CPT® Code 87390

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; HIV-1

The CPT® Code 87390 refers to the detection of the human immunodeficiency virus (HIV) antigen through various immunoassay techniques. This procedure involves testing a blood or saliva sample to identify the presence of HIV-1 antigens, which are proteins produced by the virus. The immunoassay techniques utilized in this process include enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), fluorescence immunoassay (FIA), and immunochemiluminometric assay (IMCA). These methods are designed to detect even minute quantities of the HIV antigen when it is bound to its specific antibody in the sample. The significance of this testing lies in its ability to identify HIV infections, which can be transmitted through sexual contact, unscreened blood transfusions, shared needles, and from mother to child during pregnancy or breastfeeding. HIV primarily targets the immune system by destroying T cells, also known as CD4 cells, which are crucial for the body’s defense against infections. If left untreated, HIV can progress to acquired immunodeficiency syndrome (AIDS), the most severe phase of the infection. During the testing process, a sample is collected and either placed in a fixative or sent fresh to a laboratory for analysis. The EIA and ELISA techniques work by adding a secondary enzyme-labeled antibody to the sample, which binds to the HIV antigen. A chromogenic reaction occurs, resulting in a visible color change or fluorescence that indicates the presence of the antigen. The qualitative and semi-quantitative results are determined through colorimetric readings. The FIA method employs a fluorescent compound to detect the binding of the detection antibody to the analyte molecule, while the IMCA method utilizes antibodies labeled with a chemiluminescent substance to identify and quantify the antigen-antibody complex through light emission. It is important to note that CPT® Code 87390 is specifically used for testing HIV-1 alone, while other codes are designated for testing HIV-1 with HIV-2 antibodies or HIV-2 alone.