Sacroiliitis in inflammatory bowel disease on abdominal computed tomography: prevalence, misses, and associated factors.

OBJECTIVE: To evaluate the prevalence and rate of a missed diagnosis of sacroiliitis on abdominal computed tomography (CT) in patients with inflammatory bowel disease (IBD). Factors associated with sacroiliitis were also assessed. METHOD: This retrospective study included 210 patients with IBD (mean age 31.1 years) who underwent abdominal CT. Based on a validated abdominal CT scoring tool, bilateral sacroiliac (SI) joints on abdominal CT in the whole study population were retrospectively reviewed. Subsequently, patients were classified into the 'patients with sacroiliitis' group and the 'patients without sacroiliitis' group. Univariate and multivariate regression analyses were used to clarify the factors associated with sacroiliitis. RESULTS: Sacroiliitis was identified in 26 out of 210 patients (12.4%). However, sacroiliitis was recognized on the primary reading in only five of these 26 patients (19.2%) and was missed on the initial report in the remaining 21 patients (80.8%). Among the 21 patients, 20 (95.2%) were finally diagnosed with axial spondyloarthritis (axSpA). There was a higher prevalence of female sex (p = 0.04), upper gastrointestinal involvement (p = 0.04), and back pain (p < 0.01) in patients with sacroiliitis than in those without sacroiliitis. However, on multivariate analysis, back pain was the only factor associated with sacroiliitis (p = 0.01). CONCLUSION: Physicians should carefully evaluate SI joints on abdominal CT in patients with IBD to enable early detection of sacroiliitis, potentially leading to an early diagnosis of axSpA. In addition, if patients with IBD present with back pain, the possibility of sacroiliitis should be considered.

Comparison of demographic, clinic and radiological features of patients with axial spondyloarthritis accompanying familial Mediterranean fever to patients with each condition alone.

OBJECTIVE: To compare the demographic, clinical, and radiological features of patients with axial spondyloarthritis (axSpA) accompanying familial Mediterranean fever (FMF) to patients with each condition alone. METHOD: Hacettepe University Hospital database was screened regarding ICD-10 codes for FMF (E85.0) and axSpA (M45). The diagnosis of FMF was confirmed by Tel-Hashomer criteria, and axSpA by the presence of sacroiliitis according to the modified New York criteria or active sacroiliitis on magnetic resonance imaging. As control groups, 136 gender-matched, consequent FMF patients without axSpA and 102 consequent axSpA patients without FMF previously treated with any biological agents were included in the analysis. RESULTS: In patients with FMF + axSpA compared to the axSpA group, age at axSpA symptom onset and age at diagnosis were lower [median with interquartile range (IQR): 21 (17-30) vs 27 (21-37), p < 0.001; 23 (21-38) vs 32 (24-43) years, p = 0.001], moderate to severe hip disease and total hip replacement were more prevalent (23.4% vs 4.7%, p < 0.001; 11.2% vs 2.8%, p = 0.016). In patients with FMF + axSpA compared to the FMF group, age at FMF symptom onset and age at diagnosis were higher [13 (6-30) vs 11 (5-18), p = 0.057; 23 (13-33) vs 18 (10-31) years, p = 0.033] and amyloidosis was more prevalent (6.6% vs 2.2%, p = 0.076). Although the M694V variant (in one or two alleles) was more prevalent in the FMF + axSpA group, the difference was not statistically significant. CONCLUSION: In patients with FMF + axSpA, the age of onset of axSpA was significantly earlier, moderate to severe hip involvement and amyloidosis were more common than in patients with each condition alone.

Prevalence and neglected rate of sacroiliitis on lumbar spine CT in patients with low back pain.

