Extractable nuclear antigens
- Sjogren's syndrome
- Cutaneous lupus
- Neonatal lupus
- Congenital complete heart block
- Mixed Connective Tissue Disease
- Systemic Sclerosis
Detection of IgG autoantibodies against saline extracted
Samples are initially screened by an EIA which includes the
following antigens: RNP; Sm; SSa (Ro); SSb (La); Scl-70; Jo-1 and
centromere B. If found to be positive, samples are subsequently
tested for the individual specificities
Request via ICE
Screening test is performed daily (Monday-Friday). Profile is
It is essential to provide relevant clinical information.
Only samples found to be ANA positive will be referred for ENA
testing unless clinical information suggests testing may be
All samples are generally sent to referral
laboratory within 3 working days of receipt in the
laboratory. Screening test is performed daily (Monday-Friday).
Profile is performed weekly.
Samples should be transported to the laboratory immediately
Aliquot and store at 4-8°C prior to testing and at -20°C or
below for up to 1 month after receipt.
Causes for Rejection
Unlabelled/inadequately labelled sample.
Inadequately completed request form.
Delay in sample reaching laboratory
Reference range (Ratio):
||less than 0.7
||0.7 - 1.0
||1.0 - 4.0
||4.0 - 10.0
Below are listed the specificities routinely tested for and
their clinical associations:
Anti Ro (SSa): Associated with Sjogren's syndrome, SLE, cutaneous
lupus and congenital complete heart block.
Anti La (SSb): Associated with Sjogren's syndrome, SLE and
Anti Sm: Specific for SLE. Found in approximately 25 - 40% of
patients, but reported to be seen most frequently in West Indians
with SLE. Rarely found in Caucasians.
Anti RNP: Associated with SLE and, when occurring alone, to
Anti Scl-70: Found in 20 - 40% of patients with progressive
systemic sclerosis and 20% of patients with limited
Anti Jo-1: Associated with polymyositis, pulmonary fibrosis and
Anti Centromere B: Found in 70 -80% of patients with