Autoimmune Diseases That Can Be Fatal

There are over 100 autoimmune diseases, and in the large majority of cases, these diseases are not life-threatening. However, there are some conditions that can be fatal or lead to life-threatening complications.

Here is a closer look at autoimmune disease that can be fatal.

Giant Cell Myocarditis

Giant cell myocarditis is a rare cardiovascular disorder that progresses rapidly and is often fatal.

In this disease, there is inflammation in the heart muscle (myocardium). Initial symptoms can include:

• Fatigue
• Shortness of breath
• Swelling in the ankles
• Chest pain
• Heart palpitations

Irregular heartbeats (arrhythmias) can cause light-headedness or loss of consciousness. The average time span from the onset of symptoms to complications that can be life-threatening or the need for a heart transplant is five and a half months.

Both men and women can be impacted by giant cell myocarditis and the condition can occur at any age. In the majority of cases, the disease occurs in young or middle-aged people with a median age of 42. It is a rare disease with roughly 300 cases recorded in the literature.

There is no proven cure for giant cell myocarditis.

Anti-NMDA Receptor Encephalitis

Anti-NMDA receptor encephalitis was first recognized as a neurologic disease in 2007. In this autoimmune disease, the immune system creates antibodies against the NMDA receptors in the brain, which play a crucial role in memory. The antibodies interrupt signaling in the brain and cause swelling in the brain, also referred to as encephalitis. Some will also experience tumors that are associated with the disease.

The disease mainly affects young people and is more common in women.

Anti-NMDA receptor encephalitis can cause a variety of symptoms. Typically, the disease will appear with symptoms that are less severe and progress quickly to the point of hospitalization.

Common symptoms include:

• Changes to behavior (aggression, paranoia, hallucinations)
• Problems with cognition
• Difficulty with memory
• Problems with speech
• Loss of consciousness
• Abnormal movements in the face, mouth, arms, and legs
• Seizures

While many cases of anti-NMDA receptor encephalitis will result in a full recovery, in some cases it can be fatal. It’s estimated that roughly 6% of people will die from anti-NMDA receptor encephalitis.

Treatment options vary but often involve a combination of tumor removal (if needed), steroids, plasma exchange, and intravenous immunoglobulin.

Mixed Connective Tissue Disease

Mixed Connective Tissue Disease (MCTD) is a rare condition that can cause pain and inflammation in multiple joints. It is most common in women under 30.

MCTD can cause symptoms also seen in lupus, scleroderma, and rheumatoid arthritis. Signs and symptoms can include:

• Muscle weakness
• Fever
• Fatigue
• Build-up of fluid in the hands causing puffiness
• Rashes
• Violet color of the eyelids
• Hair loss
• Kidney disease
• Dysfunction in the esophagus

There is no cure for MCTD, but treatment options can help with symptoms from the condition. Over-the-counter remedies can help with pain in the joints and inflammation of muscles. If complications occur—or during disease flares—glucocorticoids may be given. Some people experiencing MCTD will require long term immunosuppressants.

Generally speaking, the long-term outlook for those living with MTCD is good, however, this varies based on the symptoms present. Some people will have symptom-free periods that can stretch for years and not require treatment. The 10-year survival rate is 80%, but even with treatment, the disease can worsen in roughly 13% of cases. In these severe cases, the disease can cause potentially fatal complications in six to 12 years of disease onset.

Autoimmune Vasculitis

Vasculitis causes narrowing and inflammation of the blood vessels, which comprise the arteries, veins, and capillaries. The blood vessels are responsible for carrying blood between the heart and other organs in the body.

In this disease, the immune system wrongly attacks the blood vessels, mistaking them for an invader like a virus or bacteria. Vasculitis can occur in isolation or alongside rheumatoid arthritis, lupus, or Sjogren's syndrome.

Signs and symptoms vary and are dependent on the organs involved and the severity of the condition. While some people will only experience mild symptoms, other people can become very ill. Common symptoms include fever, weight loss, loss of appetite, fatigue, and generalized aches and pains. 

Symptoms specific to certain organs throughout the body can include:

• Lungs: Coughing up blood, shortness of breath
• GI tract: Stomach pain, sores in the mouth. In severe cases, blockages and rupture of the intestines
• Ear, throat, nose, and sinuses: Chronic middle ear infections, hearing loss
• Eyes: Redness, itchiness, sensitivity to light, blurred vision, and in rare cases, blindness. 
• Brain: Headaches, problems with cognition, stroke-like symptoms such as paralysis
• Nerves: Numbness or tingles, loss of strength or feeling in hands

In severe cases, the disease causes blood vessels to shut, so blood can’t pass through. This can result in an aneurysm. At its severe stage, vasculitis can cause organ damage and death.

Treatment options vary based on the severity of the disease and the organs affected. Those who have severe vasculitis receive corticosteroids like prednisolone in an attempt to reduce inflammation in the blood vessels. If these don’t work, anti-rheumatic drugs may be used.

A Word From Verywell

In the large majority of cases, autoimmune diseases are not fatal, and those living with an autoimmune disease can expect to live a regular lifespan.

There are some autoimmune diseases that can be fatal or lead to life-threatening complications, but these diseases are rare. If you are concerned about your health or worry you may have an autoimmune disease, speak with your doctor.