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Extractable Nuclear Antigens (ENA)

Blood Sciences Test



Factors affecting results

Lipemic, hemolyzed or microbially contaminated samples may give poor results and should not be used

Reference Ranges

Results reported as Negative or Positive.

Test Usage

Screening test for a variety of connective tissue diseases

Includes Ro, La, Sm, RNP, Scl-70 and Jo-1:

SS-A (Ro) antibodies – associated with Sjogren’s, SLE, Cutaneous lupus, neonatal lupus and congenital complete heart block.

SS-B (La) antibodies – associated with Sjogren’s, SLE and neonatal lupus

Sm antibodies – specific for SLE, common only in West Indians

RNP antibodies – associated with mixed connective tissue disease (MCTD) and SLE. In SLE RNP antibodies occur with ds-DNA antibodies, in MCTD only RNP antibodies detected.

Scl-70 antibodies – associated with diffuse cutaneous scleroderma, associated particularly with severe skin disease, musculoskeletal and cardiopulmonary disease.

Jo-1 antibodies – found in 25% of adult patients with autoimmune myositis and in 68% patients with anti-synthetase syndrome (myositis, arthritis, raynauds, interstitial lung disease).

Turnaround time

7 days


In House

Clinical Advice

Clinical advice is available from the Immunology Medical Team at Derriford Hospital

T: 01752 431675

E: plh-tr.eden@nhs.net

Specimen Labelling Procedure
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