Neutrophil function following treatment of psoriatic arthritis patients with secukinumab: altered cytokine signalling but no impairment of host defence.

OBJECTIVES: Identifying that dysfunction of the IL-23/17 axis underlies PsA has led to the development of effective targeted therapies such as the IL-17A inhibitor secukinumab. As IL-17A stimulates the secretion of neutrophil chemoattractants, such as CXCL8 (IL-8), we examined the effect of secukinumab on neutrophil function in PsA. METHODS: Nineteen patients with active PsA were treated with secukinumab. Clinical response [PsA Response Criteria (PsARC) and Psoriasis Area and Severity Index (PASI)] and peripheral blood neutrophil function (apoptosis, receptor expression, phagocytosis/killing, chemotaxis and RNA expression) were measured at 12 week intervals for 48 weeks and compared with age- and sex-matched healthy controls. RESULTS: At 12 weeks, 12/16 (75%) patients had a PsARC response (100% at 36 weeks) and 10/14 (71%) achieved a 90% PASI response. At baseline, there were no differences in PsA neutrophil reactive oxygen species generation, constitutive or cytokine-delayed apoptosis, chemotaxis or phagocytosis of opsonized Staphylococcus aureus compared with healthy controls. Similarly, there were no differences in these functions from baseline to 12 weeks of therapy. However, surface levels of CD11b/CD18 and CD63 increased and expression of CD16 decreased during therapy. In addition, in a subgroup of early (12 week) responders to secukinumab, RNA sequencing revealed transcriptome changes predicting down-regulation of cytokine signalling and chemotaxis pathways and up-regulation of de novo gene expression pathways, including translation initiation, mRNA catabolism and translation. CONCLUSION: Complex changes in the properties of circulating neutrophils occur with secukinumab treatment in PsA that may indicate altered responsiveness to changes in both local and systemic levels of pro-inflammatory cytokines. However, host defence processes of neutrophils were unaltered.

The association between increased body mass index and response to conventional synthetic disease-modifying anti-rheumatic drug treatment in rheumatoid arthritis: results from the METEOR database.

BACKGROUND: Few data exist on the association between increased BMI and response to conventional synthetic DMARDs (csDMARDs) in RA. We aimed to explore the association between increased (overweight or obese) BMI on csDMARD prescribing, MTX dose and disease activity over 12 months. METHODS: Participants in an international RA database were stratified into early (<1 year post-diagnosis) and established RA. EULAR response, 28-joint DAS (DAS28) remission and treatments were recorded at baseline, 6 months and 12 months. Increased BMI was explored in early and established RA as predictors of good EULAR response, DAS28 remission, number of csDMARDs and MTX dose, using logistic and linear regression. RESULTS: Data from 1313 patients, 44.3% with early RA, were examined. In early RA, increased BMI was not significantly associated with remission. In established RA, obese patients on monotherapy were significantly less likely to achieve good EULAR response or DAS28 remission at 6 months and more likely to be treated with combination csDMARDs compared with normal BMI. In patients taking MTX, overweight and obese patients with early and established RA were exposed to higher MTX doses (mono- and combination therapy), with a mean dose of 20 mg/week, compared with 15 mg/week in those of normal BMI. CONCLUSION: We observed that compared with patients with normal BMI, overweight and obese individuals experienced more intensive csDMARD exposures. Similar response rates were observed in early RA but increased BMI was associated with reduced response in established RA. Optimization of targeted RA treatment remains important, particularly in those with increased BMI where response in established disease may be attenuated.

Depression and anxiety symptoms at TNF inhibitor initiation are associated with impaired treatment response in axial spondyloarthritis.

