The Phenotype of Axial Spondyloarthritis: Is It Dependent on HLA-B27 Status?

OBJECTIVE: To describe the radiographic phenotype of axial spondyloarthritis (SpA) according to the presence of HLA-B27. METHODS: An international collaboration compared the radiographic phenotype of axial SpA according to HLA-B27 status. Patients with ankylosing spondylitis (AS) and axial psoriatic arthritis (PsA) were collected. Radiographs were read centrally, blinded to clinical details. The symmetry of the sacroiliac joints and lumbar syndesmophytes and the morphology of syndesmophytes (typical marginal versus atypical chunky), together with the modified Stoke Ankylosing Spondylitis Spine Score and the Psoriatic Arthritis Spondylitis Radiographic Index, were recorded. RESULTS: A total of 244 patients with PsA and 198 patients with AS were included. In PsA, 60 patients (25%) were HLA-B27 positive while in AS, 148 patients (75%) were HLA-B27 positive. Patients with HLA-B27 were younger and more often male and had a longer duration of disease. In multivariable logistic regression, HLA-B27 was significantly associated with syndesmophyte symmetry (odds ratio [OR] 3.02 [95% confidence interval (95% CI) 1.38, 6.61]) and marginal syndesmophytes (OR 1.97 [95% CI 1.16, 3.36]) but not with sacroiliac symmetry. Mean radiographic scores were higher for patients with HLA-B27. CONCLUSION: Patients with axial SpA who are positive for HLA-B27 have more severe radiographic damage, more marginal syndesmophytes, and more frequent syndesmophyte symmetry compared to patients who are negative for HLA-B27.

PDE3A-SLCO1C1 locus is associated with response to anti-tumor necrosis factor therapy in psoriatic arthritis.

Aim: Variation at PDE3A-SLCO1C1 locus has been recently associated with the response to anti-TNF therapy in rheumatoid arthritis. We undertook the present study to determine whether PDE3A-SLCO1C1 is also associated with the response to anti-TNF therapy in psoriatic arthritis. Patients & methods: Genomic DNA was obtained from 81 psoriatic arthritis patients that had been treated with anti-TNF therapy. PDE3A-SLCO1C1 SNP rs3794271 was genotyped using Taqman realt-time PCR. The clinical response to anti-TNF therapy was measured as the change from baseline in the level of disease activity according to the DAS28 score. Results: A significant association between rs3794271 and anti-TNF response in psoriatic arthritis was found (beta = -0.71; p = 0.0036). Conclusion: PDE3A-SLCO1C1 locus is also associated with response to anti-TNF therapy in psoriatic arthritis. Original submitted 12 May 2014; Revision submitted 18 August 2014.

Individual telomere length decay in patients with spondyloarthritis.

Telomere length was sequentially determined in peripheral blood leukocytes (PBL) from patients with ankylosing spondylitis (AS; n = 44) and psoriatic arthritis (PsA; n = 42) followed through 2.93 ± 0.99 years, using a quantitative PCR (qPCR) assay. The initial telomere size from PsA patients was higher than those with cutaneous psoriasis only (n = 53), possibly due to the inflammatory condition. The qPCR assay was sensitive enough to evidence a significant telomere length shortening in PBL from practically all subjects and PsA patients showed a higher rate of loss of telomere sequence than patients with AS during the follow-up time.

Standards of care for patients with spondyloarthritis.

To define and give priory to standards of care in patients with spondyloarthritis (SpA). A systematic literature review on SpA standards of care and a specific search in relevant and related sources was performed. An expert panel was established who developed the standards of care and graded their priority (high, mild, low, or no priority) following qualitative methodology and Delphi process. An electronic survey was sent to a representative sample of 167 rheumatologists all around the country, who also gave priority to the standards of care (same scale). A descriptive analysis is presented. The systematic literature review retrieved no article specifically related to SpA patients. A total of 38 standards of care were obtained-12 related to structure, 20 to process, and 6 to result. Access to care, treatment, and safety standards of care were given a high priority by most of rheumatologists. Standards not directly connected to daily practice were not given such priority, as standards which included a time framework. The standards generated for the performance evaluation (including patient and professionals satisfaction) were not considered especially important in general. This set of standards of care should help improve the quality of care in SpA patients.

Scoring with the Berlin MRI method for assessment of spinal inflammatory activity in patients with ankylosing spondylitis: a calibration exercise among rheumatologists.

