Doctor's Assessment Included
Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
Smooth Muscle Antibodies (SMA): what a positive SMA screen means
Smooth Muscle Antibodies (SMA) are autoantibodies associated with autoimmune hepatitis. Women are more frequently affected by autoimmune hepatitis than men, and hormonal factors may influence disease development, making liver immune health an important area of attention for women.
What It Measures
This test detects the presence and level of smooth muscle antibodies, also called anti smooth muscle antibodies, in your blood. The lab often uses indirect immunofluorescence to look for these and related autoantibodies. SMA targets proteins in smooth muscle tissue and is one of the markers that may support a diagnosis of autoimmune hepatitis type 1. A positive smooth muscle antibody screen is usually read alongside other test results, such as a broader autoimmune liver panel.
Why It Matters
Detecting SMA may help with the diagnosis of autoimmune hepatitis, an autoimmune disease in which the immune system can affect the liver. SMA is sometimes also seen with primary biliary cirrhosis (also called primary biliary cholangitis) and may appear at low levels in viral hepatitis. Results are best understood together with other markers, such as liver enzymes ALT and AST, and a clinical assessment.
When to Test
Testing may be recommended when liver enzyme levels are elevated without a clear cause, when symptoms of liver disease are present, or as part of an autoimmune liver disease workup. Consult a healthcare professional for interpretation of results.
Symptoms
Low Levels
High Levels
Lifestyle Tips
Supporting liver health through a balanced diet, limited alcohol consumption, and maintaining a healthy weight can be beneficial. Avoiding unnecessary medications that may stress the liver is also recommended. Regular medical check-ups can help monitor liver function over time. Some people choose to monitor liver-related markers periodically to stay informed. Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.