OBJECTIVE: The study aims to investigate the prevalence and neglected rate of sacroiliitis on lumbar spine computed tomography (CT) in patients with low back pain. MATERIALS AND METHODS: From January 2016 to December 2020, a total of 4827 patients (mean age: 35.4 ± 9.5 years) who underwent lumbar spine CT examinations were included in this retrospective study. The CT degree of sacroiliitis in all study population were retrospectively reviewed by two radiologists. The independent sample t-test was used to compare the continuous values and chi-squared or Fisher's exact test was used to compare the categorized values. RESULTS: Sacroiliitis was identified in 514 of 4827 patients (10.6%). Patients with sacroiliitis were significantly younger than those without sacroiliitis (32.1 ± 8.9 vs. 35.8 ± 9.5 years, p < 0.001). Moreover, significantly more patients with sacroiliitis had HLA-B27 (p < 0.001) positivity and inflammatory back pain syndrome (p = 0.003) than those without sacroiliitis. Among the 514 patients, sacroiliitis was recognized on primary reading in 386 patients (75.1%) but was neglected in the remaining 128 patients (24.9%). Of the 386 patients, 371 patients were followed up, and finally, 295 patients of them (79.5%) were diagnosed with axSpA. CONCLUSION: Radiologists should pay careful and more attention to sacroiliac joint on lumbar spine CT for early diagnosis of sacroiliitis in young patients with low back pain, which could result in early diagnosis and treatment of axSpA.

Childhood-Onset Sacroiliitis: Causes and Correlation Between Clinical Findings and Magnetic Resonance Imaging.

OBJECTIVE: The aims of this study were to describe disease associations of magnetic resonance imaging (MRI)-confirmed and clinically symptomatic sacroiliitis in pediatric patients with rheumatic diseases and to examine the relationship between patient characteristics and MRI findings of the sacroiliac joint (SIJ). METHODS: Demographic and clinical data were extracted from the electronic medical records of the patients with sacroiliitis followed in the last 5 years. Active inflammatory and structural damage lesions of the SIJ-MRI were examined by the modified Spondyloarthritis Research Consortium of Canada scoring system, and correlation analysis of these results with clinical characteristics was evaluated. RESULTS: A total of 46 symptomatic patients were found to have MRI-proven sacroiliitis of 3 different etiologies: juvenile idiopathic arthritis (JIA) (n = 17), familial Mediterranean fever (FMF) (n = 14), and chronic nonbacterial osteomyelitis (CNO) (n = 8). Seven patients, FMF and JIA (n = 6) and FMF and CNO (n = 1), had a co-diagnosis that might cause sacroiliitis. Although inflammation scores and structural damage lesions did not statistically differ between the groups, capsulitis and enthesitis on the MRI were more frequently detected in the CNO group. There was a negative correlation between symptom onset and inflammation scores of bone marrow edema. Disease composite scores and acute phase reactants were correlated with MRI inflammation scores. CONCLUSIONS: We demonstrated that JIA, FMF, and CNO were the major rheumatic causes of sacroiliitis in children originating from the Mediterranean region. Quantitative MRI scoring tools can be used to assess the inflammation and damage of the SIJ in rheumatic diseases, show discrepancies between them, and have an important correlation with various clinical and laboratory features.

Factors predicting axial spondyloarthritis among first-degree relatives of probands with ankylosing spondylitis: a family study spanning 35 years.

