Impaired response to treatment with tumour necrosis factor α inhibitors in smokers with axial spondyloarthritis

Functional disability and disease activity are affected by social determinants of health in patients with rheumatoid arthritis

BACKGROUND

The relationship between social determinants of health (SDH) and disease outcomes in rheumatoid arthritis (RA) is not well documented.

METHODS

Data were extracted from the Ontario Best Practices Research Initiative (OBRI) registry for patients between January 2008 and April 2022. Adjusted mixed models analysis was used to investigate the effect of baseline SDH on disease activity (Clinical Disease Activity Index (CDAI)) and functional disability (Health Assessment Questionnaire-Disability Index (HAQ-DI)) 12 months after enrollment. The analyses were completed on multiple imputed data.

RESULTS

There were 2651 patients with a mean age of 58.1 years (SD 12.9). The majority (77.8%) were female. Greater improvements in physical function were seen in patients who were full-time employed (difference =  - 0.20; 95% CI - 0.28, - 0.11), part-time employed (difference =  - 0.10; 95% CI - 0.19, - 0.02), or retired (difference =  - 0.17; 95% CI - 0.25, - 0.08), compared to unemployed, those with highest income ($75,000 or more) (difference =  - 0.23; 95% CI - 0.37, - 0.09). Caucasian was also associated with a positive impact on functional ability (difference =  - 0.09; 95% CI - 0.17, - 0.02). In contrast, smokers had smaller improvements in physical function (difference = 0.07; 95% CI 0.002, 0.14). Interestingly, women had greater improvement in CDAI (difference =  - 2.40; 95% CI - 3.29, - 1.51), while they reported less improving in their physical function (difference = 0.33; 95% CI 0.27-0.39). Achieving CDAI low disease activity/remission state was also more common in females.

CONCLUSIONS

Our findings suggest that disease activity and functional disability are affected by different SDH factors. The effects of SDH should be better understood and addressed by rheumatologists to provide equitable healthcare for all patients with RA. Key points • This study explored a comprehensive panel of social determinants of health and their relationship to clinical outcomes. • Previously unreported factors such as employment status and income were found to influence clinical outcomes. • Our findings can help physicians to identify high-risk patients who may benefit from additional attention to their social background.

The impact of nicotine smoking on spondyloarthritis and rheumatoid arthritis

OBJECTIVE

Nicotine has major side effects on human health through numerous mechanisms, one of which is the alteration of the immune system and its genetic components. Such alteration can be a predisposing factor for autoimmune diseases such as spondyloarthritis (SpA) and rheumatoid arthritis (RA). This review aims to shed light on the effects of nicotine smoking on the pathophysiology, clinical presentation, and management of SpA and RA.

METHODS

This review looked into the studies, excluding case reports and series, which were cited by PubMed/MEDLINE.

RESULTS

Patients with established autoimmune conditions may have a different underlying pathophysiology and disease course when exposed to nicotine through cigarette smoking. Through the involvement of several cytokines, endothelial dysfunction, and epigenetic mechanisms, the severity of SpA is more prominent in smokers. The global health status, pain, and fatigue are worse in SpA patients. The evidence on the effect of nicotine smoking on the treatment of SpA is still limited. Nicotine can contribute to RA via the disruption of cellular regulatory activity, inflammatory responses, morphological, physiological, biochemical, and enzymatic responses. As such, smokers with RA have higher disease activity and are more likely to be seropositive through the citrullination of peptides. In addition, these patients are at risk of achieving a suboptimal response to tumor necrosis factor inhibitors.

CONCLUSIONS

Cigarette smoking can substantially affect the pathophysiology and clinical presentation of patients with SpA and RA. The impact of nicotine on the management of these diseases still needs to be further studied.

Explainable deep learning for disease activity prediction in chronic inflammatory joint diseases

Analysing complex diseases such as chronic inflammatory joint diseases (CIJDs), where many factors influence the disease evolution over time, is a challenging task. CIJDs are rheumatic diseases that cause the immune system to attack healthy organs, mainly the joints. Different environmental, genetic and demographic factors affect disease development and progression. The Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) Foundation maintains a national database of CIJDs documenting the disease management over time for 19'267 patients. We propose the Disease Activity Score Network (DAS-Net), an explainable multi-task learning model trained on patients' data with different arthritis subtypes, transforming longitudinal patient journeys into comparable representations and predicting multiple disease activity scores. First, we built a modular model composed of feed-forward neural networks, long short-term memory networks and attention layers to process the heterogeneous patient histories and predict future disease activity. Second, we investigated the utility of the model's computed patient representations (latent embeddings) to identify patients with similar disease progression. Third, we enhanced the explainability of our model by analysing the impact of different patient characteristics on disease progression and contrasted our model outcomes with medical expert knowledge. To this end, we explored multiple feature attribution methods including SHAP, attention attribution and feature weighting using case-based similarity. Our model outperforms temporal and non-temporal neural network, tree-based, and naive static baselines in predicting future disease activity scores. To identify similar patients, a k-nearest neighbours regression algorithm applied to the model's computed latent representations outperforms baseline strategies that use raw input features representation.

Treatment overview of axial spondyloarthritis in 2023

The treatment of patients with axial spondyloarthritis (axSpA) is characterized by non-pharmacological and pharmacological treatment options. It may depend on the type and extent of musculoskeletal and extramusculoskeletal manifestations. Recent data on non-pharmacological treatment options, such as physical activity, physiotherapy, and modification of lifestyle factors, are summarized in this review. Moreover, we have provided an overview on non-steroidal anti-inflammatory drugs and the ever-expanding number of biological and targeted synthetic disease-modifying antirheumatic drugs (bDMARDs and tsDMARDs, respectively). In addition to data on efficacy and safety, the review also encompasses data on switching/cycling, tapering, and treatment selection for specific patient subgroups to optimize treatment outcomes.

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.

