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Interleukin-17 (IL-17)

Published: July 27, 2026Updated: August 25, 2026

IL-17 is a pro-inflammatory cytokine produced by T helper 17 (Th17) cells that plays a crucial role in immune responses and inflammation.

Quick summary

IL-17 is a key biomarker for assessing inflammatory conditions and autoimmune diseases.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
pg/mL
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
R&D Systems IL-17 ELISA, Thermo IL-17
interpretation: {"text":"0–5 pg/mL: IL-17 levels within this range are considered normal and indicate a typical inflammatory response.","label":"Normal"}; {"text":">5 pg/mL: Higher levels may suggest the presence of an inflammatory or autoimmune condition that requires further evaluation.","label":"Elevated"}

IL-17 is a cytokine that stimulates the production of other pro-inflammatory molecules, such as IL-6, TNF-alpha, and chemokines, leading to the recruitment of immune cells to sites of inflammation.

Elevated levels of IL-17 are associated with various inflammatory and autoimmune conditions, including rheumatoid arthritis, psoriasis, and inflammatory bowel disease.

Measuring IL-17 levels can help in the diagnosis, monitoring, and management of these conditions, providing insights into the underlying inflammatory processes.

Frequently asked questions

What conditions are associated with high IL-17 levels?
High IL-17 levels are associated with autoimmune diseases like rheumatoid arthritis, psoriasis, and inflammatory bowel disease.
How is IL-17 testing used in clinical practice?
IL-17 testing is used to support the diagnosis of inflammatory conditions, monitor disease activity, and assess the effectiveness of treatments.
  1. 1
    IL-17 in inflammation and autoimmunitySource
  2. 2
    Role of IL-17 in autoimmune diseasesSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy