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Sacroiliac joint (SJ) imaging is the key point in the diagnosis of ankylosing spondylitis (AS). The curved anatomy of the SJ makes the interpretation of imaging difficult. The aim of this study is to evaluate the interclass and intraclass reliability of specific lesions (bone marrow edema [BME], joint space narrowing, erosions, effusion, ankylosis, bridging, sclerosis, fat deposition, and other additional pathologies) on SJ magnetic resonance imaging (MRI).In a total of 310 randomly chosen patients, 620 SJs were evaluated by three different radiologists with different radiology experiences of specialties other than musculoskeletal radiology.The agreement between readers for BME was fair to substantial, for active sacroiliitis was moderate to substantial, for sacroiliac narrowing was fair at best, for erosions was fair to moderate, for SJ sclerosis was none to slight, for chronic sacroiliitis was slight to fair, for degenerative sacroiliitis was none to slight, for normal SJ was slight, for SJ effusion was none to slight, and for fatty deposition was none. Intraclass correlation for readers 1 and 3 was usually good to excellent and for reader 2 was poor to fair.This study was designed to assess the agreement between radiologists who were not familiar with SJ MRI. The agreement between readers was usually fair to substantial and even intraclass correlation was poor to fair for reader 2. Future studies can be designed for standardization and validation of each MRI lesion for better interpretation of SJ MRI.

Isotretinoin has been reported to induce inflammatory back pain (IBP) and sacroiliitis in the patients with acne vulgaris. The aim of this study is to investigate the incidence of IBP and sacroiliitis in patients receiving isotretinoin treatment compared with oral antibiotics for acne vulgaris.A total of 201 patients with moderate-to-severe acne vulgaris who received isotretinoin (n = 100) or oral antibiotics (n = 101) were included in the study. All patients were monthly questioned for IBP symptoms during their treatment. Patients described IBP were also evaluated for sacroiliitis by c-reactive protein, sedimentation rate, HLAB27, and sacroiliac magnetic resonance imaging (MRI). Isotretinoin was discontinued in all patients diagnosed as sacroiliitis, and these patients were reevaluated after 3 months.IBP was observed in 21 (10.4%), and sacroiliitis was detected in 11 (11%) patients on isotretinoin treatment; in oral antibiotic group, we did not observe IBP or sacroiliitis. The incidence of IBP and sacroiliitis differed significantly between the isotretinoin and oral antibiotic groups (p 0.0001, p = 0.02). Complete regression was observed in the great majority of patients following cessation of isotretinoin.Our study is the largest prospective controlled study that investigated the incidence of sacroiliitis in patients receiving isotretinoin and compared with patients using oral antibiotics.

Objectives This study aimed to assess patients with axial psoriatic arthritis (AxPsA) using the Canadian Spondyloarthritis Research Consortium (SPARCC) sacroiliac joint (SIJ) scores and to seek correlations between magnetic resonance imaging (MRI) scores and disease characteristics. Methods Forty PsA patients (32 females, mean age 46.4 years) who had been documented to have active or structural lesions on SIJ MRI were retrospectively evaluated. Disease duration, medications, and disease activity, including Disease Activity in Psoriatic Arthritis (DAPSA), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), minimal disease activity (MDA), and Ankylosing Spondylitis Disease Activity Score (ASDAS) were recorded. On sacroiliac MRI scans, the SPARCC scores of sacroiliac joint inflammation (SIS) and sacroiliac joint structural damage (SSS) were evaluated. Results The mean disease duration was 51.4 +/- 70.4 months. MRI showed active inflammation in 30 patients (75%) and at least 1 structural lesion in 32 patients (92.5%). The most prevalent structural lesion was erosion (82.5%), followed by fat metaplasia (65%), backfill (12.5%), and ankylosis (2.5%). Only fat metaplasia scores were significantly higher in men than in women (P = .007). Of clinical and laboratory parameters, only C-reactive protein (CRP) was significantly higher in the presence of active inflammation (P = .01). The SIS score was significantly correlated with disease duration (r = -.35) and CRP levels (r = .42,). The SSS score was inversely correlated with BASDAI (r = -.37), ASDAS-CRP (r = -.39), and ASDAS - erythrocyte sedimentation rate (r = -.32). The overall SPARCC scores did not differ between patients in DAPSA remission and non-remission and between those in MDA and non-MDA. Conclusion Although radiologic involvement is generally not severe in AxPsA, MRI still provides additional information about inflammatory activity and structural lesions. CRP may be helpful in monitoring the radiologic disease activity in AxPsA.

AIM To evaluate clinical characteristics and natural history of non-radiographic axial spondyloarthritis (nr-axSpA) using KOrean Nonradiographic Axial SPondyloArthritis (KONASPA) data. METHODS Data were collected from 11 centers in South Korea. A total of 278 patients with nr-axSpA from January 2018 to July 2020 were included. Demographic data, clinical features, comorbidities, disease activity, medications, and laboratory results were collected. RESULTS Mean age at symptom onset was 28.2 ± 14.2 years. Of 278 patients, 152 (54.7%) were male. Mean Bath Ankylosing Spondylitis Disease Activity Index at diagnosis was 3.5 ± 2.1. Dyslipidemia was the most common comorbidity (8.4%), followed by hypertension (6.1%). Mean age at diagnosis of nr-axSpA was older in female patients than in male patients (31.8 ± 15.8 years vs 24.9 ± 12.0 years, P

Objective To investigate the anatomic location and distribution of lesions on magnetic resonance imaging (MRI) in the sacroiliac (SI) joints in patients with axial spondyloarthritis (SpA), women with and without postpartum pain (childbirth within 4-16 months), patients with disc herniation, cleaning staff, runners, and healthy persons. Methods In a prospective cross-sectional study of 204 participants, MRI of the entire cartilaginous compartment of the SI joint was scored blindly by 2 independent, experienced readers, according to Spondyloarthritis Research Consortium of Canada definitions of SI joint inflammation and structural lesions in each SI joint quadrant or half and in each of 9 slices. The locations of the lesions (unilateral/bilateral, upper/lower, sacral/iliac, and anterior/central/posterior slices) were analyzed based on concordant reads. Results Bone marrow edema (BME) occurred in all quadrants in nearly all participant groups, but rarely bilaterally, except in patients with axial SpA and women with postpartum pain. Fat lesions were mainly found in axial SpA and occurred in all quadrants, but mostly bilaterally in sacral quadrants. Erosion was rare, except in axial SpA, where it was mainly iliac and often bilateral. Sclerosis was exclusively iliac and most frequent in women with postpartum pain. Conclusion The location and distribution of common SI joint lesions in axial SpA and non-axial SpA were reported, and group-specific patterns were revealed. BME distributed bilaterally or unilaterally, both locally and more widespread in the SI joint, is common in both postpartum women with pain and axial SpA patients, which limits the use of BME to differentiate these groups. This study indicates that the presence of fat lesions, especially when widespread, and/or erosion, particularly when located centrally or posteriorly, are diagnostically important and should be investigated further.

