Clinical,radiological, and magnetic resonance imaging characteristics of axial spondyloarthritis with late onset

We aimed to investigate the clinical, diagnostic, and imaging features of patients with late onset axial spondyloarthritis (SpA) with initial symptom manifestation aged over 45 years.Participants with axial SpA were consecutively recruited. Clinical, demographic, blood, and imaging parameters were compared between the groups with early (≤45 years) and late onset (>45 years) at a cross-sectional level. Logistic regressions were used to determine the independent associations with axial SpA with late onset.A total of 455 participants were recruited. Among them, 70 (15.4%) had late onset disease. Multivariate analyses showed that axial SpA with late onset was associated with higher C-reactive protein based ankylosing spondylitis disease activity index (ASDAS-CRP) (B = 0.10; P = .04), higher intensity of spinal inflammation as measured by maximum apparent diffusion coefficient (spinal ADC max) (B = 0.27; P = .03) and mean ADC (spinal ADC mean) (B = 0.30; P = .004), lower modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) (B = –0.12; P = .02), more tender joint count (B = 0.12; P = .02), and fewer inflammatory back pain (IBP) (OR = 0.26; P < .001).Axial SpA with late onset had higher clinical disease activity, higher intensity of spinal MRI inflammation, less radiographic damage, and more tender joint count. There was also less inflammatory back pain, which could make the diagnosis more difficult.     

Spinal inflammation by magnetic resonance imaging in patients with ankylosing spondylitis: association with disease activity and outcome parameters

Magnetic resonance imaging (MRI) has major contribution in early diagnosis of ankylosing spondylitis (AS). As it is difficult to determine disease activity owing to the lack of close relation between laboratory tests, clinical findings and imaging, MRI has been used as an objective outcome measure. The aim of this study is to investigate the relation between spinal MRI findings with disease activity and other outcome measures. Fifty patients fulfilling modified New York criteria for AS were enrolled to the study. All the patients were evaluated with Bath AS Disease Activity Index (BASDAI), AS Disease Activity Score (ASDAS), Bath AS Functional Index (BASFI), Bath AS Metrology Index (BASMI), Bath AS Radiology Index (BASRI) and As Quality of Life. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured as laboratory parameters, and ASspiMR scores were determined by spinal MRI. The median total ASspiMR-a score was 5.2. Spinal inflammation was evaluated in spinal segments, and thoracic segments had the highest mean ASspiMR-a level (3.1?±?5.94). Cervical and lumbar ASspiMR were correlated with only BASRI, and total ASspiMR score was correlated with BASRI, BASMI and CRP. Thoracic ASspiMR score was correlated with patient??s and doctor??s global assessments, BASFI, BASMI, BASRI, ASDAS A, ASDAS B, ASDAS C, ASDAS D, ESR and CRP (P?<?0.05). According to our results, the thoracic spine was the most related region with disease activity parameters and clinical outcome measures, so we suggest thoracic spine MRI evaluation in order to determine the disease activity.     

Use of dynamic magnetic resonance imaging with fast imaging in the detection of early and advanced sacroiliitis in spondylarthropathy patients

Objective. To evaluate the new magnetic resonance imaging (MRI) method of dynamic MRI with fast imaging in the diagnosis of sacroiliitis among patients with spondylarthropathy. Methods. Fifteen patients with a history of inflammatory back pain without radiographic evidence of grade II or greater sacroiliitis (group 1), 25 patients with definite ankylosing spondylitis (group 2), and 12 patients with noninflammatory spinal pain (controls) (group 3) were examined. Dynamic MRI with fast imaging was performed after intravenous bolus injection of the contrast agent gadolinium—diethylenetriamine pentaacetic acid. The degree of enhancement was graded as representing acute sacroiliitis, latent sacroiliitis, or no sacroiliitis. Results. Acute sacroiliitis was detected in 22 of 30 sacroiliac (SI) joints in group 1 patients and in 27 of 50 SI joints in group 2 patients; latent sacroiliitis was seen in 25 of 80 SI joints in patients from groups 1 and 2. No group 3 patient was found to have sacroiliitis. Conclusion. Early sacroiliitis can be demonstrated by dynamic MRI in spondylarthropathy patients in whom abnormalities are not revealed by conventional radiography.     