OBJECTIVES: To test the reliability of the Berlin MRI scoring method and the effect of a calibration exercise on the score's reliability among untrained readers in MRI examinations of patients with established ankylosing spondylitis (AS). METHODS: Eleven rheumatologists read blinded images of 20 AS patients before and after a two-day workshop on the Berlin MRI scoring method. Reliability (intra- and inter-reader) and concordance with the expert (all measured by intraclass correlation coefficient (ICC)) were compared before and after 2 weeks of the training. Feasibility in terms of time and difficulty was also measured. RESULTS: The mean Berlin score increased from (mean ± standard deviation) 5.04 ± 6.41 before to 6.40±7.08 after the calibration exercise (p<0.01). Inter-reader ICC decreased from 0.83 (95% CI: 0.75-0.93) to 0.78 (95% CI: 0.66-0.90), and intra-reader ICC from 0.89 (95% CI: 0.84-0.94) to 0.87 (95% CI: 0.82-0.92). Agreement with an experienced reader improved after the calibration exercise, with ICC = 0.59 (95% CI 0.45-0.76) before vs. ICC = 0.65 (95% CI 0.50-0.80) after training. CONCLUSIONS: The Berlin method is a reliable scoring method for assessment of spinal inflammatory activity by using MRI in patients with AS, even in the hands of inexperienced readers. A calibration exercise can improve feasibility and sensitivity of the scoring method.

Comparación de 2 estrategias de derivación en el diagnóstico de la espondiloartritis axial en España. Estudio RADAR / Comparison of 2 referral strategies for the diagnosis of axial spondyloarthritis in Spain. The RADAR study

Objetivos. Mejorar la derivación de pacientes con dolor lumbar a reumatología podría acelerar el diagnóstico de la espondiloartritis axial. El estudio RADAR comparó 2 estrategias de derivación de pacientes con dolor lumbar crónico (> 3 meses) de inicio antes de los 45 años desde atención primaria a reumatología con respecto al diagnóstico de espondiloartritis axial. Pacientes y métodos. Se asignó una estrategia a cada centro de salud para derivar a sus pacientes: (a) estrategia 1, si cumplían uno de los siguientes 3 criterios: dolor lumbar inflamatorio, HLA-B27 positivo o sacroilitis en prueba de imagen; (b) estrategia 2, si cumplían 2 de 6: dolor lumbar inflamatorio, HLA-B27 positivo, sacroilitis en prueba de imagen, historia familiar de espondiloartritis axial, manifestaciones extraarticulares y buena respuesta a antiinflamatorios no esteroideos. El reumatólogo estableció el diagnóstico final. Resultados. Ochenta y ocho pacientes (edad 36,8 años [DE 8,7]; 55,7% mujeres y 44,3% hombres) en España fueron derivados, 60 usando la estrategia 1 y 28 la estrategia 2. El diagnóstico de espondiloartritis axial definitiva se realizó en el 25,4% de los pacientes en la estrategia 1 y en el 28,6% en la estrategia 2 (p = NS). El dolor lumbar inflamatorio fue el criterio de derivación más utilizado y la concordancia entre médico de atención primaria y reumatólogo fue del 75%. Conclusiones. Una estrategia de derivación sencilla, basada en uno de 3 criterios, fue igual de eficaz que una estrategia basada en 2 de 6 criterios para el diagnóstico de espondiloartritis axial. El dolor lumbar inflamatorio fue el criterio más utilizado para la derivación (AU)

Objectives: Improving referral of patients with back pain to rheumatologists could accelerate the diagnosis of axial spondyloarthritis. The RADAR study compared two strategies in the referral of patients with chronic back pain (> 3 months) with an onset before the age of 45 years from primary care centers to rheumatology departments, in relation to the diagnosis of axial spondyloarthritis. Patients and methods: Each primary care center was assigned a referral strategy for its patients: (a) strategy 1, patients who had one of the 3 following criteria: inflammatory back pain, HLA-B27 positivity or sacroiliitis in imaging; or (b) strategy 2, patients who had 2 of the following 6: inflammatory back pain, HLA-B27 positivity, sacroiliitis in imaging, family history of axial spondyloarthritis, extra-articular manifestations or good response to nonsteroidal antiinflammatory drugs. The rheumatologist established the final diagnosis. Results: Eighty-eight Spanish patients (mean age 36.8 years [SD 8.7], 55.7% females and 44.3% males) were referred for evaluation, 60 patients under strategy 1 and 28 under strategy 2. A definitive diagnosis of axial spondyloarthritis was established in 25.4% with strategy 1 and in 28.6% with strategy 2 (p = NS). Inflammatory back pain was the criterion most commonly used for referral, and the agreement rate between the primary care physician and rheumatologist was 75%. Conclusions: A simple referral strategy based on one of three3 criteria proved as effective as a strategy based on two of 6 criteria in diagnosing axial spondyloarthritis. Inflammatory back pain was the criterion most commonly used for patient referral (AU)

Comparison of 2 referral strategies for the diagnosis of axial spondyloarthritis in Spain. The RADAR study.

