CPT® Code 87799

The CPT® Code 87799 refers to a laboratory test designed for the detection of infectious agents through the analysis of nucleic acids, specifically DNA or RNA. This code is utilized when the infectious agent is not otherwise specified (NOS), meaning that the specific organism being tested for is not clearly defined within the coding guidelines. Examples of such organisms may include, but are not limited to, West Nile Virus, Human T-Lymphotropic Virus, Epstein Barr Virus, BK Virus, Adenovirus, Hepatitis E Virus, Parvovirus B19, and Human Herpesvirus 8. The procedure involves the use of a direct probe test, which identifies a unique nucleic acid sequence known as the target sequence of the suspected organism, provided it is present in the sample collected from blood, tissue, or other bodily fluids. The test employs a probe that is labeled with either fluorescent or chemiluminescent markers to facilitate the detection process. During the testing process, the sample is treated to release nucleic acids from the target organism, if it exists within the sample. The labeled probe then specifically binds to the target sequence, forming a stable hybrid that can be detected. Ribosomal RNA is often the focus of these tests due to its abundance in microorganisms, as it is typically present in thousands of copies compared to the limited copies of genomic DNA. In cases where enhanced sensitivity is required, an amplified probe technique is employed, which significantly increases the assay's sensitivity by exponentially multiplying the target sequence of the organism's DNA or RNA into millions of copies. The polymerase chain reaction (PCR) or reverse transcriptase polymerase chain reaction (RT-PCR) are the most commonly used amplification techniques. Following amplification, the replicated sequences are identified using labeled DNA probes. The quantification aspect of this test, as indicated by the CPT® Code 87799, provides an assessment of the number of microorganisms present in the sample, often utilizing quantitative or real-time PCR methods to amplify the nucleic acid segment and generate detailed reports documenting the absolute or relative amounts of the identified nucleic acid sequence.