Cardiovascular Disease and Cardiac Imaging in Inflammatory Arthritis

Cardiovascular morbidity and mortality are more prevalent in inflammatory arthritis (IA) compared to the general population. Recognizing the importance of addressing this issue, the European League Against Rheumatism (EULAR) published guidelines on cardiovascular disease (CVD) risk management in IA in 2016, with plans to update going forward based on the latest emerging evidence. Herein we review the latest evidence on cardiovascular disease in IA, taking a focus on rheumatoid arthritis, psoriatic arthritis, and axial spondylarthritis, reflecting on the scale of the problem and imaging modalities to identify disease. Evidence demonstrates that both traditional CVD factors and inflammation contribute to the higher CVD burden. Whereas CVD has decreased with the newer anti-rheumatic treatments currently available, CVD continues to remain an important comorbidity in IA patients calling for prompt screening and management of CVD and related risk factors. Non-invasive cardiovascular imaging has been attracting much attention in view of the possibility of detecting cardiovascular lesions in IA accurately and promptly, even at the pre-clinical stage. We reflect on imaging modalities to screen for CVD in IA and on the important role of rheumatologists and cardiologists working closely together.

Differentiated Effect of Smoking on Disease Activity and Quality of Life among Different Spondyloarthritis Phenotypes

BACKGROUND AND AIMS

The effect of smoking on disease activity and quality of life (QoL) in spondyloarthritis (SpA) is far from clear. We aimed to evaluate the relationship between smoking and these outcomes in patients with axial SpA (axSpA) and psoriatic arthritis (PsA).

PATIENTS AND METHODS

This cross-sectional observational multicenter study included 242 patients with axSpA and 90 with PsA. The association between conventional cardiovascular risk factors and disease activity as well as QoL, in both SpA phenotypes was evaluated. For this, univariate and multivariate regression analyses were performed, as well as confirmatory meta-analyses.

RESULTS

Regardless of age, sex, or disease duration, patients with axSpA showed significantly less association with obesity (OR 0.50 (0.26-0.96), p = 0.03) and hypertension (OR 0.33 (0.18-0.62), p = 0.0005). However, axSpA was significantly associated with smoking (OR 2.62 (1.36-5.04), p = 0.004). Patients with axSpA were more likely to be in a category of high disease activity compared with PsA (OR 2.86, p = 0.0006). Regardless of sex, age, disease duration, and education level, smoking was significantly associated with higher disease activity in axSpA (OR 1.88, p = 0.027). A fixed-effects model meta-analysis (OR 1.70, p = 0.038) confirmed the association between tobacco and disease activity. No relationship was found between smoking (or other cardiometabolic risk factors) and structural damage or worse QoL in either disease.

CONCLUSIONS

Although the cardiometabolic risk profile is clearly different between both SpA phenotypes, the only clear link between these factors and increased disease activity was observed between smoking and axSpA. Our findings need further confirmation.

Development and Validation of a Self-Administered Questionnaire Measuring Essential Knowledge in Patients With Axial Spondyloarthritis

OBJECTIVE

To develop and validate a patient knowledge questionnaire regarding axial spondyloarthritis (axSpA).

METHODS

Knowledge considered essential for patients with axSpA was identified through Delphi rounds among rheumatologists, healthcare professionals (HCPs), and patients, then reformulated to develop the knowledge questionnaire. Cross-sectional validation was performed in 14 rheumatology departments to assess internal validity (Kuder-Richardson coefficient), external validity, acceptability, reproducibility (Lin concordance correlation coefficient), and sensitivity to change (knowledge score before vs after patient education sessions and effect size).

RESULTS

The Spondyloarthritis Knowledge Questionnaire (SPAKE) is a self-administered 42-item questionnaire with a 32-item short form, both scored 0 to 100, assessing knowledge of disease, comorbidities, pharmacological treatments, nonpharmacological treatments, self-care, and adaptive skills. In the validation study (130 patients; 67 [51.5%] male, mean age 43.5 [SD 12.9] yrs), the mean (SD) score of the long-form questionnaire was 71.6 (15.4), with higher scores (better knowledge) in nonpharmacological treatments and adaptive skills and lower scores in cardiovascular comorbidity and pharmacological treatments. Acceptability was good, with no missing data; the internal validity coefficient was 0.85. Reproducibility was good (0.81, 95% CI 0.72-0.89). SPAKE showed good sensitivity to change; scores were 69.2 (15.3) then 82.7 (14.0) after patient education sessions (Hedges effect size = 0.92, 95% CI 0.52-1.31).

CONCLUSION

SPAKE is a knowledge questionnaire for patients with axSpA, developed with the involvement of HCPs and patients and reflecting current recommendations for the management of axSpA. SPAKE will be useful in assessing knowledge acquisition and self-management strategies in routine care and research.

Female Sex, Age, and Unfavorable Response to Tumor Necrosis Factor Inhibitors in Patients With Axial Spondyloarthritis: Results of Statistical and Artificial Intelligence-Based Data Analyses of a National Multicenter Prospective Registry

OBJECTIVE

Real-world studies are needed to identify factors associated with response to biologic therapies in patients with axial spondyloarthritis (SpA). The objective was to assess sex differences in response to tumor necrosis factor inhibitors (TNFi) and to explore possible risk factors associated with TNFi efficacy.

METHODS

A total of 969 patients with axial SpA (315 females, 654 males) enrolled in the BIOBADASER registry (2000-2019) who initiated a TNFi (first, second, or further lines) were studied. Statistical and artificial intelligence (AI)-based data analyses were used to explore the association of sex differences and other factors to TNFi response, using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), to calculate the BASDAI50, with an improvement of at least 50% of the BASDAI score, and using the Ankylosing Spondylitis Disease Activity Score, calculated using the C-reactive protein level (ASDAS-CRP).

RESULTS

Females had a lower probability of reaching a BASDAI50 response with a first line TNFi treatment at the second year of follow-up (P = 0.018) and a lesser reduction of the ASDAS-CRP at this time point. The logistic regression model showed lower BASDAI50 responses to TNFi in females (P = 0.05). Other factors, such as older age (P = 0.004), were associated with unfavorable responses. The AI data analyses reinforced the idea that age at the beginning of the treatment was the main factor associated with an unfavorable response. The combination of age with other clinical characteristics (female sex or cardiovascular risk factors and events) potentially contributed to an unfavorable response to TNFi.

CONCLUSION

In this national multicenter registry, female sex was associated with less response to a first-line TNFi by the second year of follow-up. A higher age at the start of the TNFi was the main factor associated with an unfavorable response to TNFi.

