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Test ID: ENA RO
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ENA RO
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Anti- Ro/ SS-A antibodies
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Useful For
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Evaluation of Extractable Nuclear Antigens Ro (ENA Ro) can aid in the clinical diagnosis of patients with signs and symptoms of connective tissue disease and positive antinuclear antibodies (ANA) test. It can assist in diagnosing Sjögren's syndrome and systemic lupus erythematosus (SLE).
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Method name and description
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Method: Fluorescence Enzyme Immunoassay (FEIA), Uses the EliA IgG method on Phadia system.
Using EliA technology solid phase, analyte molecules can be extracted from a sample. To achieve this, a well is coated with an antigen that specifically binds to target antibodies. Following the removal of non-bound antibodies, enzyme-labeled antibodies against human antibodies (EliA IgG Conjugate) are added to form an antibody conjugate complex. This complex is then incubated and non-bound conjugate is subsequently washed away. The bound complex is then incubated with a Development Solution, and after stopping the reaction, the fluorescence in the reaction mixture is measured. A higher response value indicates the presence of a more specific antibody in the specimen.
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Reporting name
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Anti- Ro/ SS-A antibodies
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Clinical information
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Detection of SS-A/Ro antibodies is of interest and significance for the clinical diagnosis of SLE (prevalence 40-50 %) and Sjögren's syndrome (prevalence 60-75 % for primary Sjögren's syndrome). They have been reported to occur in tight association with certain disease subsets, such as subacute cutaneous LE, neonatal lupus erythematosus or vasculitis in Sjögren's syndrome. As anti-SS-A/Ro may be the only antibody present in many patients with SLE or Sjögren's syndrome, failure to measure anti-SS-A/Ro leaves a diagnostic void which cannot be filled by other tests.
The SS-A/Ro antigen consists of two proteins, a 60 kDa and a 52 kDa peptide.
In half of patients, the disease occurs as a primary pathologic entity (primary Sjögren's syndrome). In the other half, it occurs in association with rheumatoid arthritis or other connective tissue disorders. Ninety percent of patients with Sjögren's syndrome are female.
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Aliases
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ENA SSA/Ro
Anti-SSA (Anti-Sjogren's Syndrome A)
Anti-Ro
Autoantibodies to SSA (Ro)
Ro (Anti-SSA)
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Specimen type / Specimen volume / Specimen container
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Specimen type: Serum sample.
Specimen Volume: At minimum 2 mL whole blood or 0.5 mL serum.
Container Tube: Plan tube /Serum gel (Yellow top tubes).
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Storage and transport instructions
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For sample transportation, the sample should remain at room temperature (18-25°C ) for no longer than eight hours.
Separated serum samples can be stored at 2-8°C for one week.
Separated serum samples should be frozen at below -20°C for any long-term storage.
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Specimen Rejection Criteria
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Quantity not sufficient (QNS)
Hemolysis
Lipemic
Wrong collection container
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Biological reference intervals and clinical decision values
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Anti-ENA SSA-Ro antibodies:
| Interpretation of Test Results |
Reference Values (U/ml) |
| Negative |
< 7 |
| Equivocal |
7 - 10 |
| Positive |
> 10 |
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Turnaround time / Days and times test performed / Specimen retention time
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Turnaround Time: 5 working days.
Days and Times test performed: Twice per week starting from Sunday through Thursday from 7:00 to 15:00.
Specimen retention time: Approximately 7 days.
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