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Test Code FACT F-Actin Ab, IgG, Serum

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Evaluating patients suspected of having autoimmune hepatitis

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Reporting Name

F-Actin Ab, IgG, S

Specimen Type


Specimen Required


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Specimen Minimum Volume

0.4 mL

Specimen Stability Information

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

Reject Due To


Mild OK; Gross OK


Mild OK; Gross OK


Mild OK; Gross OK




Reference Values

Negative: <20.0 U

Weak Positive: 20.0-30.0 U

Positive: >30.0 U


Seropositivity for anti-F-Actin antibodies is consistent with a diagnosis of autoimmune hepatitis (AIH).


A negative result for anti-F-Actin antibodies does not exclude a diagnosis of AIH.


In a study conducted at Mayo Clinic, the F-Actin ELISA had a clinical sensitivity of 92.9% when using the manufacturer’s recommended cutoff of 20.0 U. In addition, the F-Actin ELISA had a clinical specificity of 76.7% when using the aforementioned cutoffs. See Supportive Data.

Day(s) and Time(s) Performed

Thursday; Evening

Analytic Time

1 day

Specimen Retention Time

14 days

Test Classification

This test has been cleared or approved 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


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