OBJECTIVE: Factors predicting axial spondyloarthritis (axSpA) among first-degree relatives (FDRs) of ankylosing spondylitis (AS) patients need to be defined. We investigated the predictive value of the probands' HLA-B27 and radiographic sacroiliitis status on disease occurrence among their FDR. We also assessed the predictive value of features of the clinical history, including chronic inflammatory back pain (CIBP) and acute anterior uveitis (AAU), among the FDR and how they can be used to improve classification and diagnosis of axSpA. METHODS: In 1985, we studied 363 AS probands and 806 FDR who underwent rheumatologic examination, completed questionnaires, provided blood samples for HLA-typing and underwent radiography of sacroiliac joints. At follow-up in 2018-2019, 125 patients and 360 FDR were available for study, and completed a postal questionnaire about axSpA features. FDRs were asked to report whether after 1985 they had been diagnosed by Swiss rheumatologists as having axSpA. RESULTS: Among HLA-B27(+) FDR, axSpA occurred in 25.4%-26.3%, independent of the radiographic sacroiliitis status of the proband. AAU occurred in 13/34 (38.2%) FDR with axSpA vs 29/251 (11.6%) FDR without axSpA (p=0.00004, OR=4.74 95% CI 2.15 to 10.47). The presence of CIBP at baseline did not predict later occurrence of axSpA but combining CIBP and pain/discomfort at the thoracic spine and at anterior (ventral) chest wall ever, assessed at follow-up in 2018-2019, provided 83.1% sensitivity and 87.2% specificity for current axSpA. CONCLUSION: Occurrence of AAU among FDR of axSpA probands should prompt screening for axSpA. Moreover, co-occurrence of CIBP and pain/discomfort in the thoracic spine and at anterior chest wall as a three-question tool may further enhance clinical suspicion of axSpA among these FDR.

Spondyloarthritis in familial Mediterranean fever: a cohort study.

Familial Mediterranean fever (FMF) and spondyloarthritis (SpA) may show several common signs. This study aimed to evaluate the frequency of SpA and its manifestations in FMF, the impact of SpA on FMF, and the associations of non-episodic findings (heel enthesitis, protracted arthritis, and sacroiliitis) with the FMF features. Demographic, clinical, imaging, and genetic data were retrieved from medical records of the patients with adult FMF. To identify patients who met the classification criteria for SpA, data including rheumatologic inquiry were recorded. Patients with SpA and those who did not meet the criteria were compared in terms of FMF features. Regression analyses were performed to determine the factors that were most associated with sacroiliitis, enthesitis, and protracted arthritis. Of the 283 patients with FMF, 74 (26.1%) met the SpA criteria (64 axial, 10 peripheral); and 65 (22.9%) patients had sacroiliitis, 27 (9.5%) protracted arthritis, and 61 (21.6%) heel enthesitis. Patients with SpA were older and had more FMF severity, and heel pain rate than those without; however, genetic features, CRP, resistance to colchicine, and heel enthesitis did not differ. A meaningful number of patients without SpA had also displayed heel enthesitis, protracted arthritis, inflammatory back pain, heel pain, family history of SpA, and elevated CRP. Age was found to be the main predictor of heel enthesitis and protracted arthritis was linked with FMF severity. A significant number of patients with FMF meet the peripheral SpA classification criteria as well as axial SpA. SpA and its shared manifestations with FMF may have an impact on FMF.

The prevalence of sacroiliitis on abdominal MRI examinations of patients with Takayasu arteritis.

BACKGROUND: Takayasu arteritis (TA), a systemic large-vessel vasculitis, was reported to have high incidence of spondyloarthropathy. PURPOSE: To evaluate the prevalence of inflammatory sacroiliitis in patients with TA that underwent abdominal/pelvic magnetic resonance imaging (MRI) examinations as part of their vasculitis work-up. MATERIAL AND METHODS: Consecutive abdominal/pelvic MRI examinations of 34 patients with TA fulfilling the 1990 ACR criteria and 34 age- and gender-matched controls performed between 2008 and 2020 were retrospectively reviewed for the presence sacroiliitis. The presence of active and structural lesions was scored twice (with a one-month interval between reads) by one reader. Structural lesions were also evaluated on computed tomography, when available, and correlated to MRI findings. Clinical data were extracted from the patients' clinical files. MRI scores were compared between the study and control groups and correlated with the clinical data. RESULTS: Sacroiliitis was evident in 11.7% of the TA group examinations compared to 0.3% in the control group (P = 0.6). Participants with TA had significantly more erosions and fat deposition compared to the control group (Study: 0.01/0.03, Control: 0/0, P = 0.03/0.003, respectively). However, mean sacroiliitis score was not significantly different (Study: 1.06, Control: 0.78, P = 0.015). Of the four patients with TA and sacroiliitis, 3 (75%) had a diagnosis of inflammatory bowel disease (IBD). CONCLUSION: Sacroiliitis was detected in 11.7% of abdominal MRI examinations of patients with TA, 75% of which had associated IBD, suggesting that both IBD and sacroiliitis should be routinely screened in the TA population as their presence may influence treatment decisions.

