Pathology/Lab Coding Alert

Question: Our lab received an order for an IGRA test for TB for a 30-year-old patient who had BCG vaccination for TB. We received a denial for the test, stating that the Mantoux tuberculin skin is covered for a TB screen, but not IGRA. Does this reflect coverage rules for TB testing?

Washington Subscriber

Answer: Coverage for tuberculosis testing may depend on your payer. But many payers consider the Bacille Calmette-Guerin (BCG) vaccination cause for using the Interferon-gamma Release Assay (IGRA) for Mycobacterium tuberculosis, also known as QFT-Plus, instead of the Mantoux tuberculin skin test.

In fact, the Centers for Disease Control and Prevention (CDC) guidelines state that when a physician indicates the need for TB testing, patients over five years of age with a history of BCG vaccination may need the IGRA as the initial test rather than a Mantoux or tuberculin skin test.

Here’s why: The IGRA blood test is useful for people who have had prior BCG vaccination because the test measures immune response to two TB-specific proteins — ESAT-6 and CFP-10 — that were never included in the BCG vaccine. These proteins are also absent from most non-tuberculous mycobacteria, thus avoiding false-positive results for exposure to other mycobacteria. The Mantoux tuberculin skin test may show false positives for BCG-vaccinated individuals.

Know the codes: For the IGRA test, you should list the procedure as 86480 (Tuberculosis test, cell-mediated immunity antigen response measurement; gamma interferon). That’s in contrast to the code for a tuberculin skin test, which is 86580 (Skin test; tuberculosis, intradermal). CPT^® deleted the code for the older “tine” test several years ago, leaving this as the sole code for a Mantoux tuberculin skin test, possibly also called a PPD (purified protein derivative) test.

Diagnosis: You should not code an active TB case based on the results of IGRA testing. Instead, you can report findings using a code such as R76.12 (Nonspecific reaction to cell mediated immunity measurement of gamma interferon antigen response without active tuberculosis).