From the Guidelines
A full myasthenia gravis panel should include acetylcholine receptor (AChR) antibody tests, muscle-specific kinase (MuSK) antibody testing, low-density lipoprotein receptor-related protein 4 (LRP4) antibody testing, striational antibodies, and serum testing for anti-voltage-gated calcium channel antibodies. When evaluating a patient for myasthenia gravis, it is essential to consider the various antibody tests that can help confirm the diagnosis and rule out other conditions. The panel typically consists of:
- Acetylcholine receptor (AChR) antibody tests, which include binding, blocking, and modulating antibodies, as mentioned in the context of immune-related adverse events in patients treated with immune checkpoint inhibitor therapy 1
- Muscle-specific kinase (MuSK) antibody testing, which is crucial for patients who test negative for AChR antibodies
- Low-density lipoprotein receptor-related protein 4 (LRP4) antibody testing for patients negative for both AChR and MuSK antibodies
- Striational antibodies (against titin, ryanodine receptor, and other muscle proteins) to identify thymoma-associated myasthenia gravis
- Serum testing for anti-voltage-gated calcium channel antibodies to rule out Lambert-Eaton myasthenic syndrome These tests are vital for diagnosing myasthenia gravis, as they reflect the autoimmune nature of the disease, where the body produces antibodies against components of the neuromuscular junction, disrupting normal nerve-to-muscle signaling. Additionally, some panels may include complete blood count, metabolic panel, and thyroid function tests, such as thyroid-stimulating hormone (TSH) and thyroid peroxidase (TPO) antibodies, to evaluate for comorbidities or alternative diagnoses, as seen in the management of immune-related adverse events 1.
From the Research
Myasthenia Gravis Panel Components
A full myasthenia gravis panel typically includes tests for various antibodies associated with the disease. The key components are:
- Antibodies to the acetylcholine receptor (AChR) 2, 3, 4
- Antibodies to muscle-specific kinase (MuSK) 5, 3, 4, 6
- Antibodies to low-density lipoprotein receptor-related protein 4 (LRP-4) 3, 4, 6
- Other antibodies such as anti-titin, -ryanodine, -agrin, and -rapsyn, although these are less frequent and clinically less useful 4
- Omega-conotoxin receptor antibodies in Lambert Eaton Myasthenic Syndrome (LEMS) 4
Diagnostic Tests
The panel may also include various diagnostic tests, such as:
- Electrodiagnostic studies, although these may be negative in some cases, particularly in MuSK-MG patients 5
- RIPA assay to measure antibodies to the acetylcholine receptor 4
- Tests to measure each of the specific antibodies, which have recently permitted to split the diagnosis 4
Clinical Considerations
It's essential to consider the clinical presentation and symptoms of the patient when interpreting the results of the myasthenia gravis panel. The presence of certain antibodies can be associated with specific clinical phenotypes, such as bulbar form with fewer ocular symptoms in MuSK-MG patients 6.