Immunocompromised

Overall, about 5–10% of people with latent TB infection will develop active TB disease at some time in their lives. For persons whose immune systems are weak, especially those with HIV infection, the risk of developing TB disease is much higher than for persons with normal immune systems (1).

Two such populations are people living with HIV and patients receiving biologics therapy:

• People who are infected with HIV are 16 times more likely to develop active TB (2).
• TB is the leading cause of death among HIV-infected patients (3).
• Patients receiving biologic (anti-TNF-α) therapy are at a 9-fold increased relative risk of developing active TB (4).

Let’s see how systematic latent TB testing and treatment can prevent the progression of latent TB to TB disease in immunocompromised patients.

As a result of immunosuppression, people living with HIV are at increased risk for TB, and reliable surveillance is critical to protect their health.

Thus, timely diagnosis and early treatment are vital to preventing its progression to disease. The CDC recommends latent TB testing for all persons living with HIV as someone with untreated latent TB infection and HIV infection is much more likely to develop active TB disease during their lifetime than someone without HIV infection (5).

Treatment with biologic agents, in particular tumor necrosis factor-alpha (TNF-α) inhibitors, has revolutionized the treatment of autoimmune conditions like rheumatoid arthritis, Crohn’s disease and psoriasis.

However, patients receiving anti-TNF-α therapy are at increased risk of TB infection. The immune system, including TNF, suppresses latent TB infection, but when treated with anti-TNF-α, the immune system may lose control over TB infection, leading to TB activation.

To reduce this risk, pharmaceutical labeling requirements reinforce that TB testing is essential in evaluating a patient’s treatment options.

References:

1. Centers for Disease Control and Prevention. (2016) TB Risk Factors. https://www.cdc.gov/tb/topic/basics/risk.htm (accessed January 15, 2023)
2. World Health Organization. (2022) WHO Tuberculosis Key Facts. https://www.who.int/news-room/fact-sheets/detail/tuberculosis (accessed January 15, 2023)
3. Machuca, I., Vidal, E., de la Torre-Cisneros, J., Rivero-Román, A. (2018). Tuberculosis in immunosuppressed patients. Enferm Infecc Microbiol Clin. 36(6), 366–374.
4. Lobue, P. and Menzies, D. (2010) Treatment of latent tuberculosis infection: An update. Respirology. 15, 603.
5. Centers for Disease Control and Prevention. (2014) TB and HIV Coinfection. https://www.cdc.gov/tb/publications/pamphlets/tb_hivcoinfection (accessed January 15, 2023)
6. World Health Organization. (2020) WHO consolidated guidelines on tuberculosis: tuberculosis preventive treatment. https://apps.who.int/iris/bitstream/handle/10665/331525/9789240002906-eng.pdf
7. Lewinsohn, D.M., et al. (2017) Official ATS/IDSA/CDC clinical practice guidelines: Diagnosis of tuberculosis in adults and children. Clin. Infect. Dis. 64, 111–116.

QuantiFERON-TB Gold Plus (QFT-Plus) is an in vitro diagnostic aid for detection of Mycobacterium tuberculosis infection. QFT-Plus is an indirect test for M. tuberculosis infection (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. QFT-Plus Package Inserts as well as up-to-date licensing information and product-specific disclaimers can be found at www.QuantiFERON.com.