Background The precise time of appearance of bone marrow edema in acute hematogenous pelvic osteomyelitis (AHPO) is unknown. The purpose of present research is to clarify the time of appearance of bone marrow edema on MRI in AHPO. Our hypothesis was that onset is slower than in long-bone osteomyelitis. Methods We selected twelve patients (mean, 11.8 years) with MRI findings and clinical diagnosis of AHPO. The signal ratios of bone marrow (BM) and gluteus maximus muscle (M, BM/M ratio) in fat-suppressed T2- and T1-weighted images (T2WI, T1WI) were calculated to evaluate changes in bone marrow signals. The correlation between BM/M ratios and days from onset was statistically evaluated and compared to lower extremity osteomyelitis. Results BM/M ratio of T2WI increased over time after onset of the primary symptom in all patients and showed a statistically positive correlation (r = 0.36). In seven patients in whom an MRI scan was conducted twice, all showed higher values for the second MRI, and changes were more pronounced over time. The mean BM/M ratio of T2WI was 4.1 when seven days or less had elapsed from the primary symptom and 6.4 when more than seven days had elapsed . BM/M ratios in the sacroiliac joint group were lower than in the non-sacroiliac joint group. Conclusion Unlike long-bone osteomyelitis, it took one week before findings for AHPO became fully evident. A definitive diagnosis can be made in patients with suspected sacroiliitis by performing a further MRI scan at seven days or later.

BACKGROUND The sacroiliac joint is one of the most common sources of low back pain; however, it is difficult to place the needle accurately inside the joint space without image guidance. Improvement of ultrasound technology may lead to a high success rate for intra-articular drug deposition. OBJECTIVE Assessment of the success rate of ultrasound-guided intra-articular sacroiliac joint injection. DESIGN Prospective observational study. METHODOLOGY Ultrasound-guided injections were performed on 34 patients suffering from sacroiliitis. After injection of the drug solution and withdrawal of the needle, an anteroposterior fluoroscopy image was obtained and recorded for the injected joint to detect whether it was predominantly intra-articular or peri-articular. Clinical outcome using a numeric pain rating scale as well as limitation of physical functioning measured by the Oswestry Disability Index (ODI) were determined. RESULTS Thirty-three injections (84.6%) were intra-articular, while 6 injections (15.4%) were peri-articular, as confirmed by fluoroscopy, with no statistical difference regarding clinical outcome between them. The baseline mean pain score decreased from 7.21 to 1.92 1 month after injection, and the mean ODI scores improved from 61.41% to 17.13%. Intervention was well tolerated, and 91.2% of patients were satisfied or mostly satisfied. CONCLUSION Ultrasonography provides a high success rate of intra-articular sacroiliac joint injection as confirmed by fluoroscopy. No significant difference in clinical outcome between intra-articular and peri-articular injection was found.

Pustulotic arthro-osteitis (PAO) is an osteoarticular complication of palmoplantar pustulosis (PPP). Although guselkumab, an anti-interleukin-23p19 antibody, has been shown to be effective for PPP, its efficacy for PAO is still not well understood. We conducted a retrospective observational study to evaluate the effectiveness of 28-week guselkumab treatment for five PAO patients in daily clinical practice. Four patients had sternoclavicular arthritis, and one had only sacroiliitis. Guselkumab improved pain visual assessment scale scores in all five patients by 54.2% (11.1-87.5%) on average at week 28 compared with baseline, and discontinuation or dose reduction of analgesics was possible in four of them. Three patients showed clinically significant improvement in Bath Ankylosing Spondylitis Disease Activity Index of 2 or more. On the other hand, beneficial change in Ankylosing Spondylitis Disease Activity Score of 1.1 or more was observed in only one patient. Bone scintigraphy demonstrated decreased uptake in sternoclavicular joints after guselkumab treatment in all four patients with sternoclavicular arthritis. Improvement of Palmoplantar Pustulosis Area and Severity Index was also confirmed. Guselkumab can be a treatment option for intractable PAO.

Isotretinoin is widely used in severe acne. Isotretinoin has many side effects. Sacroiliitis is one of these side effects and has been rarely reported in the children. Herein, we present two children with isotretinoin-induced sacroiliitis resistant to anti-rheumatic drugs and successfully treated with adalimumab.

Isotretinoin is the mainstay treatment in severe acne; however, its musculoskeletal adverse effects such as lower-back pain can be disabling. Herein, we present four cases of isotretinoin-induced sacroiliitis with variable severity. We also present a review of the literature of isotretinoin-induced sacroiliitis. All our cases were male and human leukocyte antigen (HLA)-B27 negative. Sacroiliitis was detected a median of 55 (10-120) days after isotretinoin initiation. Two patients were responsive to baseline sulfasalazine and indomethacin treatment, while the other two patients required more intensive treatments: adalimumab in one and methotrexate in the other. We also identified 15 articles describing 33 patients (17 of whom were female) with isotretinoin-induced sacroiliitis. Most of them were responsive to low-to-medium doses of systemic steroids or non-steroidal anti-inflammatory drugs (NSAIDs). Our patients illustrate that severity of isotretinoin-induced sacroiliitis varies from patient to patient.

A 36-year-old man was treated for several years with multiple agents for ankylosing spondylitis based on positive human leukocyte antigen-B27 and sacroiliitis. He was also diagnosed with osteoporosis and hypophosphatemia. Over these years, from being an avid runner, he became dependent on a walker for ambulation. The lack of treatment response and the low phosphorus were clues that eventually led to a diagnosis of tumor-induced osteomalacia. This case discusses the importance of not solely relying on genetic markers and sacroiliitis for diagnosing ankylosing spondylitis as other conditions can cause similar presentations.

