Indirect Fluorescent Antibody (IFA), Mouse stomach kidney substrate
Positive in 50-80% of patients with chronic active hepatitis. Titers are negative in extra hepatic biliary obstruction. Antismooth muscle antibodies (SMA) are also seen in acute viral hepatitis; low titers may be seen in primary biliary cirrhosis.
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Presence of strong antinuclear antibody may interfere with the interpretation of smooth muscle antibody.
- Antismooth Muscle Antibody
- Liver Smooth Muscle Antibody
- Smooth Muscle Antibody
Collect specimen in SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate. Specimen aliquot should be frozen if it's not going to be received in Immunology within 3 days of collection.
Smooth muscle antibody measurements are useful in confirming the diagnosis of chronic active hepatitis (CAH). Titers generally range from 1:80-1:320 and persist for years. In viral hepatitis the titers are below 1:80 and are transient. Low titers (1:20 to 1:40) are found in approximately 50% of patients with primary biliary cirrhosis. If another antibody including Parietal Cell Antibody, Mitochondrial Antibody, or Liver Kidney Microsomal Antibody is noted to be present during the performance of this test, the client will be notified via a footnote in the report. Please contact the MLabs Client Services Center to request the additional auto-antibody; there will be a separate charge for each auto-antibody test ordered.