ARUP's Laboratory Test Directory

Acetylcholine Receptor Antibodies and Striated Muscle Antibody Reflexive Panels, and Titin Antibody : 2005639
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Additional Technical Information
  


Mnemonic: MGT R PAN

Methodology: Quantitative Radioimmunoassay/Semi-Quantitative Radioreceptor Assay/Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Flow Cytometry
Performed: Mon-Fri
Reported: 1-8 days
Specimen Required: Collect: Plain red top or Serum Separator Tube (SST).

Specimen Preparation: Transport 1.5 mL serum. (Min. 0.7 mL) Separate serum from cells ASAP or within one hour of collection. Transfer to an ARUP Standard Transport Tube.

Storage/Transport Temperature: Refrigerated. Frozen is also acceptable.

Remarks: Repeated freeze-thaw cycles should be avoided.

Unacceptable Conditions: Plasma. Hemolyzed, lipemic, moderately icteric serum or contaminated specimens.

Stability (collection to initiation of testing): Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year
Reference Interval:
Effective August 20, 2012
 
Test Number Components Reference Interval
0080009 Acetylcholine Receptor Binding Antibody Negative: 0.0-0.4 nmol/L
Positive:  0.5 nmol/L or greater
0099580 Acetylcholine Receptor Blocking Antibody Negative: 0-15% blocking
Indeterminate: 16-24% blocking
Positive: 25% or greater blocking
0099521 Acetylcholine Receptor Modulating Antibody Negative: 0-45% modulating
Positive: 46% or greater modulating
2005636 Titin Antibody Negative:  0.00 to 0.45 IV
Indeterminate:  0.46 to 0.71 IV
Positive:  0.72 IV or greater
 Striated Muscle Antibody IgG Screen Less than 1:40 No antibody detected
 Striated Muscle Antibody, IgG Titer Less than 1:40 No antibody detected

Interpretive Data: In early-onset myasthenia gravis patients with anti-acetylcholine receptor antibodies, the presence of titin antibody indicates a 95-100 percent likelihood of an underlying thymoma.

Refer to Statement B under Testing Information at http://www.aruplab.com.
Refer to Statement D under Testing Information at http://www.aruplab.com.
Note: If Acetylcholine Receptor Binding Antibody result is greater than 0.4 nmol/L or Acetylcholine Receptor Blocking Antibody result is greater than 15 percent, then Acetylcholine Receptor Modulating Antibody will be added. If Striated Muscle Ab is greater than or equal to 1:40, then a titer will be added. Additional charges apply.
CPT Code(s): 83519; 83516; if reflexed, add 83516 x2; 86255; if reflexed, add 86256
Cross References: Myasthenia Gravis, Myasthenia Gravis/Thymoma (Acetylcholine Receptor Antibodies and Striated Muscle