磁共振成像对早期骶髂关节炎的诊断价值研究

目的了解磁共振成像(MRI)在早期骶髂关节炎诊断中的意义。方法对82例炎症性腰背痛或不对称性下肢滑膜炎患者的骶髂关节CT扫描、MRI平扫以及病理检查结果进行分析比较。结果45例病理证实的早期骶髂关节炎中,69%(31/45)MRI显示骶髂关节存在炎症性改变。但17例病理检查骶髂关节无炎症性改变者,也有59%(10/17)MRI表现不同程度骶髂关节炎症性改变。以病理检查结果为依据,MRI对早期骶髂关节炎诊断的敏感性、特异性分别为69%和41%。结论MRI对早期骶髂关节炎的诊断有一定的敏感性,但特异性不高,临床应用要慎重考虑。     

Radiographic progression is associated with resolution of systemic inflammation in patients with axial spondylarthritis treated with tumor necrosis factor α inhibitors: A study of radiographic progression,inflammation on magnetic resonance imaging,and circulating biomarkers of inflammation,angiogenesis, and cartilage and bone turnover

Objective

To investigate the relationship of circulating biomarkers of inflammation (C‐reactive protein [CRP], interleukin‐6 [IL‐6], and YKL‐40), angiogenesis (vascular endothelial growth factor), cartilage turnover (C‐terminal crosslinking telopeptide of type II collagen [CTX‐II], total aggrecan, matrix metalloproteinase 3 [MMP‐3], and cartilage oligomeric matrix protein [COMP]), and bone turnover (CTX‐I and osteocalcin) to inflammation on magnetic resonance imaging (MRI) and radiographic progression in patients with axial spondylarthritis (SpA) beginning tumor necrosis factor α (TNFα) inhibitor therapy.

Methods

MRIs were evaluated according to the Berlin sacroiliac (SI) joint and spine inflammation scoring method at baseline, week 22, and week 46. Radiographs were evaluated using the modified Stoke Ankylosing Spondylitis Spine Score at baseline and week 46. Patients with new syndesmophytes were identified. Biomarker levels in patients were compared to levels in healthy subjects.

Results

Higher pretreatment MRI inflammation scores for SI joints and/or lumbar spine were associated with higher baseline CTX‐II levels, but not with higher levels of biomarkers of inflammation and bone turnover. During treatment with TNFα inhibitors, a decrease in MRI inflammation scores from baseline to week 22 was associated with larger percentage decreases in and a normalization of CRP and IL‐6 levels as compared to an increase or no change in MRI scores. Development of new syndesmophytes was associated with larger percentage decreases in CRP and IL‐6 levels and an increase in osteocalcin level, and with normalization of CRP and IL‐6 levels from baseline to week 22. Persistent systemic inflammation was associated with radiographic nonprogression.

Conclusion

Our findings indicate that inflammation on baseline MRI is associated with higher CTX‐II levels. Radiographic progression is associated with decreased systemic inflammation, as assessed by IL‐6 and CRP levels and MRI, supporting the notion of a link between the resolution of inflammation and new bone formation in SpA patients during anti‐TNFα therapy.

     

Molecular imaging of cartilage damage of finger joints in early rheumatoid arthritis with delayed gadolinium‐enhanced magnetic resonance imaging

Objective

To assess cartilage glycosaminoglycan content and cartilage thickness in the metacarpophalangeal (MCP) joints of patients with early rheumatoid arthritis (RA) and healthy volunteers.

Methods

After review board approval and informed consent were obtained, 22 subjects were prospectively enrolled (9 patients with early RA [7 women and 2 men with a mean ± SD age of 49 ± 13 years; range 25–68 years] and 13 healthy volunteers [10 women and 3 men with a mean ± SD age of 51 ± 12 years; range 25–66 years). In a total of 44 MCP joints of the index and middle fingers, measurements of cartilage thickness and delayed gadolinium‐enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) index (T1 [msec]) were obtained using the variable flip‐angle method and a 3T MR scanner. MRIs were evaluated for bone edema, erosions, and synovitis (using the RA MRI Scoring criteria). Student's t‐test was used to test the significance of differences between groups.

