AB1178 Is anti nuclear antobody test required correctly in daily practice? a choosing wisely analysis
Authors: D. Üsküdar Cansu, H. Üsküdar Teke, E. Gündüz, C. Korkmaz
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> The most sensitive and gold-standard test used for the detection of antinuclear antibody (ANA) is accepted as the indirect immunofluorescence (IIF) test.<sup>1</sup> International proposals, including the choice of rational examination, referred to as "choosing wisely", include significant efforts to reduce overuse of examinations such as the ANA.<sup>2</sup> <h3>Objectives</h3> Our aim was to retrospectively analyse the distribution of the ANA test samples for clinical reasons according to the clinical departments and to determine the most frequently requested reasons and to draw attention to the rational the ANA request. <h3>Methods</h3> <b><i>Detection of ANA samples.</i></b><sup>Between January 2014</sup> and August 2016, the results of the requested ANA test samples were screened for various reasons. The results of the first 4 divisions with the most common ANA test request and the reasons for the test were also analysed in detail (paediatric diseases were excluded). The ANA test was evaluated using the IIF method and the interpretation of the results was done according to the fluorescence intensity observed in the samples (+1 positive,+2 positive,+3 positive and +4 positive). <h3>Results</h3> 11407 ANA samples were evaluated. The first 5 sections requiring ANA test most were as follows: <sup>Neurology 1917</sup> (24.7%), dermatology 1825 (23.6%), rheumatology 1574 (20.3%), paediatric nephrology 1404 (18.1%) and haematology 1027 (13.3%). In all the sections dealing with children, the ANA test number was 2461 and the mean age of the patients was 12.7 years, while the number of ANA samples required in the entire adult patient group was 8946 and the mean age of the patients was 46.8 years. ANA positivity rates for neurology, dermatology, rheumatology and haematology departments are 14.9%, 15.4%, 32.6% and 14.1%, respectively. The interclinical positivity rate was statistically significant (p&lt;0.0001). Positive +1,+2,+3 and+4 positivity rates were 33.5%, 27.8%, 22.2% and 16.3%, respectively, when all positive ANA results were evaluated in terms of titre. When positivity was evaluated in terms of ANA positivity rates/titre,+4 positivity was found to be the most common in the patients from the rheumatology department (135/262=51.5%) (p&lt;0.0001). The reasons for ANA requests were determined according to ICD diagnostic codes. According to this; in neurology, headache, cerebrovascular event and multiple sclerosis; in dermatology urticaria, psoriasis and dermatitis; in rheumatology, SLE, arthritis and fibromyalgia; in haematology, anaemia and thrombocytopenia were the most common reasons for ANA requests. <h3>Conclusions</h3> Based on specific recommendations and "choosing wisely", the ANA test should be requested in patients with a high pre-test probability for autoimmune diseases. Raising awareness in terms of wisely choosing ANA test is needed in departments outside the rheumatology. <h3>References</h3> [1] Meroni PL, Schur PH. ANA screening: an old test with new recommendations. Ann Rheum Dis. 2010;69:1420–2. [2] Lesuis N, Hulscher ME, Piek E, Demirel H, van der Laan-Baalbergen N, Meek I, van Vollenhoven RF, den Broeder AA. Choosing Wisely in Daily Practice: An Intervention 3. Study on Antinuclear Antibody Testing by Rheumatologists. Arthritis Care Res (Hoboken). 2016;68:562–9. <h3>Acknowledgements</h3> None <h3>Disclosure of Interest</h3> None declared