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Mixed Connective Tissue Disease (MCTD)

By

Alana M. Nevares

, MD, The University of Vermont Medical Center

Last full review/revision Apr 2020| Content last modified Apr 2020
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Topic Resources
  • Raynaud syndrome, joint pains, various skin abnormalities, muscle weakness, and problems with internal organs can develop.

  • The diagnosis is based on symptoms and the results of blood tests to detect levels of characteristic antibodies.

  • Treatment varies depending on the severity of symptoms and may include nonsteroidal anti-inflammatory drugs, hydroxychloroquine, corticosteroids, immunosuppressive drugs, or a combination.

Mixed connective tissue disease is more common among women than men. Mixed connective tissue disease occurs worldwide and affects people of all ages, often peaking in incidence during adolescence and the 20s. The cause of mixed connective tissue disease is unknown, but it is an autoimmune disease.

Symptoms of MCTD

The typical symptoms of mixed connective tissue disease are Raynaud syndrome Raynaud Syndrome Raynaud syndrome, a functional peripheral arterial disease, is a condition in which small arteries (arterioles), usually in the fingers or toes, narrow (constrict) more tightly than normal in... read more Raynaud Syndrome (in which the fingers suddenly become very pale and tingle or become numb or blue in response to cold or emotional upset), joint inflammation (arthritis), swollen hands, muscle weakness, difficulty swallowing, heartburn, and shortness of breath. Raynaud syndrome may precede other symptoms by many years. Regardless of how mixed connective tissue disease starts, it tends to worsen, and symptoms spread to several parts of the body.

Lupus-like rashes may develop. Skin changes similar to those of systemic sclerosis also may occur, such as tightening of the finger skin. The hair may thin.

Almost everyone with mixed connective tissue disease has aching joints. About 75% of people develop the swelling and pain typical of arthritis. Mixed connective tissue disease damages the muscle fibers, so the muscles may feel weak and sore, especially in the shoulders and hips. Tasks such as lifting the arms above the shoulders, climbing stairs, and getting out of a chair can become very difficult.

The lungs are affected in up to 75% of people with mixed connective tissue disease. Fluid may collect in or around the lungs. In some people, abnormal lung function is the most serious problem, causing shortness of breath during exertion. Interstitial lung diseases Overview of Interstitial Lung Diseases Interstitial lung disease (also called diffuse parenchymal disease) is a term used to describe a number of different disorders that affect the interstitial space. The interstitial space consists... read more , which affect the tissue around the air sacs of the lungs (alveoli), are the most common lung problems. Pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension is a condition in which blood pressure in the arteries of the lungs (the pulmonary arteries) is abnormally high. Many disorders can cause pulmonary hypertension. People... read more , a condition in which blood pressure in the arteries of the lungs (the pulmonary arteries) is abnormally high, is a major cause of death.

Occasionally, the heart is weakened, leading to heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more Heart Failure (HF) . Symptoms of heart failure may include fluid retention, shortness of breath, and fatigue. The kidneys are affected in about 25% of people, and the damage is usually mild compared to the damage caused by lupus. Other symptoms may include fever, swollen lymph nodes, and abdominal pain.

Diagnosis of MCTD

  • Blood tests

  • Sometimes other tests

Doctors suspect mixed connective tissue disease when symptoms of lupus, systemic sclerosis, and polymyositis overlap.

Blood tests are done to detect levels of antinuclear antibodies (ANA) and an antibody to ribonucleoprotein (RNP), which are present in most people who have mixed connective tissue disease. People who have a high level of these antibodies but who do not have other antibodies present in similar disorders are most likely to have the disease. Although blood test results can help doctors diagnose the disease, they alone cannot confirm a definite diagnosis of mixed connective tissue disease because sometimes the abnormalities they detect are present in healthy people or in people who have other disorders. The diagnosis of mixed connective tissue disease is based on all of the information doctors gather, including symptoms, physical examination results, and all test results.

Prognosis of MCTD

Overall, the 10-year survival rate is about 80%, but the prognosis depends largely on a person's symptoms. For example, the prognosis is worse for people who have mainly symptoms of systemic sclerosis and polymyositis. Causes of death include pulmonary hypertension (mainly), kidney failure, and heart disease.

Treatment of MCTD

  • Nonsteroidal anti-inflammatory drugs, antimalarial drugs, or very low doses of corticosteroids for mild illness

  • Corticosteroids and immunosuppressive drugs for moderate to severe illness

  • Other treatments as needed for other symptoms

The treatment of mixed connective tissue disease is similar to that of lupus, systemic sclerosis, and autoimmune myositis. Corticosteroids are usually effective, especially when the disease is diagnosed early. Mild cases can be treated with nonsteroidal anti-inflammatory drugs (NSAIDs), antimalarial drugs (such as hydroxychloroquine or chloroquine), or very low doses of corticosteroids. The more severe the disease, the higher the dose of corticosteroid needed. In moderate to severe cases, immunosuppressive drugs (such as azathioprine, methotrexate, or mycophenolate mofetil) may also be needed. People whose major organs are severely affected usually require higher doses of corticosteroids and additional immunosuppressive drugs.

In general, the more advanced the disease and the greater the organ damage, the less effective the treatment. Systemic sclerosis–like damage to the skin and esophagus is least likely to respond to treatment.

People who have mixed connective tissue disease are at increased risk of atherosclerosis Atherosclerosis Atherosclerosis is a condition in which patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or... read more Atherosclerosis , are closely monitored by doctors, and are treated for specific symptoms and complications of atherosclerosis as they occur.

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