Browsing by Author "Yazici A."
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Item Investigation of the reduction of mouldboard ploughshare wear through hot stamping and hardfacing processes; [Sıcak presleme ve yüzey sertleştirme işlemleri ile kulaklı pulluk uç demirinin aşınmasının azaltılması üzerinde incelemeler](Turkiye Klinikleri, 2011) Yazici A.The effects of the hot stamping process and different hardfacing techniques, such as shielded metal arc welding (SMAW) and gas metal arc welding (GMAW), on the abrasive wear of ploughshares were investigated under field operational conditions. The abrasive wear losses were determined by measuring the weight and dimension changes before and after tillage. The wear losses of hot-stamped and hardfaced ploughshares were less significant than those of the conventionally heat-treated ploughshare specimens used under field conditions. Conventional heat treatment and hard facing by the SMAW process decreased the wear weight losses by 46.31% and the dimensional losses by 86.77% in comparison to the performance of the conventionally heat-treated ploughshares. These values were 36.90% and 88.17%, respectively, for conventional heat treatment and hard facing by the GMAW process. There were no statistically significant differences between the SMAW and GMAW hard facing processes in terms of wear losses. Hot stamping and heat treatment applications on the ploughshare also decreased wear losses by 19.03% and dimension losses by 13.82% in comparison to the conventional heat treatment process. According to the results of the overall study, hot stamping and hard facing by SMAW and GMAW processes can be recommended as efficient solutions for decreasing the wear losses of ploughshares. © TÜBİTAK.Item Wear behavior of carbonitride-treated ploughshares produced from 30MnB5 steel for soil tillage applications(2011) Yazici A.The effects of gaseous carbonitriding processes on wear characteristics of 30MnB5 steel were investigated. The matrix of the carbonitride treated samples has a better wear resistance compared to the substrates of the conventionally heat-treated sample in laboratory conditions. The carbonitriding treatment condition giving rise to the lowest wear weight loss with the pin-on-disc wear machine was selected in order to harden ploughshare specimens to be tested in field experiments. The carbonitriding process at 860°C, with 0.9% C, and 0.6 m3/h NH 3 for 105 min and quenched in 60°C oil followed by a 60 min tempering process at 140°C decreased 14.65% of total wear weight loss and 26.47% of total wear dimension loss of the ploughshare specimens in comparison to the conventional heat treatment process in field operational conditions. © 2011 Springer Science+Business Media, Inc.Item Investigation of the wear behavior of martempered 30 MnB5 steel for soil tillage(2012) Yazici A.The objective of this experimental study was to determine the wear resistance of moldboard plowshares produced from 30 MnB5 steel that were treated with different martempering conditions. The microstructures, the hardness distributions, and the wear behavior of the martempered 30 MnB5 steel were determined and compared with conventionally heat-treated samples in laboratory conditions. The wear losses of all martempered samples were less than that of the conventionally heat-treated samples in laboratory conditions, especially at the end of a longer-term wear experiment. The martempering process in which the steel was austenized at 960°C for 35 min, held at 350°C for 10 s in a salt bath, and then cooled in air produced the best results for decreasing wear loss in laboratory conditions. The martempering treatment that resulted in the lowest wear weight loss in pin-on-disc tests was selected for further testing in field conditions. The field used for the experiment