The impact of smoking status on radiographic progression in patients with ankylosing spondylitis on anti-tumor necrosis factor treatment

Background

Ankylosing spondylitis (AS) is characterized by back pain which can lead to spinal ankylosis. Anti-tumor necrosis factor (TNF) dramatically alleviates symptoms, but spinal damage can still be progressive even during anti-TNF treatment. Smoking is a one of well-known risk factors for structural damage in AS. However, it has not been confirmed that smoking can affect radiographic progression even during anti-TNF treatment.

Objective

To investigate factors associated with radiographic progression during anti-TNF treatment with a focus on smoking status which is known as one of poor prognostic factors for AS.

Materials and methods

We conducted a retrospective cohort study of AS patients who began the first-line anti-TNF treatment between 2001 and 2018 according to availability of smoking data. All enrolled patients were observed until the last visit, the first-line anti-TNF discontinuation, or December 2019. Radiographic damage was assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). The mSASSS progression rate (units/year) was calculated using the baseline mSASSS, the final mSASSS during observation period, and the duration between them. Univariable and multivariable logistic regression analyses were performed to identify associated factors of mSASSS progression rate > 1 unit/year.

Results

Among 459 AS patients, 185 (40.3%) patients were never smokers, 62 (13.5%) were ex-smokers and 212 (46.2%) were current smokers at baseline. Ex- and current smokers had higher mSASSS progression rates than never smokers [never smoker 0.1 (0.0–0.7), ex-smoker 0.6 (0.0–1.5), and current smoker 0.6 (0.0–1.5) units/year, P < 0.001]. In the multivariable logistic analysis, current smoking [adjusted odds ratio (OR) 1.69, 95% CI 1.01–2.82, P = 0.047] and higher baseline mSASSS [adjusted OR 1.03, 95% CI 1.01–1.04, P < 0.001] were associated with a mSASSS progression rate > 1 unit/year.

Conclusion

Current smoking is a modifiable risk factor for radiographic progression in patients with AS on anti-TNF treatment. Quitting smoking should be strongly recommended.

Lifestyle modification and inflammation in people with axial spondyloarthropathy-A scoping review

INTRODUCTION

People with axial spondyloarthritis (AS) have an inflammatory profile, increasing the risk of hypertension, type 2 diabetes, obesity, and dyslipidaemia. Consequently, AS is linked with co-morbidities such as cardiovascular disease (CVD). Physical inactivity, diet, smoking, alcohol consumption, and obesity influence inflammation, but knowledge of the interaction between these with inflammation, disease activity, and CVD risk in AS is dominated by cross-sectional research.

METHODS

A review of the literature was conducted between July 2020 and December 2021. The focus of the scoping review is to summarise longitudinal and randomised control trials in humans to investigate how tracking or modifying lifestyle influences inflammation and disease burden in patients with AS. KEY MESSAGES: (1) Lifestyle modifications, especially increased physical activity (PA), exercise, and smoking cessation, are critical in managing AS. (2) Smoking is negatively associated with patient reported outcome measures with AS, plus pharmaceutical treatment adherence, but links with structural radiographic progression are inconclusive. (3) Paucity of data warrant structured studies measuring inflammatory cytokine responses to lifestyle modification in AS.

CONCLUSION

Increased PA, exercise, and smoking cessation should be supported at every given opportunity to improve health outcomes in patients with AS. The link between smoking and radiographic progression needs further investigation. Studies investigating the longitudinal effect of body weight, alcohol, and psychosocial factors on disease activity and physical function in patients with AS are needed. Given the link between inflammation and AS, future studies should also incorporate markers of chronic inflammation beyond the standard C-reactive protein and erythrocyte sedimentation rate measurements.

Australian Consensus Statements for the Assessment and Management of Non-radiographic Axial Spondyloarthritis

Background

The understanding of non-radiographic axial spondyloarthritis (nr-axSpA) has accelerated over the last decade, producing a number of practice-changing developments. Diagnosis is challenging. No diagnostic criteria exist, no single finding is diagnostic, and other causes of back pain may act as confounders.

Aim

To update and expand the 2014 consensus statement on the investigation and management of non‐radiographic axial spondyloarthritis (nr-axSpA).

Methods

We created search questions based on our previous statements and four new topics then searched the MEDLINE and Cochrane databases. We assessed relevant publications by full-text review and rated their level of evidence using the GRADE system. We compiled a GRADE evidence summary then produced and voted on consensus statements.

Results

We identified 5145 relevant publications, full-text reviewed 504, and included 176 in the evidence summary. We developed and voted on 22 consensus statements. All had high agreement. Diagnosis of nr-axSpA should be made by experienced clinicians, considering clinical features of spondyloarthritis, blood tests, and imaging. History and examination should also assess alternative causes of back pain and related conditions including non-specific back pain and fibromyalgia. Initial investigations should include CRP, HLA-B27, and AP pelvic radiography. Further imaging by T1 and STIR MRI of the sacroiliac joints is useful if radiography does not show definite changes. MRI provides moderate-to-high sensitivity and high specificity for nr-axSpA. Acute signs of sacroiliitis on MRI are not specific and have been observed in the absence of spondyloarthritis. Initial management should involve NSAIDs and a regular exercise program, while TNF and IL-17 inhibitors can be used for high disease activity unresponsive to these interventions. Goals of treatment include improving the frequent impairment of social and occupational function that occurs in nr-axSpA.

Conclusions

We provide 22 evidence-based consensus statements to provide practical guidance in the assessment and management of nr-axSpA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00416-7.

Relationship between smoking, clinical, inflammatory, and radiographic parameters in patients with ankylosing spondylitis

Background

Ankylosing spondylitis (AS) is an autoimmune multisystemic disease that attacks the spine, sacroiliacs, and often causes asymmetrical peripheral oligoarthritis. It results from the interaction between the genetic factors mainly Human Leukocyte Antigen B27 (HLA B27) and environmental factors. Current smoking has been reported to be a major risk factor for the incidence and progression of ankylosing spondylitis. So, we aim to explore the relationship between smoking and each of the clinical, inflammatory markers, functional limitation, and radiographic progression in ankylosing spondylitis patients.

Results

Fifty ankylosing spondylitis patients were included in this study. Comparisons of clinical data, radiographic, and inflammatory markers among smokers and nonsmokers revealed that AS current smokers showed a statistically significant decrease in chest expansion, increase in the occiput to wall distance (p < 0.001**), higher inflammatory marker, higher disease activity indices (Ankylosing Spondylitis Disease Activity Score, Bath Ankylosing Spondylitis Disease Activity Index), higher Bath Ankylosing Spondylitis functional index, and modified Stoke Ankylosing Spondylitis Spine Score than nonsmokers (P < 0.001**). The smoking index was positively correlated with BASFI, ASDAS, (mSASSS) (r = 0.584, p = 0.005*) and negatively correlated with chest expansion.

