One-year effectiveness of long-term exercise therapy in people with axial spondyloarthritis and severe functional limitations.

OBJECTIVE: To evaluate the effectiveness of long-term, personalized, supervised exercise therapy on functional ability compared with usual care in people with axial spondyloarthritis (axSpA) and severe functional limitations. METHODS: Participants were randomly 1:1 assigned to the intervention(maximal 64 sessions, with 14 additional optional sessions of supervised active exercise therapy(e.g. aerobic and muscle strengthening) with individualized goal-setting, education and self-management regarding physical activity) or usual care(care determined by clinician(s) and participants themselves). Primary end point was the change in the Patient-Specific Complaints activity ranked 1 (PSC1 (0-10)) at 52 weeks. Secondary endpoints were the PSC activities ranked 2 and 3, the Bath Ankylosing Spondylitis Functional Index, 6-min walk test, Patient Reported Outcome Measurement Information System-Physical Function-10 and the Short Form-36 Physical and Mental Component Summary Score (SF-36 PCS and MCS). Statistical comparisons comprised independent student t-tests and linear mixed models, based on intention-to-treat. RESULTS: 214 participants(49% female, age 52 (SD 12) years), were randomized to the intervention (n = 110) or usual care (N = 104) group. In the intervention group 93% started treatment, using on average 40.5 sessions (SD 15.1). At 52 weeks, the difference in change in PSC1 between groups favored the intervention group (mean difference [95% CI]; -1.8 [-2.4 to -1.2]). additionally, all secondary outcomes, except the SF-36 MSC, showed significantly greater improvements in the intervention group with effect sizes ranging from 0.4-0.7. CONCLUSION: Long-term, supervised exercise therapy proved more effective than usual care in improving functional disability and physical quality of life in people with axSpA and severe functional limitations. CLINICAL TRIAL REGISTER NUMBER: Netherlands Trial Register NL8238, included in the International Clinical Trial Registry Platform (ICTRP) (https://trialsearch.who.int/Trial2.aspx?TrialID=NL8238).

Change in disease activity is associated with TNF-α inhibitor serum levels in patients with axial spondyloarthritis in daily clinical practice.

OBJECTIVES: To investigate, in daily clinical practice, TNF-α inhibitor serum trough levels in patients experiencing an increase in axial spondyloarthritis (ax-SpA) related symptoms. Secondly, to explore if these serum trough levels are associated with disease activity (DA) and/or change in DA. METHODS: Patients from the GLAS cohort treated with TNF-α inhibitors who had a serum trough level measurement during follow-up because of an increase in ax-SpA related symptoms between June 2015 and June 2018 were included. Serum trough levels were stratified in a therapeutic and below therapeutic range, based on published reference values of Sanquin in 2019. DA was assessed by ASDAS and BASDAI and change in DA (i.e. ΔASDAS or BASDAI compared to the visit before increasing symptoms). RESULTS: 31 patients had a serum trough level measurement because of increasing symptoms. These patients had a median treatment duration of 4.8 years (IQR 0.9-8.6). 22 (71%) had active disease according to ASDAS (score ≥2.1) and 15 (47%) had therapeutic drug levels. The increase in DA was significantly larger in patients with below therapeutic drug levels compared to patients with therapeutic levels (ΔASDAS: 0.94±0.81 vs. -0.07±1.26, p<0.05; ΔBASDAI: 1.72±1.73 vs. -0.53±1.8, p<0.005). No significant differences were found in absolute DA scores between patients with or without therapeutic drug levels. CONCLUSIONS: In this observational study in daily clinical practice, approximately half of ax-SpA patients who experienced an increase in symptoms had below therapeutic TNF-α inhibitor serum trough levels. Change in DA and not absolute DA scores was significantly associated with drug levels.

Efficacy of a tight-control and treat-to-target strategy in axial spondyloarthritis: results of the open-label, pragmatic, cluster-randomised TICOSPA trial.

