Evaluation of patients with suspected autoimmune liver disease, specifically autoimmune hepatitis or primary biliary cirrhosis
Evaluation of patients with liver disease of unknown etiology
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
AMA | Mitochondrial Ab, M2, S | Yes | Yes |
ANA2 | Antinuclear Ab, S | Yes | Yes |
SMAS | Smooth Muscle Ab Screen, S | Yes | Yes |
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
SMAT | Smooth Muscle Ab Titer, S | No | No |
If smooth muscle antibody (SMA) screen is positive then the SMA titer will be performed at an additional charge.
AMA: Enzyme Immunoassay (EIA)
SMAS: Indirect Immunofluorescence
ANA2: Enzyme-Linked Immunosorbent Assay (ELISA)
Antinuclear Antibodies, Serum
Mitochondrial Antibodies, Serum
Primary biliary cirrhosis
Smooth Muscle Antibodies, Serum
If smooth muscle antibody (SMA) screen is positive then the SMA titer will be performed at an additional charge.
Serum
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Client Test Request (T728) with the specimen.
1 mL
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 14 days |
Evaluation of patients with suspected autoimmune liver disease, specifically autoimmune hepatitis or primary biliary cirrhosis
Evaluation of patients with liver disease of unknown etiology
If smooth muscle antibody (SMA) screen is positive then the SMA titer will be performed at an additional charge.
Autoimmune liver diseases result from damage to hepatocytes or cholangiocytes caused by an inflammatory immune reaction. Included within this disease group are autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC). In some cases, patients with these diseases may present asymptomatically, with increases in various liver enzymes being identified incidentally during an unrelated clinical evaluation. On the other end of the spectrum are patients who present with clinical evidence of liver disease, including fatigue, hepatomegaly, ascites, esophageal varices, and jaundice.
Diagnosis of an autoimmune liver disease first requires that other etiologies of liver injury, including viral, drug, and metabolic causes, be excluded. In some situations, a liver biopsy may be indicated. For those patients in whom an autoimmune liver disease is suspected, autoantibody serology testing may be considered. This assay includes markers that may support a diagnosis of an autoimmune liver disease, specifically AIH or PBC. Unfortunately, there are no known autoantibodies specific for PSC that are useful as diagnostic markers.
Patients with AIH may be positive for smooth muscle antibodies (SMA) and/or antinuclear antibodies (ANA). The SMA associated with AIH are generally specific for F-actin. SMA have a specificity of 80% to 90% for AIH, although the sensitivity is only in the range of 70% to 80%. In contrast, ANA, although relatively sensitive for AIH, lack specificity, being associated with a variety of autoimmune diseases. Both SMA and ANA, along with other lab markers and biopsy evaluation, are included in the international diagnostic criteria for AIH.
Antimitochondrial antibodies (AMA) are a diagnostic marker for PBC. AMA are found in more than 90% of patients with PBC, with a specificity of greater than 95%. AMA are included in the diagnostic criteria for PBC, which were developed through an international collaborative effort.
SMOOTH MUSCLE ANTIBODIES
Negative
If positive, results are titered.
Reference values apply to all ages.
MITOCHONDRIAL ANTIBODIES (M2)
Negative: <0.1 Units
Borderline: 0.1-0.3 Units
Weakly positive: 0.4-0.9 Units
Positive: > or =1.0 Units
Reference values apply to all ages.
ANTINUCLEAR ANTIBODIES (ANA2)
Negative: < or =1.0 Units
Weakly positive: 1.1-2.9 Units
Positive: 3.0-5.9 Units
Strongly positive: > or =6.0 Units
Reference values apply to all ages.
The presence of smooth muscle antibodies (SMA) or antinuclear antibodies (ANA) is consistent with a diagnosis of chronic autoimmune hepatitis, in patients with clinical or laboratory evidence of hepatocellular damage.
The presence of antimitochondrial antibodies (AMA) is consistent with a diagnosis of primary biliary cirrhosis, in patients with clinical or laboratory evidence of hepatobiliary damage.
Smooth muscle antibodies (SMA) may be found in patients with active hepatitis caused by alcohol or drug exposure.
Antinuclear antibodies (ANA) occur in patients with a variety of systemic autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, Sjogren syndrome, and systemic sclerosis.
The presence of smooth muscle antibodies (SMA), antinuclear antibodies (ANA), and antimitochondrial antibodies (AMA) should not be exclusively relied upon to diagnose an autoimmune liver disease. Correlation with clinical presentation and other laboratory parameters of liver disease is required.
1. Invernizzi P, Lleo A, Podda M: Interpreting serological tests in diagnosing autoimmune liver diseases. Sem Liver Dis. 2007;27(2):161-172
2. Hennes EM, Zeniya M, Czaja AJ, et al: Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatol. 2008;48:169-176
3. Muratori L, Granito A, Muratori P, et al: Antimitochondrial antibodies and other antibodies in primary biliary cirrhosis: diagnostic and prognostic value. Clin Liver Dis. 2008;12:261-276
4. Karlsen TH, Schrumpf E, Boberg KM: Update on primary sclerosing cholangitis. Dig Liver Dis. 2010;42:390-400
Smooth Muscle Antibody: The patient's serum in 1:20 and 1:40 dilutions is added to fresh tissue from mouse stomach/kidney and incubated; fluorescein-conjugated antiglobulin is then added. The slides are read with a fluorescence microscope.(Package insert: Kallestad Mouse Stomach/Kidney. Bio-Rad Laboratories, Inc; 01/2018)
Mitochondrial Antibodies: This method is an enzyme immunosorbent assay that detects both IgG and IgM antibodies to M2 antigens. A dilution of patient serum is added to the wells coated with M2 antigen and incubated. After incubation and washing, all unbound human antibodies are washed away and enzyme-conjugated IgG and IgM anti-human is added. The enzyme conjugate binds to the antibody complex. Excess enzyme-conjugate is washed away and substrate is added. After incubation, the enzyme substrate reaction is stopped. The complete assay is measured on a spectrophotometer plate reader. The intensity of the color generated is proportional to the amount of IgG and IgM specific antibody in the sample.(Package insert: Kallestad Anti-Mitochondrial Kit. Bio-Rad Laboratories; 10/2014)
Antinuclear Antibodies: The method used to detect antinuclear antibody (ANA) is enzyme-linked immunosorbent assay (ELISA). A HEp-2 lysate supplemented with various purified antigens (double-stranded deoxyribonucleic acid: dsDNA, histone, SS-A [Ro], SS-B [La], Smith, RNP, Scl-70, Jo-1, plus centromere antigen) are coated onto microtiter plate wells. A dilution of patient serum is added to the well and incubated. After washing to remove unbound serum protein, an enzyme conjugated antihuman-IgG antibody is added to detect human IgG bound to the microtiter plate well. After incubation and washing to remove unbound conjugate, a substrate to the enzyme is added to the well. After incubation, the enzyme substrate reaction is stopped. The complete assay is measured on a spectrophotometer plate reader. The optical density measured is proportional to the antibody present in the patient serum.(Package insert: ELISA kits. Bio-Rad Laboratories; 07/2014)
Monday through Saturday
See Individual Test IDs
86038
86381
86015
86015-Titer (if appropriate)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
ALDG | Autoimmune Liver Disease Panel, S | 94700-2 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
AMA | Mitochondrial Ab, M2, S | 51715-1 |
ANA2 | Antinuclear Ab, S | 94875-2 |
609515 | Smooth Muscle Ab Screen, S | 26971-2 |
Change Type | Effective Date |
---|---|
Obsolete Test | 2023-06-01 |