio K, Blunck M, et al. The lived experience of myasthenia gravis: a patient-led analysis. Neurol Ther. 2021;10(2):1103-1125. doi:10.1007/s40120-021-00285-w 5. Saccà F, Salort-Campana E, Jacob S, et al. Refocusing generalized myasthenia gravis: patient burden, disease profiles, and the role of evolving therapy. Eur J Neurol. 2024;31(6):e16180. doi:10.1111/ene.16180. Epub 2023 Dec 20. 6. Jackson K, Parthan A, Lauher-Charest M, et al. Understanding the symptom burden and impact of myasthenia gravis from the patient's perspective: a qualitative study. Neurol Ther. 2023;12(1):107-128. doi:10.1007/s40120-022-00408-x. Epub 2022 Nov 2. 7. Muppidi S, Silvestri NJ, Tan R, et al. Utilization of MG-ADL in myasthenia gravis clinical research and care. Front Neurol. 2022;65:630-639. 8. Koneczny I, Herbst R. Myasthenia gravis: pathogenic effects of autoantibodies on neuromuscular architecture. Cells. 2019;8(7):671. doi:10.3390/cells8070671 9. Uzawa A, Kuwabara S, Suzuki S, et al. Roles of cytokines and T cells in the pathogenesis of myasthenia gravis. Clin Exp Immunol. 2021;203(3):366-374. doi:10.1111/cei.13546. Epub 2020 Dec 3. 10. Vilquin JT, Bayer AC, Le Panse R, Berrih-Aknin S. The muscle is not a passive target in myasthenia gravis. Front Neurol. 2019;10:1343. doi:10.3389/fneur.2019.01343 11. Petersson M, Feresiadou A, Jons D, et al. Patient-reported symptom severity in a nationwide myasthenia gravis cohort: cross-sectional analysis of the Swedish GEMG study. Neurol. 2021;97:1382-1391. doi:10.1212/WNL.0000000000012604 12. Mendoza M, Tran C, Bril V, et al. Patient-acceptable symptom states in myasthenia gravis. Neurology. 2020;95:1617-1628. doi:10.1212/WNL.0000000000010574 13. Kaminski HJ, Sikorski P, Coronel SI, et al. Myasthenia gravis: the future is here. J Clin Invest. 2017;134(12):1-12. doi.org/10.1172/JCI179742 14. Nguyen-Cao TM, Gelinas D, Griffin R, et al. Myasthenia gravis: historical achievements and the golden age of clinical trials. J Neurol Sci. 2019;406:1-11. doi.org/10.1016/j.jns.2019.116428