Mycobacterium tuberculosis Complex, Molecular Detection, PCR, Paraffin, Tissue

Casandra

Casandra Test Code MC10338Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID MTBTCPT Code 87556

Mycobacterium tuberculosis Complex, Molecular Detection, PCR, Paraffin, Tissue

Clinical Use

Use

This test is intended for the rapid detection of Mycobacterium tuberculosis complex DNA in formalin-fixed, paraffin-embedded tissue specimens. This method is preferred due to its ability to promptly identify M. tuberculosis complex, which is crucial given the organism's capacity to develop antibiotic resistance if treatment is delayed. Rapid identification allows for timely clinical intervention, vital for public health due to the contagious nature of tuberculosis spread via respiratory transmission.

Special Instructions

The test should not be used for detecting latent tuberculosis and should not replace tests like the tuberculin skin test or interferon gamma release assay for that purpose. When non-fixed specimen is available, a mycobacterial culture should be performed in addition to this test. If unable to perform a culture, order CTB / Mycobacteria and Nocardia Culture concurrently. Specimen source is required for the test.

Limitations

The PCR assay detects M. tuberculosis complex nucleic acid, thus cannot differentiate between viable organisms and DNA from prior infections. Negative results do not rule out M. tuberculosis, as concentrations may be below the detection limit. The assay does not distinguish between species within the M. tuberculosis complex. It has not been studied for use with specimens from patients undergoing antituberculous treatment and is not suitable for monitoring treatment response. Sensitivity is approximately 63% from FFPE tissue, and repeated negative results may necessitate additional specimens.

Test Details

New York Approved