Conclusions

Current smoking in ankylosing spondylitis patients is associated with higher disease activity, inflammatory markers, functional disability, and radiological progression. This may add to the disease burden and thus interferes with the personal daily activities, physical mobility, life quality, and the response to TNFi therapy. So, stopping smoking is a mandatory step in controlling the disease activity and having favorable outcome.

Smoking in spondyloarthritis: unravelling the complexities

Tobacco smoking is a major threat to health. There is no doubt about the need to promote and support cessation at every opportunity. Smoking has a clear role in RA, but what evidence is there that the same relationship exists in SpA? In this review, we examine (the less cited) paradoxes and contradictions in the existing axial SpA (axSpA) and PsA literature; for example, smoking appears to be 'protective' for some axSpA manifestations. We also highlight findings from higher quality evidence: smoking is associated with increased risk of PsA and the risk of psoriasis in axSpA. The relationship between smoking and SpA is far from simple. Our aim is to highlight the harms of smoking in SpA and bring attention to inconsistencies in the literature to inform further research.

Influence of smoking and obesity on treatment response in patients with axial spondyloarthritis: a systematic literature review

To assess whether smoking and obesity are predictors of poor treatment response in patients with axial spondyloarthritis (axSpA). A systematic literature review was performed by searching in MEDLINE and EMBASE up to June 2019 with a strategy based on the PICO approach: Population: patients with axSpA; Intervention or exposure: smoking or obesity; Comparison: non-smokers (for smoking) and normal-weight individuals (for obesity); and Outcome: any response criteria currently validated for axSpA. The 2009 Oxford Centre for Evidence-based Medicine levels were used for assessing the studies quality. Out of 1873 references retrieved, 46 studies were selected for full-text review and 12 for data extraction: six stratified patients by smoking and six by obesity. All were longitudinal observational studies, except one, which was cross-sectional. Overall, these studies included 5291 patients (3917 for smoking and 1333 for obesity), and all these patients were on anti-tumor necrosis factor (anti-TNF) therapy. The quality of evidence was graded as level 2b except that from the cross-sectional study which was graded level 4. For smoking, the evidence found is inconsistent: two studies finding negative effects in response to anti-TNF while the other four found no differences in clinical response to this therapy. Regarding obesity, the evidence is more consistent: five of the six studies describing a negative influence in response to anti-TNF. According to the scientific evidence in patients with axSpA, obesity is associated with a more unsatisfactory response to anti-TNF therapy. A poorer response in smokers has yet to be demonstrated. Key Points • Identifying predictors of treatment response in axSpA, especially those that are modifiable, is relevant. • Obesity increases the risk of poorer response to anti-TNF agents in patients with axSpA. • Scientific evidence for smoking habit as a predictor of treatment response in axSpA is inconclusive.

Predicting response to anti-TNFα therapy among patients with axial spondyloarthritis (axSpA): results from BSRBR-AS

OBJECTIVES

While many axSpA patients, eligible to receive anti-TNFα therapy, derive benefit when prescribed them, some patients do not. The current study aims to identify modifiable targets to improve outcome as well as non-modifiable targets that identify groups less likely to derive benefit.

METHODS

The BSRBR-AS is a prospective cohort study of axSpA patients who, at recruitment, were naïve to biologic therapy. Those in the 'biologic' sub-cohort commenced their first anti-TNFα therapy at recruitment or during follow-up. Prior to commencement, information was collected on socio-economic, clinical and patient-reported factors. Outcome was assessed according to ASAS20, ASAS40, ASDAS reduction and achieving a moderate/inactive ASDAS disease state.

RESULTS

335 participants commenced their first anti-TNFα therapy and were followed up at a median of 14 (inter-quartile range 12-17) weeks. Response varied between 33% and 52% according to criteria used. Adverse socio-economic factors, fewer years in education predicted lower likelihood of response across outcome measures as did not working full-time. Co-morbidities and poor mental health were clinical and patient-reported factors, respectively, associated with lack of response. The models, particularly those using ASDAS, were good at predicting those who did not respond (negative predictive value (NPV) 77%).

CONCLUSION

Some factors predicting non-response (such as mental health) are modifiable but many (such as social/economic factors) are not modifiable in clinic. They do, however, identify patients who are unlikely to benefit from biologic therapy alone. Priority should focus on how these patients receive the benefits that many derive from such therapies.

Dynamic changes in gut microbiota under the influence of smoking and TNF-α-blocker in patients with ankylosing spondylitis

OBJECTIVES

This study aimed to investigate the relationship among smoking, TNF-α-blocker therapy, and the dynamic changes in gut microbiota in patients with ankylosing spondylitis (AS).

METHODS

Using a 16S rRNA sequence, 98 fecal samples of 20 AS patients collected after 0, 1, 3 and 6 months of anti-TNF-α treatment and from 20 matched health controls were examined. The variation in composition, abundance, and diversity of gut microbiota was analyzed. The dynamic effects of smoking and treatment on gut microbiota and therapeutic efficacy in AS patients were studied.

RESULTS

The increased relative abundance of microbiota in AS nonsmokers was g_Comamonas and g_Desulfovibrio, while that in AS smokers was g_Actinomyces, g_Collinsella, g_Lachnospiraceae_UCG-008, and g_Paraprevotella. The relative abundance of gut microbiota showed dynamic variation. The improvement rate of ASDAS in AS nonsmokers was higher than that in AS smokers (2.297 vs 1.736) after anti-TNF-α treatment. The β-diversity of gut microbiota in AS smokers was lower than that in AS nonsmokers and improved with treatment.

CONCLUSIONS

Both smoking and TNF-α-blocker had significant effects on the composition, relative abundance, and diversity of gut microbiota in AS patients. The AS smokers characteristically shared g_Collinsella and g_Dorea. The relative abundance of gut microbiota revealed high variability and was in dynamic fluctuation during treatment. The response of gut microbiota to anti-TNF-α treatment was found to be heterogeneous and selective. AS nonsmokers showed a greater improvement rate of ASDAS-CRP with treatment than AS smokers did. The AS smokers showed a lower β-diversity of gut microbiota, and improved after treatment. Key Points • Characterized the dynamic variation in gut microbiota in AS patients classified as smokers and nonsmokers during treatment with anti-TNF-α. • Confirmed the interaction between smoking, anti-TNF-α therapy, and gut microbiota.

