Mixed Connective Tissue Disease (MCTD)

Mixed connective tissue disease (MCTD) is a rare autoimmune disorder. An autoimmune disorder is one in which your immune system mistakenly views your body’s own tissues as “invaders” and attacks them. Mixed connective tissue disease has features of three other connective tissue diseases:

• Systemic lupus erythematosus (SLE)
• Scleroderma
• Polymyositis

Some people also show signs of dermatomyositis, rheumatoid arthritis or Sjögren’s syndrome. About 25% of people with a connective tissue disease develop another connective tissue disease over the course of several years. This is why MCTD is known as an “overlap syndrome.”

Symptoms of mixed connective tissue disease (MCTD)

Symptoms of different connective tissue disorders typically occur over time, not all at once. MCTD symptoms may include:

• Fatigue and/or malaise (generally feeling unwell)
• Low-grade fever
• Muscle pain and weakness with no apparent cause
• Joint pain and inflammation
• Raynaud’s phenomenon (reduced blood flow to your fingers, toes, ears and nose, causing sensitivity, numbness and loss of color in these areas)
• Swollen, puffy fingers, sometimes temporary but at other times, progressing into sclerodactyly (thin fingers with hardened skin and limited movement)
• Red or reddish-brown rashes or patches on your knuckles

What does an MCTD flare-up feel like?

During an MCTD flare-up, you may feel severe joint and muscle pain. Your joints may inflame and swell, causing intense pain and stiffness. This is similar to what rheumatoid arthritis feels like.

Your fingers, hands and sometimes toes may suddenly feel numb and tingly. They may become pale and then purple or blue in response to the cold or stress. These are symptoms of Raynaud’s phenomenon.

Mixed connective tissue disease (MCTD) causes

Researchers don’t know what triggers mixed connective tissue disease. It’s not directly inherited, although some research shows that the disease may occur more often in people with a biological family history of connective tissue diseases. Exposure to certain viruses, chemicals or materials, like polyvinyl chloride and silica, are other possible causes.

Risk factors for MCTD

MCTD occurs most often in females in their 20s and 30s. But people of all ages, including children, can develop the disease.

What are the complications of MCTD?

Mixed connective tissue disease (MCTD) can lead to severe complications, including:

• High blood pressure in your lungs (pulmonary hypertension)
• Interstitial lung disease
• Heart disease
• Kidney damage
• Digestive tract damage
• Anemia
• Tissue death (necrosis)
• Hearing loss
• Nerve damage

How doctors diagnose mixed connective tissue disease (MCTD)

MCTD can be difficult for healthcare providers to diagnose because the three conditions (lupus, scleroderma and polymyositis) that combine and cause it usually don’t happen at the same time. Because they occur one after the other over a long period of time, it may take several years before a provider can make an accurate diagnosis of MCTD. You’ll likely work with a specialist called a rheumatologist in the diagnosis of MCTD.

There are four features that point to MCTD rather than another connective tissue disorder:

• High concentrations of an antibody called anti-U1-RNP (ribonucleoprotein) in blood tests
• An absence of severe kidney and central nervous system problems often found in people with lupus
• Severe arthritis and pulmonary hypertension, which may not be found in people with either lupus or scleroderma
• Raynaud’s phenomenon, swollen hands or puffy fingers, which occur in only about 25% of people with lupus

How is mixed connective tissue disease (MCTD) treated?

Treatment for MCTD depends on which organs are affected, your symptoms and how severe your condition is. Some people may need treatment only during flare-ups, while others may require constant care. There’s no cure for the disease, but medication can help you manage your symptoms. MCTD medications may include:

• Corticosteroids. For mild cases of MCTD, low-dose corticosteroids like prednisone can reduce inflammation and prevent your immune system from attacking healthy cells. Higher doses may be needed for moderate to severe MCTD.
• Antimalarial drugs. Antimalarial drugs like hydroxychloroquine may help prevent flare-ups and can treat mild mixed connective tissue disease.
• Calcium channel blockers. To treat Raynaud’s phenomenon, your provider may suggest a calcium channel blocker to help relax the muscles in the walls of your blood vessels.
• Other immunosuppressants. If major organs are affected, you may need to take other immunosuppressants to suppress the actions of your immune system.
• Antihypertensive medications. Your provider may prescribe blood pressure medications to treat pulmonary hypertension. Pulmonary hypertension can lead to heart failure and many other serious complications. It’s the most common cause of death in people with MCTD.

How do I take care of myself?

If you have mixed connective tissue disease, you’ll likely need prescription medications to manage your symptoms. But you can also take steps to manage the disease on your own by:

• Taking nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs like ibuprofen (Advil® or Motrin®) and naproxen (Aleve®), can help with mild pain and inflammation.
• Protecting your hands from the cold. Wear gloves in cold weather and do what you can to keep your hands warm to prevent Raynaud’s phenomenon.
• Quitting smoking. Smoking narrows your blood vessels, which makes the effects of Raynaud’s phenomenon worse.
• Reducing stress. Stress can trigger Raynaud’s phenomenon. Reduce your stress levels and practice relaxation techniques. Mental healthcare can also help you cope with stress.

What can I expect following treatment for mixed connective tissue disease (MCTD)?

Long-term corticosteroid use can lead to side effects like:

• Bone loss due to osteoporosis
• Tissue death due to lack of blood flow (ischemia)
• Muscle weakness
• Infections
• Cushing syndrome

You must see your healthcare provider on a regular basis to monitor and control these possible effects.

Women with MCTD who are thinking of becoming pregnant should talk to their provider first. Pregnancy can increase flare-ups of the disease, and babies born to women with MCTD may have low birth weight.

People who have a long-term, incurable condition like MCTD should develop ways of dealing with their disease. This includes:

• Seeking advice from your primary care provider.
• Consulting with a mental health professional for conditions like depression and anxiety.
• Following proper healthy eating and physical activity plans (if not overly fatigued).
• Learning as much as possible about the disease.
• Joining a chronic illness support group.

When should I see my healthcare provider?

You should see a healthcare provider if you develop any of the signs or symptoms of a connective tissue disease, especially if they interfere with your daily routine. Any new muscle or joint pain, puffy fingers or signs of Raynaud’s phenomenon should warrant a call to a provider to see what’s going on.

If you’re going to see your provider about a possible mixed connective tissue disease diagnosis, you may want to ask the following questions:

• What is causing my symptoms?
• Do I have more than one connective tissue disorder?
• What tests do I need?
• What treatments are available for my condition?
• How can I prevent flare-ups?

What is the life expectancy of someone with mixed connective tissue disease?

As MCTD is composed of a number of connective tissue disorders, there are many different possible outcomes, depending on:

• The organs affected
• The degree of inflammation
• How quickly the disease progresses
• The age at which your symptoms started

With proper treatment, 80% of people survive at least 10 years after diagnosis. But your healthcare provider is the best source of information for your specific case.