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.

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.

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.

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:

• Addison's disease affects the adrenal glands
• Autoimmune hepatitis affects the liver
• Crohn's disease affects the gastrointestinal tract
• Multiple sclerosis (MS) affects the central nervous system
• Type 1 diabetes affects the pancreas
• Ulcerative colitis affects the gastrointestinal tract

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

• Juvenile dermatomyositis affects the skin and muscles
• Juvenile idiopathic arthritis affects the joints and sometimes the skin and lungs
• Lupus affects the joints, skin, liver, kidneys, heart, brain, and other organs
• Scleroderma affects the skin, joints, intestine, and sometimes the lungs

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.

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

There's no single set of symptoms that covers the spectrum of autoimmune disease. The most common symptoms tend to be nonspecific, meaning they could be caused by a condition that has nothing to do with the immune system. This can make it harder for doctors to diagnose autoimmune diseases. As a result, a child may need a number of tests to narrow down the possible cause for their symptoms.

Signs that a child may be having an immune system problem include:

• Low-grade fever
• Fatigue or chronic tiredness
• Dizziness
• Weight loss
• Rashes and skin lesions
• Stiffness in the joints
• Brittle hair or hair loss
• Dry eyes and/or mouth
• General "unwell" feeling

Recurring fever, fatigue, rashes, weight loss, and so on are not concrete proof that a child has an autoimmune disease, but they do mean the child is ill and needs medical attention. A pediatrician can refer the family to a specialist, likely a pediatric rheumatologist, if they suspect an autoimmune disease.

The exact reason that some children's immune systems begin attacking their own bodies is still a mystery. We do know that autoimmune diseases are not contagious, and they don't appear to be caused by any one thing in particular. Instead, scientists believe there's a multi-step process at work:

• Heredity: Certain genes passed down by parents make some children susceptible to an autoimmune disease.
• Environmental factors: An autoimmune disease may not reveal itself until it's triggered by something like an infection or exposure to certain toxins or drugs.
• Hormonal factors: Given that many autoimmune diseases tend to affect adolescent girls and young women, certain female hormones may also play a role in when these illnesses flare up.

Researchers are now working to discover which genes are involved and how they interact. They are also investigating a number of potential environmental and hormonal triggers so that one day it may be possible to cure, or even prevent, autoimmune diseases.

Autoimmune diseases present a special challenge for physicians. Many of the earliest symptoms like fever and fatigue are nonspecific, meaning they're found in a variety of illnesses. Symptoms often come and go. A single autoimmune disease can show up in different ways in different people or include features of other autoimmune diseases.

For reasons like these, diagnosis can be a long and stressful journey for many families. It's important to remember that such difficulties are not a sign there's something uniquely wrong with your child. Even when doctors aren't 100 percent sure which specific autoimmune illness a child has, they often can learn enough from the diagnostic process to begin treatments to improve their health and quality of life.

A rheumatologist will first look at your child's full health history including any family history of autoimmune disease — and conduct a thorough physical exam. If the doctor suspects a autoimmune disease, they will gather more information through lab tests, including:

• Antinuclear antibody (ANA), which can detect certain abnormal proteins called antinuclear antibodies that the immune system makes when attacking the body's own tissues.
• Rheumatoid factor (RF), which, like ANA, can detect an abnormal protein that the immune system makes when attacking the body. It can be useful in classifying a certain kind of juvenile idiopathic arthritis (JIA). However, children with some non-autoimmune ailments may test positive for RF, and most kids who actually have arthritis may test negative.
• Complete blood count (CBC), a collection of tests measuring the size, number and maturity of different blood cells in a specific amount of blood. Two important tests are: white blood cell count (WBC), which measures the number of white blood cells present, and hematocrit, which measures the number of red blood cells present.
• Complement, which measures the blood's level of complement, a group of proteins that are part of the immune system. Low levels of complement may indicate an autoimmune problem.
• C-reactive protein (CRP), which measures the amount of a special protein made in the liver. CRP levels tend to shoot upward when there's severe inflammation like the kind seen in autoimmune diseases somewhere in the body.
• Erythrocyte sedimentation rate (ESR or sed rate),which measures how quickly red blood cells fall to the bottom of a test tube. If the cells to clump together and fall more rapidly than normal, it can signal inflammation in the body.
• Anti-cyclic citrullinated peptide (anti-CCP) antibody, a relatively new blood test that may be ordered along with an RF test to help characterize a certain kind of JIA.

The doctor may also want to take a closer look at your child’s actual organs and tissues to rule out things like infections, tumors and fractures. To do this, the doctor might use such imaging tests as:

• Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed pictures of the body's organs, bones and tissues. Because children have to lie very still for an MRI, which can last half an hour or more, some may need general anesthesia or a sedative.
• Ultrasound also known as sonography or ultrasonography, which uses high-frequency sound waves to create pictures of internal structures. Though ultrasound shows less detail than an MRI, it's very fast and doesn't require a child to be sedated.

