[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Immunology](https://durgical.com/en/immunology/) › [Cytokines and molecules](https://durgical.com/en/immunology/#a-molecules) › TNF-α [Immunology](https://durgical.com/en/immunology/) · [Cytokines and molecules](https://durgical.com/en/immunology/#a-molecules) # TNF-α - Molecule TNF-α is a powerful inflammation signal from macrophages. It holds tuberculosis granulomas together, and blocking it treats arthritis and bowel disease. Updated 2026-11-01 ## Key points - Source: macrophages above all; receptors TNFR1 and TNFR2. - Systemic effects: fever, vasodilation and capillary leak (septic shock), cachexia. - Essential for granulomas: blocking it can reactivate latent tuberculosis. - Anti-TNF drugs: infliximab, adalimumab, golimumab (antibodies), certolizumab (pegylated Fab), etanercept (TNFR2-Fc fusion protein). - Before any anti-TNF: screen for latent tuberculosis (skin test or IGRA) and hepatitis B. - Infliximab and adalimumab carry a higher tuberculosis risk than etanercept. ## What it is Tumour necrosis factor-α is made mainly by macrophages and monocytes, and also by T cells, neutrophils and other cells; it exists as a membrane form and a soluble form, and both are active. It acts on TNFR1 (on almost all nucleated cells) and TNFR2 (mostly immune cells). TNF starts a cascade that includes IL-1 and IL-6, activates endothelium and is needed to build and maintain granulomas. ## Function - Activates endothelium (adhesion molecules) and recruits leukocytes. - Activates macrophages together with IFN-γ. - Induces IL-1 and IL-6 and the acute-phase response. - Can trigger apoptosis of target cells through TNFR1. ## Clinical notes - Rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, juvenile idiopathic arthritis and psoriasis respond to anti-TNF therapy, often combined with methotrexate in RA. - Crohn disease and ulcerative colitis: infliximab, adalimumab and others. - Septic shock: TNF is one of the mediators of vasodilation and organ damage. - Anti-TNF therapy increases serious bacterial, viral and fungal infections; tuberculosis often appears as extrapulmonary or disseminated disease. - In Colombia and Latin America, where tuberculosis is common, screening and treatment of latent infection before anti-TNF is essential. ## In the lab - Latent tuberculosis screening: tuberculin skin test or interferon-γ release assay, plus chest X-ray. - Hepatitis B serology before starting. ## Memory aid TNF is the cement of the granuloma: remove it and the wall around the tuberculosis bacillus falls down. ## Test yourself Think of the answer, then tap the question to see it. ## Why must latent tuberculosis be ruled out before an anti-TNF drug? TNF is needed to keep granulomas intact; blocking it can reactivate dormant Mycobacterium tuberculosis, often as disseminated disease. ## How does etanercept differ in structure from infliximab? Etanercept is a soluble TNFR2 receptor fused to an IgG Fc fragment; infliximab is a chimeric monoclonal antibody against TNF. ## Which systemic effects of TNF-α explain septic shock and cachexia? Vasodilation and capillary leak with low blood pressure, plus loss of appetite and muscle and fat breakdown in chronic inflammation. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/immunology/tnf/) ## Related - [Cytokines: the table to know](https://durgical.com/en/immunology/cytokines-the-table-to-know/) - [Interleukin-1](https://durgical.com/en/immunology/interleukin-1/) - [Interleukin-6](https://durgical.com/en/immunology/interleukin-6/) - [Interferon-γ](https://durgical.com/en/immunology/interferon/) - [Granulomatous inflammation](https://durgical.com/en/immunology/granulomatous-inflammation/) - [Acute-phase response and fever (CRP, ESR, procalcitonin)](https://durgical.com/en/immunology/acute-phase-response-and-fever/) - [Tuberculin skin test and IGRA](https://durgical.com/en/immunology/tuberculin-skin-test-and-igra/) - [Monoclonal antibodies and biologics: naming and targets](https://durgical.com/en/immunology/monoclonal-antibodies-and-biologics-naming-and-targets/) - [Monocyte and macrophage](https://durgical.com/en/immunology/monocyte-and-macrophage/) ## Related conditions - [Rheumatoid arthritis](https://durgical.com/en/conditions/rheumatoid-arthritis/) - [Sepsis and septic shock](https://durgical.com/en/conditions/sepsis-and-septic-shock/) - [Crohn disease](https://durgical.com/en/conditions/crohn-disease/) - [Ulcerative colitis](https://durgical.com/en/conditions/ulcerative-colitis/) - [Ankylosing spondylitis](https://durgical.com/en/conditions/ankylosing-spondylitis/) - [Tuberculosis](https://durgical.com/en/conditions/tuberculosis/) ## Microorganisms - [Mycobacterium tuberculosis](https://durgical.com/en/microbiology/mycobacterium-tuberculosis/) ## In Pharmacology - [Infliximab](https://durgical.com/en/pharmacology/infliximab/) - [Adalimumab](https://durgical.com/en/pharmacology/adalimumab/) - [Etanercept](https://durgical.com/en/pharmacology/etanercept/) - [Certolizumab pegol](https://durgical.com/en/pharmacology/certolizumab-pegol/) - [Golimumab](https://durgical.com/en/pharmacology/golimumab/) - [Methotrexate](https://durgical.com/en/pharmacology/methotrexate/) [← All of immunology](https://durgical.com/en/immunology/) Educational content on the immune system; not a treatment or individual vaccination guide and no substitute for a health professional's advice. No doses are given. Sources: [Tumor Necrosis Factor (TNF) Bioactivity at the Site of an Acute Cell-Mediated Immune Response Is Preserved in Rheumatoid Arthritis Patients Responding to Anti-TNF Therapy](https://frontiersin.org/articles/10.3389/fimmu.2017.00932/full) (Frontiers in Immunology, 2017); [Infliximab Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a604023.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [Etanercept Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a602013.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [Pro-Inflammatory and Anti-Inflammatory Interleukins in Infectious Diseases: A Comprehensive Review](https://pmc.ncbi.nlm.nih.gov/articles/PMC10818686/) (Tropical Medicine and Infectious Disease (PubMed Central), 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. 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