OBJECTIVES: Improving referral of patients with back pain to rheumatologists could accelerate the diagnosis of axial spondyloarthritis. The RADAR study compared two strategies in the referral of patients with chronic back pain (>3 months) with an onset before the age of 45 years from primary care centers to rheumatology departments, in relation to the diagnosis of axial spondyloarthritis. PATIENTS AND METHODS: Each primary care center was assigned a referral strategy for its patients: (a) strategy 1, patients who had one of the 3 following criteria: inflammatory back pain, HLA-B27 positivity or sacroiliitis in imaging; or (b) strategy 2, patients who had 2 of the following 6: inflammatory back pain, HLA-B27 positivity, sacroiliitis in imaging, family history of axial spondyloarthritis, extra-articular manifestations or good response to nonsteroidal antiinflammatory drugs. The rheumatologist established the final diagnosis. RESULTS: Eighty-eight Spanish patients (mean age 36.8 years [SD 8.7], 55.7% females and 44.3% males) were referred for evaluation, 60 patients under strategy 1 and 28 under strategy 2. A definitive diagnosis of axial spondyloarthritis was established in 25.4% with strategy 1 and in 28.6% with strategy 2 (p=NS). Inflammatory back pain was the criterion most commonly used for referral, and the agreement rate between the primary care physician and rheumatologist was 75%. CONCLUSIONS: A simple referral strategy based on one of three3 criteria proved as effective as a strategy based on two of 6 criteria in diagnosing axial spondyloarthritis. Inflammatory back pain was the criterion most commonly used for patient referral.

Identification of multiple risk variants for ankylosing spondylitis through high-density genotyping of immune-related loci.

Ankylosing spondylitis is a common, highly heritable inflammatory arthritis affecting primarily the spine and pelvis. In addition to HLA-B*27 alleles, 12 loci have previously been identified that are associated with ankylosing spondylitis in populations of European ancestry, and 2 associated loci have been identified in Asians. In this study, we used the Illumina Immunochip microarray to perform a case-control association study involving 10,619 individuals with ankylosing spondylitis (cases) and 15,145 controls. We identified 13 new risk loci and 12 additional ankylosing spondylitis-associated haplotypes at 11 loci. Two ankylosing spondylitis-associated regions have now been identified encoding four aminopeptidases that are involved in peptide processing before major histocompatibility complex (MHC) class I presentation. Protective variants at two of these loci are associated both with reduced aminopeptidase function and with MHC class I cell surface expression.

Risk variants for psoriasis vulgaris in a large case-control collection and association with clinical subphenotypes.

Recent genome-wide association studies (GWASs) have identified >20 new loci associated with the susceptibility to psoriasis vulgaris (PsV) risk. We investigated the association of PsV and its main clinical subphenotypes with 32 loci having previous genome-wide evidence of association with PsV (P < 5e-8) or strong GWAS evidence (P < 5e-5 in discovery and P < 0.05 in replication sample) in a large cohort of PsV patients (n = 2005) and controls (n = 1497). We provide the first independent replication for COG6 (P = 0.00079) and SERPINB8 (P = 0.048) loci with PsV. In those patients having developed psoriatic arthritis (n = 955), we found, for the first time, a strong association with IFIH1 (P = 0.013). Analyses of clinically relevant PsV subtypes yielded a significant association of severity of cutaneous disease with variation at LCE3D locus (P = 0.0005) in PsV and nail involvement with IL1RN in purely cutaneous psoriasis (PsC, P = 0.007). In an exploratory analysis of epistasis, we replicated the previously described HLA-C-ERAP1 interaction with PsC. Our findings show that common genetic variants associated with a complex phenotype like PsV influence different subphenotypes of high clinical relevance.

FCGR2A/CD32A and FCGR3A/CD16A variants and EULAR response to tumor necrosis factor-α blockers in psoriatic arthritis: a longitudinal study with 6 months of followup.