was flat and free of crop residue with a uniformly dispersed soil type (sandy and sandy loam). A reversible plow was used to measure the wear. The abrasive wear losses were determined by measuring the plowshare's weight and dimensions before and after tillage. By achieving a more uniform hardness distribution, the lath-type martensitic and bainitic microstructure of the martempered plowshares significantly increased their wear resistance. The martempering process decreased the wear weight loss by 40.8% and the wear dimension loss by 38.5% compared to conventionally heat-treated plowshares in field conditions. © 2012 American Society of Agricultural and Biological Engineers.Item Impact of rheumatoid arthritis in Turkey: A questionnaire study(Clinical and Experimental Rheumatology S.A.S., 2014) Direskeneli H.; Akkoç N.; Bes C.; Çakir N.; Çefle A.; Çobankara V.; Dalkiliç E.; Dinç A.; Ertenli I.; Gül A.; Hamuryudan V.; Inanç M.; Kalyoncu U.; Karaaslan Y.; Kaşifoǧlu T.; Keser G.; Keskin G.; Kisacik B.; Kiraz S.; Masatlioǧlu S.; Onat A.M.; Özbek S.; Öztürk M.A.; Pamuk Ö.N.; Pay P.; Pirildar T.; Sayarlioǧlu M.; Şenel S.; Şentürk T.; Taşan D.; Terzioǧlu E.; Yazici A.; Yücel E.Objective: Unmet needs of rheumatoid arthritis (RA) patients regarding physician/patient communication, treatment preferences and quality of life issues were investigated in a Turkish survey study. Methods: The study was conducted with the contribution of 33 rheumatologists, and included 519 RA patients. The study population included patients who had been on biologic therapy for >6 months and were still receiving biologic therapy (BT group), and those who were biologic naive, but found eligible for biologic treatment (NBT group). Of the RA patients, 35.5% initially had a visit to an internal disease specialist, 25.5% to a physical therapy and rehabilitation specialist, and 12.2% to a rheumatology specialist for their RA complaints. The diagnosis of RA was made by a rheumatologist in 48.2% of patients. Results: The majority of RA patients (86.3%) visit their doctor within 15-week intervals. Most of the physician-patient communication focused on disease symptoms (99.0%) and impact of the disease on quality of life (61.8%). The proportion of RA patients who perceived their health status as good/very good/excellent was higher in the BT group than in the NBT group (74.3% vs. 51.5%, p<0.001). However, of those RA patients in the NBT group, only 24.8% have been recommended to start a biologic treatment by their doctors. With respect to dose frequency options, once-monthly injections were preferred (80%) to a bi-weekly injection schedule (8%). Conclusion: In conclusion, RA patients receiving biologic therapy reported higher rates of improved symptoms and better quality of life and seemed to be more satisfied with their treatment in our study. © Clinical and Experimental Rheumatology 2014.Item A study of soil tillage tools from boronized sintered iron(Springer New York LLC, 2017) Yazici A.; Çavdar U.Acomparative analysis of the properties of boronized sintered iron and quenched steels 30MnB5, 28MnCrB5 used for making soil tillage tools is performed. The microstructure, phase composition, hardness and strength characteristics of the materials are studied. The composition of the boride phase formed in the sintered iron after boronizing is determined by an x-ray method. The losses to abrasive wear are evaluated with the help of a device containing a special bin with a sample of abrasive soil. © 2017 Springer Science + Business Media New York.Item Corrosion resistance and mechanical properties of quenched and tempered 28MnCrB5 steel in two acidic environments(Carl Hanser Verlag, 2017) Yazici A.; Sadrettin Zeybek M.; Manisa; Güler H.; Izmir; Pinar A.M.; Tücer R.Korrosionwiderstand und mechanische Eigenschaften eines abgeschreckten 