ENA antibodies are a group of autoantibodies that react against extractable nuclear antigens. Several individual parameters can be distinguished. These include:
- Actin
- Centromere protein-A/-B
- Hsp90
- Ku (Ki)
- Jo-1
- M2
- PCNA
- Scl-70
- Sm
- SS-A (Ro)
- SS-B (La)
- To/Th
- U1-RNP
ENA antibodies can often be detected in collagenoses. Collagenoses include (frequency of detection):
- Dermatomyositis (anti-Jo-1 40%) – disease that affects the skin and muscles and is associated primarily with diffuse movement pain.
- Lupus erythematosus (anti-Ro 20-60%; anti-La 15-40%; anti-Sm 10-30%; anti U1-RNP 10%) – systemic disease that affects the skin and connective tissue of the vessels, leading to vasculitides(vascular inflammation) of numerous organs such as the heart, kidneys or brain.
- Polymyositis (anti-Jo-1 40%) – systemic inflammatory disease of skeletal muscle with perivascular lymphocytic infiltration.
- Progressive systemic sclerosis (anti-Scl70 50-70%; centromere-AK 50-90%) – see scleroderma.
- Sharp syndrome (anti-U1 RNP 100%) – chronic inflammatory connective tissue disease that includes symptoms of several collagenoses such as lupus erythematosus, scleroderma or polymyositis.
- Scleroderma (anti-Scl70 50-70%) – rare autoimmune disease associated with connective tissue induration of the skin alone or of the skin and internal organs (especially digestive tract, lungs, heart, and kidneys)
- Sjögren’s syndrome (anti Ro 40-70%; anti La 30-50%) (group of sicca syndromes) – autoimmune disease from the group of collagenoses, which leads to a chronic inflammatory disease of the exocrine glands, most often the salivary and lacrimal glands; typical sequelae or complications of sicca syndrome are:
- Keratoconjunctivitissicca (dry eye syndrome) due to lack of wetting of the cornea and conjunctiva with tear fluid.
- Increased susceptibility to caries due to xerostomia (dry mouth) due to decreased salivary secretion.
- Rhinitis sicca (dry nasal mucous membranes), hoarsenessand chronic cough irritation and impaired sexual function due to disruption of mucus gland production of the respiratory tract and genital organs.
The procedure
Material needed
- Blood serum
Preparation of the patient
- Not necessary
Disruptive factors
- Not known
Normal value
| Normal value | Immunoblot negative |
Indications
- Suspicion of collagenosis
Interpretation
Interpretation of increased values
- Dermatomyositis (anti-Jo-1 40%).
- Lupus erythematosus (anti-Ro 20-60%; anti-La 15-40%; anti-Sm 10-30%; anti U1-RNP 10%).
- Polymyositis (anti-Jo-1 40%).
- Progressive systemic sclerosis (anti-Scl70 50-70%; centromere-AK 50-90%).
- Sharp syndrome (anti-U1 RNP 100%).
- Scleroderma (anti-Scl70 50-70 %)
- Sjögren’s syndrome (anti Ro 40-70%; anti La 30-50%)
Note
- Detection of dsDNA-AAK and ENA-AAK is highly specific for autoimmune disease!