OBJECTIVES: To compare the benefits of a tight-control/treat-to-target strategy (TC/T2T) in axial spondyloarthritis (axSpA) with those of usual care (UC). METHODS: Pragmatic, prospective, cluster-randomised, controlled, open, 1-year trial (NCT03043846). 18 centres were randomised (1:1). Patients met Axial Spondylo Arthritis International Society (ASAS) criteria for axSpA, had an Ankylosing Spondylitis Disease Activity Score (ASDAS) ≥2.1, received non-optimal treatment by non-steroidal anti-inflammatory drugs and were biologic-naive. INTERVENTIONS: (1) TC/T2T: visits every 4 weeks and prespecified strategy based on treatment intensification until achieving target (ie, ASDAS <2.1); (2) UC: visits every 12 weeks and treatment at the rheumatologist's discretion. MAIN OUTCOME: Percentage of patients with a ≥30% improvement on the ASAS-Health Index (ASAS-HI). Other efficacy outcomes and adverse events were recorded. A health economic evaluation was performed. STATISTICAL ANALYSIS: Two-level mixed models were used to estimate efficacy outcomes. Cost-effectiveness was assessed by the incremental cost per quality-adjusted life-year (QALY) gained for TC/T2T versus UC. RESULTS: 160 patients were included (80/group). Mean (SD) age was 37.9 (11.0) years and disease duration was 3.7 (6.2) years; 51.2% were men. ASDAS at inclusion was 3.0 (0.7), and ASAS-HI was 8.6 (3.7). ASAS-HI improved by ≥30% in 47.3% of the TC/T2T arm and in 36.1% of those receiving UC (non-significant). All secondary efficacy outcomes were more frequent in the TC/T2T arm, although not all statistically significant. Safety was similar in both arms. From a societal perspective, TC/T2T resulted in an additional 0.04 QALY, and saved €472 compared with UC. CONCLUSION: TC/T2T was not significantly superior to UC for the primary outcome, while many secondary efficacy outcomes favoured it, had a similar safety profile and was favourable from a societal health economic perspective. TRIAL REGISTRATION NUMBER: NCT03043846.

Central sensitization, illness perception and obesity should be considered when interpreting disease activity in axial spondyloarthritis.

OBJECTIVES: Many patients with axial spondyloarthritis (axSpA) report persistent pain even when treated with anti-inflammatory agents. Our aim was to explore the presence of central sensitization (CS) and different types of illness perceptions in patients with axSpA, and to assess their associations with disease activity assessments. METHODS: Consecutive outpatients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort were included. Besides standardized assessments, patients filled out the Central Sensitization Inventory (CSI), Illness Perception Questionnaire (IPQ-R) and Pain Catastrophizing Scale (PCS). Univariable and multivariable linear regression analyses were used to investigate the association between questionnaire scores, patient characteristics and disease activity assessments ASDASCRP, BASDAI and CRP. RESULTS: We included 182 patients with a mean symptom duration of 21.6 years. Mean ASDASCRP was 2.1, mean BASDAI 3.9, and median CRP 2.9. Mean CSI score was 37.8 (scale 0-100) and 45% of patients scored ≥40, indicating a high probability of CS. CSI score, IPQ-R domain identity (number of symptoms the patient attributes to their illness), and IPQ-R domain treatment control (perceived treatment efficacy), and obesity were significantly and independently associated with both ASDASCRP and BASDAI, explaining a substantial proportion of variation in these disease activity scores (R2=0.35 and R2=0.47, respectively). Only obesity was also independently associated with CRP. CONCLUSION: CS may be common in patients with long-term axSpA. CS, as well as specific illness perceptions and obesity were all independently associated with the widely used (partially) patient-reported disease activity assessments ASDASCRP and BASDAI. Treating physicians should take this into account in the follow-up and treatment of their patients.

Bone mineral density improves during 2 years of treatment with bisphosphonates in patients with ankylosing spondylitis.

