CPT® Code 87564

Infectious agent detection by nucleic acid (DNA or RNA); Mycobacterium tuberculosis, rifampin resistance, amplified probe technique

The CPT® Code 87564 pertains to the detection of the infectious agent Mycobacterium tuberculosis, specifically focusing on its resistance to the antibiotic rifampin. This resistance is identified through a molecular technique known as the amplified probe technique, which includes methods such as the Xpert MTB/RIF assay and the MLP-RAP assay. Rifampin resistance arises from mutations in the core region of the rpoB gene, which is critical for the bacterium's survival and replication. The global rise in drug-resistant tuberculosis represents a significant public health challenge, making the detection of rifampin resistance crucial for effective treatment and control of the disease. The testing process utilizes a sputum sample, which is analyzed to determine the presence of rifampin-resistant strains of Mycobacterium tuberculosis. Rapid assay tests, such as the Xpert MTB/RIF, facilitate early detection, allowing healthcare providers to promptly select appropriate treatment regimens and implement necessary infection control measures. The procedure involves mixing the sputum sample with a reagent that contains molecular beacons designed to amplify a specific sequence within the rpoB gene. This mixture is then placed in a GeneXpert machine, which automates the testing process and provides results within a two-hour timeframe. Other molecular beacon tests may employ multiple labeled probes in a single tube polymerase chain reaction (PCR) assay, each targeting different sequences of the rpoB gene and labeled with distinct color fluorophores. The detection of luminescence from all five colors during PCR amplification indicates the presence of rifampin-resistant Mycobacterium tuberculosis.