RECOGNIZING
ANTI-MuSK
Ab+ gMG

Anti-MuSK Ab+ generalized myasthenia gravis (gMG) has distinct signs and symptoms1

gMG is a chronic, unpredictable, neuromuscular autoimmune disease. It is a more severe form of myasthenia gravis that has progressed beyond ocular muscle weakness and is characterized by muscle weakness and fatigue that worsens with activity and improves with rest.2-4

Approximately 5% to 10% of patients with gMG are anti-MuSK Ab+5

Despite being a rare subtype, there are recognizable and distinct signs and symptoms that make early diagnosis possible.1

Epidemiology of anti-MuSK Ab+ gMG1,6,7:

  • Occurs primarily in females
  • Onset in late 20s and 30s
  • Higher rates in African Americans and Asians

Anti-MuSK Ab+ gMG typically begins with acute onset, rapid progression, and more severe clinical signs.1,6

Bulbar muscle involvement is predominant, with presenting symptoms of ptosis and diplopia.6

Symptoms of anti-MuSK Ab+ gMG1,6:

  • Ptosis
  • Diplopia
  • Dysarthria
  • Dysphonia with nasal voice
  • Dysphagia
  • Masticatory difficulty
  • Muscle atrophy in face and tongue
  • Jaw muscle fatigue

Treating adults with anti-MuSK Ab+ gMG

Conventional therapies can be less effective when treating patients with anti-MuSK Ab+ gMG and management can be difficult. Higher doses of treatment are often needed. Yet, even with higher doses, there are patients left with refractory disease.1,6

Early diagnosis and targeted treatment of anti-MuSK Ab+ gMG have led to a reduction in treatment-refractory patients1

Ab+=antibody positive; MuSK=muscle-specific tyrosine kinase.

References:

  1. Vakrakou AG, Karachaliou E, Chroni E, et al. Immunotherapies in MuSK-positive myasthenia gravis; an IgG4 antibody-mediated disease. Front Immunol. 2023;14:1212757. doi:10.3389/fimmu.2023.1212757
  2. 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
  3. Bril V, Drużdż A, Grosskreutz J, et al. Safety and efficacy of rozanolixizumab in patients with generalised myasthenia gravis (MycarinG): a randomised, double-blind, placebo-controlled, adaptive phase 3 study. Lancet Neurol. 2023;22(5):383-394. doi:10.1016/S1474-4422(23)00077-7
  4. Trouth AJ, Dabi A, Solieman N, et al. Myasthenia gravis: a review. Autoimmune Dis. 2012;2012:1-10. doi:10.1155/2012/874680
  5. Gambino CM, Agnello L, Ciaccio AM, et al. Detection of antibodies against the acetylcholine receptor in patients with myasthenia gravis: a comparison of two enzyme immunoassays and a fixed cell-based assay. J Clin Med. 2023;12(14):4781. doi:10.3390/jcm12144781
  6. Rodolico C, Bonanno C, Toscano A, et al. MuSK-associated myasthenia gravis: clinical features and management. Front Neurol. 2020;11(660):1-5. doi:10.3389/fneur.2020.00660
  7. Morren JA, Li Y. Myasthenia gravis: frequently asked questions. Cleve Clin J Med. 2023;90(2):103-113. doi:10.3949/ccjm.90a.22017

UP NEXT

RYSTIGGO MOA