Assessing safety and efficacy of TNFi treatment in late onset ankylosing spondylitis: a TURKBIO registry study.

Clinical data on the use of tumour necrosis factor inhibitors (TNFi) in late-onset ankylosing spondylitis (LoAS) are limited. The present study aimed to evaluate efficacy, safety, and treatment adherence associated with the initial use of TNFi therapy in biologic naive patients diagnosed with LoAS. Patients whose age of onset was ≥ 45 years and < 45 years were classified as having LoAS and YoAS, respectively, based on the age of symptom onset. There were 2573 patients with YoAS and 281 LoAS. Baseline disease activity measures were similar between the groups. No significant differences were seen between the two groups in response to treatment and in remaining on the first TNFi at 6, 12 and 24 months. In the LoAS group, the analysis showed that TNFi discontinuation was linked to VAS pain score (HR 1.04; 95% CI 1.01-1.06). Patient groups had similar rates of adverse events (YoAS: 8.7% vs. LoAS: 11.7%). In both biologic naive LoAS and YoAS patients, the study showed that the initial TNFi therapy was equally effective and safe.

Biological treatment in elderly and young patients with ankylosing spondylitis: TURKBIO real-life data results.

Objectives: This study aims to investigate the effect of age on disease activity and biological treatment in patients with ankylosing spondylitis (AS). Patients and methods: A total of 811 AS patients registered in the TURKBIO registry database between 2011 and 2019 were categorized according to their age at the time of entry into the registry and assigned to one of two groups: young patients, defined as <60 years of age (n=610), and those aged ≥60 years (n=201) were recorded as elderly patients. Demographic, clinical, and laboratory characteristics, along with disease activity markers and other follow-up parameters, as well as current and prior treatments, were electronically recorded during each visit using open-source software. Results: The mean age of the elderly patients was 67±5.8 years, while the mean age of the younger patients was 49.2±10.9 years. Male predominance was lower in the older AS group compared to the younger AS group (p=0.002). During follow-up period, 397 patients (comprising 318 young and 79 elderly individuals) had a history of using at least one biological disease-modifying agent (bDMARD). There was no significant difference between the groups in terms of DMARD and bDMARD-use distributions. First tumor necrosis factor inhibitor (TNFi) retention rates were found to be similar in both groups over 10 years of follow-up. Adverse events were found to be similar in young (19.9%) and elderly (26.8%) AS patients. Conclusion: Research in the TURKBIO cohort reveals that both older and younger patients with AS exhibited similar disease activity levels with comparable treatment approaches. Moreover, the results of TNFi treatments in elderly patients were the same as those observed in younger patients, with no notable increase in safety concerns.

Comparison of methotrexate and azathioprine as the first-line steroid-sparing immunosuppressive agents in patients with Takayasu's arteritis.

BACKGROUND: Immunosuppressive (IS) agents are recommended for the first-line treatment of patients with active Takayasu's arteritis (TAK) together with glucocorticoids (GCs). However, there is limited data comparing the efficacy and outcomes of different IS agents for this purpose. OBJECTIVES: In this study, we aimed to compare the outcomes of two most frequently used first-line IS agents, namely methotrexate (MTX) and azathioprine (AZA) in TAK patients. METHODS: TAK patients who received any IS agent in addition to GCs as the initial therapy were included in this multicentre, retrospective cohort study. Clinical, laboratory and imaging data of the patients were assessed. In addition, a matched analysis (cc match) using variables 'age', 'gender' and 'diffuse aortic involvement' was performed between patients who received MTX or AZA as the first-line IS treatment. RESULTS: We recruited 301 patients (F/M: 260/41, mean age: 42.2 ± 13.3 years) from 10 tertiary centres. As the first-line IS agent, 204 (67.8 %) patients received MTX, and 77 (25.6 %) received AZA. Less frequently used IS agents included cyclophosphamide in 17 (5.6 %), leflunomide in 2 (0.5 %) and mycophenolate mofetil in one patient. The remission, relapse, radiographic progression and adverse effect rates were similar between patients who received MTX and AZA as the first-line IS agent. Vascular surgery rate was significantly higher in the AZA group (23% vs. 9 %, p = 0.001), whereas the frequency of patients receiving ≤5 mg/day GCs at the end of the follow-up was significantly higher in the MTX group (76% vs 62 %, p = 0.034). Similarly, the rate of vascular surgery was higher in AZA group in matched analysis. Drug survival was similar between MTX and AZA groups (median 48 months, MTX vs AZA: 32% vs 42 %, p = 0.34). IS therapy was discontinued in 18 (12 MTX, 6 AZA) patients during the follow-up period due to remission. Among those patients, two patients had a relapse at 2 and 6 months, while 16 patients were still on remission at the end of a mean 69.4 (±50.9) months of follow-up. CONCLUSIONS: Remission, relapse, radiographic progression and drug survival rates of AZA and MTX were similar for patients with TAK receiving an IS agent as the first-line f therapy. The rate of vascular surgery was higher and the rate of GC dose reduction was lower with AZA compared to MTX at the end of the follow-up.