Prevalence of sacroiliitis among patients referred for hip MR arthrography.

OBJECTIVE: To determine the prevalence of sacroiliitis among patients who have been referred for MR arthrography. MATERIALS AND METHODS: A retrospective search identified 130 consecutive MR arthrograms of the hip performed on a 1.5T Siemens Avanto at our institution from August 2013 to August 2014. Four studies were excluded due to the absence of a coronal short tau inversion recovery sequence of the pelvis, leaving 126 studies for analysis. A musculoskeletal radiology fellow and three attending musculoskeletal radiologists reviewed the images for the presence of bone marrow edema affecting the sacroiliac joints. Only cases of bone marrow edema meeting the Assessment of SpondyloArthritis international Society definition were considered positive. The two-tailed Fisher's exact test was used to compare the prevalence of positive MRI findings among age and gender groups. GraphPad InStat (GraphPad Software) was used for statistical calculations. RESULTS: Patients less than 40 years of age demonstrated a statistically higher prevalence of positive MRI findings of sacroiliitis when compared to patients older than 40 (p = 0.0082). No difference in prevalence was found between genders. Overall prevalence of MRI signal alteration suggestive of sacroiliitis as defined by the Assessment of SpondyloArthritis international Society was 4.8%. Among the six patients with positive findings, two were subsequently diagnosed with spondyloarthritis. CONCLUSION: Hip pain may be a presenting symptom of spondyloarthritis and attention should be paid to the sacroiliac joints during screening examinations, particularly in patients less than 40 years of age.

Axial and peripheral spondyloarthritis: does psoriasis influence the clinical expression and disease burden? Data from REGISPONSER registry.

OBJECTIVE: To evaluate whether the presence of psoriasis influences the clinical expression, disease activity and disease burden in both axial and peripheral phenotypes of spondyloarthritis (SpA). METHODS: Patients from the Spanish REGISPONSER registry classified as having SpA according to the ESSG criteria were included. Patients were classified as psoriatic or non-psoriatic depending on the presence of cutaneous or nail psoriasis; thereafter, they were classified as having either axial [presence of radiographic sacroiliitis OR inflammatory back pain (IBP)] or peripheral phenotype (absence of radiographic sacroiliitis AND absence of IBP AND presence of peripheral involvement). Pair-wise univariate and multivariate analyses among the four groups (psoriatic/non-psoriatic axial phenotypes and psoriatic/non-psoriatic peripheral phenotypes) were performed with adjustment for treatment intake. RESULTS: A total of 2296 patients were included in the analysis. Among patients with axial phenotype, psoriasis was independently associated (P < 0.05) with HLA-B27+ [odds ratio (OR) 0.27], uveitis (OR 0.46), synovitis (ever) (OR 2.59), dactylitis (OR 2.78) and the use of conventional synthetic DMARDs (csDMARDs) (OR 1.47) in comparison with non-psoriatic patients. Among patients with peripheral phenotype and adjusting for csDMARD intake, psoriasis was independently associated with higher age at disease onset (OR 1.05), HLA-B27+ (OR 0.14) and heel enthesitis (OR 0.22). Higher scores for patient-reported outcomes and greater use of treatment at the time of the study visit were observed in psoriatic patients with either axial or peripheral phenotype. CONCLUSION: These findings suggest that, among all patients with SpA, psoriasis is associated with differences in clinical expression of SpA, a greater disease burden and increased use of drugs.

Sacroiliitis in systemic lupus erythematosus : The rates of involvement of the forgotten joint.

