Classification Criteria For Axial Spondyloarthritis Research Articles

Evaluation of the Possibility of Axial Psoriatic Arthritis Patients Meeting Classification Criteria for Axial Spondyloarthritis and Ankylosing Spondylitis.

The objective of the study was to analyze whether axial psoriatic arthritis (axPsA) patients meet classification criteria for axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS). A total of 104patients (66 men and 38 women) with PsA according to CASPAR criteria were examined, all patients had back pain. Patients were evaluated for presence of inflammatory back pain (IBP) by ASAS criteria. Back pain not meeting the ASAS criteria was taken to be chronic back pain (chrBP). Patients underwent hands, feet and pelvis, cervical spine and lumbar spine X-rays. Erosions, osteolysis, and juxta-articular new bone formation were evaluated. Definite radiographic sacroiliitis (d-rSI) was defined as bilateral grade ≥ 2 or unilateral grade ≥ 3. Nineteen patients without d-rSI underwent sacroiliac joints MRI. Ninety-three patients underwent HLA B27 examination. The number of patients who met the criteria for axSpA (ASAS) and the modified New York (mNY) criteria for AS was determined. IBP was identified in 67 (64.4%) patients; chrBP, in 37 (35.6%) patients; 31 (29.8%) patient were of older age (over 40) at the onset of IBP/chrBP; 57 (58.8%) patients had d-rSI; 6 (31.6%) patients had MRI-SI; syndesmophytes were detected in 57 (58.8%) cases. Among 40 patients without d-rSI, 19 (47.5%) had syndesmophytes. In 38/97(39.2%) patients d-rSI was detected along with syndesmophytes, while 19/97(19.6%) patients had isolated d-rSI without spondylitis, and 19/97(19.6%) patients had isolated syndesmophytes without d-rSI. HLA B27 was present in 28 (30.1%) cases. 51 (55.4%) patients met criteria for axSpA. Forty-one (44.6%) patients did not meet criteria for axSpA; however, 27 (65.9%) of them had syndesmophytes. Forty-eight (48.5%) PsA patients met mNY criteria for AS. Among these patients, a set of specific features was revealed: 18 (37.5%) had no IBP, 18 (37.5%) were of older age (over 40) at the onset of IBP/chrBP, 34 (70.8%) had dactylitis, 38 (79.2%) had erosive polyarthritis, 23 (48.8%) had juxta-articular new bone formation, 14 (30.2%) had osteolysis, 23 (48.9%) had "chunky" non-marginal syndesmophytes, and 40 (82.6%) had nail psoriasis; 28 (66.6%) patients were HLA-B27 negative. Forty-five percent of axPsA patients do not meet criteria for axSpA. Characteristic features have been identified to differentiate axPsA from AS.

Twenty Years of SPARTAN: From Inception to Impact (SPARTAN 2023 Annual Meeting Proceedings).

This review takes a look at the past, present, and future of SPARTAN, the Spondyloarthritis Research and Treatment Network, an organization of North American healthcare professionals dedicated to advancing research, education, and patient care in spondyloarthritis. In 2022, SPARTAN completed the Classification of Axial SpondyloarthritiS Inception Cohort (CLASSIC) study, a collaboration with the Assessment in SpondyloArthritis International Society (ASAS). CLASSIC aimed to validate the 2009 ASAS classification criteria for axial spondyloarthritis. Other ongoing SPARTAN endeavors include the development of US referral recommendations for axial spondyloarthritis, an update of the 2019 ACR/SAA/SPARTAN treatment recommendations for axial spondyloarthritis and multiple educational initiatives. Twenty years after its inception, SPARTAN continues to grow and broaden its impact, guided by the SPARTAN vision of "a world free of spondyloarthritis through leadership in research and education."

MRI for axial SpA: Diagnosis, disease activity assessment, and recent advances.

Magnetic resonance imaging (MRI) is a sensitive imaging modality to detect early inflammatory changes in axial spondyloarthritis (SpA). Over a decade has passed since the inclusion of MRI assessment in the 2009 Assessment of SpondyloArthritis International Society (ASAS) classification criteria for axial SpA. Evidence and clinical experience of MRI in axial SpA have accumulated rapidly since. This has led to a better understanding of the clinical utility of MRI in early diagnosis, disease activity assessment, and monitoring of treatment response in axial SpA. Furthermore, technological advancements have paved the way for the development of novel MRI sequences for the quantification of inflammation and image optimization. The field of artificial intelligence has also been explored to aid medical imaging interpretation, including MRI in axial SpA. This review serves to provide an update on the latest understanding of the evolving roles of MRI in axial SpA.

