CPT® Code 87336

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 dispar group

The CPT® Code 87336 refers to a laboratory test designed to detect the presence of antigens associated with the Entamoeba histolytica dispar group. This test employs various immunoassay techniques, including enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), fluorescence immunoassay (FIA), and immunochemiluminometric assay (IMCA). The primary purpose of this test is to identify the antigen in a fecal sample, which is crucial for diagnosing infections caused by this parasite. Entamoeba histolytica is known to be a pathogenic organism that can lead to serious health issues such as liver abscesses, intestinal inflammation, acute colitis, and in severe cases, toxic megacolon and peritonitis. Symptoms of infection typically manifest as abdominal pain and diarrhea. The transmission of this parasite can occur through sexual contact or ingestion of contaminated food and water. The Entamoeba histolytica species has two distinct morphological forms: a resilient, tetra-nucleated cyst that is infective, and a fragile trophozoite that can cause disease. While the E. histolytica dispar group is generally considered non-invasive and non-pathogenic, it can occasionally lead to diarrheal illnesses. In contrast, the E. histolytica group is more invasive and pathogenic, often linked to acute clinical presentations. For the test, a fecal sample is collected and either preserved in a fixative or sent fresh to the laboratory for analysis. The immunoassay techniques utilized in this test are sensitive and capable of detecting minute quantities of the antigen when it binds to its specific antibody. The detection process involves adding a secondary enzyme-labeled antibody, which facilitates a chromogenic reaction that results in a visible color change or fluorescence, allowing for qualitative or semi-quantitative assessment of the antigen's presence.