What is the recommended treatment for a patient with a positive Quantiferon Gold (Interferon-Gamma Release Assay) result indicating latent tuberculosis infection (LTBI)?

From the Guidelines

The recommended treatment for latent tuberculosis infection (LTBI) diagnosed by a positive Quantiferon Gold test is typically a short-course rifamycin-based regimen, such as 3 months of once-weekly isoniazid plus rifapentine, 4 months of daily rifampin, or 3 months of daily isoniazid plus rifampin, as these regimens have been shown to be effective and have higher treatment completion rates compared to longer-course isoniazid monotherapy 1.

Key Considerations

• Treatment should be initiated after active TB disease has been ruled out through symptom screening, chest X-ray, and possibly sputum testing.
• Baseline liver function tests are recommended before starting therapy, with periodic monitoring during treatment, especially for those with risk factors for hepatotoxicity.
• Vitamin B6 (pyridoxine) 25-50mg daily is typically given with isoniazid to prevent peripheral neuropathy.
• The choice of regimen should be individualized based on potential drug interactions, comorbidities, and likelihood of adherence, with shorter regimens generally preferred when appropriate due to better completion rates.

Treatment Options

• 3 months of once-weekly isoniazid (900mg) plus rifapentine (900mg), known as 3HP, is a preferred regimen for treatment of LTBI, including in persons with HIV infection and in children aged 2-17 years 1.
• 4 months of daily rifampin (600mg) is another effective option for treatment of LTBI.
• 3 months of daily isoniazid plus rifampin can be considered for patients who cannot tolerate other options.

Importance of Treatment Completion

• Treatment completion is essential as it reduces the risk of progression to active TB disease by 60-90%.
• Shorter regimens, such as the rifamycin-based regimens, generally have better completion rates compared to longer-course isoniazid monotherapy.

From the FDA Drug Label

PRIFTIN is indicated in adults and children 2 years and older for the treatment of latent tuberculosis infection caused by Mycobacterium tuberculosis in patients at high risk of progression to tuberculosis disease PRIFTIN must always be used in combination with isoniazid as a 12-week once-weekly regimen for the treatment of latent tuberculosis infection

The recommended treatment for a patient with a positive Quantiferon Gold result indicating latent tuberculosis infection (LTBI) is rifapentine (PRIFTIN) in combination with isoniazid as a 12-week once-weekly regimen.

• Key points:
  • The treatment is for patients at high risk of progression to tuberculosis disease.
  • Active tuberculosis disease should be ruled out before initiating treatment for latent tuberculosis infection.
  • PRIFTIN in combination with isoniazid is not recommended for individuals presumed to be exposed to rifamycin-resistant or isoniazid-resistant M. tuberculosis 2.

From the Research

Treatment Options for Latent Tuberculosis Infection (LTBI)

• The recommended treatment for a patient with a positive Quantiferon Gold result indicating LTBI includes several options, such as once-weekly isoniazid plus rifapentine for 3 months, daily rifampin for 4 months, daily isoniazid plus rifampin for 3-4 months, and daily isoniazid for 6-9 months 3.
• A study comparing 3 months of rifapentine and isoniazid to 9 months of isoniazid found that the combination therapy was as effective in preventing tuberculosis and had a higher treatment completion rate 4.
• Another study predicted that a 6-week monotherapy regimen of rifapentine could result in equal or better efficacy than the 1-month and 3-month combination regimens with isoniazid, without the potential added toxicity of isoniazid 5.

Efficacy and Safety of Treatment Regimens

• A systematic review and meta-analysis found that the 3-month isoniazid-rifapentine regimen was as safe and effective as other recommended LTBI regimens and achieved significantly higher treatment completion rates 6.
• A retrospective cohort study comparing treatment completion rates for 9 months of isoniazid, 4 months of rifampin, and 3 months of isoniazid and rifapentine found that patients were equally likely to complete the 3-month isoniazid and rifapentine or 4-month rifampin regimens, with higher completion rates than the 9-month isoniazid regimen 7.

Treatment Completion Rates

• Treatment completion rates vary among regimens, with the 3-month isoniazid and rifapentine regimen and the 4-month rifampin regimen showing higher completion rates compared to the 9-month isoniazid regimen 4, 6, 7.
• The type of treatment offered and monitoring type can impact treatment completion rates, but the associations between treatment regimen and completion rate remain statistically significant even after adjusting for these factors 7.