Cohort Definition Name: “Mixed connective tissue disease”
Contributor name: Joel N. Swerdel
Contributor OrcId: 0000-0001-9491-2737
Logic Description: First occurrence of Mixed connective tissue disease.
Recommended study application: outcome, indication
Assertion statement: This cohort definition was executed on at least one real person-level observational health data source and resulted in a cohort with at least 1 person.
Submitted cohort definition:
mixedConTis.txt (1.3 KB)
Target Clinical Description
Mixed Connective Tissue Disease (MCTD) is a rare autoimmune disorder that shares characteristics with other connective tissue diseases, including systemic lupus erythematosus (SLE), scleroderma, and polymyositis. MCTD is characterized by the presence of specific autoantibodies, particularly anti-U1 ribonucleoprotein (anti-U1 RNP), and a combination of symptoms from various connective tissue diseases. While MCTD primarily affects women in their late teens to early twenties, it can occur at any age. The cause of MCTD is not well-understood, and its course can vary widely from person to person.
Presentation for Mixed Connective Tissue Disease:
- Raynaud’s phenomenon (fingers and toes become pale, blue, or purple in response to cold or stress)
- Joint pain and swelling, resembling arthritis
- Muscle weakness and inflammation
- Skin changes, such as puffy fingers, skin tightening, and skin rash
- Fatigue
- Fever
- Swollen fingers and hands
- Gastrointestinal problems (e.g., acid reflux)
- Heart and lung involvement in severe cases
- Neuropathy (nerve damage) and kidney involvement in some individuals
Assessment for Mixed Connective Tissue Disease:
- Clinical evaluation of symptoms and physical examination
- Blood tests to detect specific autoantibodies (e.g., anti-U1 RNP)
- Imaging studies (e.g., X-rays, MRI, CT scans) to assess joint and organ involvement
- Electromyography (EMG) to evaluate muscle and nerve function
- Skin biopsy in cases of skin involvement
Differential Diagnoses for Mixed Connective Tissue Disease:
- Systemic lupus erythematosus (SLE)
- Scleroderma (systemic sclerosis)
- Polymyositis
- Rheumatoid arthritis
- Other autoimmune diseases with overlapping symptoms
Treatment Plan for Mixed Connective Tissue Disease:
- Medications to manage symptoms and reduce inflammation (e.g., nonsteroidal anti-inflammatory drugs, corticosteroids)
- Disease-modifying antirheumatic drugs (DMARDs) for joint and muscle symptoms
- Immunosuppressive drugs (e.g., methotrexate) for severe cases
- Treatment of specific complications, such as Raynaud’s phenomenon or pulmonary hypertension
- Physical and occupational therapy to improve joint and muscle function
- Regular medical monitoring and follow-up to manage disease progression
Prognosis for Mixed Connective Tissue Disease: The prognosis for individuals with MCTD varies, with some experiencing mild, manageable symptoms and others facing more severe complications. Early diagnosis and treatment can help control symptoms and improve the quality of life for those with MCTD. While MCTD is a chronic condition, many individuals can lead fulfilling lives with appropriate medical management and support.