OBJECTIVES: Depression and anxiety are associated with more severe disease in cross-sectional studies of axial spondyloarthritis (axSpA). We examined the association between baseline symptoms of depression or anxiety and response to TNF inhibitors (TNFi) in axSpA. METHODS: Biologic naïve participants from a national axSpA register completed the Hospital Anxiety and Depression Scale (HADS) before initiating TNFi. Symptoms of anxiety and depression were each categorized as moderate-severe (≥11), mild (8-10) and 'none' (≤7), and compared against change in disease indices [BASDAI and AS Disease Activity Score (ASDAS)] over time and time to treatment discontinuation using marginal structural models. Inverse-probability weights balanced baseline age, gender, BMI, deprivation, education and baseline values of respective disease indices. RESULTS: Of the 742 participants (67% male, mean age 45 years), 176 (24%) had moderate-severe and 26% mild depression; 295 (40%) had moderate-severe and 23% mild anxiety. Baseline disease activity was higher in higher HADS symptom categories for both depression and anxiety. Participants with moderate-severe depression had significantly poorer response compared with those with 'none' throughout follow-up. At 6 months, the difference was approximately 2.2 BASDAI and 0.8 ASDAS units after balancing their baseline values. Equivalent comparisons for anxiety were 1.7 BASDAI and 0.7 ASDAS units. Treatment discontinuation was 1.59-fold higher (hazard ratio 95% CI: 1.12, 2.26) in participants with moderate-severe anxiety compared with 'none'. CONCLUSIONS: Symptoms of depression and anxiety at TNFi initiation are associated with poorer treatment outcomes. Targeted interventions to optimize mental health have potential to substantially improve treatment response and persistence.

Diagnostic delay in axial spondyloarthritis: a systematic review and meta-analysis.

BACKGROUND: Delay to diagnosis in axial SpA (axSpA) is longer than in many other rheumatic diseases. Prolonged delay is associate with poorer outcomes, including functional impairment and quality of life. Our aims were to describe global variation in delay to diagnosis, factors associated with delay, and delay compared with PsA. METHODS: We searched MEDLINE, PubMed, Embase and Web of Science using a predefined protocol. Diagnostic delay was defined as years between the age at symptom onset and at diagnosis. We pooled the mean delay using random effects inverse variance meta-analysis. We examined variations in pooled estimates using prespecified subgroup analyses and sources of heterogeneity using meta-regression. RESULTS: A total of 64 studies reported the mean diagnostic delay in axSpA patients. The pooled mean delay was 6.7 years (95% CI 6.2, 7.2) with high levels of heterogeneity. Delay to diagnosis did not improve over time when stratifying results by year of publication. Studies from high-income countries (defined by the World Bank) reported longer delays than those from middle-income countries. Factors consistently reported to be associated with longer delays were lower education levels, younger age at symptom onset and absence of extra-articular manifestations (EAMs). The pooled estimate for diagnostic delay from 8 PsA studies was significantly shorter, at 2.6 years (95% CI 1.6, 3.6). CONCLUSION: For axSpA patients, delay to diagnosis remains unacceptably prolonged in many parts of the world. Patient factors (e.g. education) and disease presentation (onset age and EAMs) should inform campaigns to improve delay.

Association between comorbidities and disease activity in axial spondyloarthritis: results from the BSRBR-AS.

OBJECTIVE: Whether comorbidities influence disease activity assessment in axial SpA (axSpA) is unclear. Comorbidities inflate DAS28 in rheumatoid arthritis through the patient global score. We examined whether axSpA disease activity measures are differentially affected, and whether comorbidities inflate the AS disease activity score (ASDAS) through the patient global component. METHODS: We used baseline data from the British Society for Rheumatology Biologics Register for AS, including 14 physician diagnosed comorbidities. Linear models were used to compare disease activity (BASDAI, spinal pain, ASDAS) and ESR/CRP according to comorbidity count, adjusted for age, gender, BMI, smoking, socioeconomic status, and education. The same models were used to examine whether the patient global score was associated with comorbidities, additionally adjusting for other ASDAS components. RESULTS: The number of participants eligible for analysis was 2043 (67% male, mean age 49 years); 44% had at least one comorbidity. Each additional comorbidity was associated with higher BASDAI by 0.40 units (95% CI: 0.27, 0.52) and spinal pain by 0.53 (95% CI: 0.37, 0.68). Effect size for ASDAS (0.09 units; 95% CI: 0.03, 0.15) was not clinically significant. ESR and CRP were not associated with comorbidity count. Depression, heart failure and peptic ulcer were consistently associated with higher disease activity measures, but not CRP/ESR. Patient global was associated with comorbidity count, but not independently of other ASDAS components (P = 0.75). CONCLUSION: Comorbidities were associated with higher patient reported disease activity in axSpA. Clinicians should be mindful of the potential impact of comorbidities on patient reported outcome measures and consider additionally collecting ASDAS when comorbidities are present.

