Results: 273 patients with AAV (131 women, 48%) and 2717 controls differences in the genetic characteristics of MPO- and PR3-ANCA associated diseases might affect the consequences of triggering the immune system by different microorganisms. Disclosures: The study was supported by Lund University and Region Skane. ABSTRACT 159 TABLE 1: Odds ratio of developing AAV after exposure to different infections diagnosed  6 months prior to the onset of AAV Types of infections All OR (95% CI) MPO-ANCA OR (95% CI) PR3-ANCA OR (95% CI) All infections 1.25 (0.93-1.68) 1.70 (1.08-2.68) 0.79 (0.52-1-21) URTI 1.43 (1.01-2.01) 1.81 (1.08-3.03) 0.99 (0.59-1.66) Pneumonia/Influenza 1.70 (1.02-2.24) 2.13 (1.07-4.24) 1.42 (0.56-3.07) LRTI 1.13 (0.64-1.99) 1.02 (0.44-2.37) 1.30 (0.57-2.99) Skin-infections 0.41 (0.19-0.86) 0.32 (0.96-1.06) 0.58 (0.22-0.51) ENT infections 1.54 (0.93-2.54) 2.71 (1.31-5.65) 0.59 (0.20-1.70) UTI 1.15 (0.60 -2.10) 0.70 (0.23-2.09) 1.20 (0.51-2.84) URTI: Upper respiratory tract infections, LRTI: lower respiratory infections, ENT: ear-nose and throat, UTI: urinary tract infection OF REMISSION AND SIDE A STUDY PROTOCOL Mazzetti 3 , Secore 4 , Gordon Guyatt 1 , Walsh 3 on behalf of and Vasculitis Foundation 2 Vasculitis Foundation Hamilton, ON 5 University of (AAV) is a multi-system remitting course. As new are developed and tested in minimally important differ- importance. With patient partners, we designed a survey instrument called the Vasculitis: Effects of Remission maintenance Therapies on relapse and Side effects on patient preferences (VERITAS) to assess the MID from the perspective of patients with vasculitis. Methods: An on-line survey was developed with patient partners and piloted in a single centre for use with patients with vasculitis through the online Vasculitis Patient-Powered Research Network (VPPRN). The survey instrument assesses patients’ acceptance of therapy under a range of baseline risks of relapse, effect sizes of treatment on risk of relapse, and risks of serious adverse events. The survey was piloted in a Rheumatology clinic in Hamilton and after three successful iterations without any patient-driven changes the survey version was determined to be final. Survey responses will be summarized as a distribution of the proportions of patients that will accept each level of risk reduction for each level of absolute risk reduction and risk of serious adverse events. Participants will be randomized to either an unnamed therapy or to naming the therapy prednisone, a treatment with which most patients are familiar to further determine whether known treatments alter perceptions of acceptability. The effects of naming of therapy as well as the effects of patient demographics on the MID will be assessed with mixed effects models. Conclusion: Here we report the study protocol for VERITAS, an instrument designed to assess the distribution of preferences of patients with vasculitis for therapies that reduce the risk of relapse. The distribution of preferences will be useful in determining patient- important MID and sample size estimates for future clinical trials. Disclosures: This work was supported by the Vasculitis Clinical Research Consortium and the Vasculitis Foundation. 161. AUGMENTED IL-6 IMPLIES UN-SEVERE VASCULAR A CROSS-SECTIONAL 1 and Lindi Jiang 1 Shanghai, China is the most serious complication overall stenosis patients remain to discover the VS in the first is closely associated with TA markers are correlated with conducted in the Zhongshan hospital Cohort of Takayasu’s arteritis (ECTA) to the hospital for the first time were recruited for further analysis (n ¼ 450), and were divided into subgroups based on the extent of stenosis (without, mild, moderate, severe). The optimal TA patients, defined as naı ¨ve patients who were diagnosed and treated at Zhongshan hospital, were extracted as a subgroup. We evaluated the