Test Details
Methodology
Enzyme immunoassay (EIA)
Result Turnaround Time
4 - 6 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Aid in the diagnosis of autoimmune hepatitis (AIH)1-4
Limitations
A negative SLA IgG does not rule out autoimmune hepatitis.
Footnotes
References
Custom Additional Information
Autoimmune hepatitis (AIH) is a chronic, progressive, heterogeneous inflammatory liver disease of unknown etiology.4 Diagnosis is often difficult since there is no single diagnostic test for AIH and presenting symptoms can be quite varied. Diagnosis includes evaluation of clinical laboratory and histological findings as well as the exclusion of other causes of chronic hepatitis. Diagnosis is particularly difficult with patients classified with cryptogenic hepatitis, described as having an undefined chronic hepatitis without antibodies to viral or the conventional profile of autoimmune markers. Early diagnosis of AIH and immunosuppressive treatment are essential to help prevent severe liver damage.
AIH patients are generally divided into two groups based on the presence of specific autoantibodies.2,4 AIH type 1 (also referred to as classic, active chronic, lupoid, plasma cell, or autoimmune chronic active hepatitis) is the more common type of AIH. AIH-1 is characterized by antinuclear, antismooth muscle (directed against both antiactin and nonactin components), and perinuclear and antineutrophil cytoplasmic antibodies. Liver/kidney microsome antibodies and antiliver cytosol antigen (LC-1) characterize AIH type 2.
Autoantibodies against soluble liver antigen (anti-SLA) show a high specificity (approximately 99%) for AIH;1,2 however, they are detectable in only 10% to 30% of patients with AIH.3 SLA is a 50 kilodalton cytosolic protein that is thought to be involved in the selenocysteine pathway.2,4 Anti-SLA and the independently described anti-LP are identical.3 The findings of anti-SLA has been associated with an increased prevalence of the HLA-DR3 genotype and a decreased prevalence of the HLA-DR4 genotype.2,3 Anti-SLA positive patients have a higher rate of relapse after corticosteroid than seronegative patients.3 Recent studies have suggested that patients with anti-SLA/LP have a more severe course of autoimmune hepatitis, although the exact function and role of this autoantibody remain unclear.3
Specimen Requirements
Specimen
Serum
Volume
0.6 mL
Minimum Volume
0.3 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube or gel-barrier tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 7 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
• Negative: 0.0−20.0 units
• Equivocal: 20.1−24.9 units
• Positive: >24.9 units
Storage Instructions
Room temperature
Causes for Rejection
Nonserum specimen received; specimen in azide or other preservative; microbially-contaminated specimen; heat-treated specimen; gross lipemia or hemolysis
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 007441 | Soluble Liver Ag (IgG Ab) | 38420-6 | 007442 | Anti-SLA, IgG | units | 38420-6 |
| Order Code | 007441 | |||||
| Order Code Name | Soluble Liver Ag (IgG Ab) | |||||
| Order Loinc | 38420-6 | |||||
| Result Code | 007442 | |||||
| Result Code Name | Anti-SLA, IgG | |||||
| UofM | units | |||||
| Result LOINC | 38420-6 |