Comorbidity and response to TNF inhibitors in axial spondyloarthritis: longitudinal analysis of the BSRBR-AS.

OBJECTIVE: Comorbidities influence disease assessment in axial spondyloarthritis (axSpA), but their association with response to TNF inhibitors (TNFi) is unclear. We examined associations between comorbidity history at TNFi initiation and: (i) change in disease indices over time; (ii) binary response definitions; and (iii) time to treatment discontinuation. METHODS: We studied participants starting their first TNFi from a national axSpA register. Comorbidity categories were created from 14 physician-diagnosed conditions and compared against: change in disease indices over time using linear mixed effects models; BASDAI50/2 (50% or 2-unit reduction) and BASDAI < 4 at 6 months using logistic models; and time to treatment discontinuation using Cox models. Models were adjusted for age, gender, BMI, deprivation and education. RESULTS: In total, 994 were eligible for analysis (68% male, mean age 45 years); 21% had one comorbidity and 11% had ≥2. Baseline disease severity was higher in those with comorbidities across all indices, but absolute improvement over time was comparable for BASDAI and spinal pain. Participants with ≥2 comorbidities had smaller absolute improvement in BASFI and quality of life. This group also had numerically reduced odds of achieving BASDAI50/2 [odds ratio (OR) 0.81; 95% CI: 0.45, 1.45] and BASDAI < 4 (OR 0.57; 95% CI: 0.32, 1.04). Treatment discontinuation was increased in those with two comorbidities [hazard ratio (HR) 1.32; 95% CI: 0.88, 2.00] and ≥3 comorbidities (HR 2.18; 95% CI: 1.20, 3.93) compared with none. CONCLUSIONS: Participants with multiple comorbidities had poorer treatment outcomes, particularly increased treatment discontinuation and poorer improvements in function and quality of life. These results inform clinicians and educate patients about response to the first TNFi given comorbidity burden.

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.

Prevalence and impact of comorbidities in axial spondyloarthritis: systematic review and meta-analysis.

OBJECTIVES: Comorbidities are common in people with axial spondyloarthritis (axSpA). In this systematic review and meta-analysis, we aimed to: (i) describe the prevalence of commonly reported comorbidities, (ii) compare comorbidities between axSpA and control populations, and (iii) examine the impact of comorbidity burden on axSpA outcomes. METHODS: We systematically searched Medline, PubMed, Scopus and Web of Science using a predefined protocol in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. We excluded studies of only one comorbid condition or a few closely related diseases within one organ system. Where possible, meta-analysis was performed using random-effects models. RESULTS: A total of 40 studies were included for analysis. 36 studies reported prevalence of comorbidities, amounting to a combined sample size of 119 427 patients. The number of comorbidities studied ranged from 3 to 43. The most prevalent individual comorbidities were hypertension (pooled prevalence 23%), hyperlipidaemia (17%) and obesity (14%). Eleven studies consistently showed higher prevalence of comorbidities in axSpA than controls, particularly large differences were seen for depression [pooled odds ratio (OR) 1.80] and heart failure (OR 1.84). Comorbidities (total number of and individual conditions) were also associated with axSpA disease activity, functional impairment, quality of life, work productivity and mortality. CONCLUSIONS: Comorbidities are common in axSpA, particularly cardiovascular diseases and risk factors. Most comorbidities were more prevalent in axSpA patients than in control populations. Overall comorbidity burden, and many individual conditions, were associated with axSpA outcomes including worse disease severity, work productivity and mortality.

