SS-A (Ro)
Understanding SS-A (Ro)
What is SS-A (Ro)?
SS (Sjogren Syndrome) -A (Ro) is a blood test used for the evaluation of patients with signs and symptoms of Sjogren Syndrome (an autoimmune disease characterized by dry mouth and dry eyes). SS-A (Ro) is commonly referred to as extractable nuclear antigen (ENA). Antibodies to ENA are found in 60- 90% of the patients with Sjogren Syndrome, 40-60% of the cases of systemic lupus erythematosus, and in rheumatoid arthritis patients.
ELISA (Enzyme-Linked Immunosorbent Assay) method is used to measure the IgG antibodies. The reference values are <1.0 U for a negative test and ≥1.0 U for a positive test. The positive test indicates connective tissue diseases. A positive result in pregnant women with LE indicates an increased risk for congenital heart block in neonates.
What is SS-A (Ro) used for?
The test must be performed in patients suspected of Sjogrens Syndrome or LE. Patients with such health issues show signs of congenital heart blockage, vasculitis, nephritis, leukopenia, lymphadenopathy, rheumatoid factor positivity, neonatal lupus, interstitial lung disease, palpable pupura/cutaneous vasculitis, subacute cutaneous lupus or photosensitivity.
Interpreting SS-A (Ro) results
Interpretations
A positive result for the SS-A (Ro) test gives a spotted appearance under ultraviolet immunofluorescence.