28MnCrB5-Stahles in zwei sauren Umgebungen. Die Mikrostruktur, die Härteverteilung, die Zugfestigkeit und das Bruchverhalten des angelassenen Stahles 28MnCrB5 wurden jeweils vor und nach Korrosionsversuchen untersucht. Das Korrosionsverhalten des angelassenen Stahles 28MnCrB5 wurde in zwei verschiedenen sauren Umgebungen analysiert, dabei wurde zum einen eine Salzsäurelösung mit einem 10 % molaren Anteil und zum anderen Döngemittel-haltige Erde verwendet. Die Proben wurden in beide Lösungen för 24, 48, 72, 96, 120, 144 und 168 Stunden und in die Döngemittel-haltige Erde zudem för 240 Tage getaucht. Es wurden die Korrosionsverluste mittels Gewichtsänderungsmessungen bestimmt und die entsprechenden Korrosionsraten berechnet. In der Probe des abgeschreckten Werkstoffes wurde vor und nach 168 Stunden in der Salzsäurelösung sowie in der Döngemittel-haltigen Erde duktiles Bruchverhalten beobachtet. Allerdings zeigte die Probe, die för 240 Tage der Korrosion in Döngemittel-haltiger Erde ausgesetzt war, sprödes Bruchverhalten und die Bruchoberfläche lies eine interkristalline Spaltbruchfläche erkennen. Nach dem 240-Tage-Korrosionsversuch in der Döngemittel-haltigen Erde nahm die Duktilität des Werkstoffes erheblich ab. Die Oberfläche der gehärteten Stahlproben wies am Ende des 168-Stunden-Korrosionsversuchs in Salzsäure Löcher, Risse und Abschälungen auf. Am Ende des 240-Tage-Tests in der Döngemittel-haltigen Erde zeigte die Oberfläche der Proben tiefe Abschälungen und Risse.Item Effect of carbonitriding on corrosion resistance of steel 30MnB5 in two acidic environments(Springer New York LLC, 2017) Yazici A.; Zeybek M.S.; Güler H.; Koç M.; Pekıtkan F.G.Corrosion resistance of steel 30MnB5 is studied after carbonitriding, after conventional quenching, and without treatment. Corrosion tests are performed for from 24 to 168 h in two acidic environments (in a hydrochloric acid solution with 10% mole fraction and in fertilizer-containing soil). It is shown that the rate of corrosion of the steel in both environments after carbonitriding is lower than after quenching). © 2017 Springer Science + Business Media New York.Item Effect of quenching and tempering temperature on corrosion behavior of boron steels in 3.5 wt.% NaCl solution(Electrochemical Science Group, 2019) Aydin G.; Yazici A.This study was carried out to examine the impact of austenitization and tempering temperatures on the corrosion characteristics of boron steels. Boron steel samples were austenitized at 850 °C, 900 °C, and 950 °C, and then quenched in environmental water. After quenching, the samples were tempered at 150 °C, 300 °C, and 450 °C for 30 minutes to prepare specimens. The corrosion characteristics of quenched and tempered boron steels in a 3.5 wt.% NaCl solution were examined using Tafel extrapolation method. Significant statistical differences have been observed between the tested boron steels in terms of corrosion rate. Changing C concentration affected the corrosion rates of boron steels after their immersion into a 3.5 wt% NaCl solution and increasing C content generally accelerated the corrosion rate. A poor correlation has been found between average ferrite grain size and corrosion rate under the examined heat treatment conditions for tested boron steels. © 2019 The Authors.Item Identification of susceptibility loci for Takayasu arteritis through a large multi-ancestral genome-wide association study(Cell Press, 2021) Ortiz-Fernández L.; Saruhan-Direskeneli G.; Alibaz-Oner F.; Kaymaz-Tahra S.; Coit P.; Kong X.; Kiprianos A.P.; Maughan R.T.; Aydin S.Z.; Aksu K.; Keser G.; Kamali S.; Inanc M.; Springer J.; Akar S.; Onen F.; Akkoc N.; Khalidi N.A.; Koening C.; Karadag O.; Kiraz S.; Forbess L.; Langford C.A.; McAlear C.A.; Ozbalkan Z.; Yavuz S.; Çetin G.Y.; Alpay-Kanitez N.; Chung S.; Ates A.; Karaaslan