Results

The mean ± SD dGEMRIC index was 497 ± 86 msec in healthy volunteers and was significantly lower in the early RA group (421 ± 76 msec) (P = 0.042). There was no joint space narrowing seen on standard radiographs. No significant difference was found between cartilage thickness in patients with early RA and that in controls (index finger mean ± SD 1.27 ± 0.23 mm in RA patients versus 1.46 ± 0.34 mm in controls [P = 0.16] and middle finger 1.26 ± 0.23 mm in RA patients versus 0.97 ± 0.47 mm in controls [P = 0.10]). No significant correlation was noted between cartilage thickness and dGEMRIC index (R = 0.36, P = 0.88 in RA patients; R = 0.156, P = 0.445 in controls).

Conclusion

Our findings indicate that cartilage damage is present in the MCP joints of patients with early RA despite the absence of joint space narrowing on standard radiographs and MRI. Cartilage damage in RA can be imaged with dGEMRIC.

     

Cross-sectional association of 10 molecular markers of bone, cartilage, and synovium with disease activity and radiological joint damage in patients with hip osteoarthritis: the ECHODIAH cohort

OBJECTIVE: To investigate the associations of molecular markers of joint tissue turnover with clinical and radiological variables in patients with hip osteoarthritis (OA). METHODS: Patients of the ECHODIAH trial cohort (60% female; mean age 63 yrs, disease duration 5 yrs) fulfilling the American College of Rheumatology criteria for hip OA were studied. Pain was assessed using a 100 mm visual analog scale, and the presence of night pain and morning stiffness was observed as the index of joint inflammation. Joint space width (JSW) and subchondral bone sclerosis were assessed on hip radiographs. Ten markers were measured, 8 in serum: N-propeptides of collagen type I (PINP) and type III (PIIINP), cartilage oligomeric matrix protein (COMP), YKL-40, hyaluronan (HA), matrix metalloproteases (MMP1 and MMP3), and ultrasensitive C-reactive protein (CRP); and 2 in urine: C-terminal crosslinking telopeptides of collagen type I (CTX-I) and type II (CTX-II). Analyses of 376 patients with measurements of all the markers included principal component analyses to identify independent clusters of markers; followed by stepwise multivariate regressions to determine associations between markers, clinical variables, and radiographic signs of joint damage. RESULTS: Markers could be segregated into independent clusters: CTX-II, PINP, and CTX-I for cartilage degradation and bone turnover; COMP, PIIINP, and HA as potential markers of synovitis; and CRP and YKL-40, which are likely to indicate systemic inflammation; plus MMP1 and MMP3. After adjustment for age, sex, and body mass index, pain was significantly associated with CTX-II (p = 0.0095) and CRP (p = 0.046) and joint inflammation with COMP (p = 0.013). Radiographic signs of joint damage were associated with CTX-II (p = 0.001 for JSW; p = 0.007 for bone sclerosis). CONCLUSION: This cross-sectional study of OA molecular markers in a large cohort may provide biological evidence of different pathophysiological processes involved in hip OA. Among the markers measured, CTX-II showed the most consistent association with the symptoms and joint damage of OA.     

Cardiac magnetic resonance imaging in patients with coronary disease

Opinion statement Cardiac magnetic resonance (CMR) has emerged as a versatile noninvasive tool for the comprehensive evaluation of patients with suspected or established coronary artery disease (CAD). In a single imaging session, CMR can assess left ventricular anatomy and function, myocardial perfusion, viability, and coronary luminal stenosis. Using specific pulse sequences, left ventricular global and regional function can be assessed by cine CMR at rest and in response to inotropic stress; first-pass perfusion quantified by vasodilator stress; myocardial viability evaluated by delayed enhancement imaging and also by functional reserve; and coronary artery stenosis assessed by angiography. All these modalities can be achieved with high spatial resolution and image contrast, without exposure to ionizing radiation, and within a reasonable time frame of about 1 hour of scan time. Also, the imaging planes can be programmed to provide identical views of the heart for each type of image, thereby facilitating intermodality comparisons. There is early but accumulating evidence that the accuracy and prognostic values of many of these modalities are comparable or superior to radionuclide scintigraphy and echocardiography in head-to-head studies. Current limitations unique to CMR include the inability to perform exercise stress testing inside the CMR suite and exclusion of patients with indwelling metallic devices such as defibrillators and pacemakers. Despite these limitations, CMR is unique in its multifaceted approach that can be specifically tailored to the clinical question at hand, making it arguably the best tool for the diagnosis and management of CAD. With the rapid pace of advancement in CMR hardware and pulse sequence technologies, the clinical use of this powerful technique is likely to grow even greater in this area.     