AIMS: To evaluate whether 2 years of treatment with bisphosphonates in combination with calcium/vitamin D supplements has an effect on lumbar spine and hip bone mineral density (BMD) in ankylosing spondylitis (AS) patients starting tumour necrosis factor-α inhibitors or receiving conventional treatment. Secondly, to explore the development of radiographic vertebral fractures. METHODS: Patients from the Groningen Leeuwarden AS cohort receiving bisphosphonates based on clinical indication and available 2-year follow-up BMD measurements were included. BMD of lumbar spine (L1-L4) and hip (total proximal femur) were measured using dual-energy X-ray absorptiometry. Spinal radiographs (Th4-L4) were scored for vertebral fractures according to the Genant method. RESULTS: In the 20 included patients (median 52 years, 14 males), lumbar spine and hip BMD Z-scores increased significantly; median from -1.5 (interquartile range [IQR] -2.2 to 0.4) to 0.1 (IQR -1.5 to 1.0); P < .001 and median from -1.0 (IQR -1.6 to -0.7) to -0.8 (IQR -1.2 to 0.0); P = .006 over 2 years, respectively. In patients also treated with tumour necrosis factor-α inhibitors (n = 11), lumbar spine and hip BMD increased significantly (median 2-year change +8.6% [IQR 2.4 to 19.6; P = .009] and +3.6% [IQR 0.7-9.0; P = .007]). In patients on conventional treatment (n = 9), lumbar spine BMD increased significantly (median 2-year change +3.6%; IQR 0.7 to 9.0; P = .011) and no improvement was seen in hip BMD (median -0.6%; IQR -3.1 to 5.1; P = .61). Overall, younger AS males with limited spinal radiographic damage showed most improvement in lumbar spine BMD. Four mild radiographic vertebral fractures developed in 3 patients and 1 fracture increased from mild to moderate over 2 years in postmenopausal women and middle-aged men. CONCLUSION: This explorative observational cohort study in AS showed that 2 years of treatment with bisphosphonates in combination with calcium/vitamin D supplements significantly improves lumbar spine BMD. Mild radiographic vertebral fractures still occurred.

B Cell Involvement in the Pathogenesis of Ankylosing Spondylitis.

Extensive research into ankylosing spondylitis (AS) has suggested the major role of genetics, immune reactions, and the joint-gut axis in its etiology, although an ultimate consensus does not yet exist. The available evidence indicates that both autoinflammation and T-cell-mediated autoimmune processes are actively involved in the disease process of AS. So far, B cells have received relatively little attention in AS pathogenesis; this is largely due to a lack of conventional disease-defining autoantibodies. However, against prevailing dogma, there is a growing body of evidence suggestive of B cell involvement. This is illustrated by disturbances in circulating B cell populations and the formation of auto-reactive and non-autoreactive antibodies, along with B cell infiltrates within the axial skeleton of AS patients. Furthermore, the depletion of B cells, using rituximab, displayed beneficial results in a subgroup of patients with AS. This review provides an overview of our current knowledge of B cells in AS, and discusses their potential role in its pathogenesis. An overarching picture portrays increased B cell activation in AS, although it is unclear whether B cells directly affect pathogenesis, or are merely bystanders in the disease process.

High prevalence of hip involvement and decrease in inflammatory ultrasound lesions during tumour necrosis factor-α blocking therapy in ankylosing spondylitis.

OBJECTIVES: To assess the prevalence of clinical, US and radiographic hip involvement in AS patients with active disease and to explore the associations between these assessments. Furthermore, to evaluate the effect of 6 months of TNF-α blocking therapy on tender and inflammatory power Doppler US lesions of hip joints. METHODS: Consecutive AS patients starting TNF-α blocking therapy were evaluated for hip joint involvement. At baseline, patient-reported history of hip involvement was assessed and radiographic evaluation (BASRI-hip) was performed. Clinical examination (tender hip joints) and US examination took place before and after 6 months of treatment. RESULTS: Of the 111 included patients, 20% reported a history of hip involvement. At baseline, tender hip joints were present in 23% of patients. US examination showed inflammatory lesions in 17% of patients, of which 74% had positive power Doppler. Structural lesions were present in 20% of patients, of which 55% had osteophytes. Structural radiographic damage was seen in 10% of patients. Highest concordance was found between history of hip involvement and radiographic hip involvement (phi coefficient 0.333). After 6 months of TNF-α blocking therapy, significant decrease was found in tender hip joints (from 29 to 11), total number of inflammatory US lesions (from 29 to 9) and positive power Doppler (from 22 to 6). CONCLUSION: The prevalence rate of hip involvement in AS patients varies from 10 to 23%, depending on the type of hip assessment. TNF-α blocking therapy significantly improved tender hip joints, and inflammatory US lesions including positive power Doppler.