Y.; McKinnon-Maksimowicz K.; Monach P.A.; Ozer H.T.E.; Seyahi E.; Fresko I.; Cefle A.; Seo P.; Warrington K.J.; Ozturk M.A.; Ytterberg S.R.; Cobankara V.; Onat A.M.; Duzgun N.; Bıcakcıgil M.; Yentür S.P.; Lally L.; Manfredi A.A.; Baldissera E.; Erken E.; Yazici A.; Kısacık B.; Kaşifoğlu T.; Dalkilic E.; Cuthbertson D.; Pagnoux C.; Sreih A.; Reales G.; Wallace C.; Wren J.D.; Cunninghame-Graham D.S.; Vyse T.J.; Sun Y.; Chen H.; Grayson P.C.; Tombetti E.; Jiang L.; Mason J.C.; Merkel P.A.; Direskeneli H.; Sawalha A.H.Takayasu arteritis is a rare inflammatory disease of large arteries. We performed a genetic study in Takayasu arteritis comprising 6,670 individuals (1,226 affected individuals) from five different populations. We discovered HLA risk factors and four non-HLA susceptibility loci in VPS8, SVEP1, CFL2, and chr13q21 and reinforced IL12B, PTK2B, and chr21q22 as robust susceptibility loci shared across ancestries. Functional analysis proposed plausible underlying disease mechanisms and pinpointed ETS2 as a potential causal gene for chr21q22 association. We also identified >60 candidate loci with suggestive association (p < 5 × 10−5) and devised a genetic risk score for Takayasu arteritis. Takayasu arteritis was compared to hundreds of other traits, revealing the closest genetic relatedness to inflammatory bowel disease. Epigenetic patterns within risk loci suggest roles for monocytes and B cells in Takayasu arteritis. This work enhances understanding of the genetic basis and pathophysiology of Takayasu arteritis and provides clues for potential new therapeutic targets. © 2020 American Society of Human GeneticsItem A national, multicenter, secondary data use study evaluating efficacy and retention of first-line biologic treatment with tocilizumab in patients with rheumatoid arthritis in real-life setting: results from TURKBIO registry(Nature Research, 2022) Yazici A.; Özdemir Işık Ö.; Dalkılıç E.; Koca S.S.; Pehlivan Y.; Şenel S.; Inanc N.; Akar S.; Yılmaz S.; Soysal Gündüz Ö.; Cefle A.; Karakaş Ö.F.; Onen F.Tocilizumab (TCZ) is a recombinant humanized monoclonal antibody that targets the IL-6 receptor. TCZ found to be efficacious and has a good tolerated safety profile in rheumatoid arthritis (RA) patients. The aim of this study was to describe the disease activity and retention rate in Turkish RA patients who were prescribed TCZ as first-line biologic treatment in a real-world setting. Secondary data obtained from adult RA patients’ files was used in a multicenter and retrospective context. Clinical Disease Activity Index (CDAI), Disease Activity Score in 28 joints with ESR (DAS28-ESR), and retention rates of TCZ were evaluated at related time points. 130 patients (87.7% female) with a mean age of 53 years (SD; 15.0) were included in the study. Mean RA duration was 14 years and median duration of follow-up was 18.5 months. Number of patients with ongoing TCZ treatment at 6, 12, and 24 months were 121 (93%), 85 (65%), and 46 (35%), respectively. Remission rates at 6, 12, and 24 months per CDAI (< 2.8) and DAS28-ESR (< 2.6) scores were 61.5, 44.6, 30%, and 54.6, 40.8, 27.7%, respectively. Both CDAI and DAS28-ESR scores significantly improved at 6, 12 and 24 months (p < 0.001 for both). At 24 months, 23 patients (17.6%) discontinued TCZ, of whom majority (17/23) were due to unsatisfactory response. Retention rates of TCZ at 6, 12, and 24 months were 93, 84.3, and 72.2%, respectively. In this real-world study, TCZ as a first-line biologic therapy was found to be efficacious and showing high retention rates. These real-world study results are in line with previous randomized studies. © 2022, The Author(s).Item The impact of smoking on response to tumor necrosis factor-α inhibitor treatment in patients with ankylosing spondylitis(Turkiye Klinikleri, 2023) Yarkan Tuğsal H.; Kenar