OBJECTIVE: Although musculoskeletal system involvement is a well-known manifestation in systemic lupus erythematosus (SLE), the probability of sacroiliac joint involvement and its effect on patients might be ignored. The aim of the study was to investigate the association between SLE and sacroiliitis and to evaluate the relationship between clinical parameters and sacroiliitis in SLE. METHODS: The study was designed as a case-control study. A total of 63 patients with SLE and 31 age- and sex-matched healthy controls were included in the study. The clinical and demographic variables of the study population were documented. The sacroiliac joints of patients and controls were evaluated with sacroiliac magnetic resonance imaging. Human leukocyte antigen (HLA) B27 was assessed using flow cytometry (Beckman Coulter Navios-model 3, Beckman Coulter Inc., Brea, CA, USA). Multinomial logistic regression analysis was used to determine the clinical risk factors related to sacroiliitis. RESULTS: Among the 63 patients, acute sacroiliitis was found in 25 patients (39.7%) and chronic sacroiliitis was found in 21 patients (33.3%). Sacroiliitis was higher in patients than in controls (p = 0.001). Acute sacroiliitis was more frequently observed in patients when compared with the control group (p = 0.001). Higher C­reactive protein (CRP) concentrations (odds ratio = 1.75, 95% confidence interval: 1.30-2.35; p < 0.001) were found to be a risk factor for acute sacroiliitis. CONCLUSION: The ratio of sacroiliitis was higher in patients with SLE than in controls. Increased CRP concentrations were determined as a risk factor for acute sacroiliitis. Thus, one should keep in mind that patients with SLE and higher CRP concentrations may have sacroiliitis.

Update on Juvenile Spondyloarthritis.

Spondyloarthritis (SpA) is a blanket term encompassing entities such as enthesitis-related arthritis, nonradiographic axial SpA, and ankylosing spondylitis. These diseases share many clinical features, including a predilection for inflammation of the entheses and the sacroiliac joints. The nomenclature is based on the evolution of the classification of the disease and the age of the patient. SpA has a prevalence of approximately 1% of the population of the United States, with 10% to 20% of patients experiencing the onset during childhood. Children with onset of arthritis before age 16 years are classified as having juvenile idiopathic arthritis. Children with enthesitis and/or sacroiliitis are further classified as belonging to the enthesitis-related arthritis subtype of juvenile idiopathic arthritis. The initial manifestations can be subtle and will usually include a peripheral pattern of arthritis and enthesitis. It may take several years for axial disease to develop in children. Except for an association with the human leukocyte antigen (HLA-B27) serotype, there are no laboratory markers for the disease, and the radiographic findings are often negative. A careful clinical evaluation for evidence of inflammation in the entheses and the joints and a search for comorbidities are required. Magnetic resonance imaging facilitates the early detection of sacroiliitis, an important feature that may be clinically silent. Because recent studies indicate that earlier introduction of therapy can help achieve better outcomes, rapid identification and treatment of children with SpA is essential.

High prevalence of spondyloarthritis-like MRI lesions in postpartum women: a prospective analysis in relation to maternal, child and birth characteristics.

