CPT® Code 87385

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; Histoplasma capsulatum

The CPT® Code 87385 refers to a laboratory test designed to detect the presence of the antigen associated with Histoplasma capsulatum, a pathogenic fungus commonly found in environments rich in bat or bird droppings. This test employs various immunoassay techniques, including enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), fluorescence immunoassay (FIA), and immunochemiluminometric assay (IMCA). These methodologies are crucial for identifying the antigen in biological samples, which may include blood or respiratory secretions. The detection of Histoplasma capsulatum is particularly significant as exposure to its spores can lead to a range of health issues, from mild respiratory symptoms such as cough, fever, and fatigue to more severe systemic infections, especially in individuals with weakened immune systems. The test is performed by obtaining a sample that is either preserved in a fixative or sent fresh to the laboratory for analysis. The immunoassay techniques utilized in this test are adept at identifying even minute quantities of the antigen by employing specific antibodies that bind to the antigen, followed by a secondary detection method that produces a measurable signal, such as a color change or fluorescence. This allows for both qualitative and semi-quantitative assessments of the antigen's presence in the sample.