Impact of Smoking in Response to Tumor Necrosis Factor Inhibitors in Axial Spondyloarthritis: Methodologic Considerations for Longitudinal Observational Studies

OBJECTIVE

Observational data facilitate examination of treatment-effect heterogeneity, but the risk of bias is substantial. The present study was undertaken to highlight methodologic considerations through an analysis of whether smoking affects response to tumor necrosis factor inhibitors (TNFi) in axial spondyloarthritis (SpA).

METHODS

We used longitudinal data from the British Society for Rheumatology Biologics Register for Ankylosing Spondylitis. Participants fulfilling the Assessment of SpondyloArthritis international Society criteria for axial SpA who started their first TNFi were eligible for analysis. In comparing the impact of smoking status, weighted generalized estimating equations were used to examine changes in several continuous outcome measures, including the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS). Inverse probability weights were used to account for differences in baseline covariates and excluded participants. We separately assessed response in the first 3 months to account for nonrandom dropout.

RESULTS

For 840 participants who started on TNFi, 1,641 assessments from 627 individuals were analyzed (69% male, mean age 46 years). A total of 33% were current smokers and 30% ex-smokers. Ex-smokers and current smokers had worse disease than never smokers at baseline. Accounting for these differences, response did not differ according to smoking status. Compared to never smokers, ex-smokers (β = -0.6, 95% confidence interval [95% CI] -1.4, 0.3) and current smokers (β = -0.4, 95% CI -1.1, 0.4) had a similar response according to the BASDAI and ASDAS (ex-smokers β = -0.1, 95% CI -0.5, 0.3; current smokers β = -0.01, 95% CI -0.4, 0.4) at 3 months.

CONCLUSION

TNFi response did not differ according to baseline smoking status in this UK cohort. Conflicting results from previous studies were likely due to methodologic differences. This analysis highlights potential sources of bias that should be addressed in future studies.

[Current treatment of axial spondylarthritis : Clinical efficacy]

Drug treatment in patients with axial spondylarthritis (axSpA) aims to modify symptoms and complaints and currently includes the substance groups of nonsteroidal anti-inflammatory drugs (NSAID) and biologicals (disease-modifying antirheumatic drugs, bDMARDS). Treatment with NSAIDs is the first line treatment according to international and national recommendations. Patients with persisting high disease activity despite continuous standard treatment with NSAIDs, should be treated with biologicals. In Germany treatment with tumor necosis factor (TNF) inhibitors or interleukin 17 inhibitor (secukinumab) are currently approved for treating patients with ankylosing spondylitis (AS). Treatment of patients with non-radiographic axSpA (nr-axSpA) is restricted to TNF inhibitors (except infliximab) in Germany. The efficacy and safety are documented for both substance groups; however, due to the longer time since approval longitudinal data for TNF inhibitors are more robust and the data contain information about switching within a substance group. Although overall retention rates of TNF inhibitors are similar despite the difference in formation of antidrug antibodies, data from cohorts provide information about long-term loss of efficacy, switching and also discontinuation strategies. In the meantime, various biosimilars have been approved for infliximab, etanercept and adalimumab. Conventional basic treatment (csDMARDs) and in particular intra-articular administration of glucocorticoids can only be prescribed for axSpA patients with peripheral arthritis.

How Does Smoking Cessation Affect Disease Activity, Function Loss, and Quality of Life in Smokers With Ankylosing Spondylitis?

BACKGROUND

Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease that can progressively restrict spinal mobility.

OBJECTIVE

This study aimed to investigate how smoking cessation by AS patients affects disease activity and their psychological state, physical mobility, lung function, and quality of life.

MATERIALS AND METHODS

This was a longitudinal, single-blind, controlled, and observational study on 92 AS patients. Pulmonary function test, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index, chest expansion, Short-Form 36, and Ankylosing Spondylitis Quality of Life were evaluated. The patients were divided into smokers (group 1 = 54) and nonsmokers (group 2 = 38). The smokers were divided further into subgroups of those who quit smoking (group 1a = 17) and those who did not (group 1b = 37). Groups 1a and 1b patients were compared in terms of their baseline data and data 6 months after smoking cessation. In addition, group 1a patients' baseline data and data 6 months after smoking cessation were compared statistically.

RESULTS

There was no statistically significant difference between groups 1a and 1b after 6 months in terms of the evaluated parameters, except for BASDAI. Bath Ankylosing Spondylitis Disease Activity Index was significantly lower in group 1a than group 1b (p = 0.02), indicating that. When the baseline data and data after 6 months of group 1a were compared, a significant improvement was found in BASDAI (p = 0.001), Bath Ankylosing Spondylitis Functional Index (p = 0.001), chest expansion (p = 0.001), ankylosing spondylitis quality of life (p = 0.003), and subparameters physical function (p = 0.015), physical role strength (p = 0.05), power/live/vitality (p = 0.025), social functioning (p = 0.039), pain (p = 0.036), and general health perception (p = 0.05) of Short-Form 36, as well as forced expiratory volume in the first second (p = 0.003) and forced vital capacity (p = 0.007).

CONCLUSIONS

We observed significant improvements in disease activity, physical mobility, and quality of life in AS patients who quit smoking.

Associations between smoking and extra-axial manifestations and disease severity in axial spondyloarthritis: results from the BSR Biologics Register for Ankylosing Spondylitis (BSRBR-AS)

OBJECTIVE

The effects of smoking on disease manifestations in axial SpA are inadequately described. Utilizing a large and well-characterized cohort, we investigated the association between smoking and extra-axial manifestations, and smoking and disease severity measures.

METHODS

Baseline data from the British Society for Rheumatology Biologics Register for Ankylosing Spondylitis were explored. Our analyses focused on extra-axial manifestations and other disease severity measures, including scales for fatigue, sleep, anxiety and depression. Logistic and linear models were used to quantify associations between disease characteristics according to smoking status (current/ex/never) and quantity (heavy/light), adjusting for age, gender, BMI, education, deprivation, comorbidities, symptom duration and alcohol status.

