FRI0437 Is extended auto antibody profiling associated with the prevalence of disease complications?
Authors: B. Kersten, R. Smeets, F. van den Hoogen, R. van der Molen, W. Alkema, E. van den Ende, M. Vonk
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Auto antibodies play a prominent role in both classification and disease prognosis of systemic sclerosis (SSc). In several cohorts the association between auto antibodies and prognostic factors has been described. In recent years, new methods of antibody profiling have become available, and have shown an important prognostic role for anti-RNApolymerase 3 antibodies (anti-RNAP3). However, it is uncertain whether other auto antibodies have associations with complications as well. <h3>Objectives</h3> The aim of this study is to determine prevalence of auto antibodies in a well characterised cohort of SSc and to evaluate the associations with complications. <h3>Methods</h3> A total of 319 patients from the Nijmegen SSc Cohort were consecutively included in this study. All patients fulfilled the ACR/EULAR 2013 classification criteria for SSc. Patients were subclassified as limited cutaneous SSc (LcSSc), diffuse cutaneous SSc (DcSSc) or SSc overlap syndrome according to Leroy and Medsger. Blood samples were collected at regular outpatient clinic visits and analysed using LIA. (SSc and ENA immunoblot, Euroimmun, Lubeck, Germany). Clinical data was collected prospectively. <h3>Results</h3> The Nijmegen cohort comprises mainly of Caucasians. The percentage of male patients and diffuse patients is higher compared to other cohorts<sup>1</sup> (table 1). There is a relative anticentromere antibody (ACA) dominance in our cohort and ACA antibodies are more common in patients with pulmonary arterial hypertension (PAH), which is consistent with previous studies.<sup>1</sup> However, in our cohort we found a relatively high prevalence of anti-RO52 antibodies in patients with complications (figure 1). <h3>Conclusions</h3> The distribution of the main auto-antibodies is comparable to other Caucasian cohorts.<sup>1</sup> Because the prevalence of anti-RNAP3 is relatively low, it is of limited value in our population. In contrast, the prevalence of anti-Ro52 was high in patients with the three major disease complications, but this antibody was also present in a number of patients who did not (yet) have these complications. Previous studies have shown ambiguous results concerning the relevance of this autoantibody.<sup>2</sup> Furthermore, RNP/SM and RNP-70 may be associated with cardiac involvement. To evaluate the prognostic value of anti-Ro52, RNP/SM and RNP-70 in SSc, a large prospective cohort study is necessary. <h3>References</h3> [1] Domsic RT, et al. Scleroderma: the role of serum autoantibodies in defining specific clinical phenotypes and organ system involvement. Curr Opin Rheumatol. 2014;26(6):646–52. [2] Wodkowski M, et al. Monospecific anti-Ro52/TRIM21 antibodies in a tri-nation cohort of 1574 systemic sclerosis subjects: evidence of an association with interstitial lung disease and worse survival. Clinical and experimental rheumatology2015;33(4Suppl 91):S131–5. <h3>Disclosure of Interest</h3> None declared