Long-term drug survival and clinical effectiveness of etanercept treatment in patients with ankylosing spondylitis in daily clinical practice.

OBJECTIVES: Randomised controlled trials and open-label extension studies have demonstrated the clinical efficacy and safety of tumour necrosis factor-alpha (TNF-α) blocking therapy in pre-selected study patients with ankylosing spondylitis (AS). Our aim was to investigate the 7-year drug survival and clinical effectiveness of etanercept treatment in AS patients in daily clinical practice. METHODS: Consecutive AS patients from the prospective observational GLAS cohort who started etanercept because of active disease were included and evaluated over 7 years according to a fixed protocol. Continuation of treatment was based on BASDAI improvement and/or expert opinion. RESULTS: Of the 89 included AS patients, 45 (51%) were still using etanercept at 7 years of follow-up. Reasons for treatment discontinuation were adverse events (n=22), inefficacy (n=13), or other reasons although good clinical response (n=9). Etanercept treatment resulted in a rapid (after 6 weeks) and sustained improvement in disease activity (BASDAI, ASDAS, CRP, physician GDA), spinal mobility, physical function (BASFI), quality of life (ASQoL), and extra-spinal manifestations (swollen joints, tender joints and tender entheses). Furthermore, concomitant NSAID or DMARD use decreased significantly during follow-up. At 7 years, low disease activity and remission were present in 67-73% and 29-30% of the 45 patients, respectively. Of the patients who discontinued etanercept, 18 switched successfully to a second or third TNF-α blocker during follow-up. CONCLUSIONS: In a large cohort of AS patients treated with etanercept, approximately 50% continued this treatment for 7 years. Our broad evaluation of clinical endpoints proves the long-term effectiveness of etanercept treatment in daily clinical practice.

Radiographic vertebral fractures develop in patients with ankylosing spondylitis during 4 years of TNF-α blocking therapy.

OBJECTIVES: To determine the prevalence and incidence of radiographic vertebral fractures in ankylosing spondylitis (AS) patients treated with TNF-α blocking therapy for 4 years and to explore the relationship with patient characteristics, clinical assessments, radiographic damage, and bone mineral density (BMD). METHODS: This study included consecutive AS patients with active disease from the Groningen Leeuwarden AS (GLAS) cohort treated with TNF-α blocking therapy for 4 years and with available thoracic and lumbar radiographs at baseline and at 4 years. Vertebral fractures were assessed by two readers (mild: ≥20-<25%, moderate: ≥25-<40%, severe: ≥40% reduction in vertebral height). RESULTS: In 27 of 105 (26%) AS patients, radiographic vertebral fractures were observed at baseline. These patients were significantly older, had larger occiput-to-wall distance, and more spinal radiographic damage. During 4 years of TNF-α blocking therapy, 21 (20%) patients developed at least one new fracture. Older age, smoking, higher BASFI, low lumbar spine BMD (Z-score ≤-2), presence of moderate vertebral fractures, and use of anti-osteoporotic treatment at baseline were associated with the development of new fractures. Most fractures were mild and occurred in the thoracic spine. The improvement in lateral spinal mobility and lumbar spine BMD during treatment was significantly less in patients with new fractures (median change of 0.8 vs. 2.8 cm and 0.3 vs. 0.8 Z-score, respectively). CONCLUSIONS: The prevalence of radiographic vertebral fractures was high in AS patients with active disease. Although clinical assessments and BMD improved significantly, new vertebral fractures still developed during 4 years of TNF-α blocking therapy.