Concept and understanding of non-radiographic axial spondyloarthritis

Since the publication of the classification criteria for axial spondyloarthritis (axSpA) by Assessment of SpondyloArthritis international Society (ASAS), a new disease concept "non-radiographic axial spondyloarthritis (nr-axSpA)" has emerged. Some domestic experts in China have translated it as "radiologically negative" axSpA, but it can easily lead to misunderstandings literally, as not all patients with nr-axSpA are completely free from radiological abnormalities. This article briefly describes the evolution of the concept of axSpA, proposes to translate the term of nr-axSpA directly rather than "radiologically negative" axSpA, compares the differences and similarities between nr-axSpA and radiologically negative axSpA, delineates the relationship between nr-axSpA and early ankylosing spondylitis, and points out not all the patients who meet the ASAS classification criteria for nr-axSpA are genuine patients with axSpA, because of the relatively low specificity of the ASAS classification criteria. Five common scenarios easily leading to misdiagnosis of nr-axSpA are exampled to remind domestic colleagues.

Evaluation of the possibility of axial psoriatic arthritis patients meet classification criteria for axial spondyloarthritis and ankylosing spondylitis

Objective – to analyze whether axial psoriatic arthritis (axPsA) patients meet classification criteria for axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS).Subjects and methods. 104 patients (66 men and 38 women) with PsA according to CASPAR criteria were examined, all patients had back pain. Patients were evaluated for presence of inflammatory back pain (IBP) by ASAS criteria. Back pain not meeting the ASAS criteria was taken to be chronic back (chrBP). Patients underwent hands, feet and pelvis, cervical spine and lumbar spine X-rays. Erosions, osteolysis, and periarticular osteo-proliferative lesions were evaluated. Radiographically significant sacroiliitis (r-sSI) was defined as bilateral grade ≥2 or unilateral grade ≥3. 19 patients without r-sSI underwent sacroiliac joints MRI. 93 patients underwent HLA B27 examination. The number of patients who met the criteria for axSpA (ASAS) and the modified New York (mNY) criteria for AS was determined.Results. IBP was identified in 67 (64.4%), chrBP in 37 (35.6%) patients; 31 (29.8%) patients were of advanced age (over 40) at the onset of IBP/chrBP; 57 (58.8%) cases had r-sSI; 6 (31.6%) patients had MRI-SI; syndesmophytes were detected in 57 (58.8%) cases. Among 40 patients without r-sSI, 19 (47.5%) had syndesmophytes. In 38 (39.2%) out of 97 patients r-sSI was detected along with syndesmophytes, while 19 (19.6%) out of 97 patients had isolated r-sSI without spondylitis, and 19 (19.6%) out of 97 patients had isolated syndesmophytes without r-sSI. HLA B27 was present in 28 (30.1%) cases. 51 (55.4%) patients met criteria for axSpA. 41 (44.6%) patients didn’t meet criteria for axSpA, however 27 (65.9%) of them had syndesmophytes. 48 (48.5%) PsA patients met mNY criteria for AS.Among these patients a set of specific features was revealed: 18 (37.5%) had no IBP, 18 (37.5%) were of advanced age (over 40) at the onset of IBP/ chrBP, 34 (70.8%) had dactylitis, 38 (79.2%) – erosive polyarthritis, 23 (48.8%) – periarticular osteo-proliferative lesions, 14 (30.2%) – osteolysis, 23 (48,9%) – “chunky” non-marginal syndesmophytes, 40 (82,6%) – nail psoriasis, 28 (66,6%) patients were HLA-B27 negative.Conclusion. 45% of axPsA patients don’t meet criteria for axSpA. Characteristic features have been identified to differentiate axPsA from AS.

Influence of Sex on Early Axial Spondyloarthritis: A Six-Year Longitudinal Analysis From a Large National Cohort.

