Recommendations of the Dutch EASI-team for the laboratory diagnostics of ANA, anti-dsDNA and anti-ENA antibodies

 

The Dutch EASI team was the first EASI group sending out a questionnaire to laboratories in their country evaluating the testing algorithms. A summary of the results was presented at the last EASI conference in May, 2010 (see here »). As a conclusion  of the results, the Dutch EASI Group in collaboration with skml generated the following recommendations:

 

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1. ANA-testing should be included in the autoantibody detection as part of the diagnostic work-up of systemic autoimmune diseases.
    
2. ANA-tests based on a (restricted) mixture of defined antigens should not be referred to as ANA-test.
    
3. In case of a positive ANA-test, it is recommended to perform a titration; the result should be reported in a semi-quantitative way (i.e. staining intensity or titre).
    
4. Reading the ANA-pattern is recommended; report of the pattern to the clinician is optional (to be decided in agreement with the wishes of the clinicians).
    
5. The method used for anti-dsDNA antibody detection should be communicated to the clinician.
    
6. Results of anti-dsDNA antibody detection should be reported quantitatively.
    
7. It is recommended to type anti-ENA antibodies to all 7 standard ENA (SS-A/Ro60, SS-B, Sm, RNP, CENP-B, Scl-70, and Jo-1), alternatively stepwise.
    
8. Results of anti-ENA antibody detection should be reported, preferentially in a qualitative manner, for all 7 standard ENA separately (including the negative results); if the result of a screening-assay is reported as negative, it is sufficient to communicate which ENA are present in that assay.
    
9. It is recommended to detect and report anti-SS-A/Ro60 and anti-Ro52 antibodies separately.
    
10. In case of clinical suspicion of congenital heartblock/neonatal lupus/Sjögren’s syndrome and a negative test-result for anti-SS-A/Ro60 antibodies, additional testing for the presence of anti-Ro52 antibodies is recommended. 
     
11. Anti-Sm antibodies should preferentially be detected as SmD-specific. These antibodies may be reported as anti-Sm antibodies; reporting anti-SmB antibodies should not occur.
     
12. At least the anti-dsDNA antibody test should be allowed to be requested as rapid-test, i.e. to be performed within 24 hours.
     
13. At least in case of an homogenous ANA-pattern during the diagnostic work-up, it is recommended to add an anti-dsDNA antibody test, or to advise the clinician to request for this test.
     
14. In case of a positive ANA-test during the diagnostic work-up, it is recommended to add an anti-ENA antibody test, or to advise the clinician to request for this test.
     
15. Clinical suspicion of myositis (anti-Jo-1 antibodies) or congenital heartblock/neonatal lupus/Sjögren’s syndrome (anti-SS-A/Ro60 antibodies), or the special request of the clinician, requires the detection of anti-ENA antibodies irrespective of the result of the ANA-test.