Actin (Smooth Muscle) Antibodies (ASMA; anti-F-actin) are autoantibodies that target proteins in smooth muscle cells. They are most often linked to autoimmune hepatitis (AIH), especially type 1, but they can also appear in chronic active hepatitis and, less commonly, in primary biliary cholangitis (PBC, historically called “primary biliary cirrhosis”). Positivity is reported in about 52–85% of people with AIH or chronic active hepatitis and about 22% with PBC. ASMA often appears together with ANA (antinuclear antibodies) and high IgG levels, which form a typical autoimmune antibody pattern in AIH.
Why the test is done
-
Helps identify autoimmune hepatitis (AIH): If liver enzymes (ALT, AST) are high and other causes are ruled out, ASMA can point toward immune-related liver inflammation.
-
Helps distinguish liver conditions: Along with ANA, anti-LKM-1, anti-SLA, AMA, and total IgG, this test helps doctors tell AIH apart from PBC and other chronic liver diseases.
-
Strengthens the autoimmune suspicion: Higher levels increase the likelihood of an autoimmune cause, though the test is not diagnostic on its own.
How to interpret results
-
0–19 (Negative): Does not support autoimmune hepatitis by itself. If liver tests are abnormal, doctors will consider other causes (such as viral hepatitis, alcohol-related injury, metabolic disease, or medication effects) and may order other antibody or IgG tests.
-
20–30 (Weak positive): Borderline result suggesting possible autoimmune activity. Doctors interpret this together with liver enzyme patterns, other antibodies (ANA, AMA, anti-LKM-1, anti-SLA), IgG levels, liver-related symptoms (fatigue, itching, jaundice, joint pain), and imaging. Repeat testing or confirmation with an anti-F-actin ELISA test may sometimes be recommended.
-
Over 30 (Moderate to strong positive): Stronger evidence for AIH, particularly if IgG is elevated, ANA is also positive, and ALT/AST are high. Even then, diagnosis usually requires a combination of test results, scoring systems (such as IAIHG), and sometimes a liver biopsy to confirm characteristic inflammation and assess disease stage.
Important things to know
-
Specificity: ASMA is a useful piece of the diagnostic puzzle but not perfectly specific. It can also show up in PBC, viral hepatitis, or other autoimmune conditions.
-
Follow-up and monitoring: Antibody levels may fall with treatment, but changes in titers are not reliable for tracking disease activity. Doctors mainly monitor liver enzymes, bilirubin, IgG, symptoms, and may use imaging or biopsy.
-
Test methods differ: Some labs report ASMA qualitatively or as titers (such as 1:40, 1:80). These results correspond to the negative/weak/positive categories outlined above.
What happens next
-
If positive: Your doctor may suggest a full evaluation, including liver blood tests (ALT, AST, ALP, GGT, bilirubin), IgG, antibody panels (ANA, AMA, anti-LKM-1, anti-SLA), a viral hepatitis panel, and imaging (ultrasound or elastography). A liver biopsy may be considered to confirm and stage the disease.
-
If negative but suspicion remains: If liver enzymes stay high or autoimmune features continue, your doctor may still order other antibody tests, IgG, or imaging, and may repeat ASMA testing.
-
Treatment implications: If autoimmune hepatitis is confirmed, treatment usually involves immunosuppressive medication (often corticosteroids and sometimes azathioprine) to reduce liver inflammation and prevent progression to fibrosis or cirrhosis.
What does it mean if your Actin (Smooth Muscle) Antibody result is too high?
An elevated ASMA result means your immune system is producing higher levels of antibodies that mistakenly target proteins in smooth muscle. This test result is most often linked to autoimmune hepatitis (AIH), especially type 1, but it can also appear in chronic active hepatitis, primary biliary cholangitis (PBC), viral hepatitis, and other autoimmune conditions.
What elevated results mean
-
Moderate to strong positives (>30): Provide stronger evidence for an autoimmune cause of liver disease.
-
Typical in AIH: Found in more than half of people with autoimmune hepatitis.
