CPT® Code 87337

Infectious agent antigen detection by immunoassay technique, (eg, enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], fluorescence immunoassay [FIA], immunochemiluminometric assay [IMCA]) qualitative or semiquantitative; Entamoeba histolytica group

The CPT® Code 87337 refers to a laboratory test designed to detect the presence of antigens associated with the Entamoeba histolytica group. This test employs various immunoassay techniques, including enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), fluorescence immunoassay (FIA), and immunochemiluminometric assay (IMCA). Entamoeba histolytica is a parasitic organism that can lead to serious health issues such as liver abscesses, transient intestinal inflammation, acute colitis, toxic megacolon, and peritonitis. Common symptoms of infection include abdominal pain and diarrhea. The transmission of this parasite can occur through sexual contact or ingestion of contaminated food and water. The Entamoeba histolytica organism exists in two forms: a resilient, tetra-nucleated cyst that is infective, and a fragile trophozoite that can cause disease. It is important to note that the E. histolytica dispar group is generally considered non-invasive and non-pathogenic, although it may occasionally lead to diarrheal illness. In contrast, the E. histolytica group is recognized as invasive and pathogenic, often linked to more severe acute illnesses. To perform the test, a fecal sample is collected and either placed in a fixative or sent fresh to the laboratory for analysis. The immunoassay techniques utilized in this test are capable of detecting very small amounts of the antigen when it is bound to its specific antibody. For instance, EIA and ELISA methods involve adding a secondary, enzyme-labeled antibody that binds to the antigen-antibody complex, resulting in a chromogenic reaction that produces a visible color change or fluorescence. The qualitative and semi-quantitative results are determined through colorimetric readings. In the case of FIA, a fluorescent compound is used to detect the binding of the detection antibody to the analyte molecule, while IMCA employs antibodies labeled with a chemiluminescent substance to identify and quantify the antigen-antibody complex through light emission. This comprehensive approach allows for accurate detection and assessment of the Entamoeba histolytica group in fecal samples.