OBJECTIVE: The efficacy of antibody-based biological therapies currently used in psoriatic arthritis (PsA) depends not only on their blocking effect on the targeted molecule but also on their binding affinity to genetically defined variants of cell-surface Fc-γ receptors. Our objective was to assess the potential influence of functionally relevant FCGR2A/CD32A (H131R) and FCGR3A/CD16A (V158F) genetic polymorphisms on the EULAR response to tumor necrosis factor-α (TNF-α) blocker therapy in PsA. METHODS: In total 103 patients with PsA starting anti-TNF-α therapy were included. The efficacy of therapy was evaluated according to EULAR response criteria at 3 and 6 months. FCGR2A-R131H and FCGR3A-F158V polymorphisms were genotyped. Potential correlations between clinical response and the FCGR2A-R131H and FCGR3A-F158V polymorphisms were evaluated. RESULTS: EULAR response (moderate plus good) was 85.4% at 3 months and 87.4% at 6 months, while good EULAR response was 61.2% and 62.1%, respectively. More patients with high-affinity FCGR2A genotypes (homozygous or heterozygous combinations) achieved a EULAR response at 6 months compared to patients with the low-affinity genotype (RR; p = 0.034, adjusted comparison error rate < 0.025). This association was due mainly to the group of patients treated with etanercept. No correlation was found for the FCGR3A polymorphism. Similarly, no effect of C-reactive protein levels was observed. CONCLUSION: Our data indicate that FCGR2A polymorphism may influence the response to TNF-α blockers (namely etanercept) in PsA in a direction opposite to that previously found in patients with rheumatoid arthritis.

Clinical features of late-onset ankylosing spondylitis: comparison with early-onset disease.

OBJECTIVE: Ankylosing spondylitis (AS) is generally observed in young patients but can occur later in life or in persons ≥ 50 years of age. Our objective was to characterize the clinical features of late-onset AS in a large multicenter national cohort. METHODS: We studied late-onset AS in the National Registry of Spondyloarthritis of the Spanish Society of Rheumatology (REGISPONSER database) cohort (n = 1257), of whom 3.5% had onset at age ≥ 50 years versus a control group with onset at < 50 years. RESULTS: There were no differences between late-onset and early-onset AS according to sex and family history of spondyloarthropathies. Patients in the late-onset group more often showed involvement of the cervical spine (22.7% vs 9.7%; p = 0.03) and arthritis of the upper (13.6% vs 3.0%; p = 0.002) and lower limbs (27.3% vs 15.2%; p = 0.03) as first manifestations than did patients in the early-onset group. A higher percentage of mixed forms (axial and peripheral joint disease) during the course of the disease was also recorded in the late-onset group (50% vs 24%; p = 0.0001). CONCLUSION: Our study suggests that age at onset of AS affects the patients' presenting clinical form. Arthritis of the upper limbs requires a differential diagnosis with other conditions frequent in patients over 50 years of age, such as rheumatoid arthritis or crystal-induced arthropathy.

Factores pronóstico en la artritis psoriásica / Prognostic factors in Psoriatic Arthritis

La artritis psoriásica con afección periférica es una enfermedad inflamatoria progresiva, cuyo impacto, tanto a nivel de daño estructural como en la función y calidad de vida de los pacientes, es similar a otras poliartritis crónicas. A pesar del tratamiento con FAME sintéticos o biológicos, la remisión solo se alcanza en un 30% de los pacientes. Desde el punto de vista clínico, la actividad articular mantenida (dolor e hinchazón) es un factor de progresión del daño articular, por ello existe la necesidad de un seguimiento y tratamiento estrecho de estos pacientes (AU)

Peripheral psoriatic arthritis is an inflammatory and progressive disease; its burden, either at the structural level or the function and quality of life, is similar to other chronic poliarthritidies. In spite of treatment with synthetic or biologic DMARDs, remission is only achieved in about 30% of the patients. From a clinical point of view, persistent joint activity (tender and swollen joints) is a factor leading to joint damage progression. These data indicate the need for a tight follow up and treatment of the patients (AU)

[Prognostic factors in psoriatic arthritis]. / Factores pronóstico en la artritis psoriásica.

Peripheral psoriatic arthritis is an inflammatory and progressive disease; its burden, either at the structural level or the function and quality of life, is similar to other chronic poliarthritidies. In spite of treatment with synthetic or biologic DMARDs, remission is only achieved in about 30% of the patients. From a clinical point of view, persistent joint activity (tender and swollen joints) is a factor leading to joint damage progression. These data indicate the need for a tight follow up and treatment of the patients.

