Does Humira Cause TB?
No, Humira (adalimumab) does not cause tuberculosis (TB). It suppresses the immune system by blocking tumor necrosis factor (TNF), which increases the risk of TB reactivation in people already infected with latent TB bacteria. The FDA label warns of this risk and requires screening for latent TB before starting treatment.[1]
How Does Humira Increase TB Risk?
Humira impairs the body's ability to fight mycobacteria like those causing TB. Clinical trials showed higher TB rates in patients on TNF blockers: 0.4% for Humira versus 0.1% in placebo groups. Most cases involved latent TB reactivating, often extrapulmonary.[1][2] Active TB transmission from others is rare but possible under immunosuppression.
Who Gets Screened Before Starting Humira?
Doctors test for latent TB with skin (PPD) or blood (IGRA) tests, plus chest X-rays. If positive and untreated, patients delay Humira until TB therapy completes. Guidelines from the CDC and American College of Rheumatology mandate this for rheumatoid arthritis, psoriasis, and Crohn's patients.[2][3]
What Happens If You Start Humira Without TB Screening?
Undiagnosed latent TB can reactivate within months. Post-marketing data report hundreds of TB cases globally, with fatalities in severe instances. Risk is highest in TB-endemic areas or with travel history.[1]
TB Rates Compared to Other Biologics
Humira's TB risk aligns with other TNF inhibitors like Enbrel (etanercept) or Remicade (infliximab), but lower than older drugs like infliximab due to subcutaneous dosing and monitoring. JAK inhibitors (e.g., Xeljanz) carry similar warnings but different mechanisms.[2]
Signs of TB on Humira and What to Do
Watch for persistent cough, fever, weight loss, or night sweats. Stop Humira immediately and seek testing if symptoms appear. Prophylactic isoniazid reduces reactivation risk by 80-90% in screened patients.[3]
[1]: FDA Humira Label
[2]: CDC TNF Blocker Guidelines
[3]: ACR Guidelines on TB Screening