Alternative name
Muscle Skeletal (Striated) Antibodies
Description
Found in patients with Myasthenia Gravis usually in the presence of Anti-acetylcholine receptor antibodies are far more characteristic. The presence of striated muscle antibodies in myasthenia suggests the presence of thymoma. IgM anti striated muscle antibodies may also occur in some patients with nuclear hepatitis, acute viral infections and polymyositis. Low titres may occur in viral infections notably EBV and infectious hepatitis.
Indication
Test is of limited value, anti-acetylcholine receptor antibody being the test of choice for myasthenia. Main indication is myastenia associated with thymoma.
Interpretation
Anti-striated muscle antibodies are found in 25-40% of patients with Myasthenia Gravis but primarily those with thymoma. Absence of anti-skeletal muscle antibodies is strong evidence against the presence of thymoma except in a small group of young myasthenics, usually male. Presence of these autoantibodies predicts the risk of myasthenia in patients with thymoma and reoccurance of thymoma after surgery.
Sample
Serum Separator Tube (SST)
Assay details
Indirect immunfluorescence primate tissue (striated muscle)
Restrictions
Referred test
Reference range
Negative/positive
Turnaround time
28 days
Analysing laboratory
Sheffield PRU