Spotlight on Mixed Connective Tissue Disease

This month, we shine our spotlight on mixed connective tissue disease (MCTD), an autoimmune disorder that is considered an overlap disease, meaning it is a combination of other disorders.

Written by: Bonnie Feldman, DDS, MBA, Anna Simon, Ellen M. Martin

We have referred to autoimmune disease in the past as an “invisible epidemic” — despite affecting roughly 16% of the US population, autoimmunity remains largely under-recognized, underserved and under-researched. To combat this lack of awareness, as well as connect patients and their families with valuable resources, our team at Your Autoimmunity Connection has developed a series of “spotlights” on individual autoimmune diseases. This time, mixed connective tissue disease takes the stage.

What is mixed connective tissue disease?

This month, we shine our spotlight on mixed connective tissue disease (MCTD), an autoimmune disorder that is considered an overlap disease, meaning it is a combination of other disorders. MCTD is characterized by symptoms similar to lupus, systemic sclerosis, and polymyositis; these three conditions usually occur one after the other over a long period of time. MCTD is a rare disease, most commonly occurring in women under the age of 30.

The cause of MCTD is currently unknown, but a lead theory is that the disease is related to an immune response to ribonucleoprotein (RNP) molecules. Normally sequestered in the nuclei of cells, RNPs can become exposed to the acquired immune system when cells die. Mistaking the RNPs for foreign invaders, immune defenses instead attack normal body cells with the RNP signature. Early symptoms include swelling of fingers and whitening/numbness of fingertips. Other common symptoms include Raynaud’s phenomenon (cold hands and feet), joint pain and arthritis, skin abnormalities, muscle weakness, heartburn, and problems with internal organs. Kidney disease, neurologic abnormalities, and anemia are less frequent symptoms. Genetics may predispose people to MCTD, although it does not appear to be simply inherited. Environmental factors such as exposure to certain viruses (which trigger the cell death that exposes RNP to the immune system) may play a role as well.

How is mixed connective tissue disease diagnosed?  

A healthcare provider uses multiple sources of information to diagnose MCTD, including a clinical evaluation, patient history, and specialized tests, such as a blood test that measures levels of an antibody against RNP called anti-U1-RNP. Diagnosis may take a long time – due to the overlapping nature of the disease, it is easy to mistake MCTD for any of the diseases it overlaps with.

We strongly believe that there is strength in numbers, and strength in raising awareness as an initial step towards action. Read on to become connected with available statistics, research initiatives, supportive patient communities, and still more resources. And check out our Facebook page and forum for more MCTD-related updates!

What do the numbers show?

Current available statistics estimate that…

  • 75% of people with MCTD are women.
  • The prevalence of MCTD is currently unknown.
  • The disease is most often diagnosed between the ages of 15-30.
  • Race and ethnicity do not seem to be predictive factors in who contracts the disease.

With both genetic and environmental triggers, pinpointing precise causes of this disease can be challenging. While the National Organization for Rare Disorders, along with other leading organizations, works towards reevaluating the current state of mixed connective tissue disease, our team at Your Autoimmunity Connection is connecting patients with one another and with currently available resources.

The good news for those of you reading this – whether you are affected by mixed connective tissue disease, have a loved one who is affected, or are simply generally interested – is that the recent rise in understanding from alternative approaches suggests that lifestyle changes, including diet, supplements, and exercise, may help moderate symptoms, reduce flares, and complement or replace the need for pharmaceutical treatments.

Connecting you with available resources

Brush up on the basics of mixed connective tissue disease

If you’ve reached this page and read this far along, chances are high that you already have at least some background knowledge about MCTD, but it can’t hurt to brush up on the basics. Since MCTD is an overlapping disease, it is often confused with lupus, systemic sclerosis, and polymyositis, its overlapping conditions. Reading up on the basics can help minimize such confusion. The following pages each provide a comprehensive overview of MCTD:

For anyone affected – find your patient community

    • Daily Strength: MCTD Support Group
      • Connect with others affected by the disease, read about their stories, and post your own if you would like to share it.
    • Facebook Support Groups
      • Connect online with other patients to receive and offer helpful knowledge and support. A quick search will yield several options, but the patients in these forums seem to be particularly active and engaged:

What’s happening in research?

We’ve picked out a few of our favorite research resources – get caught up on recent findings, informed of future directions, and tap into your potential for involvement as a patient:

What is one thing everyone should know about mixed connective tissue disease?

When looking at the big picture, we must remember that mixed connective tissue disease falls within the larger category of autoimmune diseases, of which there are over 100 individual diseases. The American Autoimmune Related Diseases Association (AARDA) estimates that 50 million Americans suffer from one or more autoimmune diseases. What’s more, a research study estimated that approximately 25% of patients with autoimmune diseases have a tendency to develop additional autoimmune diseases.1

We hope that our spotlight on mixed connective tissue disease this month connects you with beneficial resources and information, but we would like to emphasize the need to take a holistic approach in tackling the autoimmune disease epidemic. By looking at all autoimmune diseases together, we can move away from the fragmented view that hides the magnitude of the problem and towards concerted action in reshaping research, diagnosis, and treatment. Our model is the revolution in cancer research and treatment that has come from viewing cancer as a group of diseases with common etiologies, thus garnering more resources than individual types of cancer.

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[1] Cojocaru, M, Inimioara Mihaela Cojocaru, and Isabela Silosi. “Multiple Autoimmune Syndrome.” Mædica 5.2 (2010): 132–134. Print.


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