Factors associated with acute anterior uveitis history in patients with axial spondyloarthritis: Results of a longitudinal study.

BACKGROUNDS: Acute anterior uveitis (AAU) is the most common extra-musculoskeletal manifestation in axial spondyloarthritis (axSpA). OBJECTIVES: The aim of the study is to evaluate the factors associated with AAU attacks in patients with axSpA during a 36-month follow-up period. METHODS: In total, 469 patients with axSpA were included in this observational study. Demographic data, clinical characteristics, disease activity measurements, and treatment patterns were compared between patients with and without a history of AAU. The development of AAU and its related factors were investigated using generalized estimating equations, which is a technique for longitudinal data analysis. RESULTS: Overall, 99 (21%) out of 469 patients experienced at least one AAU attack, with 77 patients (78%) having a history of AAU and 53 patients (58% of whom had a history of AAU) experiencing AAU attacks during the follow-up period. At baseline, patients with a history of AAU were found to be older (p = .001), be more likely to have peripheral arthritis (p < .001), have higher serum CRP levels (p = .016), have a higher frequency of sulfasalazine (SLZ) and tumor necrosis factor inhibitors (TNFi) use (p < .001 and p < .001, respectively). In the longitudinal analysis, having a history of AAU was identified as the only independent determinant of the development of AAU. CONCLUSIONS: AAU history might be a risk factor for the development of AAU attacks in patients with axSpA. Although TNFi and SLZ were prescribed more frequently to patients with a history of AAU, the effectiveness of these agents in preventing further AAU attacks was not demonstrated.

Unveiling cancer risk in ANCA-associated vasculitis: result from the Turkish Vasculitis Study Group (TRVaS).

To investigate cancer incidence in patients with ANCA-associated vasculitis (AAV), compare it with the age/sex-specific cancer risk of the Turkish population, and explore independent risk factors associated with cancer. This multicenter, incidence case-control study was conducted using the TRVaS registry. AAV patients without cancer history before AAV diagnosis were included. Demographic and AAV-related data of patients with and without an incident cancer were compared. Standardized cancer incidence rates were calculated using age-/sex-specific 2017 Turkish National Cancer Registry data for cancers (excluding non-melanoma skin cancers). Cox regression was performed to find factors related to incident cancers in AAV patients. Of 461 AAV patients (236 [51.2%] male), 19 had incident cancers after 2022.8 patient-years follow-up. Median (IQR) disease duration was 3.4 (5.5) years, and 58 (12.6%) patients died [7 with cancer and one without cancer (log-rank, p = 0.04)]. Cancer-diagnosed patients were older, mostly male, and more likely to have anti-PR3-ANCA positivity. The cumulative cyclophosphamide dose was similar in patients with and without cancer. Overall cancer risk in AAV was 2.1 (SIR) ((1.3-3.2), p = 0.004); lung and head-neck [primary target sites for AAV] cancers were the most common. In Cox regression, male sex and ≥ 60 years of age at AAV diagnosis were associated with increased cancer risk, while receiving rituximab was associated with decreased cancer risk. Cancer risk was 2.1 times higher in AAV patients than the age-/sex-specific cancer risk of the Turkish population population, despite a high rate of rituximab use and lower dose of cyclophosphamide doses. Vigilance in cancer screening for AAV patients covering lung, genitourinary, and head-neck regions, particularly in males and the elderly, is vital.

Challenges and insights in managing difficult-to-treat rheumatoid arthritis: real-world clinical perspectives.

