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Soluble Liver Antigen (SLA) IgG Antibody

CPT 83516
Synonyms
  • SLA, IgG Antibody

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.

Related Documents

Use

Aid in the diagnosis of autoimmune hepatitis (AIH)1-4

Limitations

A negative SLA IgG does not rule out autoimmune hepatitis.

Footnotes

1. Ballot E, Homberg JC, Johanet C. Antibodies to soluble liver antigen: An additional marker in type 1 autoimmune hepatitis. J Hepatol. 2000; 33(2):208-215. 10952238
2. Czaja AJ, Norman GL. Autoantibodies in the diagnosis and management of liver disease. J Clin Gastroenterol. 2003; 37(4):315-329. 14506390
3. Strassburg CP, Manns MP. Autoantibodies and autoantigens in autoimmune hepatitis. Semin Liver Dis. 2002; 22(4):339-352. 12447706
4. Czaja AJ. Autoantibodies in autoimmune liver disease. Adv Clin Chem. 2005; 40:127-164.16355922

References

Luxon BA. Autoimmune hepatitis. Making sense of all those antibodies. Postgrad Med. 2003; 114(1):79-82, 85-88.12875057

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 Code007441
Order Code NameSoluble Liver Ag (IgG Ab)
Order Loinc38420-6
Result Code007442
Result Code NameAnti-SLA, IgG
UofMunits
Result LOINC38420-6