OBJECTIVES: Bone marrow oedema (BMO) on MRI of sacroiliac joints (SIJs) represents a hallmark of axial spondyloarthritis (SpA), yet such lesions may also occur under augmented mechanical stress in healthy subjects. We therefore sought to delineate the relationship between pregnancy/delivery and pelvic stress through a prospective study with repeated MRI. Results were matched with maternal, child and birth characteristics. METHODS: Thirty-five women underwent a baseline MRI-SIJ within the first 10 days after giving birth. MRI was repeated after 6 months and, if positive for sacroiliitis according to the Assessment of SpondyloArthritis International Society (ASAS) definition, after 12 months. BMO and structural lesions were scored by three trained readers using the Spondyloarthritis Research Consortium of Canada (SPARCC) method. RESULTS: Seventy-seven per cent of the subjects (27/35) displayed sacroiliac BMO immediately postpartum, 60% fulfilled the ASAS definition of a positive MRI. After 6 months, 46% of the subjects (15/33) still showed BMO, representing 15% (5/33) with a positive MRI. After 12 months, MRI was still positive in 12% of the subjects (4/33). Few structural lesions were detected. Intriguingly, in this study, the presence of BMO was related to a shorter duration of labour and lack of epidural anaesthesia. CONCLUSION: A surprisingly high prevalence of sacroiliac BMO occurs in women immediately postpartum. Our data reveal a need for a waiting period of at least 6 months to perform an MRI-SIJ in postpartum women with back pain. This study also underscores the importance of interpreting MRI-SIJ findings in the appropriate clinical context.

Prevalence of axial spondyloarthritis in Poland.

The prevalence of axial spondyloarthritis (axSpA) in the published data varies significantly. Two types of axSpA can be distinguished depending upon the presence of abnormalities consistent with sacroiliitis on plain radiography: ankylosing spondylitis (AS) and nonradiographic axial SpA (nr-axSpA). The aim of this study is to perform a retrospective analysis of axSpA prevalence in Poland in the years 2008-2017. The National Health Fund (NHF) database for the period 2008-2017 was analysed. Data of all patients with the ICD-10 codes M46 (M46.1, M46.8, M46.9) or M45 (further named other inflammatory spondylopathies-OIS and AS, respectively) as the main or co-existing diagnosis were extracted and analysed. The AS prevalence was stable during the period under examination amounting to approximately 0.083%, while the OIS prevalence increased from 0.036 to 0.059%. For both men and women, the AS prevalence increased with age, reaching a maximum around the age of 70; however, in men, a marked increase in prevalence was observed earlier as compared to women (20-24 vs. 40-44 years, respectively). The OIS prevalence also increased with age; however, the maximum was reached earlier as in case of AS. Moreover, a sharp increase in OIS prevalence occurred earlier than in AS (15-19 years) with no difference between sexes. In Poland, approximately 0.1% of the population suffers from AS-the prevalence remained stable over the last decade. The prevalence of OIS increased markedly over the studied period which presumably reflects an increasing prevalence of nr-axSpA as the effect of the introduction of ASAS classification criteria for axSpA.

Clinical peripheral enthesitis in the DESIR prospective longitudinal axial spondyloarthritis cohort.

OBJECTIVES: We aimed to describe the prevalence and characteristics of peripheral enthesitis in recent onset axial spondyloarthritis, estimate the incidence of peripheral enthesitis over time, and determine the factors associated with the presence of peripheral enthesitis. METHODS: 708 patients with recent onset axial spondyloarthritis were enrolled in the DESIR cohort ( prospective multi-centre, longitudinal). Data regarding the patients and spondyloarthritis characteristics at baseline with a specific focus on enthesitis and occurrence of peripheral enthesitis were collected during the five years of follow-up. RESULTS: At inclusion, 395 patients (55.8%) reported peripheral enthesitis. The locations were mainly the plantar fascia (53.7%) and the Achilles tendon (38.5%). During the 5-year follow-up period, 109 additional patients developed peripheral enthesitis resulting in an estimated (Kaplan-Meier method) percentage of 71% (95% CI: 68-75). Variables associated with peripheral enthesitis in the univariate analysis were: older age, male gender, absence of HLA B27, MRI sacroiliitis and fulfilled Modified NY criteria, presence of anterior chest wall pain, peripheral arthritis, dactylitis, psoriasis, high BASDAI, BASFI, mean score ASAS-and the use of NSAIDs. Only the history of anterior chest wall pain and of peripheral arthritis were retained in the multivariate analysis (odds ratio (OR)=1.6 [95% confidence interval [1.1-2.3], and OR=2.1 [1.4-3.0], respectively). CONCLUSIONS: This study highlights the high prevalence of peripheral enthesitis in recent onset axial spondyloarthritis, and suggests that in combination with peripheral arthritis, enthesitis might have an impact on the burden of the disease.