OBJECTIVES: The treatment options for rheumatoid arthritis (RA) have expanded with the availability of biological and targeted synthetic disease-modifying anti-rheumatic drugs. Despite all these developments and treatments, an important group of patients remain symptomatic and have not achieved clinical remission. The terminology "difficult-to-treat" (D2T) has been developed to describe this group. This study aimed to determine the frequency of D2T RA among our patients according to the EULAR 2021 definition of D2T RA and to identify the differences in demographic and disease characteristics, contributing factors, and disease burden. METHODS: The study included 302 consecutive patients diagnosed with RA according to the 2010 ACR criteria. These patients were categorised into the D2T and non-D2T RA groups. Risk factors independently associated with D2T RA were identified using logistic regression analysis. RESULTS: Of the 302 patients (mean age, 56.5 years, 80.1% female, 75% seropositive), 27 (8.9%) had D2T RA. Those with D2T RA had a lower age at diagnosis and longer disease duration and showed significantly higher rates of peripheral erosion, Sjögren's syndrome, extra-articular manifestations, and PtGA-PhGA discordance, together with high disease activity scores. Furthermore, the median number of comorbidities and concomitant fibromyalgia was significantly higher in the D2T RA group. In the multiple regression analysis, D2T RA was independently associated with higher HAQ-DI, RF levels, and concomitant fibromyalgia. CONCLUSIONS: D2T RA requires more intensive management, and patients with D2T RA have higher disease activity, poorer functional status, and quality of life than those without D2T RA.

The impact of smoking on response to tumor necrosis factor-α inhibitor treatment in patients with ankylosing spondylitis.

BACKGROUND: 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). 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. DISCUSSION: 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.

Second and third TNF inhibitors in European patients with axial spondyloarthritis: Effectiveness and impact of the reason for switching.

OBJECTIVE: To investigate real-world effectiveness of tumor necrosis factor inhibitors (TNFi) in patients with axial spondyloarthritis (axSpA) and the association with 1) treatment line (second and third TNFi-series) and 2) reason for withdrawal from the preceding TNFi (lack of efficacy (LOE) versus adverse events (AE)). METHODS: Prospectively collected routine care data from 12 European registries were pooled. Rates for 12-month drug retention and 6-month remission (Ankylosing Spondylitis Disease Activity Score C-reactive protein inactive disease (ASDAS-ID)) were assessed in second and third TNFi-series and stratified by withdrawal reason. RESULTS: We included 8254 s and 2939 third TNFi-series; 12-month drug retention rates were similar (71%). Six-month ASDAS-ID rates were higher for the second (23%) than third TNFi (16%). Twelve-month drug retention rates for patients withdrawing from the preceding TNFi due to AE versus LOE were similar for the second (68% and 67%) and third TNFi (both 68%), while for the second TNFi, rates were lower in primary than secondary non-responders (LOE < 26 versus ≥26 weeks) (58% versus 71%, p< 0.001). Six-month ASDAS-ID rates for the second TNFi were higher if the withdrawal reason was AE (27%) versus LOE (17%), p< 0.001, while similar for the third TNFi (19% versus 13%, p= 0.20). CONCLUSION: A similar proportion of axSpA patients remained on a second and third TNFi after one year, but with low remission rates for the third TNFi. Remission rates on the second TNFi (but not the third) were higher if the withdrawal reason from the preceding TNFi was AE versus LOE.

The predictors of paradoxical reactions, especially psoriasis, to biologic therapy-findings from the TReasure database: a 5-year follow-up study.

