What Is Hyperimmunoglobulin D Syndrome (HIDS)?
Hyperimmunoglobulin D syndrome is a disease that triggers episodes of inflammation in your body. It’s also called hyper-IgD syndrome, or HIDS. It’s a less severe form of a metabolic disorder called mevalonate kinase deficiency (MKD).
The condition causes these symptoms:
- Joint pain
- Fever
- Rash
- Belly pain
- Swollen lymph nodes
HIDS is something you’re born with. Symptoms typically show up in your first year of life. There’s no cure, but treatment can help you manage your symptoms.
Causes
It's an autosomal recessive genetic disorder. This means both copies of the gene in each of your cells have the mutation that causes HIDS. You get one from your dad and one from your mom. Parents with the mutation often don’t have the disorder. They may just be carriers with one copy of the gene.
The gene mutation that causes HIDS affects the shape of the MVK protein, making it unstable. This keeps it from working the way normal MVK would.
Researchers aren’t sure what triggers HIDS symptoms. They think it might be linked to a buildup of mevalonic acid, which MVK uses when it works the right way.
You may also have fewer molecules that help control inflammation. This means certain triggers for inflammation in your body can lead to an HIDS episode. They include:
- Infection
- Emotional or physical stress
- Trauma
- Surgery
- Vaccinations
There’s no clear reason most of the time. But episodes tend to happen less often as you get older.
Symptoms
A high fever is the main symptom of HIDS. Fevers typically happen every 2-12 weeks. They tend to come on suddenly with shaking chills. The fever can last 3-7 days. You don’t have any symptoms between episodes.
Other symptoms include:
- Swollen lymph nodes
- Belly pain
- Diarrhea
- Vomiting
- Loss of appetite
- Flu-like symptoms
- Headache
- Joint pain
- Larger liver (hepatomegaly)
- Larger spleen (splenomegaly)
- Skin rashes
- Canker sore
- Bleeding in your GI tract
Everyone with HIDS has different symptoms. It’s rare, but you can have a buildup of protein deposits in certain organs, including your kidneys. This condition, called amyloidosis, which s a complication of many different conditions that cause chronic inflammation. It is a rare (3%) but serious complication of HIDS. Depending on where the amyloid protein lays down it can present with kidney problems and/or intestinal or heart problems.
Most people with HIDS have high blood levels of certain immune system proteins called immunoglobulin D (IgD) and immunoglobulin A (IgA). Experts aren’t sure why this happens in some people and not in others. It doesn’t seem to cause any symptoms.
Getting a Diagnosis
Because HIDS is rare, it’s best to see a doctor who’s treated the disease to find out if you have it. You typically can find them by reaching out to:
- Support groups
- Researchers doing clinical trials for medication
- Researchers who’ve published studies on the syndrome
Universities and large medical centers may also have connections to doctors who can help. Your doctor can get the most information by doing certain tests during an episode. They may ask for these tests:
Blood test. It can show if you have high levels of IgD. It can also show if you have certain markers for inflammation. The test doesn’t always confirm you have the syndrome. That’s because high IgD can be a sign of other autoinflammatory diseases. The test also doesn’t work on kids under age 3.
Urine test. Your urine may show high levels of mevalonic acid during an episode.
Genetic test. Your doctor will ask you to see a genetic specialist to be sure you have HIDS. They can look at your genes to see if there’s a defect in the MVK gene.
Questions for Your Doctor
You may find it helpful to bring a list of questions and concerns to your doctor’s appointment. Some things you can ask include:
- Do I need more tests?
- What can I do at home to manage my symptoms?
- What is the best treatment for me?
- What are the goals of my treatment?
- What side effects should I watch for from my treatment?
- Are there any medicines I should avoid?
- Are there clinical trials that might help me?
Treatment
Because HIDS is genetic, you can’t cure it. But there are treatments to help with symptoms.
You can take non-steroidal anti-inflammatory drugs (NSAIDs) during an episode to help deal with pain. These include ibuprofen and naproxen. Your doctor may also prescribe steroids to help with inflammation.
You may also need biologic therapy. These are drugs that use substances from living things to treat conditions. Biologic therapies for HIDS work by blocking inflammatory proteins. This can ward off an attack or keep you from having them as often.
Options include:
Anakinra (Kineret). This drug blocks the inflammatory marker interleukin-1. You get it as a shot under your skin at the beginning of an episode to help ease symptoms.
Canakinumab (Ilaris). This is also an interleukin-1 blocker. You can get this shot once a month to stop attacks from happening as often.
Etanercept (Enbrel). It’s a type of biologic called a tumor necrosis factor blocker. Doctors often prescribe this if you have a more severe form of the disease.
You can also ask your doctor if taking part in a clinical trial might help you.
Taking Care of Yourself
You can ward off episodes by avoiding triggers as much as you can. These stress-relieving practices may help:
- Meditation
- Deep breathing exercises
- Yoga
You should also try to:
- Exercise
- Get enough sleep
- Eat healthy
- Avoid smoking, alcohol, and processed foods.
Ask your doctor about other ways to steer clear.
What to Expect
Although there’s no cure for HIDS, your episodes will likely get better and happen less often over time. This usually happens after your teenage years. You may still have up to 6 episodes a year as an adult. HIDS doesn’t shorten your life.
Children with HIDS may miss a lot of school because they have a fever. But it’s not contagious. You can’t pass it to anyone like a cold or the flu.
Getting Support
There are organizations that can give you more information about the disease. They also make it easier to connect with other people who have it. You may be able to find online or in-person support groups, depending on where you live.
Organizations focused on HIDS and other autoinflammatory conditions include:
- Autoinflammatory Alliance
- Rare Inflammatory Condition Community UK (RACC-UK)
- Familial Mediterranean Fever & Autoinflammatory Diseases (FMF & AID Global Association)
- International Society of Systemic Auto-Inflammatory Diseases (ISSAID)
Tell your doctor if HIDS is causing symptoms of depression or anxiety. They can help you find a therapist or other mental health professional to talk with about what you’re feeling.