symptoms, vascular imaging, serum biomarkers including IL-6, and drugs. The logistic and ordinal regression models were used. ROC curve was performed to observe the effect indicators. Results: Among 446 TA patients with vascular imaging, 87.8% were diagnosed with VS. After adjusting age, sex, and course, IL-6 was negatively independently associated with both the presence and the extent of VS in both TA patients and optimal TA patients (odds ratio [x5 pg/ml]: 0.84 to 0.87, P < 0.05 for all). The cut-off point for IL-6 to diagnose the ‘‘without þ mild’’ VS was 4.45 pg/ml, with the sensitivity of 0.653 and specificity 0.577 respectively. Conclusion: Most TA patients have VS. The level of IL-6 is negatively associated with the VS independently. The elevated IL-6 indicates un- severe VS in TA, which deserves effective intervention timely. Disclosures: The investigation was supported by the National Natural Science Foundation of China [NSFC 81771730 and 81601398]; and the Animal Research Project of Shanghai Science and Technology Commission [grant number 17140902000]. 162. CLUSTER ANALYSIS TO EXPLORE CLINICAL SUBCLASSIFICATION OF EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS (CHURG–STRAUSS) Emma Rubenstein 1 , Carla Maldini 1 , Augusto Vaglio 2 , Paolo Bottero 3 , Phillip Bremer 4 , Giacomo Emmi 5 , Paolo Fraticelli 6 , Andrea Gioffredi 2 , Gina Gregorini 7 , Julian Grosskreutz 8 , Giuseppe Guida 9 , Bernhard Hellmich 10 , Claus Kroegel 8 , Federica Maritati 11 , Alberto Pesci 12 , Matthieu Resche-Rigon 1 , David Saadoun 13 , Renato Sinico 11 , Barbara Sokolowska 14 , Wojciech Szczeklik 14 , Jochen Zwerina 15 , Frank Moosig 16 , Thomas Neumann 17 and Alfred Mahr 1 1 Saint Louis Hospital Paris, France, 2 University Hospital of Parma, Italy, 3 Ospedale di Magenta Milano, Italy, 4 Clinical Center Bad Bramstedt Bad Bramstedt, Germany, 5 University of Firenze, Florence, Italy, 6 Ospedali Riuniti Ancona, Italy, 7 Spedali Civili Brescia Brescia, Italy, 8 University Hospital of Jena Jena, Germany, 9 Birago di Vische Hospital Torino, Italy, 10 Vasculitis Center Tu ¨ bingen-Kirchheim Kirchheim unter Teck, Germany, 11 University of Parma Parma, Italy, 12 University of Milano Bicocca Milan, Italy, 13 Pitie ´ -Salpe ˆ trie ` re University Hospital Paris, France, 14 Jagiellonian University Medical College Krakow, Poland, 15 Hanusch Hospital Vienna, Austria, 16 Rheumazentrum Schleswig- Holstein Mitte Neumu ¨ nster, Germany, 17 Kantonsspital St. Gallen St Gallen, Switzerland Background: Previous studies of eosinophilic granulomatosis with polyangiitis (Churg–Strauss, EGPA) suggested that EGPA may involve clinically distinct phenotypes. In particular, clinical manifestations might be determined by the presence or absence of antineutrophil cytoplasmic antibodies (ANCAs) and reflect more prominent under- lying vasculitic than eosinophilic disease processes. This study explored whether EGPA involves several subcategories by using hierarchical cluster analysis. Methods: This study used clinical data for patients diagnosed with EGPA in 16 centers in Austria, France, Germany, Italy and Poland collected with a standardized case report form. The analyses pertained to patients reported to have asthma and who fulfilled the Lanham and American College of Rheumatology criteria, with ANCA positivity (by immunofluor- escence or ELISA test) as an additional item. We used a multiple correspondence analysis followed by hierarchical cluster analysis with the Ward method. The cluster model included 10 clinical variables assessed at diagnosis (arthromuscular, mucocutaneous, ophthalmological, ENT, cardiovascular, pulmonary, gastrointestinal, renal, central or peripheral neurological involvement); a second model added ANCA positivity as an ii70 EPIDEMIOLOGY Downloaded from https://academic.oup.com/rheumatology/article/58/Supplement_2/kez059.039/5421994 by guest on 29 September 2021