G.; Can G.; Çapar S.; Zengin B.; Akar S.; Dalkiliç E.; Şenel S.; Koca S.S.; Göker B.; Yazici A.; İnanç N.; Ellidokuz H.; Akkoç N.; Önen F.Background/aim: To investigate the impact of smoking on disease activity, treatment retention, and response in patients with ankylosing spondylitis (AS) treated with their first tumor necrosis factor-α inhibitor (TNFi). Materials and methods: AS patients who started their first TNFi treatment for the active axial disease (BASDAI ≥ 4) from TURKBIO Registry were included. Treatment response of smoker (current and ex-smokers) and nonsmoker (never smoker) patients were primarily evaluated as achievement of BASDAI50 or improvement in BASDAI at least 20 mm at 3 months and 6 months compared to baseline. Results: There were 322 patients with AS (60% male, 59% smoker, mean age: 38.3 years). The median follow-up time was 2.8 years (Q1– Q3: 1.3–3.8), and disease duration was 3.5 years (Q1–Q3: 0.7–8.2). Smokers had male predominance (p < 0.001), lower ESR (p = 0.03), higher BASDAI (p = 0.02), BASFI (p = 0.05), HAQ-AS (p = 0.007), and ASDAS-CRP (p = 0.04) compared with nonsmokers at baseline. In the multivariate analysis, male gender [OR 2.7 (95%CI 1.4–5), p = 0.002], and concomitant conventional synthetic disease-modifying antirheumatic drug use [OR 2.4 (95%CI 1.1–5.2), p = 0.03] were associated with better treatment response. There was an association of male gender [HR 2.4 (95%CI 1.6–3.7), p < 0.001], older age (≥30years) [HR 1.8 (95%CI 1.1–2.8), p = 0.01], and response to treatment [HR 1.8 (95%CI 1.2–2.9), p = 0.008] with better treatment retention. No impact of smoking status was found on treatment retention and response in univariate and multivariate analyses. Conclusion: This study suggested that smoking was associated with poorer patient-reported outcomes in biologic naïve AS patients initiating their first TNFi treatment, but it had no impact on the TNFi treatment response and retention rate. © TÜBİTAK.Item Unintentional Monotherapy in Rheumatoid Arthritis Patients Receiving Tofacitinib and Drug Survival Rate of Tofacitinib(Lippincott Williams and Wilkins, 2023) Inanc N.; Abacar K.Y.; Ozturk M.A.; Tufan A.; Karadeniz H.; Sari I.; Can G.; Erez Y.; Pehlivan Y.; Dalkilic H.E.; Ocak T.; Cefle A.; Yazici A.; Senel A.S.; Akar S.; Durak-Ediboǧlu E.; Koca S.S.; Piskin-Sagir R.; Yilmaz S.; Gulcemal S.; Soysal-Gunduz O.; Basibuyuk C.S.; Alkan S.; Cesur T.Y.; Onen F.Objective To determine the rate of unintentional monotherapy (UM; switching to monotherapy from combination therapy of patients' own volition) in rheumatoid arthritis patients receiving tofacitinib and to evaluate tofacitinib survival rate. Methods This national, multicenter study included patients' data from the TURKBIO Registry. Demographics, clinical characteristics, disease duration and activity, comorbidities, and treatments were analyzed. Results Data of 231 rheumatoid arthritis patients (84.8% female, median age, 56 years) were included; 153 were initially prescribed combination therapy and continued to their therapies; 31 were initially prescribed combination therapy but switched to monotherapy on their own volition (UM); 21 were initially prescribed monotherapy and switched to combination therapy; 26 were initially prescribed monotherapy and continued to their therapies. The rate of comorbidities at the time of data retrieval was higher in the UM group than in the combination group (83.3% vs. 60.3%, p = 0.031). Presence of comorbidities was a significant factor affecting switching to monotherapy (p = 0.039; odds ratio, 3.29; 95% confidence interval, 1.06-10.18). The combination and UM groups did not differ regarding remission rate assessed by Disease Activity Score 28-joint count C-reactive protein (60.5% and 70%, respectively; p = 0.328). Drug survival rates of the UM and combination