Patient-tailored dose reduction of TNF-α blocking agents in ankylosing spondylitis patients with stable low disease activity in daily clinical practice.

OBJECTIVES: Tumour necrosis factor-alpha (TNF-α) blocking agents are very effective in controlling systemic inflammation and improving clinical assessments in ankylosing spondylitis (AS). In view of potential side effects and high costs of long-term treatment, our aim was to investigate whether dose reduction of TNF-α blocking agents is possible without loss of effectiveness in AS patients in daily clinical practice. METHODS: Patients from the prospective observational GLAS cohort, fulfilling the modified New York criteria for AS, with active disease before start of TNF-α blocking therapy and stable (≥6 months) low disease activity on the conventional dose regimen, who started with dose reduction of TNF-α blocking therapy before June 2011 were studied. Dose reduction was patient-tailored (step-by-step approach) and consisted of lowering the dose and/or extending the interval between doses. RESULTS: Between June 2005 and March 2011, 58 AS patients started dose reduction of etanercept (n=39), infliximab (n=10), or adalimumab (n=9). Of all patients, 74%, 62%, and 53% maintained their reduced dose or dosing frequency after 6, 12, and 24 months, respectively. The mean dose of TNF-α blocking therapy over time corresponded to 62% of the standard dose regimen. Disease activity remained low in the majority of patients who maintained dose reduction after 24 months (94% had BASDAI<4). If there was recurrence of disease symptoms, patients achieved good clinical response after returning to the conventional regimen (88% reached BASDAI<4). CONCLUSIONS: In this observational cohort, patient-tailored dose reduction of TNF-α blocking agents was successful preserving stable low disease activity over 24 months in approximately half of the AS patients.

Clinical studies on bone-related outcome and the effect of TNF-α blocking therapy in ankylosing spondylitis.

PURPOSE OF REVIEW: To provide an overview of clinical trials and observational studies investigating the effect of tumor necrosis factor-alpha (TNF-α) blocking therapy on bone formation and bone loss in patients with ankylosing spondylitis (AS). RECENT FINDINGS: The effect of TNF-α blocking therapy on excessive bone formation or osteoproliferation remains inconclusive. Radiographic assessment of spinal osteoproliferation is complicated by the overall slow rate of progression and the high variability between individual AS patients. Multiple studies demonstrated that TNF-α blocking therapy results in a significant increase in bone mineral density (BMD) at the lumbar spine and hip. Based on bone turnover marker (BTM) analysis, this can mainly be explained by an increase in mineralization and decrease in bone resorption. SUMMARY: Both osteoproliferation (e.g. syndesmophytes and ankylosis of vertebrae) and excessive bone loss resulting in osteoporosis and vertebral fractures are frequently present in AS. Previous studies showed that BMD increases during TNF-α blocking therapy. Long-term follow-up in a large cohort of patients is needed to investigate whether TNF-α blockers can consolidate or stop spinal osteoproliferation and prevent vertebral fractures. Future studies should focus on the effect of these agents on bone-related outcome in AS patients with early vs. advanced disease.

Higher levels of physical activity are associated with less evasive coping, better physical function and quality of life in patients with axial spondyloarthritis.

