CPT® Code 87562

The CPT® Code 87562 refers to a laboratory test designed for the detection of the infectious agent Mycobacteria avium-intracellulare (MAI) through the analysis of nucleic acids, specifically DNA or RNA. Mycobacteria avium-intracellulare is part of the Mycobacteria avium complex (MAC), which consists of two species of gram-positive, acid-fast, atypical bacteria that are often indistinguishable from one another. These bacteria are commonly found in environmental sources such as water and soil, and they can also be carried by birds and farm animals. Infections caused by MAI primarily affect the lungs and can lead to a range of symptoms including a productive cough with significant sputum production, fever, weight loss, fatigue, and night sweats. The testing process involves a direct probe test that identifies a unique nucleic acid sequence, known as the target sequence, of the MAI organism if it is present in various biological samples such as blood, tissue, cerebrospinal fluid (CSF), or synovial fluid. This probe is labeled with either fluorescent or chemiluminescent markers to facilitate detection. The sample undergoes treatment to release nucleic acids from the target organism, allowing the labeled probe to specifically bind to the matching target sequence, forming a stable hybrid. Ribosomal RNA is typically the focus of these tests due to its abundance in microorganisms, as it exists in thousands of copies compared to the limited copies found in genomic DNA. To enhance the sensitivity of the assay, an amplified probe technique is employed, which involves exponentially multiplying the target sequence of MAI DNA or RNA into millions of copies. The most prevalent amplification methods include polymerase chain reaction (PCR) and reverse transcriptase polymerase chain reaction (RT-PCR). Following amplification, the replicated sequences are identified using labeled DNA probes. The quantification aspect of this test, as indicated by CPT® Code 87562, provides an assessment of the number of microorganisms present in the sample. Quantitative or real-time PCR is often utilized to amplify the isolated nucleic acid segment, generating reports that document the absolute or relative amounts of the known nucleic acid sequence at each stage of the testing process.