Autoimmune Liver Disease Evaluation with Reflex to Smooth Muscle Antibody (SMA), IgG by IFA
Ordering Recommendation
Initial test in conjunction with ANCA-associated vasculitis profile for evaluation of autoimmune liver disease.
Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody
Refer to individual components
1-4 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
Serum separator tube (SST).  
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1.0 mL serum to an ARUP Standard Transport Tube. (Min: 0.6 mL)  
Storage/Transport Temperature
Unacceptable Conditions
Non-serum specimens. Contaminated, heat-inactivated, grossly hemolyzed, grossly icteric, severely lipemic specimens or inclusion of fibrin clot.  
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)  
Reference Interval
Test NumberComponentsReference Interval
0050065Mitochondrial M2 Antibody, IgG (ELISA)20.0 Units or less: Negative
20.1-24.9 Units: Equivocal
25.0 Units or greater: Positive
0055241Liver-Kidney Microsome - 1 Antibody, IgG0.0-20.0 U: Negative
20.1-24.9 U: Equivocal
Greater than or equal to 25.0 U: Positive
0055248F-Actin (Smooth Muscle) Antibody, IgG19 Units or less: Negative
20-30 Units: Weak Positive - Suggest repeat testing in two to three weeks with fresh specimen
31 Units or greater: 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 been shown to have greater sensitivity and specificity for autoimmune liver disease than anti-smooth muscle antibodies.

Liver-Kidney Microsome-1 Antibody, IgG by ELISA: A positive result indicates the presence of IgG antibodies to recombinant human P450 2D6 and suggests the possibility of autoimmune hepatitis, type 2. A negative LKM-1 does not rule out the presence of autoimmune hepatitis, type 2.

If F-Actin, IgG result is 20 Units or greater, then Smooth Muscle Antibody, IgG titer will be added. Additional charges apply.
CPT Code(s)
83516 x2; 86376; if reflexed, add 86256
Component Test Code*Component Chart NameLOINC
0050065Mitochondrial (M2) Antibody, IgG14251-3
0055241Liver-Kid Microsome-1 Ab, IgG by ELISA47318-1
0055248F-Actin (Smooth Muscle) Ab, IgG by ELISA44706-0
* 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.
  • AMA M2
  • anti-M2
  • Antinuclear Antibodies, Serum
  • F Actin
  • F-actin
  • F-Actin (Smooth Muscle) Antibody, IgG
  • Liver-Kidney Microsome-1 Antibody, IgG
  • LKM1 IgG
  • Mito M2
  • Mitochondrial Antibodies, Serum
  • Mitochondrial M2 Antibody, IgG (ELISA)
  • SMA
  • SMA Titer
  • Smooth Muscle Antibodies, Serum
  • Smooth Muscle Antibody, IgG Titer