OBJECTIVE: To evaluate daily physical activity (PA) in relation to psychosocial factors, such as anxiety, depression and different types of coping strategies, as well as patient- and disease-related factors in patients with axial spondyloarthritis (axSpA). METHODS: Consecutive outpatients from the Groningen Leeuwarden AxSpA (GLAS) cohort completed the modified Short Questionnaire to assess health-enhancing PA (mSQUASH), Hospital Anxiety and Depression Scale (HADS) and Coping with Rheumatic Stressors (CORS) questionnaires, as well as standardized patient- and disease-related assessments. Univariable and multivariable linear regression analyses and comparison of lowest and highest PA tertiles were performed to explore associations between the HADS, CORS, patient- and disease-related factors and PA. RESULTS: In total, 84 axSpA patients were included; 60% male, mean age 49 (SD ±14) years, median symptom duration 20 (25th-75th percentiles: 12-31) years, mean ASDAS 2.1 (±1.0). Higher PA levels were significantly associated with better scores on patient-reported disease activity (BASDAI), physical function (BASFI) and quality of life (ASQoL). Furthermore, higher levels of PA were associated with less impact of axSpA on wellbeing and lower HADS depression scores. In the multivariable linear regression model, less use of the coping strategy 'decreasing activities' (ß: -376.4; p 0.003) and lower BMI (ß:-235.5; p: 0.030) were independently associated with higher level of PA. Comparison of patients from the lowest and highest PA tertiles showed results similar to those found in the regression analyses. CONCLUSION: In this cohort of axSpA patients, higher levels of daily PA were associated with better patient-reported outcomes and lower depression scores. Additionally, the passive coping strategy "decreasing activities" and lifestyle factor BMI were independently associated with PA. Besides anti-inflammatory treatment, coping strategies and lifestyle should be taken into account in the management of individual axSpA patients. Incorporating these aspects into patient education could increase patient awareness and self-efficacy. In the future, longitudinal studies are needed to better understand the complex relationship between patient-, disease- and psychosocial factors associated with daily PA.

Patients' Perspectives on Axial Pain in Relation to Inflammation and Structural Damage in a Large Cohort of Axial Spondyloarthritis Patients.

OBJECTIVE: The objective of this study was to explore to what extent patients with axial spondyloarthritis (axSpA) link experienced pain in the neck, back, and hips to inflammation and/or structural damage. METHODS: Patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort visiting the outpatient clinic between 2016 and 2019 filled out two additional questions in relation to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) question 2: (1) "To what extent do you think the pain you experience in your neck, back, and hips is related to inflammation caused by axSpA?" and (2) "To what extent do you think the pain you experience in your neck, back, and hips is related to damage of the spine and joints caused by axSpA?" Answers had to be depicted on a numeric rating scale from 0 (none) to 10 (very much); a difference of ≥2 points between the scores of these questions was considered clinically relevant in favor of the highest scoring question. RESULTS: A total of 688 patients with axSpA (24% with nonradiographic axSpA [nr-axSpA]) were included (62% male, mean ± SD age 48 ± 14 years, and mean ± SD Ankylosing Spondylitis Disease Activity Score [ASDAS] 2.3 ± 1.0). Seventy-five percent of patients could not link the origin of their pain, 15% linked axial pain predominantly to inflammation, and 10% linked axial pain predominantly to damage. Patients in the inflammation group were younger, had shorter symptom duration, were more frequently diagnosed with nr-axSpA, had higher ASDASCRP , had more often elevated CRP levels, had fewer comorbidities, had better spinal mobility, and had less spinal radiographic damage. CONCLUSION: In our large observational cohort, the majority of patients with axSpA could not differentiate the origin of experienced axial pain. If patients were able to link axial pain to clinical inflammation or damage, it was in concordance with clinical assessments and radiographic outcome, which may be helpful in establishing the origin of pain and supporting better patient-centered treatment decisions.

Improvement of bone mineral density and new vertebral fractures during 8 years of TNF-α inhibition in patients with axial spondyloarthritis.

