JIA Causes and the Role of the Immune System

Learn how the immune system plays a role in juvenile idiopathic arthritis.

By Robyn Abree

Although the exact cause of juvenile idiopathic arthritis (JIA) is unknown, doctors know that the immune system plays an important role.  Researchers are trying to better understand that role, which may be different for different subtypes of JIA.  There are two main theories:

  1. JIA is an autoimmune disease.  - Autoimmune diseases result from an error in the acquired or adaptive immune system. This complex arm of the immune system develops throughout life and learns to recognize harmful foreign invaders over time. Once a threat has been identified, the adaptive immune system releases proteins called antibodies to help fight it. In some types of JIA, this process goes awry, and the adaptive immune system mistakes the body’s cells for foreign invaders. As a result, antibodies attach to the body’s own tissue instead (chiefly joint tissue), signaling the immune system to attack them. 
  2. JIA is an autoinflammatory disease. - Many researchers believe that at least one type of JIA – systemic JIA (SJIA) – is an auto-inflammatory disease.  Auto-inflammatory diseases result from an error in the innate immune system. Unlike the adaptive immune system, which develops over time, the innate immune system is present at birth. It’s also the body’s first line of defense against infection. The quick inflammatory response that happens when you cut yourself (e.g. swelling, redness, warmth) is an example of the innate immune system at work. As such, autoinflammatory diseases often trigger episodes of intense inflammation for unknown reasons, usually causing high spiking fevers and rash. 

JIA Causes and Triggers 
Some researchers believe that JIA may share some aspects of both autoimmune and auto-inflammatory diseases. Although no one knows for sure what causes the immune system to function improperly and cause JIA, the disease is believed to result from genetic and environmental factors. In other words, children may inherit genes that put them at risk of JIA, but something in their environment, like catching a virus, may set the disease in motion. To date, more than a dozen genes have been identified as strongly associated with JIA. 

Regardless of its cause, uncontrolled inflammation can cause damage to the joints and other tissues. Prompt treatment is key to managing the disease and preventing complications and possible comorbidities. 

Diagnosed With Juvenile Arthritis?

Get the latest news and tips about living with Juvenile Arthritis in the Living Your Yes! e-newsletter.

I Want to Contribute
I Need Help
  • Donate


    Every gift to the Arthritis Foundation will help people with arthritis across the U.S. live their best life.

  • Volunteer


    Join us and become a Champion of Yes. There are many volunteer opportunities available.

  • Live Yes! INSIGHTS

    Live Yes! INSIGHTS

    Take part to be among those changing lives today and changing the future of arthritis.

  • Partner


    Proud Partners of the Arthritis Foundation make an annual commitment to directly support the Foundation’s mission.


Ways to Give

Every gift to the Arthritis Foundation will help people with arthritis across the U.S. live their best life. Whether it is supporting cutting-edge research, 24/7 access to one-on-one support, resources and tools for daily living, and more, your gift will be life-changing.

Make a Donation

Help millions of people live with less pain and fund groundbreaking research to discover a cure for this devastating disease. Please, make your urgently-needed donation to the Arthritis Foundation now!

Become a Member

Become an Arthritis Foundation member today for just $20. You'll receive a year's worth of Arthritis Today magazine, access to helpful tools, resources, and more.

Make a Honor or Memorial Gift

Honor a loved one with a meaningful donation to the Arthritis Foundation. We'll send a handwritten card to the honoree or their family notifying them of your thoughtful gift.

Gift Planning

I want information on ways to remember the AF in my will, trust or other financial planning vehicles.


Volunteer Opportunities

The Arthritis Foundation is focused on finding a cure and championing the fight against arthritis with life-changing information, advocacy, science and community. We can only achieve these goals with your help. Strong, outspoken and engaged volunteers will help us conquer arthritis. By getting involved, you become a leader in our organization and help make a difference in the lives of millions. Join us and become a Champion of Yes.

More About Volunteering


Give Just 10 Minutes.

Tell us what matters most to you. Change the future of arthritis.

By taking part in the Live Yes! INSIGHTS assessment, you’ll be among those changing lives today and changing the future of arthritis, for yourself and for 54 million others. And all it takes is just 10 minutes.

Your shared experiences will help:

- Lead to more effective treatments and outcomes
- Develop programs to meet the needs of you and your community
- Shape a powerful agenda that fights for you

Now is the time to make your voice count, for yourself and the entire arthritis community. 

Currently this program is for the adult arthritis community.  Since the needs of the juvenile arthritis (JA) community are unique, we are currently working with experts to develop a customized experience for JA families. 

How are you changing the future?

By sharing your experience, you’re showing decision-makers the realities of living with arthritis, paving the way for change. You’re helping break down barriers to care, inform research and create resources that make a difference in people’s lives, including your own.

Get Started


Meet Our Partners

As a partner, you will help the Arthritis Foundation provide life-changing resources, science, advocacy and community connections for people with arthritis, the nations leading cause of disability. Join us today and help lead the way as a Champion of Yes.


Our Trailblazers are committed partners ready to lead the way, take action and fight for everyday victories. They contribute $2,000,000 to $2,749,000


Our Visionary partners help us plan for a future that includes a cure for arthritis. These inspired and inventive champions have contributed $1,500,00 to $1,999,999.


Our Pioneers are always ready to explore and find new weapons in the fight against arthritis. They contribute $1,000,000 to $1,499,999.


Our Pacesetters ensure that we can chart the course for a cure for those who live with arthritis. They contribute $500,000 to $999,000.


Our Signature partners make their mark by helping us identify new and meaningful resources for people with arthritis. They contribute $250,000 to $499,999.


Our Supporting partners are active champions who provide encouragement and assistance to the arthritis community. They contribute $100,000 to $249,999.