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Test Code FACT F-Actin Ab, IgG, Serum

Reporting Name

F-Actin Ab, IgG, S

Useful For

Evaluating patients with chronic liver disease in whom the diagnosis of chronic active autoimmune hepatitis is suspected

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL


Specimen Minimum Volume

0.4 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 21 days
  Frozen  21 days

Reference Values

Negative: <20.0 U

Weak Positive: 20.0-30.0 U

Positive: >30.0 U

Day(s) and Time(s) Performed

Thursday; Evening

Test Classification

This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

83516

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FACT F-Actin Ab, IgG, S 44706-0

 

Result ID Test Result Name Result LOINC Value
FACT F-Actin Ab, IgG, S 44706-0

Clinical Reference

1. Mieli-Vergani G, Vergani D, Czaja AJ, et al: Autoimmune hepatitis. Nat Rev Dis Primers. 2018;4:18017

2. Terziroli Beretta-Piccoli B, Mieli-Vergani G, Vergani D: Serology in autoimmune hepatitis: A clinical-practice approach. Eur J Intern Med. 2018;48:35-433. Hennes EM, Zeniya M, Czaja AJ, et al: Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008;48:169-176

3. Hennes EM, Zeniya M, Czaja AJ, et al: Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008;48:169-176

Method Description

The method used to detect antibodies directed against filamentous-actin (F-actin) is enzyme-linked immunosorbent assay (ELISA). Prediluted controls and diluted patient sera are added to separate wells, allowing any actin antibodies present to bind to the antigen. Unbound sample is washed away, and an enzyme labeled anti-human IgG is added to each well. A second incubation allows the enzyme labeled anti-human IgG to bind to any patient antibodies, which have become attached to the microwells, and any unbound conjugate is removed by another wash step. The bound conjugate is visualized with 3,3',5,5' tetramethylbenzidine (TMB) substrate, which gives a blue reaction product, the intensity of which is proportional to a concentration of autoantibody in the sample. Sulfuric acid is added to each well to stop the reaction. This produces a yellow endpoint color, which is read at 450 nm. Testing is performed on the  DS2 instrument by  Dynex.(Package insert: QUANTA Lite Actin IgG ELISA 708785. INOVA Diagnostics; Rev. 5, 2/2015)

Analytic Time

1 day

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK
Heat treated specimens Reject

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Secondary ID

61620