Striated Muscle Antibodies, IgG with Reflex to Titer

Casandra

Casandra Test Code AR14982Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0050746CPT Code 86255

Striated Muscle Antibodies, IgG with Reflex to Titer

Also known as: STM R

Clinical Use

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Use

This test is recommended for differential evaluation of neuromuscular junction diseases, including myasthenia gravis (MG). Striated muscle antibodies detected in conjunction with acetylcholine receptor (AChR) antibodies may indicate late-onset MG. These antibodies bind in a distinctive pattern to skeletal and heart muscle tissue sections and recognize epitopes on three major muscle proteins: titin, ryanodine receptor (RyR), and Kv1.4, which is an alpha subunit of the voltage-gated potassium channel (VGKC). Detection of striated muscle antibodies can also occur in patients with certain autoimmune diseases, rheumatic fever, myocardial infarction, and post-cardiotomy procedures.

Special Instructions

If striated muscle antibodies are detected, a titer will be added, and additional charges may apply. Specimens should be separated and transported appropriately to ensure sample integrity during the testing process.

Limitations

Results should be interpreted in conjunction with clinical findings and other laboratory tests. The presence of striated muscle antibodies alone is not diagnostic of any specific disease and may be found in various conditions. This test was developed and its performance characteristics determined by ARUP Laboratories and not cleared or approved by the US Food and Drug Administration. It is performed in a CLIA certified laboratory and intended for clinical purposes. False positives may occur in certain clinical scenarios, and further clinical correlation is necessary.

Test Details

New York Approved