OBJECTIVE: In our prospective cohort with standardized bi-annual measurements of bone mineral density (BMD) and spinal radiographs, we evaluated the long-term course of BMD and the development of radiographic vertebral fractures (VFs) during 8 years of TNFi treatment in patients with radiographic axial spondyloarthritis (r-axSpA). METHODS: Consecutive axSpA patients from the GLAS cohort receiving TNFi for ≥8 years were included. Patients who received anti-osteoporotic treatment were excluded. Lumbar spine (LS) BMD was assessed at baseline, 1 year and bi-annually using DEXA. Radiographic VFs were evaluated using the Genant classification. RESULTS: 126 axSpA patients were included; 75 % male, mean age 42 ± 11 years, ASDAS 3.8 ± 0.8, median LS BMD Z-score -0.5 (IQR -1.4-0.7) and 20 % had radiographic VFs at baseline. Disease activity improved rapidly and sustained. LS BMD Z-score improved significantly up to 4 years compared to the previous time point and sustained thereafter. Median percentage of improvement compared to baseline was 8.9 % (2.8-15.8) and 7.2 % (2.2-14.7) after 4 and 8 years, respectively. Of 90 patients with baseline and 8-year radiographs, 14 (16 %) developed new VFs and 5 (6 %) showed an increase in severity of existing VFs. Of all 44 VFs present at 8 years, 30 % were grade 2 (n = 12) or grade 3 (n = 1). CONCLUSION: In r-axSpA patients treated with TNFi for 8 years, LS BMD Z-score increased significantly, especially during the first 4 year of treatment. Radiographic VFs continued to develop or progressed, irrespective of improvement in BMD. Therefore, clinical attention for trabecular bone loss is important in daily clinical practice.

High BMI is associated with lower TNF-α inhibitor serum trough levels and higher disease activity in patients with axial spondyloarthritis.

BACKGROUND: TNF-α inhibitor (TNFi) serum trough levels have previously been found to be related to disease activity in axial spondyloarthritis (axSpA). However, most research regarding serum trough levels has been conducted in patients who only recently started TNFi therapy. Therefore, our objective was to explore TNFi serum trough level measurements in relation to disease activity and BMI in the total axSpA population in daily clinical practice, also including patients on long-term TNFi therapy. METHODS: Consecutive patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort were approached for a TNFi serum trough level measurement during their regular outpatient visit at the UMCG. Spearman's correlation coefficient was used to analyse the relation of serum trough levels with disease activity and BMI. Logistic regression was performed to analyse the relation between therapeutic drug levels and disease activity, corrected for potential confounders, including BMI. RESULTS: Thirty-four patients on adalimumab and 21 patients on etanercept were included. Mean age was 45 ± 12 years, 47% were male, median BMI was 26.4 (IQR 23.9-32.5) and median treatment duration was 41 months (range 2-126). According to definitions of Sanquin, 47% of patients had therapeutic serum trough levels. No significant correlations were found between TNFi levels and disease activity (ASDAS-CRP: adalimumab: ρ = -0.16, p = 0.39; etanercept: ρ = -0.29, p = 0.20). TNFi levels were moderately correlated with BMI (adalimumab: ρ = -0.48, p = 0.004; etanercept: ρ = -0.50, p = 0.021). Patients with active disease (ASDAS ≥ 2.1) showed higher BMI than patients with inactive disease (median 29.7 vs. 24.6, p = 0.015). In multivariable regression analyses, BMI was identified as the only confounder for the relationship between therapeutic drug levels and ASDAS. CONCLUSION: In this cross-sectional, observational study of axSpA patients mainly on long-term treatment with TNFi, higher BMI was significantly associated with lower adalimumab and etanercept serum trough levels and higher disease activity.

Psoriasis seems often underdiagnosed in patient with axial spondyloarthritis.

BACKGROUND: Axial spondyloarthritis (axSpA) is known to be associated with several extra-skeletal manifestations (ESM), including the inflammatory skin disease psoriasis. It is important to recognize and diagnose psoriasis timely in axSpA in order to provide optimal treatment and outcome for both axSpA and psoriasis. METHODS: In this observational study, all patients from the Dutch Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort included before June 2016 were sent a questionnaire with self-screening psoriasis questions including prototypical color pictures. RESULTS: Of the 592 questionnaires sent, 448 (75.7%) were eligible for analysis. Of these 448 respondents, 58 (13%) had a positive self-screening for psoriasis symptoms, currently or in the past. In 28 (48%) of 58 patients, psoriasis diagnosis could be verified by medical records, resulting in a psoriasis prevalence rate of 6.3%. In comparison with patients with a confirmed psoriasis diagnosis, patients reporting psoriasis symptoms without a verified diagnosis mentioned more mild than moderate-severe psoriasis symptoms (25% vs. 3%, p = 0.02), and their psoriasis lesions were less often located on the torso area (3% vs. 18%, p = 0.04), the intergluteal cleft (0% vs. 25%, p = 0.02), and legs (7% vs. 43%, p < 0.01). Of the 31 axSpA patients who reported currently active psoriasis, 74% had only mild psoriasis symptoms. CONCLUSIONS: Especially mild psoriasis seems often underdiagnosed in patients with axSpA using a patient questionnaire with prototypical pictures of psoriasis lesions. This questionnaire could be beneficial in tracing patients with undiagnosed psoriasis in daily clinical practice. As a next step, further validation of this questionnaire is needed.