Incorporating natural language processing to improve classification of axial spondyloarthritis using electronic health records.

OBJECTIVES: To develop classification algorithms that accurately identify axial SpA (axSpA) patients in electronic health records, and compare the performance of algorithms incorporating free-text data against approaches using only International Classification of Diseases (ICD) codes. METHODS: An enriched cohort of 7853 eligible patients was created from electronic health records of two large hospitals using automated searches (⩾1 ICD codes combined with simple text searches). Key disease concepts from free-text data were extracted using NLP and combined with ICD codes to develop algorithms. We created both supervised regression-based algorithms-on a training set of 127 axSpA cases and 423 non-cases-and unsupervised algorithms to identify patients with high probability of having axSpA from the enriched cohort. Their performance was compared against classifications using ICD codes only. RESULTS: NLP extracted four disease concepts of high predictive value: ankylosing spondylitis, sacroiliitis, HLA-B27 and spondylitis. The unsupervised algorithm, incorporating both the NLP concept and ICD code for AS, identified the greatest number of patients. By setting the probability threshold to attain 80% positive predictive value, it identified 1509 axSpA patients (mean age 53 years, 71% male). Sensitivity was 0.78, specificity 0.94 and area under the curve 0.93. The two supervised algorithms performed similarly but identified fewer patients. All three outperformed traditional approaches using ICD codes alone (area under the curve 0.80-0.87). CONCLUSION: Algorithms incorporating free-text data can accurately identify axSpA patients in electronic health records. Large cohorts identified using these novel methods offer exciting opportunities for future clinical research.

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 (ß = 0.3, 95% CI 0.1-0.6; ß = 0.9, 95% CI 0.6-1.2) and BASFI (ß = 0.5, 95% CI 0.2-0.8; ß = 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.

Comparison of comorbidities and treatment between ankylosing spondylitis and non-radiographic axial spondyloarthritis in the United States.

OBJECTIVES: This study aimed to compare comorbidities and biologic DMARD (bDMARD) use between AS and non-radiographic axial SpA (nr-axSpA) patients, using a large cohort of patients from routine clinical practice in the United States. METHODS: We performed a cross-sectional study using electronic medical records from two academic hospitals in the United States. Data were extracted using automated searches (⩾3 ICD codes combined with text searches) and supplemented with manual chart review. Patients were categorized into AS or nr-axSpA according to classification criteria. Disease features, comorbidities (from a list of 39 chronic conditions) and history of bDMARD prescription were compared using descriptive statistics. RESULTS: Among 965 patients identified, 775 (80%) were classified as having axSpA. The cohort was predominantly male (74%) with a mean age of 52.5 years (s.d. 16.8). AS patients were significantly older (54 vs 46 years), more frequently male (77% vs 64%) and had higher serum inflammatory markers than those with nr-axSpA (median CRP 3.4 vs 2.2 mg/dl). Half of all patients had at least one comorbidity. The mean number of comorbidities was 1.5 (s.d. 2.2) and similar between AS and nr-axSpA groups. A history of bDMARD-use was seen in 55% of patients with no difference between groups. The most commonly prescribed bDMARDs were adalimumab (31%) and etanercept (29%). Ever-prescriptions of individual bDMARDs were similar between AS and nr-axSpA. CONCLUSION: Despite age differences, nr-axSpA patients had similar comorbidity burdens as those with AS. Both groups received comparable bDMARD treatment in this United States clinic-based cohort.

Comorbidity burden in axial spondyloarthritis: a cluster analysis.

