Autoimmune Diseases

What are autoimmune diseases?

If it weren't for the immune system — the human body's natural defense against outside invaders — we would be sick all the time. This complex network of cells, organs and molecules fights off things like bacteria and viruses 24 hours a day, from our head to our toes. It's a powerful protection when it's working for us, but can also be a powerful threat when it turns against us, in what's called an autoimmune disease ("auto" meaning self).

Autoimmune diseases in children are rare. When they occur they can be challenging to diagnose and difficult to treat. Doctors are still learning about this large group of mostly chronic illnesses — more than 80 in all — most of which have no cure yet. If your child has an autoimmune problem, much depends on figuring out what it is and then treating the condition aggressively.  

How the immune system works

Autoimmune diseases affect an estimated 23 million Americans, yet the study of the immune system (immunology) is still an evolving field. Doctors and researchers are still learning about the body's natural defense system and what happens when it malfunctions.

To better understand your child's autoimmune disease, it helps to know some basic facts about how the immune system works:

  • When a foreign invader (antigen) like bacteria, a virus or pollen, enters the body, it encounters the innate immune system.
  • The innate system is our inborn, nonspecific response to antigens. It's a general set of defenses that includes barriers like skin and mucous membranes, and reactions like coughing and sneezing reflexes.
  • The innate system also includes white blood cells called phagocytes (literally, eating cells), designed to devour any antigen that gets through the outer defenses.
  • The innate system will either destroy the invader or buy time for the more complex adaptive immune system to work.
  • The adaptive system is the continually evolving, specific response to antigens. It's a targeted defense that identifies an invader and makes unique proteins (antibodies) to mark it for attack.
  • Among the key players in the adaptive system are special white blood cells called B cells, which produce antibodies, and T cells which coordinate and carry out the attack — and, importantly, also signal when the attack should stop.

What happens when a child has autoimmune disease?

In autoimmune disease, the immune system mistakenly begins attacking healthy cells and tissues — and fails to shut off the attack. This is different from other immune system malfunctions, such as acquired immunodeficiency disorders, like AIDS, in which the immune system is weakened or ineffective, and allergic disorders, in which the immune system overreacts to things like pollen or nuts.

Autoimmune diseases can affect almost any part of the body, though they often target connective tissues (skin, muscle and joints). Symptoms can range from fatigue and mild rashes to rare, serious side effects, like seizures. Diagnosis can be difficult, because many symptoms tend to come and go and are frequently nonspecific. They occur in different kinds of autoimmune diseases as well as other types of illnesses, like infection and cancer.

Autoimmune diseases occur most often in females by a 3-to-1 margin over males.

Doctors don't know why some children's immune systems begin attacking their own bodies. We do know it's related to something in their genes and likely a number of other, unknown factors. It's important for parents to know that their child's disease wasn't caused by anything they did, and there's nothing they could have done to prevent it.

What types of autoimmune disease affect children?

The immune system is designed to protect the entire body. When it malfunctions, it can attack virtually any part of the body, from the skin to the joints to the blood vessels—which all respond in different ways and often require different treatment strategies.

In general, autoimmune diseases often fall into one of two basic groups:

Organ-specific disorders (also called localized) focus on one organ or a specific type of tissue:

Non-organ-specific disorders (also called systemic) cause problems throughout the body:

Who is at risk for autoimmune disease?

Because there are several dozen kinds of autoimmune diseases, risk factors can vary by illness. In general, though, researchers have found strong links to the following factors:

  • Gender: Girls are almost three times as likely as boys to have an autoimmune disease, with adolescent girls and young women being at greatest risk. For some diseases, such as scleroderma and lupus (SLE), more than 85 percent of patients are female. However, one of the more common autoimmune diseases in children, type 1 diabetes, affects boys and girls almost equally.
  • Age: Most autoimmune diseases affect younger and middle-aged people. Some illnesses begin specifically in childhood, as their name suggests—juvenile idiopathic arthritis and juvenile dermatomyositis, for example.
  • Genetics: A family history of autoimmune disease puts a child at higher risk. In fact, it’s estimated that about one-third of the risk of developing an autoimmune disease is tied to something in a child’s genes.
  • Race: Some reports suggest that children of different races may be more prone to certain autoimmune diseases. African-American children, for instance, seem to be more likely than Caucasians to develop lupus (SLE) and scleroderma, but the opposite is true of multiple sclerosis (MS), which more often affects Caucasian children.
  • Other illnesses: Children with one autoimmune disease tend to be at higher risk of developing another. For example, kids with type 1 diabetes appear to be more susceptible to developing celiac disease or Addison's disease.

Can autoimmune disease be prevented?

So far, there’s no way to prevent a person from developing an autoimmune disease, although researchers are working toward that long-term goal. The National Institutes of Health outlined three challenges that researchers face:

  • recognizing the specific genetic patterns of people susceptible to autoimmune disease
  • zeroing in on environmental factors (viruses, toxins, etc.) that may trigger disease
  • coming up with ways to intervene before the disease begins, along with creating public screening programs

How we care for autoimmune diseases

While the health care team for children with autoimmune disease may include many kinds of specialists, the doctors with the greatest expertise in these illnesses are called pediatric rheumatologists. Of the roughly 200 pediatric rheumatologists in the country, more than half a dozen work at Boston Children’s Hospital. This, and the many other resources we offer, makes Boston Children’s a unique and powerful force in fighting autoimmune disease:

  • Our Rheumatology program is one of the biggest in the U.S., treating more than 4,000 outpatients and almost 1,000 inpatients every year.
  • Our Samara Jan Turkel Clinical Center brings together pediatric rheumatologists and consulting specialists from across the hospital to offer comprehensive, coordinated care, from providing outpatient and inpatient treatment to helping children and families connect to a wide range of support services.
  • The Division of Immunology and Rheumatology Departments collaborate to help children with multiple autoimmune symptoms that don't fit a single diagnosis through the hospital's Multiple Manifestations of Autoimmune Disease Clinic
  • The Dermatology-Rheumatology Center unites rheumatologists and dermatologists in caring for children with autoimmune diseases that involve the skin, such as psoriatic arthritis, scleroderma and juvenile dermatomyositis.

Our areas of innovation for autoimmune diseases

Home to the world’s largest pediatric research enterprise, Boston Children’s is also looking toward the future. Through initiatives like the Manton Center for Orphan Disease Research and the Program in Cellular and Molecular Medicine, our clinicians and scientists are working together on new ways to identify, treat and potentially cure autoimmune diseases.