BACKGROUND: Spondyloarthritis is the most frequent extra-intestinal manifestation of IBD. AIM: To present simple strategies to identify and differentiate inflammatory joint pain in IBD patients. METHODS: A panel of Belgian gastroenterologists and rheumatologists developed seven algorithms for IBD patients with joint symptoms based on a Delphi exercise conducted between April and December 2016. Here, we focus on referral strategies for patients with chronic back pain (evidence-based strategy), large joint monoarthritis, oligo- or polyarticular arthritis or arthralgia (based on expert opinion). We also present management tools for IBD patients with acute back pain and small joint monoarthritis (Supplementary file). RESULTS: The reported algorithm for IBD patients with chronic back pain uses basic clinical criteria to identify which patients should be referred to the emergency room (spondylodiscitis), physical medicine and rehabilitation (mechanical back pain) or rheumatologist (spondyloarthritis). IBD patients with large joint monoarthritis should be referred to emergency room if septic arthritis is suspected; in other patients, blood analyses and referral to a rheumatologist for articular puncture with evacuation of synovial fluid are recommended. The analysis of synovial fluid allows for identification of non-inflammatory (e.g., osteoarthritis) and inflammatory (e.g., [pseudo]-gout, peripheral spondyloarthritis and Borrelia burgdorferi arthritis) conditions. In patients with inflammatory oligoarticular or polyarticular arthralgia, erythrocyte sedimentation rate, concomitant therapies, anti-nuclear factor and anti-double-stranded DNA antibody levels should be evaluated; in anti-tumour necrosis factor-treated patients, a drug-induced lupus-like syndrome should be considered. CONCLUSION: We propose straightforward strategies for IBD patients with joint symptoms, which are specific enough to select initial treatment and referral pattern. ispartof: ALIMENTARY PHARMACOLOGY & THERAPEUTICS vol:50 issue:11-12 pages:1204-1213 ispartof: location:England status: published

Degenerative sacroiliac joint disease is a cause of lumbosacral pain in dogs; however, published information on cross-sectional imaging characteristics is limited. Objectives of this retrospective, secondary analysis, methods-comparison study were to test hypotheses that CT lesions reported in humans with degenerative sacroiliac joint disease are also present in dogs, and that CT is comparable to gross pathology for detecting these lesions. Matched CT and gross pathology slice images of 30 sacroiliac joints were retrieved from a previous prospective, canine cadaver study. A veterinary radiologist interpreted randomized CT images for each joint based on previously published CT characteristics of lesions in humans with degenerative sacroiliac joint disease. A veterinary pathologist independently interpreted randomized gross pathology images using the same criteria. All joints had at least one CT lesion consistent with degenerative sacroiliac joint disease. A new CT lesion was also identified and termed "subarticular cleft." The CT and gross pathology methods agreed for detecting joints with subchondral sclerosis, subchondral erosion, and intra-articular ankylosis lesions (P > .05, McNemar's test), but disagreed for detection of joints with subchondral cyst, para-articular ankylosis, and subarticular cleft lesions (P ≤ .05). Using gross pathology as the reference standard, CT had 100% sensitivity for detection of subarticular cleft and subchondral cyst lesions, with 56% and 22% specificity, respectively. Para-articular ankylosis lesions were detected by CT but not by gross pathology. Findings supported the hypothesis that CT lesions reported in humans with degenerative sacroiliac joint disease are also present in dogs, and partially supported the hypothesis that CT is comparable to gross pathology for detecting joints with these lesions.

AIM The aim of the study was to assess the distribution of human leukocyte antigen (HLA)-B*27 subtypes and its correlation with disease phenotypes in children with enthesitis-related arthritis variant of juvenile idiopathic arthritis (JIA-ERA). METHOD One hundred and sixty patients (132 males, 28 females) satisfying the International League Against Rheumatism (ILAR) classification criteria for JIA-ERA were assessed and relevant demographic, clinical and radiographic data were documented. HLA-B*27 typing was done for all the patients and B*27 positive samples were subjected to high-resolution gene sequencing. The effect of duration of illness, HLA-B*27, its subtypes, and gender on the clinical phenotype were analyzed. RESULTS The mean age of disease onset was 12.69 ± 2.4 years with a male:female ratio of 4.7:1.0. HLA-B*27 was positive in 109/160 patients and HLA-B*27:04 was detected in 63% followed by B*27:05 (30%). Duration of illness was greater in patients with skeletal deformity, hip arthritis, sacroiliitis, cervical spine involvement and acute anterior uveitis (AAU) (P

Objective To evaluate radiographic progression in the sacroiliac (SI) joints and to identify its predictors during long-term treatment (up to 6 years) with the tumor necrosis factor (TNF) inhibitor etanercept in patients with early axial spondyloarthritis (SpA). Methods Patients with early axial SpA who were treated with etanercept for up to 6 years in the Etanercept versus Sulfasalazine in Early Axial Spondyloarthritis (ESTHER) trial were selected based on the availability of radiographs of the SI joints. Two readers who were blinded with regard to clinical data scored the radiographs according to the modified New York criteria (range 0-4 per SI joint). A sacroiliitis sum score (total range 0-8) was calculated as the mean of the scores of the 2 readers. Active and chronic inflammatory changes in the SI joints on magnetic resonance imaging (MRI) performed at baseline, year 2, and year 4 were assessed according to the Berlin MRI scoring system. Results Of the 76 patients originally included in the study, 42 had radiographs of the SI joints available at baseline and at least 1 follow-up time point (year 2, 4, or 6). The mean ± SD change in the sacroiliitis sum score was 0.13 ± 0.73, -0.27 ± 0.76, and -0.09 ± 0.68, in the time intervals baseline to year 2, year 2 to year 4, and year 4 to year 6, respectively. In the longitudinal mixed model analysis, elevated C-reactive protein level (β = 0.58 [95% confidence interval 0.24, 0.91]) and MRI SI joint osteitis score (β = 0.06 [95% confidence interval 0.03, 0.10]) were independently associated with progression of the sacroiliitis sum score. Conclusion Our findings indicate that long-term anti-TNF therapy decelerates the progression of structural damage in the SI joints. Elevated CRP level and presence of osteitis on MRI were independently associated with radiographic sacroiliitis progression.

A 53-year-old woman with no significant medical history presented with 10/10 right buttock pain that radiated to the right groin. With no reported recent injury, the absence of fever, and no identifiable risk factors, an infectious etiology, including septic sacroiliitis (SSI), is at the end spectrum of the differential. SSI is a rare condition with nonspecific findings that can lead to major complications, including death. To our knowledge, there are only 4 recent major literature reviews on SSI, with most cases reported to have at least 1 risk factor or clinical sign indicating the possibility of an infectious etiology. The patient reported in this case had no identifiable risk factors; therefore, high clinical suspicion is needed to prevent debilitating consequences from prolonged infection. LEVEL OF EVIDENCE: V.

