From the Guidelines
Striational antibodies are a diagnostic marker for myasthenia gravis (MG), particularly in older patients or those with thymoma, and are found in approximately 30-40% of MG patients. When considering the diagnosis of MG, it is essential to evaluate the patient's symptoms, such as muscle weakness, in conjunction with the presence of striational antibodies and other MG-specific antibodies like acetylcholine receptor (AChR) antibodies and muscle-specific kinase (MuSK) antibodies 1. The presence of striational antibodies can indicate a more severe disease course or the need to investigate for thymoma, but they are not specific to MG alone and can occasionally appear in other autoimmune conditions or in elderly individuals without MG. Some key points to consider when evaluating striational antibodies in the context of MG include:
- Striational antibodies are found in approximately 30-40% of MG patients
- These antibodies are more common in older patients with MG and those with thymoma
- The presence of striational antibodies can indicate a more severe disease course or the need to investigate for thymoma
- Striational antibodies are considered a supportive diagnostic finding rather than a definitive test for MG
- Testing for striational antibodies is typically done as part of a comprehensive autoantibody panel that includes other MG-related antibodies.
From the Research
Definition and Prevalence of Striational Antibodies in MG
- Striational antibodies are a type of autoantibody found in some patients with myasthenia gravis (MG) 2, 3.
- These antibodies react with epitopes on muscle proteins such as titin, ryanodine receptor (RyR), and Kv1.4 2, 3.
- Striational antibodies are frequently found in MG patients with late-onset and thymoma 2, 3.
Clinical Significance of Striational Antibodies in MG
- The presence of striational antibodies is associated with more severe disease in all MG subgroups 2.
- Anti-Kv1.4 antibody is a useful marker for the potential development of lethal autoimmune myocarditis and response to calcineurin inhibitors 2.
- Detection of striational antibodies provides more specific and useful clinical information in MG patients 2, 3.
- Striational antibodies may correlate with MG severity and predict an unsatisfactory outcome after thymectomy 3.
Relationship between Striational Antibodies and MG Symptoms
- A case report suggests that anti-striational antibodies may be involved in the development of severe bradycardia in a patient with late-onset MG 4.
- The detection of anti-striational antibodies, including anti-titin and anti-Kv1.4 antibodies, may be useful in identifying patients with MG who are at risk of developing severe cardiac complications 4.