Mixed connective tissue disease (MCTD)

Mixed connective tissue disease (MCTD) is a rare inflammatory rheumatic condition that affects different parts of the body in different ways. It gets its name from the fact that it combines symptoms from three individual connective tissue diseases: polymyositis, scleroderma and systemic lupus erythematosus. MCTD is also known as Sharp syndrome.

MCTD usually affects adults, but it sometimes affects children who are 10 or older. Advocate Health Care provides comprehensive care for connective tissue diseases, with experts in all the specialties that may collaborate in treating this complicated disease.

Through our partnership with the Chicagoland Children's Health Alliance, we also cooperate with other health care providers in the region that deal with complex conditions like MCTD.

What is mixed connective tissue disease?

Mixed connective tissue disease is a very rare autoimmune disorder that affects connective tissues. Autoimmune diseases cause the immune system to mistakenly attack normal tissues as if they were harmful.

Connective tissue diseases in general affect your body’s connective tissues, which provide support for other body tissues including bones, muscles, blood vessels and organs such as the heart. Connective tissue diseases lead to abnormalities in proteins such as collagen and elastin, which are found in connective tissues.

Mixed connective tissue disease symptoms

The symptoms of MCTD may overlap between symptoms common to polymyositis, scleroderma and lupus. Each person who’s affected is likely to have a different set of symptoms. Mixed connective tissue disease symptoms also change over time.

Raynaud’s phenomenon is a set of symptoms that affect more than 90% of people with MCTD and often occur before other symptoms occur. Raynaud’s affects blood flow to your fingers, toes, ears and nose, and it causes sensitivity to cold resulting in tingling, numbness and loss of color in the affected areas.

Other symptoms of MCTD found early in the disease include:

• Fatigue
• Joint pain and swelling
• Low-grade fever
• Muscle pain and weakness

Other symptoms seen most often in mixed connective tissue disorder include:

• Swollen, sausage-shaped fingers
• Weakness of muscles in hips and shoulders
• Pulmonary hypertension

Because mixed connective tissue disease includes symptoms from various connective tissue diseases, there are many other symptoms that may affect your child. These include skin rashes, hair loss, heartburn, kidney disease, nerve issues, blood disorders, lung problems, trouble swallowing solid foods and symptoms that resemble Rheumatoid arthritis.

Mixed connective tissue disease symptoms tend to occur in flares (or flare-ups), which are times when symptoms get worse.

What’s the life expectancy of someone with MCTD?

The 10-year survival rate for MCTD is about 80%. The life-shortening effect of MCTD depends on what organs are affected, how much inflammation there is and the severity of your child’s disease. Most deaths from MCTD are caused by pulmonary hypertension, kidney failure or heart disease.

MCTD diagnosis

Confirming a diagnosis for MCTD is complex. Doctors rely on your child’s symptoms, results of physical examination and results from some types of testing.

Blood tests help identify the presence of specific antibodies associated with MCTD and the absence of antibodies connected to other diseases. Pulmonary function tests will be performed to test your child’s lung function. Echocardiography is done to assess the heart. If your child has MCTD symptoms related to their muscles, a muscle biopsy may be performed.

MCTD treatment

There’s no known cause or cure for mixed connective tissue disease. Your child’s treatment will consist of treatment for their individual symptoms of MCTD. Your child’s primary care doctor and a rheumatologist will likely be involved in your child’s care, along with other specialists depending on what organs and bodily systems are involved.

One of the most important parts of treatment for MCTD is having frequent check-ins with your child’s health care team. During these visits, providers can perform any needed testing and check for new symptoms, symptoms that have gone away temporarily or symptoms that have become more intense.

Keeping in touch with your care team helps them keep up with changing needs for medication based on your child’s current combination of MCTD symptoms.

Types of medications that may be prescribed for mixed connective tissue disease include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Antimalarial medications
• Corticosteroids
• Medications to suppress the immune system

Some of the medications your child receives may have side effects and may interact with other drugs. Some medications may put your child at risk of infections, infertility, osteoporosis or future cardiovascular disease.

Lifestyle changes for living with MCTD

If your child is being treated with corticosteroids, you may be advised to keep them on a diet that is low-fat, calcium-sufficient and that has no added salt.

If your child has symptoms of Raynaud’s phenomenon, it’s important for them to avoid becoming too cold by dressing warmly.

You may benefit from finding a support group through your doctor or online. The more you learn about living with mixed connective tissue disease, the more you’ll be able to help your child.