groups did not differ. The median drug survival duration of tofacitinib was 27+ months with 1- and 4-year drug survival rates of 89.6% and 60.2%, respectively, in the UM group. Conclusions Although 13.4% of the study population started monotherapy unintentionally, drug survival and remission rates of the UM and combination groups were not different. Comorbidity was a factor affecting transition from combination therapy to monotherapy. © Wolters Kluwer Health, Inc. All rights reserved.Item Body mass index does not affect response of rituximab in patients with rheumatoid arthritis: results from the TURKBİO registry(Turkiye Klinikleri, 2023) Karataş A.; Pişkin Sağir R.; Koca S.S.; Dalkiliç E.; Can G.; Pehlivan Y.; Yazici A.; İnanç N.; Cefle A.; Ertürk Z.; Akar S.; Şenel S.; Birlik M.; Akkoç N.; Önen F.Background/aim: Adipose tissue produces several inflammatory mediators. Thus, obesity affects the disease course and the responses to the antirheumatic agents in inflammatory diseases. The aim of the study was to determine whether the body mass index (BMI) is involved in the response to rituximab in rheumatoid arthritis (RA). Materials and methods: This multicenter retrospective study included 206 RA patients who received rituximab from the Turkish Biologic (TURKBIO) registry between 2011 and the end of May 2017. Demographic and clinical data including age, sex, disease type, disease duration, and previous or current treatment with disease-modifying antirheumatic drugs (DMARDs) and biological drug durations are stored in the database. Patients with a BMI ≥30 kg/m2 were classified as obese, and patients with a BMI <30 kg/m2 were classified as nonobese. Kaplan-Meier survival analysis was performed to estimate the drug survival. The subgroups were compared using the log-rank test. Results: The mean BMI of 206 patients included in the study was 27.05 (17.2–43.4) kg/m2. There were 59 (28.6%) patients in the obese group and 147 (71.4%) patients in the nonobese group. The mean age, female percentage, and baseline disease activity score 28 (DAS28) were higher in the obese group than in the nonobese group. However, the ΔDAS28 at both 6 and 12 months were not significantly different between the groups (p = 0.785 and p = 0.512, respectively). Patient pain Visual Analogue Scale (VAS), patient fatigue VAS, and patient global VAS scores were also significantly higher at baseline in the obese group (p = 0.003, p = 0.006, and p = 0.006, respectively). However, no significant difference was found in terms of changes in patient pain VAS, patient fatigue VAS, patient global VAS and physician global VAS scores at 6 and 12 months compared to those at baseline. Rituximab treatment was ongoing for 71.2% of the obese and 63.3% of the nonobese patients (p = 0.279). The median drug survival duration was 77 months in the obese group and 62 months in the nonobese group (p = 0.053). The estimated drug survival rates for rituximab were not statistically significantly different in the obese and nonobese groups. Rituximab-related side effects were also similar between the groups. Conclusion: In obese and nonobese patients with RA, rituximab treatment exhibits similar side effects and similar long-term efficacy. These results suggest that obesity does not alter drug survival for rituximab and response rates, in RA and rituximab may be a favorable treatment agent in patients with RA and obesity. © TÜBİTAK.Item Efficacy and Safety of CT-P13 as First- and Second-Line Treatment in Patients with Ankylosing Spondylitis(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Uslu S.; Gülle S.; Sen G.; Capar S.; Senel S.; Dalkılıc E.; Akar S.; Koca S.S.; Tufan A.; Yazici A.; Yilmaz S.; Inanc N.; Birlik M.; Solmaz D.; Cefle A.; Goker B.; Direskeneli H.; Yolbas S.; Steen Krogh N.; Yilmaz N.; Erten S.; Bes C.; Soysal Gündüz