RESULTS

A total of 2031 participants were eligible for the current analysis (68% male, mean age 49 years). Of these, 24% were current and 32% ex-smokers. When compared with non-smokers, current smokers had lower odds of uveitis [OR 0.7, 95% CI 0.5-0.9] and higher odds of psoriasis (ORadj 1.6, 95% CI 1.1-2.3). Ex- and current smokers had incrementally more severe disease than never smokers, with higher BASDAI (β = 0.3, 95% CI 0.1-0.6; β = 0.9, 95% CI 0.6-1.2) and BASFI (β = 0.5, 95% CI 0.2-0.8; β = 1.3, 95% CI 1.0-1.6); similar associations were observed for fatigue, sleep, anxiety and depression.

CONCLUSION

In this large cross-sectional study, we observed that smoking is independently associated with an adverse disease profile in axial SpA, including worse fatigue, sleep, anxiety and depression, and higher odds of psoriasis. The paradoxical association between current smoking and reduced odds of uveitis is interesting and warrants further investigation.

Taiwan Rheumatology Association consensus recommendations for the management of axial spondyloarthritis

Aim

To establish guidelines for the clinical management of axial spondyloarthritis that take into account local issues and clinical practice concerns for Taiwan.

Method

Overarching principles and recommendations were established by consensus among a panel of rheumatology and rehabilitation experts, based on analysis of the most up‐to‐date clinical evidence and the clinical experience of panelists. All Overarching Principles and Recommendations were graded according to the standards developed by the Oxford Centre for Evidence Based Medicine, and further evaluated and modified using the Delphi method.

Results

The guidelines specifically address issues such as local medical considerations, National Health Insurance reimbursement, and management of extra‐articular manifestations.

Conclusion

It is hoped that this will help to optimize clinical management outcomes for axial spondyloarthritis in Taiwan.

Smoking status and cause-specific discontinuation of tumour necrosis factor inhibitors in axial spondyloarthritis

Background

The impact of smoking on TNF inhibition (TNFi) therapy is unclear. We examined the effect of smoking on all-cause and cause-specific TNFi discontinuation in axial spondyloarthritis (axSpA).

Methods

We used longitudinal data from the British Society for Rheumatology Biologics Register for Ankylosing Spondylitis (BSRBR-AS). Patients fulfilling the ASAS criteria for axSpA, who started their first TNFi, were eligible for analysis. Inverse-probability weights were used to balance differences in baseline disease severity and other confounders. We used marginal structural Cox proportional hazard models to estimate hazard ratios (HR) for TNFi discontinuation according to smoking status. In analyses of cause-specific discontinuation, competing risk events were considered as censoring, using inverse-probability weights.

Results

A total of 758 participants were included in the analysis (66% male, mean age 45 years), providing 954 patient-years of follow-up. TNFi was discontinued in 174 (23%) patients, among whom 26% stopped due to infections, 20% due to other adverse events and 44% due to inefficacy or other reasons. Thirty-four percent were current smokers and 30% ex-smokers. Compared to never smokers, current smokers’ risk of TNFi discontinuation was HR 0.79 (95%CI 0.53 to 1.20) and ex-smokers HR 0.68 (95%CI 0.45 to 1.04). Our data did not show evidence that current smoking influenced discontinuation due to infections (HR 0.79, 95%CI 0.40 to 1.54), other adverse events (HR 0.86, 95%CI 0.41 to 1.78) or inefficacy/other causes (HR 1.44, 95%CI 0.86 to 2.41).

Conclusion

Baseline smoking status did not impact TNFi discontinuation in this UK cohort of axSpA participants.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1958-z) contains supplementary material, which is available to authorized users.

2018 APLAR axial spondyloarthritis treatment recommendations

INTRODUCTION

Despite the availability of axial spondyloarthritis (SpA) recommendations proposed by various rheumatology societies, we considered that a region-specific guideline was of substantial added value to clinicians of the Asia-Pacific region, given the wide variations in predisposition to infections and other patient factors, local practice patterns, and access to treatment across countries.

MATERIALS AND METHODS

Systematic reviews were undertaken of English-language articles published between 2000 and 2016, identified from MEDLINE using PubMed, EMBASE and Cochrane databases. The strength of available evidence was graded using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Recommendations were developed through consensus using the Delphi technique.

RESULTS

Fourteen axial SpA treatment recommendations were developed based on evidence summaries and consensus. The first 2 recommendations cover non-pharmacological approaches to management. Recommendations 3 to 5 describe the following: the use of non-steroidal anti-inflammatory drugs as first-line symptomatic treatment; the avoidance of long-term corticosteroid use; and the utility of conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) for peripheral or extra-articular manifestations. Recommendation 6 refers to the indications for biological DMARDs (bDMARDs). Recommendation 7 deals specifically with screening for infections endemic to Asia, prior to use of bDMARDs. Recommendations 7 to 13 cover the role of bDMARDs in the treatment of active axial SpA and include related issues such as continuing therapy and use in special populations. Recommendation 14 deals with the utility of surgical intervention in axial SpA.

CONCLUSION

These recommendations provide up-to-date guidance for treatment of axial SpA to help meet the needs of patients and clinicians in the Asia-Pacific region.

Impact of extra-articular spondyloarthritis manifestations and comorbidities on drug retention of a first TNF-inhibitor in ankylosing spondylitis: a population-based nationwide study

Objectives

To assess the impact of extra-articular spondyloarthritis (SpA) manifestations (anterior uveitis, psoriasis and inflammatory bowel disease (IBD)), and of comorbidities, on tumour necrosis factor alpha inhibitor (TNFi) drug retention in ankylosing spondylitis (AS).

Methods

We identified all bio-naïve patients with AS starting a first ever TNFi July 2006 to December 2015 from the Swedish Rheumatology Quality register and followed these from treatment start through December 2015. We determined the presence of extra-articular SpA-manifestations, comorbidities (cardiovascular disease, affective disease, diabetes, malignancies, chronic lung disease and kidney disease) and socioeconomic status before TNFi start, through linkage to five other national registers, and calculated, for each factor, crude and adjusted HRs for discontinuing the TNFi.

