TNF blockers are a class of medications known as biologics, prescribed to manage inflammatory conditions. These drugs are a type of disease-modifying anti-rheumatic drug (DMARD) designed to suppress inflammation by targeting a specific protein in the immune system. They are used to treat various autoimmune and autoinflammatory diseases.
Understanding Tumor Necrosis Factor
Tumor Necrosis Factor (TNF) is a cytokine, a type of protein that acts as a chemical messenger in the immune system. It aids the body’s natural defense against threats like germs by inducing inflammation. This response is a normal part of healing and fighting infection.
In autoimmune disorders, the body can overproduce TNF. This excess protein leads to chronic inflammation that damages healthy tissues and drives the progression of these diseases.
Mechanism of Action
TNF blockers are engineered to interrupt the inflammatory process driven by excess TNF. These lab-created antibodies or receptor fusion proteins target and bind to TNF molecules, neutralizing them before they can attach to cell receptors. This prevents TNF from binding to its receptors, silencing the signaling cascade that triggers inflammation.
The blockade stops the release of other inflammatory molecules and prevents the recruitment of immune cells to the site of inflammation. This results in reduced inflammation, with many patients feeling symptom improvement within weeks to months of starting treatment.
Commonly Treated Conditions
TNF blockers are approved to treat a range of autoimmune diseases due to their targeted anti-inflammatory action. These conditions include:
- Rheumatoid arthritis, where they reduce joint inflammation, pain, and potential damage to cartilage and bone.
- Psoriatic arthritis, helping to manage both joint inflammation and the skin lesions of psoriasis.
- Inflammatory bowel disease, such as Crohn’s disease and ulcerative colitis, by controlling inflammation in the gastrointestinal tract.
- Ankylosing spondylitis, a type of arthritis affecting the spine, where they reduce inflammation to relieve stiffness and improve mobility.
Administration and Medical Oversight
TNF blockers are delivered in one of two ways. Some medications, like adalimumab and etanercept, are administered by subcutaneous injection, which patients can often perform at home on a weekly, bi-weekly, or monthly basis. Other TNF blockers, such as infliximab, are given as an intravenous (IV) infusion in a clinical setting, which can take a few hours and are scheduled every four to eight weeks.
All treatment methods require medical supervision. Before starting therapy, patients are screened for infections like tuberculosis (TB) and hepatitis B, and ongoing monitoring with blood tests and physical assessments is standard.
Associated Side Effects and Risks
Common side effects include reactions at the injection site like redness or swelling, headaches, nausea, and an increased risk of upper respiratory infections. These effects are often mild and may lessen over time.
A more significant risk is serious infections, as these drugs suppress the immune system. This can make it harder to fight new infections and may reactivate latent ones like tuberculosis. Due to this risk, the U.S. Food and Drug Administration (FDA) has issued a black box warning for these medications.
There is also a small, elevated risk of developing certain cancers, such as lymphoma and skin cancer, which requires regular monitoring by a healthcare provider.