BACKGROUND Conventional magnetic resonance (MR) imaging is limited in providing sufficient information on microstructure or in quantitatively evaluating certain inflammation processes. Functional MR sequences such as diffusion kurtosis imaging (DKI) might help to evaluate the sacroiliac joint in ankylosing spondylitis (AS) patients. PURPOSE To explore the application of DKI in evaluating the disease activity of AS. STUDY TYPE Prospective. POPULATION Forty-four patients with a diagnosis of AS according to the Assessment in SpondyloArthritis International Society (ASAS) criteria. FIELD STRENGTH/SEQUENCE 3.0T MRI including the DKI sequence (b = 0, 500, 1000, 1500, 2000 s/mm2 ). STATISTICAL TESTS Two-independent-samples t-test and one-way analysis of variance (ANOVA) were used to compare the DKI parameters among different groups, and post-hoc Scheffe's method was adopted. Receiver operating characteristic (ROC) analysis and Spearman's rank correlation were performed to test the diagnostic performance of DKI parameters in distinguishing different activity grades and the correlation between them, respectively. ASSESSMENT AS disease activity was evaluated according to the Ankylosing Spondylitis Disease Activity Score (ASDAS), and four disease activity states were chosen by consensus: inactive disease and moderate, high, and very high disease activity. The three cutoffs selected to separate these states were: 1.3, 2.1, and 3.5 units, respectively. RESULTS The corrected ADC (D) and apparent diffusion coefficient (ADC) values of sacroiliac joints in the active group were significantly higher, while the the kurtosis of diffusion (K value) value was significantly lower than those of the inactive group (all P

Objective Reactive arthritis (ReA) is an inflammatory disorder occurring several weeks after gastrointestinal or genitourinary infections. HLA-B27 positivity is considered a risk factor, though not necessarily predictive of disease incidence. Among non-genetic factors, the intestinal microbiome may play a role in disease susceptibility. The objective of this study was to characterize the gut microbiota and host gene interactions in ReA and post-infectious spondyloarthritis. Methods Adult peripheral spondyloarthritis and control subjects with preceding infections that did not develop arthritis were prospectively recruited from a highly prevalent geographic region. Clinical variables, HLA status, and 16S rRNA gene sequencing of intestinal microbiota were analyzed. Results ReA subjects showed no significant differences from controls in gut bacterial richness or diversity. However, there was a significantly higher abundance of Erwinia and Pseudomonas, and increased prevalence of typical enteropathogens associated with ReA. Subjects with ultrasound evidence of enthesitis were enriched in Campylobacter, while subjects with uveitis and radiographic sacroiliitis were respectively enriched in Erwinia and unclassified Ruminococcaceae, and both enriched in Dialister. Host genetics, particularly HLA-A24, were associated with differences in gut microbiota diversity irrespective of disease status. We determined several co-occurring taxa that were also predictive of HLA-A24 status. Conclusion This is the first culture-independent study characterizing the gut microbial community of post-infectious arthritis. Although bacterial factors correlated with disease presence and clinical features of ReA, host genetics also appeared to be a major independent driver of intestinal community composition. Understanding of these gut microbiota host-genetic relationships may further clarify the pathogenesis of post-infectious spondyloarthropathies. This article is protected by copyright. All rights reserved.

Objective To describe the magnetic resonance imaging (MRI) findings in diffuse idiopathic skeletal hyperostosis (DISH) patients and to assess the proportion of DISH patients whose MRI findings would fulfill the Assessment of Spondyloarthritis International Society (ASAS) criteria for a positive MRI of axial spondyloarthritis (SpA). Methods This study involved all DISH patients who had a spine or sacroiliac (SI) joint MRI performed between January 2009 and December 2014. Sociodemographic and clinical data were collected. Available radiographs and MRI were analyzed and blindly scored by an experienced reader, using the Spondyloarthritis Research Consortium of Canada (SPARCC) scores for both spine and SI joint MRI. Results A total of 53 symptomatic DISH patients was included in the analysis. The mean ± SD SPARCC score of the spine was 18.3 ± 23.4. Thirty-five patients (67.3%) had at least 1 fatty corner. Thirty patients (57.7%) met the ASAS definition of a spine MRI suggestive of axial SpA, but only 6 patients (15.8%) with an available SI joint MRI had sacroiliitis according to ASAS criteria. Only 1 patient (3.3%) had ≥3 erosions on the SI joint. Conclusion Inflammatory lesions of the spine are common on the MRI of symptomatic DISH patients, and more than half fulfilled the ASAS criteria for a spine MRI suggestive of axial SpA. However, only a few patients met the ASAS definition of active sacroiliitis, suggesting that MRI of the SI joint but not of the spine might allow the differential diagnosis of DISH versus axial SpA in the elderly.

Objective To evaluate the validity of different spondyloarthritis (SpA) features included in the Berlin diagnostic algorithm and the Assessment of SpondyloArthritis international Society (ASAS) classification criteria in an early SpA cohort. Methods This was a longitudinal multicenter study including patients from the ESPeranza program cohort who were suspected to have SpA. Subjects were ≤45 years old, and SpA symptom duration was 3–24 months. Patients with axial SpA symptoms were selected and categorized according to diagnosis (yes/no) of axial SpA. Descriptive analysis was performed, and the sensitivity, specificity, predictive value, and likelihood ratio (LR) of each feature were calculated. Results Of 775 patients suspected to have SpA, 665 had predominantly axial symptoms and 516 of these patients were diagnosed with axial SpA. The most useful SpA features were sacroiliitis on magnetic resonance imaging (positive LR 6.6) or radiograph (positive LR 31.1) and peripheral arthritis (positive LR 8.9). The features with the lowest diagnostic utility were a family history of SpA (positive LR 1.5) and good response to nonsteroidal antiinflammatory drugs (positive LR 1.6). Inflammatory back pain (IBP; according to ASAS criteria) was described in only 27% of SpA patients, with a positive LR of 2.3. HLA–B27 positivity was present in 245 (48%), and the positive LR was 2.8. Conclusion The diagnostic value of SpA features in patients with early axial SpA seems to be different than in patients with longstanding disease. Chronic back pain is better than IBP as an entry point to the diagnostic algorithm. Sacroiliitis on imaging is very important for early diagnosis, while the use of HLA–B27 status as a key factor is questionable.

Objective To evaluate the prevalence of sacroiliitis, the radiographic hallmark of inflammatory spondyloarthropathy, among patients diagnosed with fibromyalgia syndrome (FMS), using the current Assessment of SpondyloArthritis International Society (ASAS) criteria and magnetic resonance imaging. Methods Patients experiencing FMS (American College of Rheumatology 1990 criteria) were interviewed regarding the presence of spondyloarthritis (SpA) features and underwent HLA–B27 testing, C-reactive protein (CRP) level measurement, and magnetic resonance imaging examinations of the sacroiliac joints. FMS severity was assessed by the Fibromyalgia Impact Questionnaire and the Short Form 36 health survey. SpA severity was assessed by the Bath Ankylosing Spondylitis Disease Activity Index. Results Sacroiliitis was demonstrated among 8 patients (8.1%) and ASAS criteria for diagnosis of axial SpA were met in 10 patients (10.2%). Imaging changes suggestive of inflammatory involvement (e.g., erosions and subchondral sclerosis) were demonstrated in 15 patients (17%) and 22 patients (25%), respectively. The diagnosis of axial SpA was positively correlated with increased CRP level and with physical role limitation at recruitment. Conclusion Imaging changes suggestive of axial SpA were common among patients with a diagnosis of FMS. These findings suggest that FMS may mask an underlying axial SpA, a diagnosis with important therapeutic implications. Physicians involved in the management of FMS should remain vigilant to the possibility of underlying inflammatory disorders and actively search for such comorbidities.