OBJECTIVES: To examine how comorbidities cluster in axial spondyloarthritis (axSpA) and whether these clusters are associated with quality of life, global health and other outcome measures. METHODS: We conducted a cross-sectional study of consecutive patients meeting ASAS criteria for axSpA in Liverpool, UK. Outcome measures included quality of life (EQ5D), global health and disease activity (BASDAI). We used hierarchical cluster analysis to group patients according to 38 pre-specified comorbidities. In multivariable linear models, the associations between distinct comorbidity clusters and each outcome measure were compared, using axSpA patients with no comorbidities as the reference group. Analyses were adjusted for age, gender, symptom duration, BMI, deprivation, NSAID-use and smoking. RESULTS: We studied 419 patients (69% male, mean age 46 years). 255 patients (61%) had at least one comorbidity, among whom the median number was 1 (range 1-6). Common comorbidities were hypertension (19%) and depression (16%). Of 15 clusters identified, the most prevalent clusters were hypertension-coronary heart disease and depression-anxiety. Compared with patients with no comorbidities, the fibromyalgia-irritable bowel syndrome cluster was associated with adverse patient-reported outcome measures; these patients reported 1.5-unit poorer global health (95%CI 0.01, 2.9), reduced quality of life (0.25-unit lower EQ5D; 95%CI -0.37, -0.12) and 1.8-unit higher BASDAI (95% CI 0.4, 3.3). Similar effect estimates were found for patients in the depression-anxiety cluster. CONCLUSION: Comorbidity is common among axSpA patients. The two most common comorbidities were hypertension and depression. Patients in the depression-anxiety and fibromyalgia-IBS clusters reported poorer health and increased axSpA severity.

Concomitant fibromyalgia complicating chronic inflammatory arthritis: a systematic review and meta-analysis.

Objectives: This systematic review and meta-analysis will describe the prevalence of concomitant FM in adults with inflammatory arthritis and quantify the impact of FM on DAS. Methods: Cochrane library, MEDLINE, Psychinfo, PubMed, Scopus and Web of Science were searched using key terms and predefined exclusion criteria. As appropriate, proportional and pairwise meta-analysis methods were used to pool results. Results: Forty articles were identified. In RA the prevalence of FM ranged from 4.9 to 52.4% (21% pooled). In axSpA the range was 4.11-25.2% (13% pooled in AS only). In PsA the range was 9.6-27.2% (18% pooled). The presence of concomitant FM was related to higher DAS in patients with RA and AS (DAS28 mean difference 1.24, 95% CI: 1.10, 1.37 in RA; BASDAI mean difference 2.22, 95% CI: 1.86, 2.58 in AS). Concomitant FM was also associated with higher DAS in existing PsA studies. Self-reported, rather than objective, components of DAS appear to be raised in the presence of FM (e.g. tender joint count and Visual Analogue Scale (VAS) pain scores). Conclusion: FM is common in RA, AxSpA and PsA. Comorbid FM appears to amplify DAS and could therefore influence management of these rheumatic conditions.

Alcohol and disease activity in axial spondyloarthritis: a cross-sectional study.