The objective was to determine sex differences in disease outcomes in recent axial spondyloarthritis (SpA) over time. We analyzed the first 6 years of follow-up of the prospective French multicenter DESIR cohort. Patients analyzed had <3 years of disease, were naive to disease-modifying antirheumatic drugs, and fulfilled the Assessment of SpondyloArthritis international Society classification criteria for axial SpA. Disease activity (Ankylosing Spondylitis Disease Activity Score [ASDAS] using the C-reactive protein [CRP] level), patient global assessment (PtGA), CRP level, and radiographic sacroiliitis were compared between men and women (self-reported sex) by linear and logistic mixed-effects models.Models were created for trajectories of disease activity over 6 years in men and women, using k-means. Of 494 patients analyzed (mean ± SD age 31.9 ± 7.5 years, symptoms duration 20.7 ± 11.7 months), 50.4% were men. Over 6 years of follow-up, both men and women showed clear improvements in ASDAS-CRP, PtGA, and CRP level. Women had higher ASDAS-CRP and PtGA over time compared to men (both P < 0.0001) with overall similar CRP levels (P=0.089), whereas structural damage increased more in men (P < 0.0001). One-third of both men (33%) and women (34%) belonged to persistent high/very high disease activity trajectories, but ASDAS-CRP was globally higher in women in these trajectories. In early axial SpA, clinical outcomes (disease activity and symptoms) were worse in women than men over 6 years of follow-up, whereas CRP was similar and structural damage was more frequent in men. Although similarly distributed, disease activity scores were higher in women in high/very high disease activity trajectories. Sex appears to be an important contextual factor in axial SpA.

Characterisation of gut microbiota composition in patients with axial spondyloarthritis and its modulation by TNF inhibitor treatment

ObjectiveTo assess whether gut microbiota composition is associated with patient characteristics and may have predictive value on the response to TNF inhibitor (TNFi) treatment in axial spondyloarthritis (AxSpA).MethodsThe study involved...

Predictors of not Achieving Remission or Low Disease Activity in Axial Spondyloarthritis Patients from Middle Eastern Countries: A Prospective, Multicenter, Real-world Study.

ObjectivesWe sought to identify the predictors of not achieving remission or low disease activity (LDA) among axial spondyloarthritis (SpA) patients in four Middle Eastern countries.MethodsIn this multicenter prospective real-world study, adult patients with axial SpA diagnosed clinically during January–June 2019, and who met the Assessment of SpondyloArthritis International Society classification criteria for axial SpA, were enrolled from the participating centers of four countries—Lebanon, Oman, Qatar, and the UAE. Patient demographics, disease history, comorbidities, treatment, and compliance data were obtained at baseline. The primary outcome was to determine the percentage of patients who did not achieve the clinical target of remission or LDA as indicated by Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP) < 2.1 after a three-month follow-up period. Secondary outcomes were assessing the demographic and clinical characteristics of ‘achievers’ and ‘non-achievers’ and to study the predictors of ASDAS-CRP ≥ 2.1 in different clinical subsets.ResultsThe participants were 309 patients of both sexes, with a median age of 43 years. Women had a slight majority (53.7%). At the end of the study, 72.2% of patients achieved the clinical target of ASDAS-CRP < 2.1. Non-achievers were significantly more likely to have enthesitis, positive human leukocyte antigen B 27 status, psoriasis, peripheral involvement, fibromyalgia, and a lower score on Compliance Questionnaire for Rheumatology (CQR). Multiple regression analysis showed that low CQR score, enthesitis, psoriasis, and family history of SpA were independent predictors of ASDAS-CRP ≥ 2.1.ConclusionsThis real-world study suggests that low compliance, positive human leukocyte antigen B 27 status, peripheral involvement, and presence of enthesitis, psoriasis, and fibromyalgia are predictors of not achieving remission or LDA in axial SpA patients.

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

To analyse the clinical and laboratory factors associated with bamboo spine. 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). 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. 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.

Whole-body magnetic resonance imaging vs. clinical evaluation of enthesitis in patients with spondyloarthritis

Whole-body magnetic resonance imaging vs. clinical evaluation of enthesitis in patients with spondyloarthritis

Clinical performance of ASAS Health Index in patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis: real-world evidence from Multicenter Nationwide Registry.