OBJECTIVES: The objectives of this study were to assess the clinical characteristics, predictive factors, and practical algorithms of paradoxical reactions (PRs), specifically paradoxical psoriasis (PP). METHODS: The TReasure database is a web-based prospective observational cohort comprised of patients with RA and SpA from 17 centres around Turkey since 2017. A cohort study and a case-control study nestled within the cohort were identified. RESULTS: In total, 2867 RA and 5316 SpA patients were evaluated. The first biologic agent was found to have caused PRs in 60% of the 136 patients (1.66%) who developed the PRs. The median time interval between the PRs and biological onset was 12 months (range 1-132 months, mean 21 months). The most common types of PP, constituting 92.6% of PRs, were pustular (60.3%) and palmoplantar (30.9%). Adalimumab (30.9%), infliximab (19%) and etanercept (17.4%) were the most common agents causing the PP. In the treatment of most PP patients (73.2%), switching biologic agents was favoured, with TNF inhibitor (TNFi) chosen in 46.03% and non-TNFi in 26.9% of cases. The three most frequently selected drugs were etanercept (24.6%), secukinumab (9.5%) and adalimumab (8.7%). Only 5.17% of patients who switched to another TNFi showed progression. The odds ratios (s) for SSZ, HCQ, and LEF use were significantly higher in RA controls than in PP patients (P = 0.033, OR = 0.15; P = 0.012, OR = 0.15; and P = 0.015, OR = 0.13, respectively). In the PP group with SpA, the number of smokers was significantly higher (P = 0.003, OR: 2.0, 95% CI: 1.05, 3.81). CONCLUSION: Contrary to expectations based on earlier research suggesting that paradoxical reactions develop with the class effect of biological agents, the response of patients who were shifted to another TNFi was favourable.

Peripheral T-cell lymphoma mimicking granulomatosis with polyangiitis.

Upper respiratory tract involvement is common in patients with granulomatosis with polyangiitis (GPA), but malignancies should be kept in mind in the differential diagnosis. A 68-year-old man was referred to rheumatology to investigate for GPA after nasal excisional biopsy. After careful radiologic and pathologic assessment, he was diagnosed with peripheral T­cell lymphoma, nasal type. This is a rare case of T­cell lymphoma in a patient who was referred as GPA.

Mortality in psoriatic arthritis patients, changes over time, and the impact of COVID-19: results from a multicenter Psoriatic Arthritis Registry (PsART-ID).

BACKGROUND: This study aimed to assess the mortality of PsA before and during the COVID-19 pandemic. METHODS: From the prospective, multicenter PsART-ID (Psoriatic Arthritis Registry-International Database), patients from Turkey were analyzed by linking the registry to the Turkish Cause of Death Registry. The outcome of interest was death from any cause, pre-pandemic (since the onset of registry-March 2014-March 2020), and during the pandemic (March 2020-May 2021). The crude mortality rate and standardized mortality ratio (SMR) were determined. RESULTS: There were 1216 PsA patients with a follow-up of 7500 patient-years. Overall, 46 deaths (26 males) were observed. In the pre-pandemic period, SMR for PsA vs the general population was 0.95 (0.61-1.49), being higher in males [1.56 (0.92-2.63)] than females [0.62 (0.33-1.17)]. The crude mortality rate in PsA doubled during the pandemic (pre-pandemic crude mortality rate: 5.07 vs 10.76 during the pandemic) with a higher increase in females (2.9 vs 8.72) than males (9.07 vs 14.73). CONCLUSION: The mortality in PsA was found similar to the general population in the pre-pandemic era. The mortality rates in PsA doubled during the pandemic. Whether PsA patients have more risk of mortality than the general population due to COVID-19 needs further studies. Key Points • Decrease in mortality in PsA might be expected with the more effective treatment options and better disease control. • A crude mortality rate is comparable to the general population and not increased until the pandemic. • Currently, there is a 2-fold increase in crude mortality rate possibly due to the COVID-19.

Clinical and laboratory factors associated with bamboo spine in patients with axial spondyloarthritis: are there clues for bamboo spine?

OBJECTIVES: To analyse the clinical and laboratory factors associated with bamboo spine. METHODS: Data of patients fulfilling the 2009 ASAS classification criteria for axial spondyloarthritis, registered in the national, multicentre, longitudinal, and observational database of TReasure was analysed. Radiographs were assessed using the Bath Ankylosing Spondylitis Radiologic Index (BASRI). Data of patients with a bamboo spine (Group 1) was compared to data derived from patients with a longstanding disease of at least 15 years but no syndesmophytes (Group 2). RESULTS: Out of the 5060 patients, 1246 had eligible radiographs. There were 111 patients (8.9%) with a bamboo spine. Male sex was more common among patients with bamboo spine. The median BMI of 27.7 (25.8-31.1) in Group1 was higher than the BMI of 25.9 (22.9-29.2) in Group 2 (p<0.001). Hip arthritis, present or documented by a physician, was more common in Group 1 [(58/108 (53.7%) vs. 35/103 (34%), p=0.004]. There was a tendency towards a more prevalent enthesitis in these patients [29.1% (25/86) vs. 15.9%(11/69), p=0.054]. HLA-B27 status did not differ between groups. Smoking was more prevalent in Group 1. Multivariate logistic regression analysis revealed that male sex, body mass index, hip arthritis, and enthesitis are associated with bamboo spine in axSpA. CONCLUSIONS: Bamboo spine was more common in the male sex and associated with a delay in diagnosis, high BMI, hip involvement, and enthesitis. The constellation of increased body weight, hip arthritis, and enthesitis may imply that mechanical stress contributes to radiographic damage in the presence of chronic inflammation.