Correlation between magnetic resonance imaging (MRI) findings and the new bone formation factor Dkk-1 in patients with spondyloarthritis

Clinical Rheumatology - In recent years, MRI has been regarded as a major diagnostic tool for spondyloarthritis (SpA), and anti-TNF therapy has been widely confirmed as an effective treatment...     

Efficacy of long-term nonsteroidal antiinflammatory drug treatment on magnetic resonance imaging-determined bone marrow oedema in early,active axial spondyloarthritis patients

Clinical Rheumatology - To assess the efficacy of long-term treatment with nonsteroidal antiinflammatory drugs (NSAIDs) on bone marrow oedema (BMO) of the sacroiliac joint in newly diagnosed axial...     

Follow up and prognostic value using magnetic resonance imaging in patients with spondyloarthritis treated with biologic agents

Early diagnosis and assessment of the response to treatment in patients suffering from spondyloarthritis have always been challenging due to the lack of imaging techniques able to demonstrate spinal and sacroiliac inflammation.The last 2 years have seen important advances in the use of magnetic resonance imaging (MRI) for the study of spondyloarthritis. The possibility of quantification of inflammatory lesions using different scoring systems allows not only an early diagnosis, but the assessment of the response to several therapeutic agents, especially those known as «biological therapies».A number of randomized controlled trials of anti-tumor necrosis factor agents have been published showing regression of inflammatory lesions in MRI. This review discusses briefly the techniques and scoring systems used and all the evidences that exist about assessing treatment in spondyloarthritis.     

Changes in biomarkers of inflammation and bone turnover and associations with clinical efficacy following infliximab plus methotrexate therapy in patients with early rheumatoid arthritis

OBJECTIVE: To determine if changes in biomarkers of inflammation and bone turnover in response to treatment with infliximab plus methotrexate (MTX) versus MTX alone are associated with improvement in clinical measures of signs, symptoms, and structural damage in early rheumatoid arthritis. METHODS: Sera were collected from patients in the ASPIRE study who received 3 mg/kg (n = 48) or 6 mg/kg infliximab plus MTX (n = 55), or MTX alone (n = 41). Several baseline biomarker levels correlated with changes in median percentage of American College of Rheumatology improvement (ACR-N), 50% improvement in ACR response (ACR50), and van der Heijde-modified Sharp score (vdHSS) at Week 54. RESULTS: Infliximab plus MTX treatment resulted in more rapid decreases in levels of matrix metalloproteinase-3 (MMP-3), intercellular cell adhesion molecule-1, interleukin 8 (IL-8), and tumor necrosis factor-a than treatment with MTX alone. Baseline levels and decreases from baseline to Weeks 6 and 54 in MMP-3 correlated with improvement in ACR-N response at Week 54. An increase in IL-8 levels from baseline to Week 54 correlated with worsening in vdHSS at Week 54 in the MTX-alone group. Regression analysis of markers at baseline showed that MMP-3 was the only variable associated with ACR50 response and less worsening in vdHSS at Week 54. CONCLUSION: Treatment with infliximab plus MTX resulted in a rapid decrease in inflammation markers. MMP-3 levels at different timepoints were consistently associated with clinical improvements at Week 54 in the infliximab plus MTX group, while increases in IL-8 levels correlated with a worsening in vdHSS at Week 54 in the MTX-alone group.     