The Assessment of SpondyloArthritis international Society Health Index (ASAS HI) is used as a new instrument in measuring the function, disability and health of patients with spondyloarthritis (SpA). However, the real-world evidence of ASAS HI is very limited. In the present study, our objective is to evaluate the psychometric properties and performance of ASAS HI in the real-world setting as well as comparing ASAS HI with the current instruments to assess the construct validity and determine the cut-off points in patients with both ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). A total of 991 patients with axSpA who fulfilled either the ASAS classification criteria for axial SpA (axSpA) or the Modified New York Criteria (mNY) for AS were recruited from the Biologic and targeted Synthetic antirheumatic drugs Registry (BioStaR) SpA. The construct validity of ASAS HI against the Bath Ankylosing Spondylitis Disease Activities Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score-C-Reactive Protein (ASDAS-CRP) the Bath Ankylosing Spondylitis Functional index (BASFI) was performed. Using the receiver operating characteristic (ROC) curves analysis, the cut-off points were calculated. Of all the recruited patients, 851 (85.9%) were AS and 140 (14.1%) were nr-axSpA. The difference in the mean ASAS HI scores of the patients with AS and the ones with nr-axSpA were not statistically significant (6.12 ± 4.29 and 6.42 ± 4.86, respectively). The mean ASAS HI score was significantly higher in females and small city residents. The ASAS HI had a strong construct validity against ASDAS-CRP, BASDAI and BASFI. A cut-off point of ≤ 4 was determined to discriminate good and moderate, as well as ≥ 12 to discriminate moderate and poor health status. In conclusion, ASAS HI is a reliable instrument to evaluate health and functioning for both patients with AS and nr-axSpA in clinical practice.

Ultrasonographic and clinical assessment of peripheral enthesitis and arthritis in an Italian cohort of inflammatory bowel disease patients

AimsTo evaluate the prevalence of clinical and ultrasonographic musculoskeletal involvement in Italian patients with inflammatory bowel disease (IBD). MethodsIn this cross-sectional multicenter study, 148 consecutive patients with IBD were evaluated by a gastroenterologist and a rheumatologist. All patients underwent a B-mode and power Doppler ultrasonographic examination of 6 pairs of entheses and of knee and ankle joints. ResultsA positive history for at least one musculoskeletal manifestation was reported by 40.5% of patients, more frequently in ulcerative colitis (UC) (p = 0.033). Inflammatory back pain was reported by 13.5% of patients, and a past history of peripheral arthritis by 14.9%, entheseal inflammation by 14.2% and dactylitis by 2.7%. At clinical examination, arthritis was observed in 19.6% of patients and enthesitis in 33%. Oligoarthritis and enthesitis at clinical examination were more frequently observed in UC than in Crohn disease (CD). 37.8% of total IBD patients fulfilled ASAS classification criteria for axial and/or peripheral spondyloarthritis, 8.1% ASAS classification criteria for axial spondyloarthritis, and 29.7% ASAS classification criteria for peripheral spondyloarthritis. With ultrasonographic examination, signs of entheseal involvement were observed in 87.8% of patients, while at power Doppler, ≥1 abnormality was observed in 27.1%. ASAS+ patients compared to those ASAS- had a significantly higher frequency at ultrasonography of acute entheseal abnormalities, power Doppler entheseal positivity and joint involvement. These abnormalities at ultrasonography were also observed in 34%, 13% and 12% of ASAS- patients. ConclusionsMusculoskeletal manifestations occur frequently in patients with IBD. Ultrasonographic entheseal and joint involvement were also observed in asymptomatic patients.

Do we need new trial designs in spondyloarthritis?

In the last two decades drug trials in ankylosing spondylitis (AS) have been extremely successful and many effective new drugs have been approved for the treatment of patients with AS. In 2009, new classification criteria for axial spondyloarthritis (axSpA) have been released that capture not only AS, but also patients with presumably earlier non-radiographic axSpA. These criteria have served as inclusion criteria for patients to be enrolled in drug trials for the indication of nr-axSpA. The theme to be discussed in this article pertains to changes in the design of clinical trials required to optimize the process of drug-testing and -approval in a changed environment. Additional treatment criteria (MRI-and CRP-positivity), better response measurement (ASDAS) and trial homogeneity will be addressed against the background of the expansion of the disease spectrum of axSpA which has been the consequence of the new classification criteria for axSpA.