The objective of this study was to explore associations between alcohol consumption and disease activity in axial spondyloarthritis (axSpA). We conducted a cross-sectional study of axSpA participants meeting the ASAS criteria. Associations between self-reported current alcohol use and disease activity (BASDAI, spinal pain, ASDAS), functional impairment (BASFI), and quality of life were explored using multivariable linear models, adjusting for age, gender, symptom duration, use of TNF inhibition therapy, smoking, deprivation, and anxiety and depression (A&D). Within alcohol drinkers, effect of increased alcohol intake (defined as > 14 units/week) was explored with moderate drinking (≤ 14 units/week) as reference. The study cohort comprised 229 axSpA patients and 76% were male with mean age 46.5 years (SD ± 13.8). Alcohol drinking was reported by 64%, with a median of 6 units per week among drinkers. Compared with non-drinkers, drinkers had lower BASDAI (ß = - 0.83; 95% CI - 1.49, - 0.17), ASDAS (ß = - 0.36; 95% CI - 0.66, - 0.05) and BASFI (ß = - 1.40; 95% CI - 2.12, - 0.68). These associations were in contrast to, and independent of, the detrimental effects of smoking, depression, and deprivation. Subgroup analysis in alcohol drinkers did not reveal significant associations between disease severity and increased alcohol intake. Stratified analyses by smoking revealed that in never-smokers without depression, alcohol was associated with greater reduction in disease activity: BASDAI (ß = - 1.69; 95% CI - 2.93, - 0.45), ASDAS (ß = - 0.60; 95% CI - 1.18, - 0.02). Favourable axSpA disease activity and function were observed in association with alcohol consumption in this cross-sectional study. Longitudinal study is required to explore whether this relationship is due to biological effects of alcohol on disease process or disease-associated behaviour modification.

Autoantibodies to Osteoprotegerin are Associated with Low Hip Bone Mineral Density and History of Fractures in Axial Spondyloarthritis: A Cross-Sectional Observational Study.

Osteoporosis is a recognised complication of axial spondyloarthritis (axSpA) and is thought to be due to functional impairment and the osteoclast-activating effects of proinflammatory cytokines. The development of autoantibodies to OPG (OPG-Ab) has been associated with severe osteoporosis and increased bone resorption in rheumatoid arthritis. In this study, we screened for the presence of OPG-Ab in axSpA and reviewed their clinical significance. We studied 134 patients, recruited from two centres in the United Kingdom. Their mean age was 47.5 years and 75% were male. Concentrations of OPG-Ab were related to bone mineral density (BMD) and fracture history using linear and logistic regression models adjusting for age, gender, disease duration and activity, body mass index and bisphosphonate use. We detected OPG-Ab in 11/134 patients (8.2%). Femoral neck and total hip BMD were significantly reduced in OPG-Ab positive patients (0.827 vs. 0.967 g/cm2, p = 0.008 and 0.868 vs. 1.028 g/cm2, p = 0.002, respectively). Regression analysis showed that the presence of OPG-Ab was independently associated with total hip osteopenia (ORadj 24.2; 95% CI 2.57, 228) and history of fractures (ORadj 10.5; 95% CI 2.07, 53.3). OPG-Ab concentration was associated with total hip BMD in g/cm2 (ß = -1.15; 95% CI -0.25, -0.04). There were no associations between OPG-Ab concentration and bone turnover markers, but free sRANKL concentrations were lower in OPG-Ab-positive patients (median 0.04 vs. 0.11 pmol/L, p = 0.050). We conclude that OPG-Ab are associated with hip BMD and fractures in axSpA suggesting that they may contribute to the pathogenesis of bone loss in some patients with this condition.

Increasing smoking intensity is associated with increased disease activity in axial spondyloarthritis.

A history of ever-smoking appears to be associated with a more severe disease phenotype in axial spondyloarthritis (axSpA). However, evidence is sparse for the effect of increased smoking exposure on disease outcomes or whether smoking reduction or cessation improves outcomes. The aim of this study was to explore whether a dose-response relationship exists between pack-years and disease activity and functional impairment in axSpA. Consecutive patients meeting ASAS criteria for axial SpA were recruited from a spondyloarthritis service. The associations between pack-years of smoking and: (1) disease activity (BASDAI/ASDAS), (2) spinal pain, (3) functional impairment (BASFI) and (4) inflammatory markers were explored using multivariable linear models, adjusted for age, gender and use of TNF inhibition (TNFi) therapy. Pack-years were categorised into four groups (<10, 11-20, 21-40, >40) and analysed with light smoking (<10) as reference. Two hundred and thirty-eight axSpA patients were recruited: 76% were male, mean age 46.4 years (SD ± 13.7), and 33% were treated with TNFi. One hundred and twelve patients reported history of ever-smoking with median pack-year 20 [IQR10-30]. Compared to light smokers, those with higher categories of smoking exposures had higher BASDAI (21-40 pack-years, ß = 1.6 (95% CI 0.28, 2.95); >40, ß = 2.6 (0.54, 3.56)), higher BASFI (21-40, ß = 2.1 (0.42, 4.80); >40, ß = 3.2 (0.76, 5.71)), and higher ASDAS (21-40, ß = 0.82 (0.14, 1.51)). This cross-sectional study demonstrated that smoking is associated with increased axSpA severity markers in a dose-response manner. Particular effort should be made to restrict smoking exposure early before accruing a significant number of pack-years.