Consenso SER sobre la gestión de riesgo del tratamiento con terapias biológicas en pacientes con enfermedades reumáticas / Consensus statement of the spanish society of rheumatology on risk management of biologic therapy in rheumatic patients

Objetivo: Dado el creciente uso de las terapias biológicas en distintas enfermedades reumatológicas, y la importancia de la gestión de riesgo de las mismas, desde la Sociedad Española de Reumatología (SER) se ha impulsado el desarrollo de recomendaciones basadas en la mejor evidencia posible. Estas deben de servir de referencia para reumatólogos e implicados en el tratamiento de pacientes en tratamiento o en los que se quiere indicar la terapia biológica independientemente de su enfermedad de base. Métodos: Las recomendaciones se emitieron siguiendo la metodología de grupos nominales. El nivel de evidencia y el grado de recomendación se clasificaron según el modelo del Center for Evidence Based Medicine de Oxford y el grado de acuerdo se extrajo por técnica Delphi. Se utilizó toda la información de consensos y guías de práctica clínica previas. Resultados: Se realizan recomendaciones sobre la gestión del riesgo del uso de las terapias biológicas en pacientes con enfermedades reumática. Incluyen la gestión del riesgo de la indicación, gestión del riesgo antes de iniciar el tratamiento, gestión del riesgo durante el seguimiento, actitud ante acontecimientos adversos, y actitud en situaciones especiales. Conclusiones: Se presentan las recomendaciones SER sobre la gestión del riesgo del tratamiento con terapias biológicas (AU)

Objective: Due to the increasing use of biologic therapy in rheumatic diseases and the importance of its risk management, the Spanish Society of Rheumatology (SER) has promoted the development of recommendations based on the best evidence available. These recommendations should be a reference to rheumatologists and those involved in the treatment of patients who are using, or about to use biologic therapy irrespectively of the rheumatic disease. Methods: Recommendations were developed following a nominal group methodology and based on systematic reviews. The level of evidence and degree of recommendation were classified according to the model proposed by the Center for Evidence Based Medicine at Oxford. The level of agreement was established through a Delphi technique. Evidence from previous consensus and clinical guidelines was used. Results: We have produced recommendations on risk management of biologic therapy in rheumatic patients. These recommendations include indication risk management, risk management before the use of biologic therapy, risk management during follow-up, attitude to adverse events, and attitude to special situations. Conclusions: We present the SER recommendations related to biologic therapy risk management (AU)

[Consensus statement of the Spanish Society of Rheumatology on risk management of biologic therapy in rheumatic patients]. / Consenso SER sobre la gestión de riesgo del tratamiento con terapias biológicas en pacientes con enfermedades reumáticas.

OBJECTIVE: Due to the increasing use of biologic therapy in rheumatic diseases and the importance of its risk management, the Spanish Society of Rheumatology (SER) has promoted the development of recommendations based on the best evidence available. These recommendations should be a reference to rheumatologists and those involved in the treatment of patients who are using, or about to use biologic therapy irrespectively of the rheumatic disease. METHODS: Recommendations were developed following a nominal group methodology and based on systematic reviews. The level of evidence and degree of recommendation were classified according to the model proposed by the Center for Evidence Based Medicine at Oxford. The level of agreement was established through a Delphi technique. Evidence from previous consensus and clinical guidelines was used. RESULTS: We have produced recommendations on risk management of biologic therapy in rheumatic patients. These recommendations include indication risk management, risk management before the use of biologic therapy, risk management during follow-up, attitude to adverse events, and attitude to special situations. CONCLUSIONS: We present the SER recommendations related to biologic therapy risk management.

[Consensus statement of the Spanish Society of Rheumatology on the management of biologic therapies in psoriatic arthritis]. / Documento SER de consenso sobre el uso de terapias biológicas en la artritis psoriásica.

OBJECTIVE: Due to the amount and quality variability regarding the use of biologic therapy (BT) in psoriatic arthritis (PsA) patients, the Spanish Society of Rheumatology (SER) has promoted the generation of recommendations based on the best evidence available. These recommendations should serve as reference to rheumatologists and those involved in the treatment of patients with PsA, who are using, or about to use BT. METHODS: Recommendations were developed following a nominal group methodology and based on systematic reviews. The level of evidence and degree of recommendation was classified according to the model proposed by the Center for Evidence Based Medicine at Oxford. The level of agreement was established through Delphi technique. RESULTS: We have produced recommendations for the use of TB currently available for PsA in our country. These recommendations include disease assessment, treatment objectives, therapeutic scheme and switching. CONCLUSIONS: We present an update on the SER recommendations for the use of BT in patients with PsA.