Features of ankylosing spondylitis at different stages in men and women

The incidence of ankylosing spondylitis (AS) has recently increased with a substantial rise in the proportion of female patients, making this investigation relevant.Objective: to investigate the clinical and laboratory parameters of inflammatory activity and functional status in male and female patients with AS at different stages of the disease.Patients and methods. Examinations were performed in 119 patients (82 men and 37 women) (mean age, 36.4±0.9 years) with AS and 34 patients (24 men and 10 women) (mean age 27.0±1.6 years) with non-radiographic axial spondyloarthritis (nr-axSpA). The investigators used the 1984 modified New York criteria to confirm AS diagnosis and the 2009 ASAS classification criteria for axial spondyloarthritis. They also determined AS activity by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and functional status by the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Bath Ankylosing Spondylitis Metrology Index (BASMI). For the calculation of enthesites, the validated index Maastricht Ankylosing Spondylitis Enthesitis Score (MASES) was used; pain intensity in the last week was estimated using a visual analogue scale (VAS). Laboratory examination included the determination of ESR and HLA-B27 antigen. All the patients underwent a plain film of the pelvic bones; and patients with nr-axSpA had magnetic resonance imaging for sacroiliitis.Results and discussion. In both groups, there was a male preponderance and axial lesions were more common (among the patients with AS, there were 68.9% of the men with sacroiliac joint lesions and 53.7% of those with spinal involvement; among the patients with nr-axSpA, there were 80.0 and 67.6 %, respectively; p&gt;0.05). The HLA-B27 antigen was detected in the majority of patients with AS (86.6% of men and 91.7% of women) and in those with nr-axSpA (91.6 and 80.0%, respectively). Uveitis was more common in women with AS (32.4%), less common in men with AS (17.1%); (p&lt;0.05) and nr-axSpA (8.3%); uveitis was not observed in women with nr-axSpA (p&lt;0.001). The pain according to VAS was more intense in women (48.1±3.4 mm; p&lt;0.01); in the nr-axSpA group, its values were comparable in men and women (p&gt;0.05). The BASDAI and BASFI scores were similar in women at all stages of the disease (p&gt;0.05). The men with nr-axSpA had the best functional status (p&lt;0.01) with the same BASDAI activity (p&gt;0.05) compared with those with AS. The BASMI in patients with AS regardless of gender was higher than in those with nr-axSpA (p&lt;0.01). High BASDAI activity was more frequently detected in women with AS and nr-axSpA than in men (64.9 and 60.0%, respectively; p&lt;0.01). Low activity was not observed in any woman with nr-axSpA. Enthesitis was more common in women in both AS and nr-axSpA (81.0 and 80.0%, respectively; p&lt;0.05).Conclusion. In women, AS and nr-ax-SpA are more severe, starting at their early stage, which is manifested by a higher activity, functional failure, and a higher frequency of extra-axial manifestations.

Ankylosing spondylitis and axial spondyloarthritis: recent insights and impact of new classification criteria.

Development of the Assessment in Spondyloarthritis International Society (ASAS) classification criteria for axial spondyloarthritis (SpA) was one of the major breakthroughs in the field over the past decade. Despite some concerns related to the specificity of the criteria, they stimulated research into the early stage of the disease. This resulted in major advances in the understanding of the course of the disease, revealing predictors of progression, improvement in early diagnosis and treatment in axial SpA. In this review, we summarize the recent developments resulting from the introduction of the ASAS classification criteria for axial SpA and the implications for research and clinical practice.

Patients with fibromyalgia rarely fulfil classification criteria for axial spondyloarthritis.

The Assessments of Spondyloarthritis international Society (ASAS) classification criteria for axial spondyloarthritis (axSpA) have been criticized because of insufficient differentiation towards FM. The aim of this study was to compare the performance of currently used classification criteria in patients diagnosed with axSpA or FM. Patients were prospectively included if diagnosed with axSpA or FM by the treating rheumatologist and evaluated by an independent examiner for fulfilment of the classification criteria for axSpA (ASAS criteria) and/or FM (1990 ACR classification and 2010 ACR diagnostic criteria). Patients with axSpA were stratified based on classification as non-radiographic axSpA (nr-axSpA) or AS. Symptom severity was assessed by established disease-related questionnaires. Overall, 300 patients were included, 100 with FM and 200 with axSpA of which 100 each had nr-axSpA and AS. Almost all FM patients fulfilled the 2010 (100%) and 1990 ACR criteria (98%) for FM, but only 2% fulfilled the ASAS criteria. When calculations were based on only the FM patients with available HLA-B27 results (n = 40), the proportion fulfilling the ASAS criteria was 5%. All axSpA patients met the ASAS criteria but also the 2010 (24%) and 1990 (13.5%) FM criteria. More patients with AS (29% and 19%) than with nr-axSpA (19% and 8%) fulfilled the 2010 and 1990 FM criteria, respectively. FM patients only rarely fulfil classification criteria for axSpA but some axSpA patients also fulfil FM criteria. Since this was more frequent in patients with AS it may be related to the severity and duration of chronic pain in axSpA patients. Assessment instruments evaluated in axSpA are not disease-specific. The phenomenon of central pain sensitization in rheumatic diseases deserves more study.

