SAT0233 VALIDATION OF A NOVEL DISEASE CLASSIFICATION IN HACETTEPE TAKAYASU ARTERITIS COHORT
Authors: Ertuğrul Çağri Bölek, Selcan Demir, Alper Sari, Ummusen Kaya Akca, Levent Kiliç, Ali Akdoğan, Sedat Kiraz, Omer Karadag, Seza Özen
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Takayasu Arteritis (TAK) is a rare idiopathic granulomatous large vessel vasculitis and it is a clinically heterogenous disease. Various classifications and subsets which based on distribution of arterial lesions were defined in the literature in order to exhibit and predict different disease courses. <h3>Objectives:</h3> We aimed to validate a new disease subsets developed by Goel et al in our TAK series (1). <h3>Methods:</h3> We retrospectively evaluated the medical records of 164 TAK patients followed at Department of Rheumatology and Department of Pediatric Rheumatology in Hacettepe University, Ankara, Turkey between August 2005 and October 2018. The pediatric-onset (&lt; 18 years of age at disease diagnosis) and adult-onset patients fulfilled the Ankara 2008 and the American College of Rheumatology (ACR) 1990 criteria for TAK, respectively. All patients were assigned to three clusters (Cluster 1: Abdominal Predominant, Cluster 2: Aortic Arch Predominant, Cluster 3: Focal Disease) using a decision tree defined in the original study (1). Demographics, clinical and laboratory features, treatment regimens were compared between in three groups. <h3>Results:</h3> There were forty-two (25.6%), sixty-three (38.4%) and fifty-nine (36%) patients in Cluster 1, 2 and 3, respectively. Demographic and clinical data was summarized in Table-1. Cluster 1 included approximately half of patients (45.8%) with pediatric-onset TAK (p= 0.048). Baseline acute phase reactants (Erithrocyte Sedimentation Rate:ESR and C-reactive protein:CRP) and age at disease diagnosis were slightly lower in Cluster 1, however none of them did not reach statistical significance (p= 0.94, p=0.99 and 0.56, respectively). In contrast, cerebrovascular accident rates were slightly higher in Cluster 2 (p=0.24). Although anti-TNF biological agents were more frequently used for treatment in Cluster 1 (p=0.004), cyclophosphamide and/or overall biological agents usage was similar in three groups (p=0.15). <h3>Conclusion:</h3> Decision tree which defined by Goel et al. was applied to our single center pediatric and adult TAK cohort. In contrast to original validation cohorts, there was no difference among three clusters of our cohort except pediatric-onset disease and anti-TNF usage. Dissimilarities among the cohorts in terms of new classification system may be caused either number of patients or ethnic/regional differences. <h3>Reference</h3> [1] Goel R, Gribbons KB, Maksimowicz-McKinnon K, Hoffman GS, Kumar S, Joseph G, et al., editors. Discovery and Validation of Novel Disease Subsets in 806 Patients with Takayasu’s Arteritis across Four International Cohorts. ARTHRITIS &amp; RHEUMATOLOGY; 2018: WILEY 111 RIVER ST, HOBOKEN 07030-5774, NJ USA. <h3>Disclosure of Interests:</h3> Ertuğrul Çağri Bölek: None declared, Selcan Demir: None declared, Alper Sari: None declared, Ummusen Kaya Akca: None declared, Levent Kiliç: None declared, Ali Akdoğan: None declared, Sedat Kiraz: None declared, Omer Karadag: None declared, Seza Özen Consultant for: Seza Ozen is receiving consultancy fees from Novartis, Speakers bureau: Roche