Free to read Spondyloarthritis (SpA) describes a group of related inflammatory conditions, including ankylosing spondylitis (AS), psoriatic arthritis, reactive arthritis, SpA associated with inflammatory bowel disease and undifferentiated SpA.[1] Classification criteria have been developed and validated by the Assessment of SpondyloArthritis international Society (ASAS) to distinguish axial-predominant SpA from peripherally predominant SpA (Fig. 1).[1, 2] These criteria contribute to diagnosis, but are not ideal diagnostic criteria as they possess only moderate sensitivity.[3] Diagnosis of axial SpA should be established by a rheumatologist, after careful consideration of these criteria and individual patient factors.

Purpose To investigate the feasibility of using quantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) to differentiate the active and inactive stage of sacroiliitis and the correlation between quantitative parameters and disease activity as measured by clinical scores. Materials and Methods Forty-two patients with ankylosing spondylitis underwent DCE-MRI on a 3.0T MRI unit. According to the results of the blood sedimentation rate (ESR), C-reactive protein (CRP), and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the patients were grouped into inactive and active groups. Pharmacokinetic models were used to generate the semiquantitative and quantitative hemodynamic parameters of DCE-MRI. The between-group differences were analyzed using the Wilcoxon rank sum test, and the correlations between the pharmacokinetic parameters and BASDAI score were analyzed using Spearman's correlation coefficient. The efficacies of different parameters in differentiating the active and inactive phase of sacroiliitis were evaluated and compared using receiver operator characteristics (ROC) curve analysis. Results Ktrans, Kep, Ve, time to peak (TTP), max concentration (MAX Conc), and area under the curve (AUC) of the active group were significantly higher than those of the inactive stage group (P 0.05), except between AUC and MAX Conc (P = 0.0012). Conclusion Quantitative DCE-MRI parameters can differentiate between active and inactive ankylosing spondylitis. Among those, Ktrans had the highest correlation coefficient with the BASDAI score. Level of Evidence: 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:71–78

Objective To investigate whether seemingly healthy first-degree relatives of patients with ankylosing spondylitis (AS) have clinical, laboratory, or imaging features of spondyloarthritis (SpA). Methods First-degree relatives (ages 18–40 years) of HLA–B27–positive AS patients were included in the pre-spondyloarthritis (Pre-SpA) cohort, a prospective inception cohort study. Clinical, biologic, and imaging features were recorded. First-degree relatives were classified according to several sets of SpA classification criteria. Results We report baseline features of 51 first-degree relatives included in this study. Twenty-nine (57%) had back pain, 2 (4%) had psoriasis, 1 (2%) had inflammatory bowel disease, and 1 (2%) had uveitis. Three (6%) had low-grade sacroiliitis, 1 (2%) had cervical syndesmophytes on radiography, and 10 (20%) had bone marrow edema on magnetic resonance imaging of the sacroiliiac joints. Seventeen of 51 first-degree relatives (33%) fulfilled SpA classification criteria: 7 (14%) fulfilled both Assessment of SpondyloArthritis international Society (ASAS) axial SpA and European Spondylarthropathy Study Group (ESSG) classification criteria, 6 (12%) fulfilled only ASAS axial SpA classification criteria, and 4 (8%) fulfilled only ESSG classification criteria; 3 (6%) also fulfilled the Amor criteria. None fulfilled other SpA classification criteria. First-degree relatives fulfilling the ASAS axial SpA and/or ESSG classification criteria had more frequent inflammatory back pain, had a higher level of disease activity, and had more psoriasis. No differences were found in parameters of inflammation, peripheral and extraarticular disease other than psoriasis, and HLA–B27 positivity between those who did and those who did not fulfill the ASAS axial SpA and/or ESSG classification criteria. Four first-degree relatives (12%) who did not fulfill the ASAS axial SpA and/or ESSG classification criteria had imaging abnormalities suggestive of SpA. Conclusion A substantial proportion of seemingly healthy first-degree relatives of HLA–B27–positive AS patients have clinical and/or imaging abnormalities suggestive of SpA. Thirty-three percent could be classified as having SpA. Further follow-up will show which first-degree relatives will develop clinically manifest SpA.

Objective The Assessment of SpondyloArthritis international Society (ASAS) has previously published criteria for spondyloarthritis (SpA). In the Spines of Southern Denmark cohort, which included patients with persistent low back pain and an unknown proportion of patients with SpA, our objectives were 1) to estimate the prevalence of magnetic resonance imaging (MRI) findings and clinical features included in the ASAS criteria for SpA and 2) to explore the associations between MRI findings and clinical features. Methods We included patients ages 18–40 years with persistent low back pain who had been referred to the Spine Centre of Southern Denmark. We collected information on clinical features (including HLA–B27 and high-sensitivity C-reactive protein) and MRI findings in the spine and sacroiliac (SI) joints. Results Of 1,020 included patients, 537 (53%) had at least 1 of the clinical features included in the ASAS criteria for SpA. Three clinical features were common—inflammatory back pain according to the ASAS criteria, a good response to nonsteroidal antiinflammatory drugs (NSAIDs), and family history of SpA. The prevalence of these features ranged from 15% to 17%. Sacroiliitis on MRI according to the ASAS definition was present in 217 patients (21%). Of those 217 patients, 91 (42%) had the minimum amount of bone marrow edema required according to the ASAS definition (a low bone marrow edema score). The presence of HLA–B27, peripheral arthritis, a good response to NSAIDs, and preceding infection were independently positively associated with MRI findings in the SI joints (odds ratios [ORs] of 1.9–9.0). The remaining 8 clinical features were not positively associated with MRI findings. Importantly, only age was independently associated with low bone marrow edema score at the SI joints (OR of 1.1 per year). Conclusion In this population, 53% had at least 1 clinical feature included in the ASAS criteria for SpA, and 21% had sacroiliitis according to the ASAS definition; furthermore, the associations between the clinical and imaging domains were inconsistent. The results indicate a need for further investigation of the importance of these findings in SpA, including investigation of the minimum requirements for defining sacroiliitis on MRI.