阿尔茨海默病患者静息态功能磁共振信号活动强度的研究

目的研究静息状态下阿尔茨海默病(Alzheimers disease,AD)患者静息态功能磁共振信号活动强度的变化情况。方法选择AD患者35例(AD组)及认知功能正常的健康体检者27例(对照组),进行静息状态下功能磁共振扫描,比较2组静息态功能磁共振信号时间域振幅的差异。结果在校正了年龄和性别的影响后,与对照组比较,AD组后扣带回的静息态功能磁共振信号时间域振幅强度减弱(11.88±4.43 vs 14.43±4.92,P<0.05)。结论AD患者后扣带回静息状态脑局部自发活动存在显著异常,这种通过时间域信号强度反映的变化为AD的早期诊断研究提供了有益的帮助。     

Clinical assessment of sacroiliitis and HLA-B27 are poor predictors of sacroiliitis diagnosed by magnetic resonance imaging in psoriatic arthritis

OBJECTIVE: To determine the frequency and clinical predictors of sacroiliitis diagnosed by magnetic resonance imaging (MRI) in a psoriatic arthritis (PsA) population. METHODS: The studied comprised 103 patients with PsA. A careful clinical assessment for sacroiliitis was made from history and examination, and HLA-B27 testing was performed. Sixty-eight patients underwent tilted coronal fat-saturated T1-weighted and STIR MRI of the sacroiliac joints. RESULTS: Clinical features of moderate or severe sacroiliitis were found in 24/68 (35%) patients. MRI features of sacroiliitis were found in 26/68 (38%) patients. Clinical features of sacroiliitis were present in 14/42 (33%) with normal MRI scans and 10/26 (38%) with abnormal scans (normal vs abnormal scans, P = 0.7). The presence of sacroiliitis on MRI was associated with restricted spinal movements (P = 0.004) and the duration of PsA (P = 0.04). There was no correlation between HLA-B27 and sacroiliitis diagnosed by MRI. CONCLUSION: Sacroiliitis diagnosed by MRI occurs commonly in PsA but is difficult to detect clinically.     

Plain magnetic resonance imaging as an alternative in evaluating inflammation and bowel damage in inflammatory bowel disease – a prospective comparison with conventional magnetic resonance follow-through

Abstract

Objective. To compare prospectively the diagnostic accuracy of magnetic resonance imaging (MRI) without use of contrast medium orally or intravenously (plain MRI) with magnetic resonance follow-through (MRFT) in patients with inflammatory bowel disease (IBD). Material and methods. Plain MRI was carried out in addition to MRFT, to which the patients were referred. All patients underwent both examinations on the same day. For the evaluation, the bowel was divided into nine segments. Two radiologists, blinded to clinical findings, evaluated bowel wall thickness, diffusion weighted imaging (DWI), and other inflammatory changes in each bowel segments. Further, hyperenhancement of the bowel was also evaluated in MRFT. Results. A total of 100 patients (40 males and 60 females; median age: 38.5; range: 19–90) were enrolled; 44 with Crohn’s disease (CD), 25 with ulcerative colitis (UC), 24 with IBD unclassified (IBD-U), and 7 had other diagnosis. Sensitivity, specificity, and accuracy in CD ranged 50–86%, 93–94%, and 91–92% for wall thickening and 49–82%, 85–93%, and 84–89% for DWI, respectively. Sensitivity, specificity, and accuracy in UC range 0–40%, 87–100%, and 80–100% for wall thickening and 0–52%, 83–94% and 76–92% for DWI, respectively. The κ values for bowel wall thickening, DWI, and mural hyperenhancement were detected with fair agreement (κ = 0.26–0.39) at both MRI examinations, whereas only bowel wall thickening in MRFT were detected with moderate agreement (κ = 0.47) Conclusion. Plain MRI cannot currently replace MRFT in the workup of patients with IBD. Further research on plain MRI is needed to improve the protocol.     

Detection of joint pathology by magnetic resonance imaging in patients with early rheumatoid arthritis

Magnetic resonance imaging (MRI) permits the visualization of anatomical structures not appreciated by conventional radiographic imaging, and may assess inflammatory disease and its progression with greater sensitivity than conventional radiography. In this study of 30 patients with early rheumatoid arthritis (RA), which could be considered as a pilot study because of the relatively small number of patients, we compare MRI of the knee and the fifth metatarsophalangeal joint with clinical and radiographic findings. A parallel study of 10 healthy individuals served as a reference group. In all but one of the 30 patients, MRI revealed some kind of joint abnormality, whereas conventional radiography was normal in 14 patients. The present study thus suggests that MRI may detect inflammatory and/or destructive joint changes in patients with early RA, and that these changes may occur in the absence of clinical symptoms or signs and/or radiographic signs in the examined joint. If these data prove to be confirmed in further controlled studies, MRI may be of importance both for the assessment of prognosis and for the decision to treat in the early critical stages of RA.      

