Connective tissue disease

In medicine and rheumatology, connective tissue diseases are "a heterogeneous group of disorders, some hereditary, others acquired, characterized by abnormal structure or function of one or more of the elements of connective tissue, i.e., collagen, elastin, or the mucopolysaccharides."

Classification

Autoimmune disease

• Dermatomyositis - may have autoantibodies to histidine-tRNA ligase (anti-synthetase, Jo-1 antibody) and to PM-Scl nucleolar antigen complex
• Mixed connective tissue disease (MCTD). MCTD is an overlap between systemic lupus erythematosus, scleroderma, and polymyositis. Most patients with MCTD have autoantibodies to U1 small nuclear ribonucleoproteins (anti-U1 snRNP OR anti-U1 RNP)
• Polymyalgia rheumatica
• Rheumatoid arthritis - 80% a positive rheumatoid factor (autoantibodies against gamma-chain immunoglobulins)
  • Sjogren's Syndrome - 60% have autoantibodies to SS-A antigen (Anti-Ro antigen) or SS-B antigen (Anti-La antigen)
• Scleroderma - most have antinuclear antibodies or autoantibodies to centromere or DNA topoisomerase I (Anti-Scl-70)
• Systemic lupus erythematosus

Cartilage disease

• Relapsing Polychondritis

Collagen disease

• Alport Syndrome
• Ehlers-Danlos Syndrome
• Osteogenesis Imperfecta

Diagnosis

Autoimmune disease

Connective tissue disease due to autoimmune disease may have detectable autoantibodies to autoantigens such as:

• Histidine-tRNA ligase (anti-synthetase, Jo-1 antibody) and to PM-Scl nucleolar antigen complex with dermatomyositis.
• U1 small nuclear ribonucleoproteins (anti-U1 snRNP OR anti-U1 RNP) with mixed connective tissue disease.
• Gamma-chain immunoglobulins in rheumatoid arthritis.
• SS-A antigen (Anti-Ro antigen) or SS-B antigen (Anti-La antigen) with Sjogren's Syndrome
• Centromere or DNA topoisomerase I (Anti-Scl-70) with scleroderma