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Mycobacterium tuberculosis Complex PCR (LAB001981)
Test Mnemonic:

MTB DNA

Specimen Requirements:

Sputum - Appearance of sputum specimen must indicate a lower respiratory tract collection.  If the specimen is watery, looks like saliva, or contains obvious food particles, testing will be delayed.

Other sources approved for testing include: Respiratory specimens(BAL, Bronch wash), CSF, and tissue. 

All other sources will require Director on call approval before testing. 

Test Included:

An AFB culture must be ordered in addition to this test. 

Collection:

Sputum - Expectorated or induced sputum collected by standard techniques.

For information on Sputum collections, refer to the specimen collection section of the Laboratory Test Directory.

Other sources - submit in sterile, leakproof container.

 

Minimum Volume:

Sputum - minimum 3 mL

Other sources - minimum 2 mL

 

Storage/Transport:

Storage and transport varies based on specimen type. 

Room temperature: CSF, tissues

Refrigerated: Respiratory sources 

Stability:

Up to 7 days, refrigerated. 

Causes for Rejection:

Leaking containers, unlabeled or mislabeled specimens, duplicate testing

Reference Range:

Negative

Turnaround Time:

Specimens that meet the acceptance criteria are tested as received in the lab with a 4 hour turnaround time. 

Specimens that must undergo processing/concentration will be performed once a day, Monday-Friday. 

Methodology:

Real-time PCR for the qualitative detection of MTBC and rifampin resistance. 

Performed:

Clinical Microbiology

Synonyms:

MTB PCR, MTB DNA, TB PCR, TB DNA, AFB, Acid-fast bacteria, Tuberculosis

Clinical Indication:

Suspected Tuberculosis (TB) infection.

CPT 4 Code:

87556

Note:

This test will be reflexed on the first two sputum specimens (collected at least 8 hours apart) ordered for AFB culture.

Repeat testing limits per patient include 2 negative PCR results per 60 days or 1 positive result per 60 days. These tests will be canceled as duplicates per protocol.  

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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