-
Often paired with other markers: Elevated IgG, positive ANA, and high liver enzymes (ALT, AST) form a more complete autoimmune profile.
-
Not diagnostic on their own: A positive ASMA must be interpreted alongside other lab and clinical findings.
Next steps your doctor may recommend
-
Additional blood tests: ANA, AMA, anti-LKM-1, anti-SLA, IgG, viral hepatitis panel.
-
Liver panel: ALT, AST, ALP, GGT, bilirubin to check for inflammation or damage.
-
Imaging: Ultrasound or elastography to look at liver health.
-
Liver biopsy: Sometimes required to confirm inflammation (“interface hepatitis”) and determine disease stage.
Treatment considerations
If autoimmune hepatitis is confirmed, treatment usually involves immunosuppressive therapy such as corticosteroids (often prednisone) with or without azathioprine. These medications help reduce immune activity, control liver inflammation, and prevent progression to fibrosis or cirrhosis. Regular monitoring of liver enzymes, IgG, and clinical symptoms is essential, since antibody titers alone are not reliable for tracking disease activity.
All Your Lab Results.
One Simple Dashboard.
Import, Track, and Share Your Lab Results Easily
Import, Track, and Share Your Lab Results
Import lab results from multiple providers, track changes over time, customize your reference ranges, and get clear explanations for each result. Everything is stored securely, exportable in one organized file, and shareable with your doctor—or anyone you choose.
Cancel or upgrade anytime
Laboratories
Bring All Your Lab Results Together — In One Place
We accept reports from any lab, so you can easily collect and organize all your health information in one secure spot.
Pricing Table
Gather Your Lab History — and Finally Make Sense of It
Finally, Your Lab Results Organized and Clear
Personal plans
$79/ year
Advanced Plan
Access your lab reports, explanations, and tracking tools.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 5 reports entered for you
- Cancel or upgrade anytime
$250/ once
Unlimited Account
Pay once, access everything—no monthly fees, no limits.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 10 reports entered for you
- No subscriptions. No extra fees.
$45/ month
Pro Monthly
Designed for professionals managing their clients' lab reports
- Import lab results from any provider
- Track lab results for multiple clients
- Customize reference ranges per client
- Export lab histories and reports
- Begin with first report entered by us
- Cancel or upgrade anytime
About membership
What's included in a Healthmatters membership
Import Lab Results from Any Source
See Your Health Timeline
Understand What Your Results Mean
Visualize Your Results
Data Entry Service for Your Reports
Securely Share With Anyone You Trust
Let Your Lab Results Tell the Full Story
Once your results are in one place, see the bigger picture — track trends over time, compare data side by side, export your full history, and share securely with anyone you trust.
Bring all your results together to compare, track progress, export your history, and share securely.
What Healthmatters Members Are Saying
Frequently asked questions
Healthmatters is a personal health dashboard that helps you organize and understand your lab results. It collects and displays your medical test data from any lab in one secure, easy-to-use platform.
- Individuals who want to track and understand their health over time.
- Health professionals, such as doctors, nutritionists, and wellness coaches, need to manage and interpret lab data for their clients.
With a Healthmatters account, you can:
- Upload lab reports from any lab
- View your data in interactive graphs, tables, and timelines
- Track trends and monitor changes over time
- Customize your reference ranges
- Export and share your full lab history
- Access your results anytime, from any device
Professionals can also analyze client data more efficiently and save time managing lab reports.
Healthmatters.io personal account provides in-depth research on 10000+ biomarkers, including information and suggestions for test panels such as, but not limited to:
- The GI Effects® Comprehensive Stool Profile,
- GI-MAP,
- The NutrEval FMV®,
- The ION Profile,
- Amino Acids Profile,
- Dried Urine Test for Comprehensive Hormones (DUTCH),
- Organic Acids Test,
- Organix Comprehensive Profile,
- Toxic Metals,
- Complete Blood Count (CBC),
- Metabolic panel,
- Thyroid panel,
- Lipid Panel,
- Urinalysis,
- And many, many more.
You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.
If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.
We implement proven measures to keep your data safe.
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.