Documento SER de consenso sobre el uso de terapias biológicas en la artritis psoriásica / Consensus statement of the Spanish Society of Rheumatology on the management of biologic therapies in psoriatic arthritis

Objetivo. Dada la gran cantidad de información actual sobre el uso de terapias biológicas (TB) en la artritis psoriásica (APs), y la variabilidad de la misma en cuanto a su calidad, desde la Sociedad Española de Reumatología (SER) se ha impulsado la generación de recomendaciones basadas en la mejor evidencia posible. Éstas deben de servir de referencia para reumatólogos e implicados en el tratamiento de APs que vayan a utilizar o consideren la utilización de TB. Métodos. Las recomendaciones se emitieron siguiendo la metodología de grupos nominales y basadas en revisiones sistemáticas. El nivel de evidencia y el grado de recomendación se clasificaron según el modelo del Center for Evidence Based Medicine de Oxford y el grado de acuerdo se extrajo por técnica Delphi. Resultados. Se realizan recomendaciones sobre el uso de las TB disponibles en la actualidad en nuestro país para el tratamiento de la APs. Estas recomendaciones incluyen la evaluación de la enfermedad, objetivos del tratamiento, esquema terapéutico y cambios en el mismo. Conclusiones. Se presentan las actualizaciones a las recomendaciones SER para el uso de TB en pacientes con APs (AU)

Objective. Due to the amount and quality variability regarding the use of biologic therapy (BT) in psoriatic arthritis (PsA) patients, the Spanish Society of Rheumatology (SER) has promoted the generation of recommendations based on the best evidence available. These recommendations should serve as reference to rheumatologists and those involved in the treatment of patients with PsA, who are using, or about to use BT. Methods. Recommendations were developed following a nominal group methodology and based on systematic reviews. The level of evidence and degree of recommendation was classified according to the model proposed by the Center for Evidence Based Medicine at Oxford. The level of agreement was established through Delphi technique. Results. We have produced recommendations for the use of TB currently available for PsA in our country. These recommendations include disease assessment, treatment objectives, therapeutic scheme and switching. Conclusions. We present an update on the SER recommendations for the use of BT in patients with PsA (AU)

Prevalence of vertebral fractures by semiautomated morphometry in patients with ankylosing spondylitis.

OBJECTIVE: Ankylosing spondylitis (AS) is a chronic inflammatory disease mainly affecting the axial skeleton and characterized by ossification of the spinal disc, joints, and ligaments leading to progressive ankylosis. Vertebral osteoporosis is a recognized feature of AS. Studies have confirmed a moderate to high prevalence of vertebral fractures with extremely varying ranges in patients with AS. Our objective was to estimate the prevalence of vertebral fractures in a representative Spanish population of patients with AS using a validated semiquantitative method, MorphoXpress(®). METHODS: Patients were randomly selected from the 10 initial participating centers of the Spanish National Registry of Spondyloarthropathies (REGISPONSER) by consecutive sampling. All patients fulfilled the New York modified criteria for AS and had a baseline thoracolumbar radiograph. A prevalent vertebral fracture was defined according to the Genant classification criteria. RESULTS: The estimated prevalence of vertebral fractures was 32.4% (95% CI 25.5%-39.3%). The majority of fractures were localized in the thoracic segment (n = 100; 82.%) and were mild (n = 79; 64.8%). In logistic regression analysis, age (odds ratio per year 1.05, 95% CI 1.03-1.08, p < 0.001), disease duration (OR per year 1.03, 95% CI 1.01-1.06, p = 0.011), Bath Ankylosing Spondylitis Functional Index score (OR per score 1.16, 95% CI 1.03-1.30, p = 0.015), Bath Ankylosing Spondylitis Radiographic Index-TS (OR per score 1.25, 95% CI 1.12-1.39, p < 0.001), and wall-occiput distance (OR per cm 1.15, 95% CI 1.08-1.23, p < 0.001) were all associated with prevalent fracture. CONCLUSION: Semiquantitative methods are needed to improve the diagnosis of vertebral fractures in AS in order to start early treatment and to avoid complications arising from osteoporosis.