The yield of a positive MRI of the spine as imaging criterion in the ASAS classification criteria for axial spondyloarthritis: results from the SPACE and DESIR cohorts

ObjectivesTo assess the prevalence of spinal inflammation on MRI in patients with chronic back pain (CBP) of maximally 3 years duration and to evaluate the yield of adding a positive...

Performance of the ASAS classification criteria for axial and peripheral spondyloarthritis: a systematic literature review and meta-analysis

ObjectiveTo summarise the evidence on the performance of the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial spondyloarthritis (axSpA) (also imaging and clinical arm separately), peripheral (p)SpA and...

Higher body mass index and anti-drug antibodies predict the discontinuation of anti-TNF agents in Korean patients with axial spondyloarthritis

ObjectiveThe development of anti-drug antibodies against tumor necrosis factor inhibitors is a likely explanation for the failure of TNF-inhibitors in patients with spondyloarthritis. Our study determined the existence and clinical implications of ADAbs in axial spondyloarthritis patients. MethodsAccording to the Assessment of SpondyloArthritis International Society classification criteria for axial spondyloarthritis, patients treated with adalimumab or infliximab were recruited consecutively. Serum samples were collected at enrollment to measure anti-drug antibodies and drug levels. ResultsOf 100 patients, the mean duration of current TNF inhibitor use was 22.3±17.9 months. Anti-drug antibodies were detected in 5 of 72 adalimumab users compared to 5 of 28 infliximab users (6.9% vs. 17.9%). Anti-drug antibodies-positive patients had a significantly higher body mass index than anti-drug antibodies-negative patients among both adalimumab (28.4±5.9kg/m2 vs. 24.3±2.9kg/m2, respectively, p=0.01) and infliximab users (25.9±2.8kg/m2 vs. 22.6±2.8kg/m2, respectively, p=0.02). During the median 15-month follow-up period, drug discontinuation occurred more frequently in the anti-drug antibodies-positive group than the anti-drug antibodies-negative group (30.0% vs. 6.5%, respectively, p=0.04). In logistic regression, anti-drug antibodies positivity (OR=5.85, 95% CI 1.19–28.61, p=0.029) and body mass index (OR=4.35, 95% CI 1.01–18.69, p=0.048) were associated with a greater risk of stopping TNF inhibitor treatment. ConclusionsOur result suggests that the presence of anti-drug antibodies against adalimumab and infliximab as well as a higher body mass index can predict subsequent drug discontinuation in axial spondyloarthritis patients.

O maior índice de massa corporal e a presença de anticorpos antifármacos predizem a interrupção no uso de agentes anti‐TNF em pacientes sul‐coreanos com espondiloartrite axial

ObjectiveThe development of anti‐drug antibodies (ADAbs) against tumor necrosis factor (TNF) inhibitors is a likely explanation for the failure of TNF‐inhibitors in patients with spondyloarthritis (SpA). Our study determined the existence and clinical implications of ADAbs in axial SpA patients. MethodsAccording to the Assessment of SpondyloArthritis International Society classification criteria for axial SpA, patients treated with adalimumab or infliximab were recruited consecutively. Serum samples were collected at enrollment to measure ADAb and drug levels. ResultsOf 100 patients, the mean duration of current TNF inhibitor use was 22.3±17.9 months. ADAbs were detected in 5 of 72 adalimumab users compared to 5 of 28 infliximab users (6.9% vs. 17.9%). ADAb‐positive patients had a significantly higher body mass index than ADAb‐negative patients among both adalimumab (28.4±5.9kg/m2 vs. 24.3±2.9kg/m2, respectively, p=0.01) and infliximab users (25.9±2.8kg/m2 vs. 22.6±2.8kg/m2, respectively, p=0.02). During the median 15‐month follow‐up period, drug discontinuation occurred more frequently in the ADAb‐positive group than the ADAb‐negative group (30.0% vs. 6.5%, respectively, p=0.04). In logistic regression, ADAb positivity (OR=5.85, 95% CI 1.19–28.61, p=0.029) and BMI (OR=4.35, 95% CI 1.01–18.69, p=0.048) were associated with a greater risk of stopping TNF inhibitor treatment. ConclusionsOur result suggests that the presence of ADAbs against adalimumab and infliximab as well as a higher BMI can predict subsequent drug discontinuation in axial SpA patients.