Enthesitis‐related arthropathy (ERA) is severe subtype of juvenile idiopathic arthritis (JIA), and carries a substantial burden of morbidity and disability.1 Sacroiliitis is a particular problem in ERA, and up to 80% of patients with low back pain in ERA have sacroiliitis.2 However, monitoring the disease is difficult because clinical symptoms may be nonspecific; clinical assessment has been shown to be an insensitive tool for assessing sacroiliitis as diagnosed using magnetic resonance imaging (MRI).3 An accurate, specific method for diagnosis and quantification of sacroiliitis is therefore an important part of these patients' management. MRI has emerged as a valuable tool for assessing the sacroiliac joints.4 Conventional qualitative techniques rely on visual analysis of short tau inversion recovery (STIR) images,5 but recent research has demonstrated that diffusion‐weighted imaging (DWI) can be used as a fast, objective alternative.6, 7, 8, 9 However, assessment of joint inflammation in adolescence is challenging because the structure and composition of the sacroiliac joint changes substantially during skeletal maturation. Sacral ossification begins in the first two sacral segments in utero.10, 11 As the sacral apophyses ossify during childhood, residual cartilaginous connections that link the SIJs and the neural foramina gradually disappear. The apophyses typically fuse between the ages of 16 and 20, although sometimes the SIJs remain immature well into late adolescence.10, 12 Immature sacroiliac joint morphology may be misinterpreted as inflammation because unossified cartilage causes juxta‐articular areas of high signal on STIR images (Fig. ​(Fig.1).1). To our knowledge, there are no previous studies investigating the influence of joint maturity on apparent diffusion coefficient (ADC) values as measured using DWI. Figure 1 STIR and T 1‐weighted images from an 11‐year‐old female (a,b). In this case, the juxta‐articular bands of high signal on the STIR images were misdiagnosed as inflammation. Further scans (c,d) 2 years later (when the patient ... We hypothesized that ADC values would vary with joint maturity, since unossified bone would be expected to contain a higher proportion of water than fully mineralized bone (the relationship between water content and ADC is well established13. Furthermore, we hypothesized that normalized ADC (nADC) values14 would also be higher in unfused SIJs. nADC values (ie, the mean SIJ ADC value divided by a “reference” ADC obtained from normal sacral bone) are of particular interest because nADC has been investigated as a biomarker of inflammation in sacroiliitis,6 and may be less susceptible to between‐scan variability than uncorrected ADC. In this study we aimed to evaluate the association between SIJ maturity and both ADC and nADC measurements in adolescent and young adult patients with noninflammatory back pain.

Objective To evaluate the prevalence of sacroiliitis at diagnosis of juvenile spondyloarthritis (SpA) and the accuracy of physical examination and back pain to detect sacroiliitis, using imaging as the reference standard. Methods We performed a prospective cross-sectional study of 40 children with newly diagnosed juvenile SpA and 14 healthy controls. Subjects were assessed using physical examination, anteroposterior pelvic radiograph, and pelvic magnetic resonance imaging (MRI). Differences in clinical features between those children with and without sacroiliitis were assessed by Fisher's exact test for categorical variables and Wilcoxon's rank sum test for continuous variables. Accuracy of physical examination and back pain for detection of sacroiliitis was determined using MRI as the reference standard. Predicted probability of sacroiliitis was determined using exact multivariate logistic regression. Results Eight children (20%) with juvenile SpA had active sacroiliitis. Of those subjects with active changes on MRI, 7 of 8 (88%) also had evidence of erosions or sclerosis. Five children (13%) with juvenile SpA and 1 control (7%) had nonperiarticular bone marrow edema. Of the subjects with active sacroiliitis, only 3 (38%) reported a history of back pain or tenderness on palpation of the sacroiliac joints. The positive and negative predictive values of clinical examination features and back pain for detection of sacroiliitis were low. The estimated probability of having sacroiliitis was 0.84 (95% confidence interval 0.40–1.00) in HLA–B27–positive patients with an elevated C-reactive protein (CRP) level. Conclusion Active sacroiliitis by MRI is common at diagnosis in juvenile SpA and is frequently asymptomatic. Children who are HLA–B27–positive and have elevated CRP levels have the highest probability of sacroiliitis.

Aim Comparison of ankylosing spondylitis (AS) with non-radiographic axial spondyloarthritis (nr-axSpA) classified with the recent ASsessment of spondyloArthritis International Society (ASAS) criteria. Patients & Methods This study included 288 patients clinically diagnosed as having spondyloarthritis (SpA) where a satisfactory radiograph of sacroiliac (S-I) joints was available. The AS and the nr-axSpA groups were compared for the various SpA-related variables. Results Of 288 axSpA patients, there were 187 with AS. Of the remaining 101 patients without radiographic sacroiliitis, S-I joint magnetic resonance imaging (MRI) was available in 72; 54 of them showed active sacroiliitis thus classified as nr-axSpA according to the ASAS criteria. The remaining 18 patients with normal MRI and the other 29 patients without MRI of the S-I joints (total 47 patients), were classified as nr-axSpA using the ‘clinical arm’ of the ASAS criteria. On comparing the 187 AS with 101 patients in the nr-axSpA group, the AS group showed significantly more males, longer disease duration, more axial symptoms at disease onset, higher Bath Ankylosing Spondylitis Metrology Index and more syndesmophytes. Biologicals were offered significantly more often to the AS group but methotrexate as monotherapy or in combination with other disease-modifying anti-rheumatic drugs was offered more often in nr-axSpA group. There was no statistically significant difference between AS and nr-axSpA in other SpA parameters. Conclusion The differences brought out between AS and nr-axSpA groups show that they may not be the same disease. A prospective long-term follow-up of large cohorts may help in clarifying if nr-axSpA is simply an early stage in the spectrum of SpA evolving into AS over time or is there inherent difference between them.

Objective In adults, gadolinium contrast enhancement does not add incremental value to fluid-sensitive sequences for evaluation of bone marrow edema. This study was undertaken to determine if magnetic resonance imaging (MRI) contrast is necessary to assess lesions consistent with inflammatory sacroiliitis in children. Methods Patients with clinically suspected or diagnosed juvenile spondyloarthritis (SpA) underwent pelvic MRI consisting of multiplanar fluid-sensitive and postgadolinium T1-weighted fat-saturated sequences including dedicated sacral imaging. Three radiologists independently evaluated the fluid-sensitive sequences, and later, the complete study (including postcontrast images). With postcontrast imaging as the reference standard, we calculated the test properties of fluid-sensitive sequences for depiction of acute and chronic findings consistent with sacroiliitis. Results The 51 patients had a median age of 15 years, and 57% were male. Nineteen patients (22 joints) were diagnosed as having sacroiliitis based on postcontrast imaging, and none had synovitis in the absence of bone marrow edema. All 22 joints demonstrated bone marrow edema on both fluid-sensitive and postgadolinium T1-weighted fat-saturated sequences. Eighteen percent of joints with sacroiliitis had capsulitis, which was observed on both noncontrast and postcontrast imaging. Fifty-nine percent of joints with sacroiliitis had synovitis on postcontrast imaging. Sensitivity, specificity, positive predictive value, and negative predictive value of fluid-sensitive sequences for the detection of acute inflammatory lesions consistent with sacroiliitis using postgadolinium imaging as the reference standard were excellent. Interrater reliability was substantial for all parameters. Conclusion Our findings indicate that fluid-sensitive sequences are sufficient to detect acute and chronic lesions consistent with inflammatory sacroiliitis in children.

