CPT® Code 87426

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; severe acute respiratory syndrome coronavirus (eg, SARS-CoV, SARS-CoV-2 [COVID-19])

The CPT® Code 87426 refers to a laboratory test designed to detect the presence of severe acute respiratory syndrome coronavirus (SARS-CoV) and its variant SARS-CoV-2, which is responsible for COVID-19. This detection is achieved through various immunoassay techniques, including enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), fluorescence immunoassay (FIA), and immunochemiluminometric assay (IMCA). These methods are utilized to identify the antigen associated with the virus in a sample, typically obtained from respiratory secretions. The test can provide qualitative results, indicating whether the antigen is present, or semi-quantitative results, which can give an estimate of the amount of antigen detected. COVID-19 manifests with a range of symptoms, including cough, fever, chills, shortness of breath, dyspnea, chest pain, muscle aches, and fatigue. While many individuals experience mild to moderate symptoms and recover without the need for specialized treatment, severe cases can lead to significant respiratory distress, necessitating hospitalization and potentially ventilator support. Certain populations, particularly older adults and individuals with pre-existing health conditions such as heart or lung disease, cancer, or diabetes, are at an increased risk for severe illness. The testing process involves collecting a sample of respiratory secretions, which is then either placed in a fixative or sent fresh to a laboratory for analysis. The immunoassay techniques employed in this test work by detecting the antigen when it binds to a specific antibody. In the case of EIA and ELISA, a secondary enzyme-labeled antibody is introduced, which facilitates the detection of the antigen-antibody complex through a chromogenic reaction that results in a visible color change or fluorescence. The FIA method utilizes a fluorescent compound to detect the binding of the detection antibody to the analyte, while IMCA employs antibodies labeled with a chemiluminescent substance to quantify the antigen-antibody complex based on light emission. This comprehensive approach allows for effective identification of the SARS-CoV and SARS-CoV-2 antigens, aiding in the diagnosis and management of COVID-19.