Subclinical Alterations in Retinal Layers and Microvascular Structures with OCTA in ANCA-Associated Vasculitides.

PURPOSE: Using OCTA, investigate the capillary network and retinal layers in granulomatosis with ANCA associated vasculitis (AAV) patients who did not manifest apparent ocular involvement and compare the findings with healthy subjects. METHOD: The present study, which is designed as a prospective and case-control study, includes 22 AAV patients and 35 control participants. OCTA parameters were noted. RESULTS: In most of the regions, AMT, RNFL and GC-IPL thicknesses were significantly lower in the AAV group than in the control group. While the vascular indices were lower in the AAV group, except for the center 1 mm region, the FAZ parameters were similar between the two groups. CONCLUSION: In AAV patients, subclinical changes in the retinal layers and superficial vascular plexus have been shown. In the future maybe a non-invasive method such as OCTA will become available in scoring systems for prognosis determination in AAV.

A real-life analysis of patients with rheumatologic diseases on biological treatments: Data from TURKBIO Registry.

OBJECTIVE: TURKBIO registry, established in 2011, is the first nationwide biological database in Turkey. This study aimed to provide an overview of TURKBIO data collected by June 2018. METHODS: The registry included adult patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), nonradiographic axial spondyloarthritis (nr-AxSpA), and psoriatic arthritis (PsA). Demographic and clinical features, disease activity markers, and other follow-up parameters, current and previous treat- ments, and adverse events were registered electronically at each visit using open-source software. The registration of patient-reported outcome measures was carried out electronically by the patients using touch screens. RESULTS: TURKBIO registry included a total of 41,145 treatment series with biologicals. There were 2,588 patients with axSpA (2,459 AS and 129 nr-axSpA), 2,036 with RA, and 428 with PsA. The total number of patients, including those with other diagnoses, was 5,718. In the follow-up period, the number of patients and also visits steadily increased by years. The yearly mean number of visits per patient was found to be 2.3. Significant improvements in disease activity and health assessment parameters were observed following the biological treatments. Biologics were often given in combination with a con- ventional synthetic disease-modifying antirheumatic drug in patients with RA. Infections were the most commonly seen adverse events, followed by allergic reactions. Tuberculosis was observed in 12 patients, malignancy in 18, and treatment-related mortality in 31. CONCLUSION: TURKBIO provided a valuable real-life experience with the use of biologics in rheumatic diseases in Turkey.

Tuberculin skin test before biologic and targeted therapies: does the same rule apply for all?

This study aimed to compare Tuberculin Skin Test (TST) and QuantiFERON®-TB Gold In-Tube (QFT-GIT) test in rheumatoid arthritis (RA) and spondyloarthritis (SpA) patients scheduled for biological and targeted synthetic disease modifying anti-rheumatic drugs (DMARDs) in a Bacillus Calmette-Guérin-vaccinated population. Adult RA (n = 206) and SpA (n = 392) patients from the TReasure database who had both TST and QFT-GIT prior to initiation of biological and targeted synthetic DMARDs were included in the study. Demographic and disease characteristics along with pre-biologic DMARD and steroid use were recorded. The distribution of TST and performance with respect to QFT-GIT were compared between RA and SpA groups. Pre-biologic conventional DMARD and steroid use was higher in the RA group. TST positivity rates were 44.2% in RA and 69.1% in SpA for a 5 mm cutoff (p < 0.001). Only 8.9% and 15% of the patients with RA and SpA, respectively, tested positive by QFT-GIT. The two tests poorly agreed in both groups at a TST cutoff of 5 mm and increasing the TST cutoff only slightly increased the agreement. Among age, sex, education and smoking status, pre-biologic steroid and conventional DMARD use, disease group, and QFT-GIT positivity, which were associated with a 5 mm or higher TST, only disease group (SpA) and QFT-GIT positivity remained significant in multiple logistic regression. TST positivity was more pronounced in SpA compared to that in RA and this was not explainable by pre-biologic DMARD and steroid use. The agreement of TST with QFT-GIT was poor in both groups. Using a 5 mm TST cutoff for both diseases could result in overestimating LTBI in SpA.