Evaluation of magnetic resonance imaging and radionuclide bone scan in early spondyloarthropathy

IntroductionSpondyloarthropathy (SpA) comprises a small percentage of low backache (LBA) and presents with inflammatory pain. Sacroiliitis in SpAs forms the basis of diagnosis, and may take 7–8 years to become visible in plain radiographs. In order to achieve significant modification of the course of the disease it is imperative to make an early diagnosis, identify risk factors for aggressive disease and initiate the therapy right at outset. Magnetic resonance imaging (MRI) is a promising modality to pick up inflammation and structural damage early in the course of the disease.ObjectiveTo assess the role of MRI and radionuclide bone scan in patients with early SpA of less than 2 years.MethodsPatients with inflammatory LBA, defined according to the Calin criteria and satisfying the European Spondyloarthropathy Study Group (ESSG) criteria for SpA of less than 2 years duration, were included. Controls had mechanical LBA. A detailed clinical assessment and assessment of disease activity and functional impairment was done with validated measures. Radiological assessment included conventional radiograph of the pelvis, radionuclide scan and MRI of sacroiliac joints (SI joints). The sensitivity, specificity and predictive value of each modality in contributing to the diagnosis of SpA were assessed.ResultsAssessment of 132 SI joints in 33 patients (Age 31 ± 6.14 years, M:F 24:9) and 33 controls (Age 31.8 ± 7.21 years, M:F 27:5) was done. The mean disease duration of cases was 10.7 (± 6.97) months. Conventional radiograph failed to pick up sacroiliitis in any of the cases. Positive bone scan was present in 27 patients (21 bilateral sacroiliitis, 6 unilateral sacroiliitis). Bone scan had a sensitivity of 81.8% and a specificity of 88%. MRI abnormality was present in 29 patients (50 joints, bilateral in 21 and unilateral in 8) and in none of the controls. This accounted for a sensitivity of 87.9% and a specificity of 100%. The MRI changes included bone marrow oedema (89%), synovial enhancement (55%), subchondral oedema (41%), erosions (51%) and sclerosis (28%). Both inflammatory and structural changes in MRI showed positive correlation with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (P = 0.034, 0.02) and erythrocyte sedimentation rate (ESR) (P = 0.02, 0.001).ConclusionsIn patients with early SpA of less than 2 years duration, conventional radiographs did not pick up sacroiliitis; however, both the radionuclide scan and MRI were useful.     

Role of matrix metalloproteinase-3 (MMP-3) and magnetic resonance imaging of sacroiliitis in assessing disease activity in ankylosing spondylitis

The objective of this study is to evaluate the role of MMP-3 and MRI in assessing disease activity in sacroiliac joints of AS patients in comparison to the conventional measures Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Serum MMP-3 was measured in 30 patients who fulfilled the modified New York criteria for AS and in ten healthy volunteers. AS patients were categorized into those having high or low MMP-3 according to a cut-off value?=?7.1?ng/ml. MRI of the sacroiliac joints (SIJs) was performed on all patients. SIJs were evaluated for enhancement and subchondral bone marrow edema. Results of MMP-3 and findings on MRI were correlated with multiple clinical parameters including BASDAI, ESR and CRP. Serum MMP-3 was significantly elevated in AS patients with active disease. Elevated MMP-3 levels were significantly associated with high BASDAI (P?=?0.046), but not with ESR or CRP. MRI showed bone marrow edema and enhancement of SIJs in 19/30 patients with one patient showing enhancement only. These MRI findings were not correlated with MMP-3, BASDAI, CRP or ESR. In conclusion, serum MMP-3 is an objective measure reflecting clinical disease activity in AS. Bone marrow edema and enhancement detected by MRI of SIJs is another objective measure of disease activity, but are not correlated with MMP-3 or the conventional parameters as BASDAI, ESR, or CRP. Although both MMP-3 and MRI can reflect disease activity in AS they seem to be unrelated, perhaps each is reflecting a different aspect of disease activity. MMP-3 and MRI should be considered together with BASDAI in assessing disease activity and in guiding the available recommendations for initiation of biologics in AS.