Isoenzyme Testing
Isoenzyme testing is a laboratory method that determines which isoforms (isoenzymes) of an enzyme are present in a patient sample.
Purpose of Isoenzyme Testing
Isoenzyme testing is used to improve the interpretation of blood or tissue enzyme results by identifying the tissue source of an enzyme level.
Specimen and Methods
Common specimen types include serum or plasma, and the testing method may include electrophoresis or immunoassays that can differentiate enzyme isoforms.
Clinical Examples
Isoenzyme testing is classically used for cardiac and liver pattern assessment when a total enzyme value is nonspecific.
Interpretation Considerations
Results are interpreted in the context of symptoms, timing of illness, and other laboratory tests because enzyme isoenzyme patterns change over time after injury.
Relationship to Other Tests
Isoenzyme testing may be used instead of, or alongside, more modern isoform-specific assays depending on the enzyme and the laboratory platform available.