Sacroiliitis in Children With Familial Mediterranean Fever.

BACKGROUND/OBJECTIVE: Familial Mediterranean fever (FMF) is an autosomal recessive disease, characterized by recurrent, self-limited attacks of fever with serositis. Various diseases were reported to be associated with FMF. The aim of this study was to investigate the frequency and characteristics of sacroiliitis in children with FMF. METHODS: Files of FMF patients who had been seen in 2 reference hospitals in Ankara were retrospectively evaluated. Patients with FMF and concomitant sacroiliitis were included to the study. All patients had magnetic resonance imaging evidence of sacroiliitis. RESULTS: Among 650 FMF patients, 17 (11 females, 6 males; mean age, 13.32 ± 4.24 years) (2.6%) of them were found to have sacroiliitis. Familial Mediterranean fever diagnosis was done prior to sacroiliitis diagnosis in 11 patients (65%) and concurrently or afterward in 6 patients (35%). Ten patients had isolated sacroiliitis, and 7 had associated diseases (5 enthesitis-related arthritis, 1 psoriatic arthritis, and 1 ulcerative colitis). Arthritis (59%), arthralgia (77%), leg pain (71%), heel pain (41%), and enthesitis (29%) were common complaints. Sacroiliac tenderness was detected in 77%, and M694V mutation in almost 90% of the patients. All patients received colchicine therapy. Additionally, 14 of them were treated with nonsteroidal anti-inflammatory drugs, 10 were on sulfasalazine treatment, and 7 of them were on biological agents. CONCLUSIONS: Sacroiliitis can be seen in patients with FMF during childhood, and M694V mutation seems to be a susceptibility factor for its development. Inflammatory low-back pain and leg and heel pain could suggest sacroiliitis.

Axial spondyloarthritis classification criteria: the debate continues.

PURPOSE OF REVIEW: The Assessment of Spondyloarthritis International Society (ASAS) axial spondyloarthritis (axSpA) classification criteria marked a major step forward in SpA research, distinguishing axial from peripheral disease, and allowing earlier identification through MRI. This facilitated all aspects of research including epidemiology, therapeutics and patient outcomes. RECENT FINDINGS: The ASAS axSpA classification criteria have been applied broadly in research, and were validated in a recent meta-analysis of international studies. Concerns arose because of clinical differences between the clinical and imaging arms, which imply different risk for radiographic progression, and perform differently in validation studies. Low specificity of the MRI finding of sacroiliac joint bone marrow edema may lead to misclassification in populations with low axSpA prevalence. We suggest methodology to improve upon the criteria, including rigorous assessment of potential candidate criteria sets, discrete choice experiments to allow consideration of feature weights, and validation. Separately, assessment of structural and inflammatory MRI abnormalities should be performed to refine the MRI definition of sacroiliitis. SUMMARY: The debate regarding the validation and modification of the ASAS axSpA classification criteria should lead to international efforts to build upon the gains made by these criteria, to further refine the axSpA population definitions for research and ultimately improve patient outcomes.

MRI Findings of the Sacroiliac Joints in Patients with Low Back Pain: Alternative Diagnosis to Inflammatory Sacroiliitis.

