BackgroundConventional immunosuppressives (cIS) are the choice of treatment for major organ (ocular, vascular, central nervous (CNS) and gastrointestinal (GIS)) involvement to prevent relapses and organ damage in patients with Behcet’s disease (BD).ObjectivesWe aimed to investigate the rate of new major organ involvement in BD patients under cIS treatments during follow-up and to assess the characteristics and treatment protocols of these patients.MethodsThe files of 1114 patients diagnosed with BD and followed (1992-2019) in the Marmara University Behcet’s Clinic were overviewed retrospectively. Patients with follow-up duration less than 6 months were excluded. A total of 806 patients, of whom 56% were male were included in the analysis. Demographic and clinical characteristics, follow-up and treatment data of the patients were recorded from files. Relapse of the same organ and/or new major organ development during the follow-up period of patients receiving cIS was defined as “event under cIS”.ResultsMedian age at diagnosis was 29 (10-65) years and median follow-up duration was 68 months (6-272). Genital ulcer, erythema nodosum and arthritis/arthralgia were more common in women, whereas papulopustular lesions, vascular and ocular involvement were more common in men (p<0.005 for all). Presence of major organ involvement was 56.9% (n=459) and the frequencies of vascular, ocular, CNS and GIS involvement were 29.8%, 33,5%, 9.7%, and 2%, respectively.At diagnosis 232 (50.5%) patients had major organ involvement, whereas it developed in 227 patients during a follow-up of median 3 years (0.5 - 32) after diagnosis. Major organ involvement developed earlier in males compared to females (median 2 years vs 4 years, p = 0.012). In patients with a first-degree relative history of BD, major organ involvement also developed earlier, however without reaching significance (median 1 year vs 3 years) (p= 0,066). 440 patients had follow-up data under cISs with the follow-up duration of median 65.5 months (6-272). Main reason for cISs use was major organ involvement (86.8%), less frequent reasons were mucocutaneous disease (9.3%) and joint involvement (3.8%). An event under ISs (mainly relapses) occurred in 160 (36.4%) patients with median 23 months after cISs initiation. Majority of events (68%) were relapses of the same major organ (Figure 1). The most commonly used cIS agent was azathioprine (87%). Among patients having an event under cISs, 91% of the relapses and 75% of new major organ involvement developed under azathioprine treatment. In patients with an event under cISs, treatment mostly switched to other ISs such as cyclophosphamide, interferon-alpha, and high dose corticosteroids. In 22% of patients, azathioprine was switched to tumor necrosis factor (TNF) inhibitors.ConclusionIn our study, major organ involvement developed in 57% of the 806 BD patients. We observed that disease course was more severe under cIS treatment in male patients diagnosed at a younger age and with the history of familial BD. In one third (36%) of the patients under cIS treatment, a relapse or a new major organ involvement developed despite the cISs use, mainly under azathioprine. TNF-inhibitor use was approved for BD treatment within the last decade in Turkey. Therefore, azathioprine was switched to a TNF inhibitor in only 22%. Our results suggest that earlier and more aggresive treatment of major organ involvement with biologics may be an option in young male patients especially with the history of familial BD, who had the highest risk for severe disease course.Disclosure of InterestsNone declared

BackgroundAlthough onset of Behçet’s Disease (BD) is common in the second or third decade, initial symptoms occur under the age of 16 years in 4–26% of the patients [1].ObjectivesIn this study we aimed to assess the clinical course of pediatric onset BD in adulthood period.MethodsThe files of 1114 BD patients were reviewed retrospectively. 51 (4.6%) (F/M:21/30) pediatric-onset BD patients were included in the analysis. Demographic and clinical characteristics, follow-up and treatment data of the patients were recorded from files.ResultsThe median age at diagnosis was 16 (14-17) years, and the median follow-up duration was 51 (26-96) months. Of all patients, 33.3% (n=17) had ocular involvement, 27.5% (n=14) had vascular involvement, 17.6% (n=9) had central nervous system involvement, and 3.9% (n=2) had gastrointestinal system involvement. Erythema nodosum was more common in females (p=0.008) and vascular involvement was more common in males (p=0.025).At the end of follow-up, 32 (62.8%) patients had major organ involvement, half of them had at the time of diagnosis.Forty-seven (M:27/F:20) patients had a follow-up with median of 50 (20-82) months in adulthood period. Thirty-one (65.6%) patients had major organ involvement. While 20 (64.5%) patients had major organ involvement in the pediatric period, 11 (35.5%) patients developed major organ involvement in adulthood. Overall, 19 (40.4%) patients had active disease manifestations (relapse and/or new major organ involvement) in adulthood follow-up. Of these patients, 11 (57.9%) had new major organ involvement, 7 (36.8%) had a relapse of the same organ, and one (5.3%) had both new major organ involvement and a relapse. The disease course of patients is seen in Table 1.ConclusionOur results show that, about half of the pediatric-onset BD patients still have active disease manifestations (mainly new major organ involvement) in adulthood period.Table 1.Disease course of patients followed in adulthood period.Patients followed in adulthoodn=47 (%)Major organ involvement in childhood20 (42.6%)Relapse or/and new major organ involvementNo relapse or major organ involvement8 (17%)12 (25.5%)Mucocutaneous disease in childhood27 (57.4%)New major organ involvementNo major organ involvement11 (23.4%)16 (34%)Reference[1]Yildiz, M., et al., Pediatric Behçet’s disease-clinical aspects and current concepts. European journal of rheumatology, 2020.7(Suppl 1): p. S38.Acknowledgements:NIL.Disclosure of InterestsNone Declared.