After an initial balance favoring collagen formation and mineralization, bone turnover markers return to pre-treatment levels during long-term TNF-α inhibition in patients with ankylosing spondylitis.

BACKGROUND: Bone turnover balance favors bone formation, especially mineralization, during the first 3 years of treatment with TNF-α inhibitors (TNFi). Our aim was to evaluate the course of serum bone turnover markers (BTM) and to investigate if facilitation of mineralization reflected by BTM BALP continues to increase during 6 years of TNFi treatment in patients with ankylosing spondylitis (AS) in daily clinical practice. METHODS: Included were outpatients from the University Medical Center Groningen (UMCG) participating in the Groningen Leeuwarden Axial SpA (GLAS) cohort who were treated with TNFi for at least 6 years. Serum markers of collagen resorption, bone regulation, collagen formation and facilitator of bone mineralization (sCTX, OC, PINP and BALP, respectively) were measured at baseline, 3 and 6 months, 1, 2, 4 and 6 years. Z-scores were calculated to correct for age and gender. RESULTS: 53 AS patients were eligible for analyses (66% male, mean age 39±11 years). Disease activity showed rapid and sustained improvement after start of TNFi. Evaluating BTM, sCTX did not significantly change during 6 years of treatment. OC was only significantly increased at 3 months compared to baseline, with median change in Z-score of +0.5. PINP significantly increased at 3 and 6 months and 2 years of treatment, with maximum median change in Z-score of +0.3. Interestingly, BALP was significantly increased at all time points up to and including 2 years of TNFi treatment, with maximum change in median Z-score of +1.2, and decreased thereafter. CONCLUSION: In AS patients receiving long-term TNFi, bone turnover balance favored collagen formation and facilitation of mineralization during the first 2 years of treatment. Thereafter, at 4 and 6 years of follow-up, BTM Z-scores returned to pre-treatment levels.

Translation and cross-cultural adaptation of the modified Short QUestionnaire to Assess Health-enhancing physical activity (mSQUASH) into Turkish.

Aims The aim was to translate and cross-culturally adapt the modified Short Questionnaire to Assess Health-enhancing physical activity (mSQUASH) into Turkish Methods The mSQUASH was translated into Turkish and backward-translation into Dutch was performed afterwards using the Beaton method. After the Turkish version was reviewed and revised by an expert committee that included translators, two patients and the research team a pre-final version was produced. The-pre final version then entered a field-test with cognitive debriefing in 10 patients with axSpA. The final result was the Turkish mSQUASH version. Results The translation process went without difficulties. Small discrepancies were either resolved during the synthesis or expert consensus meetings. Mean (SD) time to complete the mSQUASH was 6.1 (2.4) minutes in field-test procedure. The cognitive debriefing showed that the items of the Turkish mSQUASH were clear, relevant, easy to understand and easy to complete. None of the patients reported that an important aspect of physical activity was missing from the questionnaire items. Patients raised the concern that not all sport examples were culturally suitable; tennis was replaced by volleyball and basketball after the cognitive debriefing, to make it more appropriate to the Turkish culture. Conclusion The final Turkish version of the mSQUASH showed acceptable linguistic and field validity for use in both clinical practice and research. However, further assessment of the psychometric properties (validity and reliability) of the Turkish version of the mSQUASH is needed before it can be implemented.