The immune system relies on signaling proteins called cytokines to manage its responses. These molecules are messengers that coordinate the actions of immune cells, directing them toward sites of infection or inflammation. Cytokines are involved in both starting and stopping these processes. In some health conditions, the body produces an excess of these proteins, leading to chronic inflammation that can damage tissues and organs. Therapies designed to counteract this overabundance are a focus in treating such diseases.
How Anti-Cytokine Drugs Work
Anti-cytokine drugs are biologic therapies engineered to be highly specific. They target and neutralize particular cytokines that drive inflammation. One way they work is by attaching to the cytokine, which prevents it from binding to its corresponding receptor on other cells.
Another way these drugs function is by blocking the cytokine receptors on the surface of cells. This action interrupts the signaling cascade that would otherwise perpetuate the inflammatory response. The result is a reduction in the overall level of inflammation, which can alleviate symptoms and slow disease progression.
These therapies are distinct from broader anti-inflammatory drugs because they do not suppress the entire immune system. Instead, they modulate specific pathways that have become overactive. This focused mechanism helps to restore a more balanced immune response.
Conditions Treated with Anti-Cytokine Drugs
A primary application for anti-cytokine therapies is managing autoimmune diseases, where the immune system attacks the body’s own tissues. In rheumatoid arthritis, excess cytokines like tumor necrosis factor (TNF-alpha) and interleukins contribute to joint inflammation and cartilage destruction. Blocking these cytokines can reduce the processes that cause joint damage and disability.
These therapies are also used for psoriasis and psoriatic arthritis, where cytokines drive rapid skin cell growth and joint inflammation. Drugs targeting molecules like TNF-alpha, interleukin-17 (IL-17), or interleukin-23 (IL-23) can interrupt these processes, leading to clearer skin and reduced joint symptoms.
Inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis, are also treated with these drugs. In these conditions, therapies that neutralize cytokines decrease gut inflammation, which can lead to healing of intestinal tissue and reduced symptoms. Other conditions treated include ankylosing spondylitis, a type of arthritis affecting the spine.
Types of Anti-Cytokine Therapies
The term “anti-cytokine” encompasses a variety of drugs that target different components of the inflammatory process. One of the most established categories is TNF inhibitors. These drugs were among the first anti-cytokine therapies developed and work by neutralizing tumor necrosis factor-alpha, a significant contributor to inflammation. Examples include adalimumab and etanercept, used for conditions like rheumatoid arthritis and psoriasis.
Another major class is interleukin (IL) inhibitors. This group is diverse, with different drugs designed to block specific interleukins, which are another family of cytokine proteins. For example, some therapies target IL-1 or IL-6, while others inhibit IL-17 or IL-23, each playing a part in different inflammatory diseases.
A different type of therapy is the Janus kinase (JAK) inhibitor. Unlike biologic drugs that work outside the cell, JAK inhibitors are small molecules that function inside the cell. They interfere with the JAK-STAT signaling pathway, which communicates the cytokine’s message to the cell’s nucleus. By disrupting this internal pathway, JAK inhibitors can block the effects of multiple cytokines at once.
Potential Adverse Effects and Management
A primary consideration with anti-cytokine therapies is their effect on the immune system. By design, these drugs suppress specific inflammatory pathways, which can reduce the body’s ability to fight off infections. This is because the targeted cytokines are also involved in the normal immune response, so individuals taking these medications may have a heightened risk of developing infections.
Beyond the increased risk of infection, other side effects can occur. Reactions at the injection site, such as redness, swelling, or pain, are common with biologic drugs administered via injection. Some people may also experience flu-like symptoms, especially when first starting the therapy.
To manage these risks, healthcare providers conduct thorough screenings before a patient begins treatment. This often includes testing for latent infections like tuberculosis, which can become active when the immune system is suppressed. Patients are also monitored closely throughout their treatment for any signs of infection or other adverse effects.