Cytokines and How They Work

Cytokines are proteins produced by cells, and they serve as molecular messengers between cells. In arthritis, cytokines regulate various inflammatory responses. As part of the immune system, cytokines regulate the body's response to disease and infection, as well as mediate normal cellular processes in your body.

A man rubbing his shoulder
 Terry Vine / Getty Images

Types of Cytokines

Cytokines are diverse and serve a number of functions in the body. They:

  • Stimulate the production of blood cells
  • Aid in the development, maintenance, and repair of tissues
  • Regulate the immune system
  • Drive inflammation through interferons, interleukins, and tumor necrosis factor-alpha (TNF-α)

While "cytokine" is an umbrella term that includes many types of protein messengers, more specific names are given to cytokines based on either the type of cell that makes them or the action they have in the body:

  • Lymphokines, made by lymphocytes, attract immune cells such as macrophages
  • Monokines, made by monocytes, attract neutrophils
  • Chemokines are associated with chemotactic actions
  • Interleukins are made by one leukocyte but act on other leukocytes, mediating communication between cells. Specific interleukins can have a major impact on cell-cell communication.

How Cytokines Work

The imune system is complex—different types of immune cells and proteins do different jobs. Cytokines are among those proteins. To understand inflammation, you must understand the role cytokines play.

Cells release cytokines into your blood circulation or directly into tissues. The cytokines locate the immune cells they're designed to target and bind to the cell's receptors. This interaction triggers or stimulates specific responses by the target cells.

Cytokine Overproduction

Overproduction or inappropriate production of certain cytokines by the body can result in disease.

For example, interleukin-1 (IL-1), interleukin-6 (IL-6), and TNF-α are produced in excess in rheumatoid arthritis, where they're involved in inflammation and tissue destruction.

Biologic Cytokine Inhibitors

Some biologic drugs inhibit IL-1 or TNF-α.

Some biologic drugs, such as enbrel and Kineret (anakinra), bind to cytokine receptors, thereby blocking the cytokine from binding to its receptor and inhibiting cytokine response. Actemra (tocilizumab) and Kevzara (sarilumab) work similarly but bind IL-6.

Other biologic drugs bind cytokines, preventing them from binding to their designated receptors. For example, TNF-α inhibitors (also called TNF blockers) bind to TNF and prevent it from attaching to cell-surface receptors. The TNF-α inhibitors on the market are:

Cytokine Basics

Pro-inflammatory cytokines play a role in the development of inflammatory and neuropathic pain.

Anti-inflammatory cytokines are actually inflammatory cytokine antagonists.

Evidence suggests that chemokines are involved in initiating pain and the persistence of pain.

Frequently Asked Questions

  • What are inflammatory cytokines?

    There are two different types of inflammatory cytokines:

    • Pro-inflammatory cytokines: Involved in inflammatory reactions (such as when tissues are damaged by bacteria, trauma, or any other cause)
    • Anti-inflammatory cytokines: Regulate or control the pro-inflammatory cytokine response
  • What are platelets?

    Platelets (thrombocytes) are blood cells that control blood clotting in response to injury. Cytokines are contained in platelets and play an important role in wound repair, as well as assisting with homeostasis, or the body's need to maintain a state of equilibrium (levels of temperature, sleep, hunger, thirst, and more).

  • What does a high platelet count mean?

    Thrombocytosis is a condition that refers to a dangerously high number of platelets in the blood. Without treatment, thrombocytosis can lead to conditions such as stroke or heart attack. A high platelet count can be caused by many different conditions, such as iron deficiency anemia, infection, or as a secondary effect of cancer.

  • What are interleukins?

    Interleukins are a type of cytokine made by leukocytes (a type of white blood cell), but they can also be created by other bodily cells. Leukocytes use interleukins for the purpose of cell communication. Interleukins also help control the growth and activation of immune cells.

  • What are chemokines?

    Chemokines are a type of cytokine that regulate cell migration between tissues. They also control the interactions of cells in those tissues and how they are positioned.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Ferreira VL, Borba HH, Bonetti ADF, Leonart LP, Pontarolo R. Cytokines and Interferons: Types and FunctionsAutoantibodies and Cytokines. doi:10.5772/intechopen.74550

  2. Tisoncik JR, Korth MJ, Simmons CP, Farrar J, Martin TR, Katze MG. Into the eye of the cytokine stormMicrobiol Mol Biol Rev. 2012;76(1):16–32. doi:10.1128/MMBR.05015-11

  3. Zhang JM, An J. Cytokines, inflammation, and painInt Anesthesiol Clin. 2007;45(2):27–37. doi:10.1097/AIA.0b013e318034194e

  4. MedlinePlus. Immune response.

  5. Chen Y, Zhong H, Zhao Y, et al. Role of platelet biomarkers in inflammatory responseBiomark Res 2020;8:28. doi:10.1186/s40364-020-00207-2

  6. Cleveland Clinic. Thrombocytosis.

  7. Justiz Vaillant AA, Qurie A. Interleukin. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.

  8. Chow M, Luster A. Chemokines in cancer. Cancer Immunology Research. 2014 Dec;2(12):1125–1131. doi:10.1158/2326-6066.CIR-14-0160

Additional Reading
  • Cytokines. BioBasics.

  • McInnes I. and Schett G. Cytokines in the pathogenesis of rheumatoid arthritis. Nature Immunology.

  • Regeneron and Sanofi Present Results from Pivotal Phase 3 Study of Sarilumab at American College of Rheumatology Annual Meeting. Regeneron.

  • Zhang, J-M et al. Cytokines, Inflammation and Pain. International Anesthesiology Clinics.

  • Growth Factors and Cytokines. Primer on the Rheumatic Diseases. Edition 12. Published by the Arthritis Foundation.

By Carol Eustice
Carol Eustice is a writer covering arthritis and chronic illness, who herself has been diagnosed with both rheumatoid arthritis and osteoarthritis.