Aim To detect subclinical peripheral arthritis and disease activity in axial seronegative spondyloarthritis (SpA) patients using bone scintigraphy. Methods Seronegative SpA patients with an established diagnosis and no clinically evident arthritis at the time of the study were included. After excluding symptomatic cases, 20 patients were recruited; 18 with ankylosing spondylitis (AS) and another two with psoriatic arthritis (PsA). Conventional bone scintigraphy was performed to detect the distribution of increased uptake, blood vascular pool (vascularity) and activity. Results The peripheral joints in all the patients were asymptomatic with no signs of arthritis on clinical examination. Disease activity was higher in those with hypervascularity and activity (75%) detected by scintigraphy. Scintigraphic activity of the sacroiliac joints was found in 10 patients (50%) with a mean sacroiliac joint index of 2.4 ± 0.6. Subclinical involvement of the hips, knees, shoulders, ankles, small joints of the hands, ankles and sternoclavicular joints, as well as the small joints of the feet were detected with descending frequencies (25%, 25%, 20%, 20%, 15%, 10% and 10%, respectively). Dorsal spine increased uptake was found in 35% and hypervascularity of the skull in two cases. Avascular necrosis of the hip was present in one case with hypovascularity. Conclusion The spectrum of joint involvement in seronegative SpAs should not be limited to sacroiliitis. Bone scintigraphy provides a cost-effective method for detecting the extent of involvement in this group of autoimmune systemic diseases (axial SpA) without clinical evidence of peripheral arthritis.

Spondyloarthritis (SpA) is a chronic inflammatory arthritis that affects 0.9 to 1.4% of adults in the United States1 and is characterized by peripheral arthritis, enthesitis, dactylitis, acute anterior uveitis, HLA-B27 positivity, inflammatory back pain, and sacroiliitis. The term SpA encompasses ankylosing spondylitis (AS), undifferentiated SpA, inflammatory bowel disease associated arthritis, psoriatic arthritis, and reactive arthritis. The term juvenile SpA refers to SpA that starts during childhood. Under the newer International Leagues of Associations for Rheumatology (ILAR) juvenile idiopathic arthritis (JIA) classification scheme2, most children with JSpA fall into the categories of enthesitis related arthritis (ERA), psoriatic arthritis, and undifferentiated arthritis. Treatment regimens for JSpA are suboptimal and primarily based on those developed for adults with AS, adult RA and children with other JIA categories.3 In comparison to other categories of JIA, children with JSpA have more frequent and higher intensity pain and poorer health status.4-6 They are less likely to achieve and to sustain inactive disease than other JIA categories.7,8 Further, observational studies suggest that less than 20% of children with JSpA achieve remission within five years of diagnosis.9 Progress in finding more effective therapies for JSpA cannot be made without validated and highly discriminatory instruments to assess disease activity and response to treatments. The frequent use of a highly responsive composite disease activity score (DAS) greatly contributes to improved outcomes in rheumatoid arthritis (RA).10 The Tight Control for Rheumatoid Arthritis (TICORA) study demonstrated that in comparison to routine care, intensive outpatient management that included close monitoring of a composite DAS, monthly follow-up and aggressive treatment decisions based on the DAS improved remission rates by 4-fold (16% versus 65%) at 18 months.10 Several disease activity indices have been developed for adults with AS, including the AS disease activity score (ASDAS)11, and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI).12 Since JSpA has less axial disease than adults with ankylosing spondylitis and since the BASDAI is predominantly focused on axial symptoms it is unlikely to be as useful in this pediatric population. Neither of these indices has been validated in children. Outcome measures available for monitoring JIA disease outcomes and activity include the ACR pedi-30/50/70/9013, and the Juvenile Arthritis Disease Activity Score (JADAS).14 The pedi ACR 30/50/70/90 are dichotomous and must always have a baseline measurement for comparison; therefore, the measure does not provide a continuous scale by which to assess disease activity and response levels cannot be compared across patients because each has a unique baseline value. JSpA patients were included in the validation study of the JADAS but were a minority (

Objective Exertional leg pain is a characteristic musculoskeletal manifestation of familial Mediterranean fever (FMF). We aimed to define the frequency and characteristics of exertional leg pain in a large cohort of FMF patients and to evaluate for additional signs and symptoms of spondyloarthritis (SpA) in this patient population. Methods FMF patients were allocated into study or control groups based on the presence or absence of exertional leg pain. Randomly selected patients underwent magnetic resonance imaging (MRI) of the ankle as well as plain radiography of the sacroiliac joints. Results The prevalence of exertional leg pain among the 170 FMF patients included in the study was 58.2%. Patients with exertional leg pain had significantly more joint attacks (74.7% versus 40.8%; P < 0.0001), fever attacks (35.4% versus 15.5%; P = 0.004), and pleuritis attacks (48.5% versus 29.6%; P = 0.013) as well as more attacks per year. Elevations of inflammation markers were significantly more frequent among the study group (for the erythrocyte sedimentation rate, 44.4% of patients versus 21.1% of patients; P = 0.016) (for the C-reactive protein level, 48.4% of patients versus 31.8% of patients; P = 0.013), and M694V homozygosity was more prevalent among the study group (45.5% versus 21.1%; P = 0.001). Signs compatible with enthesopathy on MRI were observed in 73.5% of patients in the study group and in 33.3% of patients in the control group (P = 0.046). Definite SpA was diagnosed in 41.2% of the patients in the study group compared to none of the controls (P = 0.07) (odds ratio 1.7 [95% confidence interval 1.2–2.3]). Conclusion Exertional leg pain is a common manifestation of FMF and is a marker of a more severe disease phenotype. Additionally, exertional leg pain is frequently associated with sacroiliitis and an underlying ankle enthesopathy and should therefore be considered a new feature of SpA.