O.; Oztürk M.A.; Haznedaroglu S.; Yavuz S.; Onen F.; Sari I.Background/Objectives: CT-P13 is a biosimilar version of infliximab, a monoclonal antibody. In individuals with ankylosing spondylitis (AS), CT-P13 has been shown to be effective and to have a well-tolerated safety profile. The aim of this study was to evaluate the long-term drug persistence, safety, and efficacy of infliximab biosimilar CT-P13 in patients with AS undergoing first-line (1st-line) and later (≥2nd-line) treatment in clinical practice. Methods: We performed an observational cohort study that included AS patients based on the biological drug database in the TURKBIO Registry between 2014 and 2021. The patients were divided into two groups: those receiving CT-P13 as first-line treatment or as a switch (≥2nd-line) from another TNF inhibitor (TNFi). Standard disease activity metrics were used to assess the effectiveness of CT-P13, and drug retention rates were investigated. Results: There were 179 AS patients using CT-P13 (47.4% male, mean age: 42.9 ± 11.3 years). Of these patients, 123 (68.7%) were receiving CT-P13 as a first-line treatment. The mean length of treatment was 3.5 years. CT-P13 drug retention rates in the general patient population were 58.6% and 48.2% in the first-line and ≥second-line treatment, respectively, after 3 years of follow-up. The most common reason for CT-P13 treatment discontinuation was lack of efficacy. The first-line CT-P13 group had statistically substantially higher ASAS20/40 response rates at three and six months. Nonetheless, both groups’ response rates at one year were comparable. Conclusions: In this real-world data analysis, AS patients who were TNFi naïve (1st-line) and subsequently treated (≥2nd-line) with CT-P13 showed encouraging drug retention rates with acceptable long-term effectiveness and safety. © 2024 by the authors.Item Does obesity affect treatment response to secukinumab and survival in ankylosing spondylitis? Real-life data from the TURKBIO Registry(Oxford University Press, 2024) Karakaş A.; Gulle S.; Can G.; Dalklllc E.; Akar S.; Koca S.S.; Pehlivan Y.; Senel S.; Tufan A.; Ozturk M.A.; Yilmaz S.; Yazici A.; Cefle A.; Yüce Inel T.; Erez Y.; Sari I.; Birlik M.; Direskeneli H.; Akkoc N.; Onen F.Objectives: The aim of this study was to evaluate the impact of obesity on the treatment response to secukinumab and drug survival rate in patients with ankylosing spondylitis (AS). Methods: We performed an observational cohort study that included AS patients based on the biological drug database in Turkey (TURKBIO) Registry between 2018 and 2021. The patients were divided into three groups: normal [body mass index (BMI) < 25 kg/m2], overweight (BMI: 25-30 kg/m2), and obese (BMI ≥ 30 kg/m2). Disease activity was evaluated at baseline, 3, 6, and 12 months. Drug retention rates at 12 months were also investigated. Results: There were 166 AS patients using secukinumab (56.6% male, mean age: 44.9 ± 11.6 years). The median follow-up time was 17.2 (3-33.2) months. Forty-eight (28.9%) patients were obese. The mean age was higher in the obese group than in others (P =. 003). There was no statistically significant difference in Bath Ankylosing Spondylitis Disease Activity Index 50, Assessment of SpondyloArthritis international Society 20 (ASAS20), ASAS40, Ankylosing Spondylitis Disease Activity Score (ASDAS) low disease activity, and ASDAS clinically important improvement responses between the three groups at 3, 6, and 12 months, although they were numerically lower in obese patients. Drug retention rates at 12 months were similar in all groups (P >. 05). Conclusions: This study suggested that obesity did not affect secukinumab treatment response and drug retention in AS patients. © 2023 Japan College of Rheumatology. Published by Oxford University Press. All rights reserved.