Connective Tissue Diseases
(Bechterew’s disease, Systemic Lupus Erythematosus, Scleroderma, Sjögren’s syndrome)
Includes: Etiology | Pathogenesis | Clinical Manifestations
Overview
Connective tissue diseases (CTDs) are systemic autoimmune diseases where the immune system attacks the body’s own connective tissues, leading to chronic inflammation and multi- organ involvement.
Bechterew's Disease (Ankylosing Spondylitis)
Etiology
- Unknown exact cause.
- Strong genetic association with HLA-B27 .
- Triggered by environmental factors (e.g., infections).
Pathogenesis
- Chronic inflammation of the axial skeleton (especially sacroiliac joints).
- Inflammatory cytokines (TNF-α, IL-17) → enthesitis (inflammation at tendon/ ligament insertion).
- Progressive fibrosis and ossification → spine fusion ("bamboo spine").
Clinical Manifestations
- Low back pain (worse at night, improves with activity).
- Morning stiffness.
- Limited spine mobility.
- Reduced chest expansion.
- Uveitis, aortic root involvement, fatigue.
Systemic Lupus Erythematosus (SLE)
Etiology
- Genetic predisposition ( HLA-DR2, DR3).
- Hormonal (more common in females, estrogen effect).
- Environmental triggers: UV light, drugs (e.g., hydralazine), viruses.
Pathogenesis
- Loss of immune tolerance → production of autoantibodies (e.g., anti-dsDNA, anti- Sm).
- Immune complexes deposit in tissues → Type III hypersensitivity.
- Complement activation → inflammation and organ damage.
✅ Clinical Manifestations
- Butterfly rash, photosensitivity.
- Arthritis (non- erosive).
- Glomerulonephritis.
- Hematologic issues: anemia, leukopenia, thrombocytopenia.
- Serositis: pleuritis, pericarditis.
- Neuro: seizures, psychosis.
- Raynaud phenomenon, fever, fatigue.