In some cases, your child's doctor will actually take a sample of your child’s tissues — called a biopsy — to help identify the disease or to get an idea of how it’s progressing.

Overall, today's diagnostic tools can help physicians home in on autoimmune disease, but can’t do much to differentiate one illness from another. To solve that problem, many researchers are now working on identifying biomarkers things that the body is doing or making that point to a specific illness — for autoimmune diseases. Such biomarkers could allow doctors to make faster, more accurate diagnoses and get started on treatment that much sooner.

Rheumatologists, who specialize in diseases of the joints and connective tissue, often diagnose autoimmune illnesses and tend to be at the center of the health care team. Depending on which tissues or organs are affected, other specialists such as a dermatologist (skin), hepatologist (liver) and nephrologist (kidneys) — may be involved in caring for your child.

While there's no cure for the vast majority of autoimmune diseases, doctors aim to do far more than just manage your child's symptoms. They will work to immediately relieve things like soreness and stiffness, and restore important substances to your child's body that the disease may be taking away (like insulin, in type 1 diabetes). But the big goals are to quench the inflammation of the autoimmune reaction to keep it from doing further damage and to & reset the immune system so that it will work normally on its own.

Broadly speaking, doctors prescribe medications that 1) fight the harmful inflammation caused by autoimmune attack and 2) suppress the overall immune system or block specific things that it's doing. Surgical therapies for autoimmune diseases are very rare.

Doctors often favor aggressive upfront treatment with an array of drugs (some of which have significant side effects, which your child's doctor will discuss with you in detail). Therapies commonly prescribed for autoimmune disease include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs), which help ease symptoms like pain, swelling and stiffness.
• Disease-modifying anti-rheumatic drugs (DMARDs), which slow down — or even halt — the progress of a disease.
• Biologics, a relatively new class of DMARDs made of synthetic proteins. The major category within biologics is tumor necrosis factor (TNF) blockers, which counteract high levels of inflammatory proteins.
• Corticosteroids, extremely powerful drugs that suppress the immune system and fight inflammation. Doctors sometimes prescribe corticosteroids in tablet form or by IV for short-term use, but tend to avoid high doses over the long term because of serious side effects. Prednisone, which has a number of brand names is the most common of the corticosteroids.
• IVIg (intravenous immunoglobulin), a blood product made up of antibodies. It is delivered by IV and can help get the immune system back on track without suppressing its normal function.

Depending on your child's autoimmune disease, they may need other kinds of medical treatment, such as:

• Plasmapheresis, a process that removes plasma — the part of the blood that carries antibodies — from a patient's blood. Because it removes good antibodies along with the bad, however, it leaves the immune system less able to fight off sickness and infection. That's why doctors typically recommend plasmapheresis only for the most serious autoimmune diseases.
• Surgery, in rare cases, to deal with certain complications of autoimmune disease such as joint damage in juvenile idiopathic arthritis or bowel obstruction in Crohn's disease.

Though essential, medication is just one part of your child's treatment program. Most kids with autoimmune diseases also require physical and occupational therapy, to increase their mobility and muscle strength and to learn ways to make day-to-day activities easier on their bodies. And because chronic illnesses like these can be mentally and emotionally tough to deal with, psychotherapy or counseling can be valuable in helping kids keep the positive outlook they need to "beat" their disease.

By and large, autoimmune diseases are considered lifelong conditions. Certain illnesses, like juvenile dermatomyositis, can be “cured,” in the sense that with successful treatment, the symptoms never recur. Many kids grow out of other illnesses, like certain types of juvenile idiopathic arthritis. But even when a child’s autoimmune disease “goes away” (this is called remission), they’ll always need to keep a close eye on their health because the immune system has already shown it’s capable of attacking healthy tissue.

If a child has a more serious autoimmune disease, they may go through periods of getting better (remission) and getting worse (relapse). A sudden, severe return of symptoms, called a flare-up, isn’t uncommon. Both medical treatment and lifestyle changes can go a long way toward bringing these shifts under control.

Even after diagnosing a child’s particular autoimmune disease, doctors can’t predict exactly what will happen. But they can give families a general sense of what the future holds and develop a treatment plan that ensures the best possible outcome.

In some cases, severe autoimmune diseases — especially those affecting the liver, kidneys, lungs, blood vessels and other vital organs — can be life threatening. Fortunately, though, these illnesses are very rare. Treatment aims to keep these vital organs healthy.

Infection is another potentially life-threatening problem for certain children; however, with appropriate monitoring and treatment, families and doctors can work together to minimize such risks.

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.

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.