FRI0416 THE EFFICACY AND SAFETY OF ANTI-TNF A TREATMENT IN ANKYLOSING SPONDYLITIS PATIENTS WITH LATE ONSET COMPARED TO THOSE WITH ADULT ONSET; THE DATA FROM TURKBIO REGISTRY

Background The first symptoms of ankylosing spondylitis (AS) patients usually begin prior to 45 years, but can occur later in life. Objectives The purpose of this study is to evaluate the efficacy and safety of anti-TNFα treatment in late-onset AS (LoAS) patients in comparison to those with adult onset AS (AoAS). Methods We studied AS patients in TURKBIO registry between the dates of January 2011 and November 2018. All the patients fulfilled the modified New York criteria for AS 1 and were classified into 2 groups based on their age at symptom onset: AoAS (age>16 but ≤45 years); and LoAS (age>45 years). In both groups, the following data were compared: (1) epidemiological variables (2) clinical manifestations, including signs and symptoms at diagnosis; (3) laboratory results (4) disease activity markers and follow-up parameters (BASDAI, ASDAS-CRP and HAQ); (5) previous and current treatments (6) adverse events. Results A total of 2551 AS patients (91,1% with AoAS and 8.9% with LoAS) were included in the study. LoAS group had more female patients, older age, shorter disease duration and diagnostic delay, higher initial ESR and less HLA-B27 positivity compared to the AoAS (Table 1). Peripheral arthritis (not statistically significant) and dactylitis was seen more common in the LoAS. The frequency of other involvements was similar between the groups (Table1). The frequency of using drugs was similar between each groups although the use of glucocorticoids and sulphasalazine was more common in the LoAS. Switching from the first anti-TNFα treatment to the second one was more common in the AoAS. However, there was found no significant difference between the two groups in 2 or more switch ratios (Table 1). At the latest visit after the anti-TNFα therapy, the mean improvement in BASDAI was significantly higher in the AoAS (Table 2). A total of 10 (4.4%) serious adverse events were reported in LoAS and 39 (1.7%) in AoAS patients in the follow-up (HR: 2.62; 95% CI: 1.32–5.18). Severe infections were the most commonly seen serious adverse events (1.3% in LoAS and 0.8% in AoAS), followed by allergic reactions (0.9% in LoAS and 0.3% in AoAS). Tuberculosis was observed in 2 patients (0.9%) in LoAS and 9 (0.4%) in AoAS, malignancy in 3 patients (1.3%) in LoAS and 6 (0.3%) in AoAS. Conclusion Our data showed that almost 8.9% of the patients with AS had late-onset of symptoms. The results suggested that LoAS patients might have different demographic, clinical features, disease activity parameters at baseline. The frequency of anti-TNFα use and response rate to the treatment was also similar in LoAS to those in AoAS patients. The LoAS patients seem to have more common severe adverse events compared to the AOAS patients possibly related to their older age. References [1] Van der Linden S, Valkenburg HA. Evaluation of diagnostic criteria for AS. Arthritis Rheum1984; 27: 361–368. Disclosure of Interests Sadettin Uslu: None declared, Gercek Can: None declared, Ayse Cefle: None declared, Sema Yilmaz: None declared, Sinem Burcu Kocaer: None declared, Tuba Yuce Inel: None declared, Semih Gulle: None declared, Suleyman Serdar Koca: None declared, Servet Yolbas: None declared, Mehmet Akif Ozturk: None declared, Soner Senel: None declared, Nevsun Inanc: None declared, Ediz Dalkilic Grant/research support from: MSD and Abbvie, Consultant for: MSD, Abbvie,Roche, UCB, Pfizer and Novartis, Speakers bureau: MSD, Abbvie,Roche, UCB, Pfizer and Novartis, Ozgul Soysal: None declared, abdurrahman tufan: None declared, Servet Akar Grant/research support from: MSD, Abbvie, Roche, UCB, Novartis, Pfizer, Amgen, Consultant for: MSD, Abbvie, Roche, UCB, Novartis, Pfizer, Amgen, Speakers bureau: Pfizer, Merih Birlik: None declared, Ismail Sari: None declared, Nurullah Akkoc: None declared, Fatos Onen: None declared