Serum urate and obstructive sleep apnoea in severe obesity.

Obstructive sleep apnoea (OSA) may increase the risk of hyperuricaemia and predispose to gout. The evidence for the effects of OSA on serum urate in severe obesity is limited. This study investigated whether OSA was associated with serum urate in severe obesity and whether continuous positive airway pressure (CPAP) treatment was associated with a fall in urate. Severely obese subjects without known OSA or gout were recruited. Baseline assessments included urate, metabolic parameters, spirometry and overnight polysomnography. OSA patients were initially naive to treatment and were offered CPAP. At follow-up, change in urate was compared between CPAP-treated and non-CPAP-treated subjects. A high urate was defined as greater than the median. Logistic regression was performed to identify associations between (1) OSA and high urate at baseline and (2) use of CPAP and change in urate at follow-up. In total, 92 subjects were recruited (61 (66%) OSA and 31 (34%) non-OSA). Median urate was 345 µmol/L. OSA was associated with high urate in females at baseline after adjusting for confounders (adjusted odds ratio ORadj = 10.2; 95% CI: 1.1, 93.5). At follow-up (14 months), 58 subjects (28 on CPAP and 30 not on CPAP) were reassessed. CPAP was significantly associated with a fall to a low urate category at follow-up ( = 0.017). Regression revealed a trend for a fall in urate category in the CPAP-treated group (ORadj = 9.3; 95% CI: 0.8, 97). Serum urate is associated with OSA in severely obese females and CPAP may reduce levels in patients with OSA. There may be a need to consider and assess for OSA in obese patients with hyperuricaemia and recurrent attacks of gout.

Systematic review of association between vitamin D levels and susceptibility and disease activity of ankylosing spondylitis.

OBJECTIVES: Vitamin D appears to have significant effects on both innate and acquired immunity and deficiency may be associated with both susceptibility and disease severity in some autoimmune conditions. There has been little focus on the potential immunomodulatory role of vitamin D in AS. This study systematically reviews the evidence for an association between vitamin D deficiency and disease susceptibility and severity in AS. METHODS: A systematic review was conducted using Medline, EMBASE, Web of Science and conference abstracts of the European League Against Rheumatism (2002-13), British Society for Rheumatology (1993-2013) and ACR (2006-13). RESULTS: Fifteen original articles and five conference abstracts met the criteria for inclusion. All were cross-sectional in design. Seven of 11 studies identified lower concentrations of 25-hydroxyvitamin D (25OHD) in AS patients compared with healthy controls. A significant inverse correlation between 25OHD and disease activity was observed in 5 of 11 studies. The majority of studies that failed to demonstrate significant findings used inappropriate statistical methods. CONCLUSION: Cross-sectional studies using appropriate statistical analyses have highlighted that AS is associated with lower vitamin D concentrations. Within groups of AS patients there is some evidence that low vitamin D concentrations are associated with higher disease activity. However, there are insufficient published data to support an immunomodulatory role for vitamin D in AS. Further study with a longitudinal design is required to understand whether optimizing vitamin D in AS has potential as a disease-modifying intervention.