Isotretinoin is used for the treatment of various acne lesions that are resistant to other treatments. The most frequent rheumatologic side effect of isotretinoin is transient muscle and/or joint pains. Here, we report a case with bilateral wrist and metacarpophalangeal joint arthritis and unilateral sacroiliitis associated with isotretinoin usage to attract attention, particularly from physiatrists, rheumatologists and dermatologists, to this rare adverse effect of isotretinoin.

Background To assess the feasibility of diagnosing sacroiliitis on MR enterography examinations (MREs) of patients with inflammatory bowel disease (IBD). Methods Consecutive MREs performed in 286 biopsy proven IBD patients and 48 controls (2005–2012) were retrospectively reviewed for sacroiliitis. A clinical telephone questionnaire focusing on inflammatory back pain (IBP) was conducted in 165 patients and 41 controls. Acute and structural variables were scored in consensus by two readers. Structural changes were also evaluated on computed tomography (CT), when present and correlated to MRE. MRE scores were compared between the study and control groups and between symptomatic and nonsymptomatic patients. Results Mean sacroiliitis score was significantly higher in the study group (Study: 1.1, Control: 0.56, P = 0.015). Sacroiliitis prevalence was 9.1% when bone marrow edema was the diagnostic criterion and increased to 15% when structural changes were added. There was significant correlation between MRE structural score and the presence of structural changes on CT (r = 0.49; P = 0.0001). Thirty-six patients reported IBP, however, no correlation was found between MRE score and the presence of IBP. Conclusion Acute and structural findings of sacroiliitis can be evaluated on MRE examinations of IBD patients and should be looked for by the evaluating radiologist. J. Magn. Reson. Imaging 2015;42:121–127. © 2014 Wiley Periodicals, Inc.

Objective To investigate the degree of agreement between local rheumatologists/radiologists and central trained readers (external standard) on the presence/absence of sacroiliitis on radiographs of the sacroiliac (SI) joints. Methods Patients with inflammatory back pain (duration ≥3 months but

Objective Important differences exist between axial psoriatic arthritis (AxPsA) and ankylosing spondylitis (AS). The Bath Ankylosing Spondylitis Radiology Index (BASRI), the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS), and the Radiographic Ankylosing Spondylitis Spinal Score (RASSS) were developed to score AS, and the Psoriatic Arthritis Spondylitis Radiology Index (PASRI) to score AxPsA. We aimed to develop a computerized scoring application and compare the intra- and interrater reliability of these scoring systems in AS and AxPsA. Methods A computerized scoring application was developed to facilitate the scoring of radiographic features and calculate total scores for established scoring methods for AS and AxPsA. Digital spinal radiographs of 18 patients with AS and 40 patients with AxPsA were read in random order individually by 4 rheumatologists, data were entered into the application, and scores were obtained. The intraclass correlation coefficients (ICC) of the intra- and interrater reliability of scores for each method were then computed. Results In AS, the intra- and interrater ICC was 0.91 and 0.80 for sacroiliitis grade, 0.96 and 0.86 for BASRI-spine, 0.98 and 0.86 for mSASSS, 0.96 and 0.75 for RASSS, and 0.99 and 0.93 for PASRI, respectively. In AxPsA, the intra- and interrater ICC was 0.81 and 0.67 for sacroiliitis grade, 0.77 and 0.52 for BASRI-spine, 0.91 and 0.65 for mSASSS, 0.90 and 0.68 for RASSS, and 0.92 and 0.88 for PASRI, respectively. Conclusion Available radiographic scoring systems perform well in AS and have moderate intra- and interrater reliability when applied to AxPsA. However, PASRI may be superior for assessing structural damage in AxPsA.

Objective To evaluate the diagnotic value of the Assessment of Spondyloarthritis International Society (ASAS) classification criteria for axial spondyloarthritis (SpA) in Chinese patients with chronic back pain and without radiographic sacroiliitis in a 2-year follow-up study. Methods Patients with chronic back pain ≥ 3 months, onset age ≤ 45 years and without radiographic sacroiliitis were enrolled, and then received 2-year follow-up. All the clinical parameters associated with SpA were recorded. The patients were followed for 2 years and the final diagnosis of axial SpA or non-SpA was confirmed by rheumatologists. Diagnostic concordance between the initial classification according to three classification criteria (ASAS criteria for axial SpA, European Spondylarthropathy Study Group (ESSG) criteria and Amor criteria) and final diagnosis was compared. Diagnostic sensitivity and specificity were compared between the two subsets of ASAS criteria (set 1: sacroiliitis plus more than one SpA feature; set 2: HLA-B27 plus two more SpA features). Result One thousand and sixty-eight patients entered the study and 867 completed the 2-year follow-up (455 axial SpA and 412 non-SpA). The concordance of ASAS criteria was better than ESSG and Amor criteria. Three hundred and thirty-three patients and 335 patients were classified as axial SpA according to the ASAS set 1 and set 2 of criteria, respectively. Further, set 1 of criteria (318/333) showed higher specificity than set 2 critera (279/335) (P = 0.000). Conclusion The ASAS classification criteria for axial SpA showed good concordance in diagnosing Chinese axial SpA patients in this prospective study. Set 1 criteria involving sacroiliitis plus more than one SpA feature had better diagnosing value.

PubMedID: 24807846 Aim: One of the major problems for systemic sclerosis (SSc) patients is suggested to be articular involvement. Mostly involved joints in SSc were reported as wrist, carpometacarpal-interphalangeal, foot, knee, hip and shoulder; however, there has been little knowledge on the sacroiliac joint. Our aim was to evaluate sacroiliac joint involvement in SSc. Methods: Fifty-seven SSc patients, 54 rheumatoid arthritis patients and 64 healthy subjects were included. Anteroposterior pelvic radiographs were obtained and graded twice by three blinded rheumatologists. One competent radiologist has re-evaluated the X-ray results. The ASAS (Assessment of Spondylo Arthritis International Society) scoring method was applied for grading sacroiliac involvement. Inflammatory back pain was also evaluated. Other clinical and laboratory data were collected as proposed by the European Study Group. Results: In the SSc group sacroiliitis was found in 13 patients (23%) and was significantly different from RA patients (two patients, 4%), P = 0.003; and the healthy control group (one participant, 2%), P < 0.001. The frequency of inflammatory back pain in SSc patients with sacroiliitis (8/13 patients, 62%) was significantly higher in SSc patients without sacroiliitis (4/44 patients, 9%), P < 0.001. The SSc patients with sacroiliitis and with inflammatory back pain (8/57 patients, 14%) were regarded as axial spondyloarthritis overlap. Male gender, diffuse subtype, inflammatory back pain and high C-reactive protein levels (odds ratio: 1.069, 1.059, 1.059 and 3.698, respectively) were found to be the significant risk factors for sacroiliitis. Conclusion: We suggest that, sacroiliitis may be a concern to be considered in SSc practice. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.