Results

2577 patients with AS (71% men) started a first TNFi during the study period. 27% had a history of anterior uveitis, 6% psoriasis and 7% IBD. Anterior uveitis was associated with a superior TNFi drug retention (HR 0.72; 0.62 to 0.83), psoriasis with an inferior (HR 1.48; 1.18 to 1.86), whereas IBD did not affect TNFi drug retention. The effect of the SpA manifestations on TNFi drug retention was of a similar magnitude to that of the comorbidities.

Conclusions

In AS, anterior uveitis and psoriasis, but not IBD, affect TNFi drug retention. Possible explanations include differential effects of TNFi on these extra-articular SpA manifestations, or inherent differences in AS, associated with the inflammatory phenotype. Further, comorbidities and socioeconomy affect TNFi drug retention to a similar magnitude as the SpA manifestations, and should, as such, receive due attention in clinical practice.

Response to Tumor Necrosis Factor Inhibition in Male and Female Patients with Ankylosing Spondylitis: Data from a Swiss Cohort

OBJECTIVE

To investigate sex differences in connection with the effectiveness of tumor necrosis factor inhibitors (TNFi) in patients with ankylosing spondylitis (AS).

METHODS

A total of 440 patients with AS (294 men; 146 women) initiating a first TNFi in the prospective Swiss Clinical Quality Management Cohort were included. We evaluated the proportion of patients achieving the 20% and 40% improvement in the Assessment of Spondyloarthritis international Society criteria (ASAS20 and ASAS40) as well as Ankylosing Spondylitis Disease Activity Score (ASDAS) improvement and status scores at 1 year. Patients having discontinued TNFi were considered nonresponders. Logistic regression analyses were performed to adjust for important predictors of response.

RESULTS

Compared to men, female patients had lower mean C-reactive protein levels, better spinal mobility, and more peripheral disease at the start. There was no sex disparity with regard to the ASDAS, the Bath Ankylosing Spondylitis Disease Activity and Functional indices, and the quality of life. At 1 year, 52% of women and 63% of men achieved an ASAS20 response (OR 0.63, 95% CI 0.37-1.07, p = 0.09). An inactive disease status (ASDAS < 1.3) was reached by 18% of women and 26% of men (OR 0.65, 95% CI 0.32-1.27, p = 0.22). These sex differences in response to TNFi were more pronounced in adjusted analyses (OR 0.34, 95% CI 0.16-0.71, p = 0.005 for ASAS20 and OR 0.10, 95% CI 0.03-0.31, p < 0.001 for ASDAS < 1.3) and confirmed for all the other outcomes assessed.

CONCLUSION

In AS, fewer women respond to TNFi and women show a reduced response in comparison to men.

Nonradiographic axial spondyloarthritis: clinical and therapeutic relevance

Current classification criteria for axial spondyloarthritis (axSpA) provide for the inclusion of patients with a wide range of presentations and manifestations. While not considered a formal subclassification, patients are often divided into radiographic or nonradiographic axSpA based on the presence or absence of radiographic sacroiliitis. This review will focus on nonradiographic axSpA and will discuss clinical manifestations of disease that distinguish, or in many cases do not distinguish, this entity from other individuals with axSpA. This review will also cover treatment paradigms for nonradiographic axSpA, particularly the use of biologic therapies, where current data suggest that nonradiographic disease should be managed largely the same as radiographic disease, or classical ankylosing spondylitis.

Rate and Predisposing Factors for Sacroiliac Joint Radiographic Progression After a Two-Year Follow-up Period in Recent-Onset Spondyloarthritis

Objective

To evaluate the rate of radiographic structural progression in the sacroiliac (SI) joints in patients with radiographic or nonradiographic axial spondyloarthritis (SpA), and to determine factors predisposing to such progression, over 2 years.

Methods

Patients with recent‐onset axial SpA (from the Devenir des Spondyloarthropathies Indifferérenciées Récentes cohort) were assigned a radiographic SI joint score according to the modified New York criteria. Demographic characteristics, smoking status, HLA–B27 positivity, inflammation on magnetic resonance imaging (MRI) of the SI joints, disease activity, and treatment were investigated as potential predisposing factors. The main analysis consisted of the evaluation of the switch from nonradiographic to radiographic axial SpA, but other definitions of radiographic progression were also evaluated.

Results

Of the 708 patients enrolled, 449 had baseline and 2‐year pelvic radiographs. Of these patients, 47% were men. Their mean ± SD age was 34 ± 9 years, 61% were B27 positive, and 37% had inflammation of the SI joints on MRI. The percentages of patients who switched from nonradiographic to radiographic axial SpA (4.9% [16 of 326]) and from radiographic to nonradiographic axial SpA (5.7% [7 of 123]) were low. The mean ± SD change in the total SI joint score (range 0–8) was small (0.1 ± 0.8) but highly significant (P < 0.001). The potential baseline predisposing factors for meeting the modified New York criteria in the multivariate analysis were current smoking, HLA–B27 positivity, and inflammation of the SI joints on MRI, with odds ratios of 3.3 (95% confidence interval [95% CI] 1.0–11.5], 12.6 (95% CI 2.3–274), and 48.8 (95% CI 9.3–904), respectively.

Conclusion

Our findings suggest that structural progression does exist in early SpA, but it is quite small and observed in a small number of patients, and that environmental (smoking status), genetic (HLA–B27 positivity), and inflammation (inflammation of the SI joints on MRI) markers might be independent predisposing factors for progression.

Does the reason for discontinuation of a first TNF inhibitor influence the effectiveness of a second TNF inhibitor in axial spondyloarthritis? Results from the Swiss Clinical Quality Management Cohort

Background

With regard to switching tumor necrosis factor inhibitors (TNFi) in axial spondyloarthritis (axSpA), conflicting results have been reported as to whether the effectiveness of a second TNFi depends on the reason for discontinuation of the first TNFi.

Methods

Patients with a clinical diagnosis of axSpA starting a second TNFi in the Swiss Clinical Quality Management cohort were included. Effectiveness of treatment at 1 year, as well as drug survival, was compared between subgroups having discontinued the first TNFi because of lack of response, adverse events (AEs), or other reasons. Lack of response was further divided into primary or secondary lack of response (PLR or SLR, respectively), depending on whether the first TNFi was stopped before or after 6 months of treatment.

