F-Actin and Mitochondrial M2 Antibodies, IgG by ELISA with Reflex to Smooth Muscle Antibody (SMA), IgG by IFA
2007209
 
Ordering Recommendation
Mnemonic
ACTIN/M2 R
Methodology
Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody
Performed
Sun-Sat
Reported
1-4 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Serum separator tube (SST).  
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 0.5 mL serum to an ARUP Standard Transport Tube. (Min: 0.3 mL)  
Storage/Transport Temperature
Refrigerated.  
Unacceptable Conditions
Non-serum, heat-inactivated, contaminated, grossly icteric, severely lipemic, grossly hemolyzed specimens or inclusion of fibrin clot..  
Remarks
 
Stability
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)  
Reference Interval
Test Number Components Reference Interval
0050065 Mitochondrial M2 Antibody, IgG (ELISA) 20.0 Units or less: Negative
20.1-​24.9 Units: Equivocal
25.0 Units or greater: Positive
0055248 F-​Actin (Smooth Muscle) Antibody, IgG 19 Units or less 20-​30 Units 31 Units or greaterNegative Weak Positive -​ Suggest repeat testing in two to three weeks with fresh specimen. Positive -​ Suggestive of autoimmune hepatitis type 1 or chronic active hepatitis.
Smooth Muscle Antibody, IgG Titer <1:20 = Normal -​ No antibody detected.
1:20-​1:80 = Weak Positive -​ Suggest repeat testing in two to three weeks with fresh specimen.
1:160 or greater = Positive -​ Suggestive of autoimmune hepatitis or chronic active hepatitis.
Interpretive Data
F-Actin Antibody, IgG by ELISA: F-actin antibodies have demonstrated a greater sensitivity and specificity for autoimmune liver disease than anti-smooth muscle antibodies.
Note
If F-Actin, IgG by ELISA is 20 Units or greater, then Smooth Muscle Antibody (SMA), IgG by IFA titer will be added. Additional charges apply.
CPT Code(s)
83516 x2; if reflexed, add 86256
Components
Component Test Code*Component Chart Name
0050065Mitochondrial (M2) Antibody, IgG
0055248F-Actin (Smooth Muscle) Ab, IgG by ELISA
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, contact interface support at interface.support@aruplab.com.
Cross References
  • AMA M2
  • AMA M2 reflex
  • anti-M2
  • Autoimmune Liver Disease Differentiation Panel
  • F Actin
  • F-actin
  • F-Actin (Smooth Muscle) Antibody, IgG
  • M2
  • Mito M2
  • Mitochondrial Antibodies, Serum
  • Mitochondrial M2 Antibody, IgG (ELISA)
  • Mitochondrial MS reflex
  • SMA
  • SMA Titer
  • Smooth Muscle Antibodies, Serum
  • Smooth Muscle Antibody, IgG Titer