Biologic treatments in Takayasu's Arteritis: A comparative study of tumor necrosis factor inhibitors and tocilizumab.

OBJECTIVE: To compare the treatment outcomes of TNF inhibitors and tocilizumab (TCZ) in patients with Takayasu arteritis. METHODS: Takayasu arteritis patients who were refractory to conventional immunosuppressive (IS) drugs and received biologic treatment were included in this multicenter retrospective cohort study. Clinical, laboratory and imaging data during follow-up were recorded. Remission, glucocorticoid (GC) sparing effect, drug survival was compared between TNF inhibitor and TCZ treatments. Also, a subgroup matched comparison was performed between groups. RESULTS: One hundred and eleven (F/M: 98/13) patients were enrolled. A total of 173 biologic treatment courses (77 infliximab, 49 TCZ, 33 adalimumab, 9 certolizumab, 3 rituximab, 1 ustekinumab and 1 anakinra) were given. Tocilizumab was chosen in 23 patients and TNF inhibitors were chosen in 88 patients as first-line biologic agent. Complete/partial remission rates between TCZ and TNF inhibitors were similar at 3rd month and at the end of the follow-up. GC dose decrease (≤4 mg) or discontinuation of GCs was achieved in a similar rate in both groups (TNF inhibitors vs TCZ: 78% vs 59%, p = 0.125). Drug survival rate was 56% in TNF inhibitors and 57% in TCZ group (p = 0.22). The use of concomitant conventional ISs did not affect the drug survival (HR =0.78, 95% CI =0.42-1.43, p = 0.42). The match analysis showed similar results between groups in terms of relapse, decrease in GC dose, surgery need and mortality. CONCLUSION: The efficacy and safety outcomes and drug survival rates seem to be similar for TNF inhibitors and tocilizumab in patients with Takayasu arteritis.

Prevalence of pistol-grip deformity in patients with axial spondyloarthritis.

OBJECTIVE: To our knowledge, the prevalence of pistol-grip deformity (PGD) has not previously been studied in patients with axial spondyloarthritis (axSpA). This study aimed to evaluate PGD prevalence in patients with axSpA and to assess its relationship with the clinical and demographic factors. METHODS: A total of 158 patients with axSpA in whom diagnosis was established according to the Assessment of SpondyloArthritis International Society criteria in rheumatology department and 193 age- and sex-matched controls admitted to the emergency room and had anteroposterior (AP) pelvic X-rays were included in the study. PGD was identified by determining the non-spherical shape of the femoral head on AP hip or pelvic X-rays. RESULTS: Prevalence of PGD was significantly higher in patients with axSpA than in controls (20.3% vs. 8.8%, respectively, p=0.002). PGD was also found to be more frequent in patients with radiographic axSpA than in those with non-radiographic axSpA (26/106 [24.5%] vs. 6/52 [11.5%]); however, this difference did not reach statistical significance (p=0.056). The presence of PGD was significantly associated with the presence of hip arthritis (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.2-8.7; p=0.023), ever smoking (OR, 4.5; 95% CI, 1.4-13.6; p=0.008), and male sex (OR, 38.7; 95% CI, 5.1-292.7; p<0.001) in univariate analyses. In multivariate model, ever smoking (OR, 2.9; 95% CI, 1.10-10.05; p=0.03) and male sex (OR, 27.0; 95% CI, 3.5-208.4; p=0.002) were associated with PGD. CONCLUSION: PGD was significantly more common in patients with axSpA. Presence of PGD correlated significantly with hip arthritis, smoking, and sex. We assume that new bone formation could be the possible reason for increased PGD prevalence. Femoroacetabular impingement should be considered as a secondary cause of hip pain in patients with axSpA.