Results

Among 632 patients with axSpA, median survival of a second TNFi was 1.1 years after PLR and 3.8 years after SLR (p = 0.003). At least moderate disease activity as defined by an Ankylosing Spondylitis Disease Activity Score using the erythrocyte sedimentation rate (ASDAS-ESR) <2.1 was achieved after 12 months by 11 %, 39 %, 26 %, and 39 % of patients who discontinued their first TNFi because of PLR, SLR, AEs, and other reasons, respectively (p = 0.01). Only 4 % of patients achieved an ASDAS-ESR inactive disease state after PLR, in comparison to 22 % of those after SLR. Similar results were demonstrated in patients fulfilling the Assessment of SpondyloArthritis international Society classification criteria for axSpA (n = 488): ASDAS-ESR <2.1 was achieved after 12 months by 9 %, 41 %, 29 %, and 39 % of patients who discontinued their first TNFi because of PLR, SLR, AEs, and other reasons, respectively (p = 0.01).

Conclusions

The effectiveness of a second TNFi is significantly impaired in patients with axSpA after PLR to a first TNFi compared with SLR.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0969-2) contains supplementary material, which is available to authorized users.

Impact of tobacco smoking on response to tumour necrosis factor-alpha inhibitor treatment in patients with ankylosing spondylitis: results from the Danish nationwide DANBIO registry

OBJECTIVES

To investigate the association between tobacco smoking and disease activity, treatment adherence and treatment responses in patients with AS treated with their first tumour necrosis factor-alpha inhibitor (TNFi) therapy in routine care.

METHODS

Observational cohort study based on the Danish nationwide DANBIO registry. Kaplan-Meier plots, Cox and logistic regression analyses by smoking status (current/never/previous) were calculated for treatment adherence and BASDAI 50%/20 mm-response. Additional stratified analyses were performed for gender and TNFi-type.

RESULTS

Of 1576 AS patients included in the study, 1425(90%) had known smoking status (current/never/previous: 43%/41%/16%). The median follow-up time was 2.02 years (IQR 0.69-5.01). At baseline, current smokers compared with never smokers had longer disease duration (4 years (1-12)/2 years (0-10)), higher BASDAI (61 mm (47-73)/58 mm (44-70)), BASFI (53 mm (35-69)/46 mm (31-66)) and BASMI (40 mm (20-60)/30 mm (10-50)) scores (all P < 0.01). Current and previous smokers had shorter treatment adherence than never smokers (current: 2.30 years (1.81-2.79) (median (95% CI)); previous: 2.48 years (1.56-3.40), never: 4.12 years (3.29-4.95)), P < 0.0001). Similar results were found in multivariate analyses (current versus never smokers, HR 1.41 (95% CI 1.21-1.65), P < 0.001), most pronounced among men. Current smokers had poorer 6 months' BASDAI50%/20 mm-response rate than never smokers (42%/58%, P < 0.001). In multivariate analyses, current smokers had lower odds of achieving BASDAI50%/20 mm-response than never smokers, both overall (OR 0.48 (95% CI 0.35-0.65), P < 0.0001) and for the different TNFi-types (adalimumab 0.45 (0.27-0.76)/etanercept 0.24 (0.10-0.61)/infliximab 0.57 (0.34-0.95)).

CONCLUSION

In this study of TNFi-treated AS patients in clinical practice, current and previous smokers had significantly poorer patient-reported outcomes at baseline, shorter treatment adherence and poorer treatment response compared with never smokers.

The effect of smoking on clinical and radiographic variables, and acute phase reactants in patients with ankylosing spondylitis

To investigate the association between smoking and clinical, inflammatory and radiographic parameters in patients with ankylosing spondylitis (AS). One hundred and six tumour necrosis factor inhibitor naïve patients with AS were included in the study. The erythrocyte sedimentation rate, C-reactive protein, Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI) and modified Stroke AS Spine Score (mSASSS) were assessed cross-sectionally for each patient. Smoking history was obtained, and smoking pack years were calculated. Current smokers had significantly higher BASDAI (p < 0.001) and a trend for higher BASFI (p = 0.059). Ever smokers had significantly higher BASFI (p = 0.035) and a trend for higher mSASSS (p = 0.063) compared to never smokers. Pack years (smoking intensity) were positively correlated with duration of inflammatory back pain (r = 0.628, p < 0.001), BASFI (r = 0.443, p < 0.001) and mSASSS (r = 0.683, p < 0.001). Multivariate regression analyses showed that current smoking was independently associated with a higher BASDAI score [regression coefficient (B) = 14.75, p < 0.001] and increasing pack years were independently associated with higher mSASSS (B = 0.26, p = 0.005). In patients with AS, current smoking was strongly and independently associated with higher disease activity, and cumulative smoking exposure with more radiographic spinal damage. In AS smokers, smoking cessation should be strongly recommended.

Non-radiographic axial spondyloarthritis and ankylosing spondylitis: what are the similarities and differences?

The development of the axial spondyloarthritis and ankylosing spondylitis (ASAS) classification criteria has had several implications for our understanding of the entire spectrum of spondyloarthritides (SpA). Going beyond the modified New York criteria, which concentrate on conventional radiographs of the sacroiliac joints (SIJ) for the classification of ankylosing spondylitis, the ASAS criteria add active inflammation of the SIJ as obtained by MRI and human leucocyte antigen (HLA) B27 to classify patients with chronic back pain starting at a young age as axial SpA (axSpA). AxSpA should be considered as one disease that includes AS, the radiographic form, as well as the non-radiographic (nr-axSpA) form. Similarities and differences between these subgroups have been described in 3 studies: 1 local study, 1 national study (German SpA Inception Cohort) and 1 international study mainly conducted to test the efficacy of a tumour necrosis factor α blocker. Most clinical features and assessments of axSpA showed the same prevalence in patients with and without radiographic changes. However, some differences have been observed: the male:female ratio, the proportion of patients with objective signs of inflammation such as bone marrow oedema as detected by MRI, and the proportion of patients with increased levels of C reactive protein were higher in patients with AS. Importantly, these factors have also been identified as prognostic factors for more severe disease in terms of new bone formation. Thus, nr-axSpA may represent an early stage of AS but may also just be an abortive form of a disease which does cause much pain but which may also never lead to structural changes of the axial skeleton. Since the cut-off between nr-axSpA and AS is artificial and unreliable, we think that the term nr-axSpA should not be used for diagnosis but only for classification for historical reasons.