Striated Muscle Antibodies, IgG with Reflex to Titer
Ordering Recommendation
Second-line test for the evaluation of myasthenia gravis. Recommended if first-line diagnostic tests are negative.
Semi-Quantitative Indirect Fluorescent Antibody
1-5 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
Serum separator tube.  
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.15 mL)  
Storage/Transport Temperature
Unacceptable Conditions
Plasma. Contaminated, hemolyzed, or severely lipemic specimens.  
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)  
Reference Interval
Less than 1:40
Interpretive Data
When detected in the presence of acetylcholine receptor (AChR) antibody, striated muscle antibodies, which bind in a cross-striational pattern to skeletal and heart muscle tissue sections, are associated with late-onset myasthenia gravis (MG). Striated muscle antibodies recognize epitopes on three major muscle proteins, including: titin, ryanodine receptor (RyR) and Kv1.4 (an alpha subunit of voltage-gated potassium channel [VGKC]). Isolated cases of striated muscle antibodies may be seen in patients with certain autoimmune diseases, rheumatic fever, myocardial infarction, and following some cardiotomy procedures.

Compliance Statement A: Analyte specific reagents (ASR) are used in many laboratory tests necessary for standard medical care and generally do not require U.S. Food and Drug Administration (FDA) approval or clearance. This test was developed and its performance characteristics determined by ARUP Laboratories. The U.S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. This test should not be regarded as investigational or for research use.
If Striated Muscle Abs detected, a titer will be added. Additional charges apply.
CPT Code(s)
86255; if reflexed, add 86256
Component Test Code*Component Chart NameLOINC
0050747Striated Muscle Antibodies, IgG Screen49692-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • Anti-Skeletal Muscle IgG Antibodies
  • Anti-Striated Antibody
  • Anti-Striated Muscle Antibody
  • Muscle (Skeletal) Antibodies
  • Myoid Antibody
  • Skeletal Muscle Antibodies
  • Striational Antibodies