BACKGROUND: Magnetic resonance imaging (MRI) is the most sensitive imaging modality for the detection of sacroiliitis. Diagnosing sacroiliitis on MRI is not always straightforward and can be challenging in some cases. OBJECTIVES: To evaluate the prevalence of alternative diagnoses suggested by MRI and characterize the MR appearance of the most common ones. METHODS: Consecutive MRI examinations of the sacroiliac joints (SIJ) performed between 2005 and 2012 were retrospectively evaluated for the presence of structural and active sacroiliitis findings according to the Assessment of SpondyloArthritis International Society guidelines. Alternative diagnoses, including degenerative changes, diffuse idiopathic skeletal hyperostosis (DISH), Osteitis condensans ilii (OCI), septic sacroiliitis/discitis, stress reaction as well as anatomic variants, were registered. RESULTS: We evaluated 281 MRI examinations, 116 males, 165 females, average age 44 ± 15 years. Sacroiliitis was found in 71 examinations (25%) and alternative diagnoses were suggested in 87 (31%) (OCI 8.9%, anatomic variants 5.3%, septic sacroiliitis 5.3%, degenerative findings 4.3%, diffuse idiopathic skeletal hyperostosis [DISH] 1.5%, stress reaction 0.7%, tumor 0.3%). A normal examination was found in the remaining 123 examinations. Patients with alternative diagnoses were older than those with sacroiliitis (62 vs. 47 years of age, respectively, P > 0.05). Alternative pathologies in the SIJ were significantly more common in females (66) than males (21), P < 0.05. CONCLUSIONS: A substantial proportion of patients with suspected sacroiliitis had normal SIJ while the rest were more commonly diagnosed with other pathologies. A referral by an experienced rheumatologist may improve the sensitivity and specificity of this important examination.

The prevalence of sacroiliitis in patients with acne vulgaris using isotretinoin.

BACKGROUND/OBJECTIVE: Acne vulgaris is a chronic inflammatory disease affecting the pilosebaceous unit in the skin. Isotretinoin is a synthetic vitamin A derivative regarded as the most effective agent in the treatment of acne. There have recently been increasing reports of adverse effects of isotretinoin on the skeletal system. Our aim in this study was to evaluate the rheumatic side-effects triggered by this drug, and particularly the prevalence of sacroiliitis. MATERIALS AND METHODS: A total of 73 patients receiving isotretinoin due to moderate or severe acne vulgaris were included. All patients were questioned about inflammatory low back pain and musculoskeletal pains during the treatment process. Inflammatory low back pain was evaluated using Assessment of Spondyloarthritis International Society (ASAS) criteria. Patients meeting ASAS criteria were evaluated with radiography and when necessary with sacroiliac magnetic resonance. RESULTS: The dose range for isotretinoin was between 0.4 and 0.8 mg/kg/day (mean 0.53 mg/kg/day). Treatment lasted for 6-8 months (mean 6.8 months). Lethargy was determined in 37 (50.7%) patients, myalgia in 31 (42.5%) and low back pain in 36 (49.3%). Mechanical low back pain symptoms were present in 20 of the patients describing low back pain and inflammatory low back pain in 16. Acute sacroiliitis was determined in six patients (8.2%) following a sacroiliac magnetic resonance imaging (MRI). Five (83.3%) of the patients with sacroiliitis were female and one (16.7%) was male. No statistically significant difference was determined between male and female patients in terms of prevalence of sacroiliitis (p = 0.392). CONCLUSION: The incidence of sacroiliitis in patients using isotretinoin is quite high. Patients using isotretinoin must be questioned about sacroiliitis findings and must be subjected to advanced assessment when necessary. Further studies regarding the development of sacroiliitis under isotretinoin therapy are now needed.

Extra-Gastrointestinal Manifestations of Inflammatory Bowel Disease May Be Less Common Than Previously Reported.

BACKGROUND AND AIMS: Extra-intestinal manifestations are well recognized in inflammatory bowel disease (IBD). To what extent the commonly recognized extra-intestinal manifestations seen in IBD patients are attributable to IBD is, however, not clear due to the limited number of controlled studies published. METHODS: We have conducted a study of these manifestations using electronic primary care records. We have identified extra-intestinal manifestations in IBD and non-IBD patients and derived odds ratios (ORs) using conditional logistic regression. RESULTS: A total of 56,097 IBD patients (32.5 % Crohn's disease, 48.3 % ulcerative colitis (UC) and 19.2 % not classified) were matched to 280,382 non-IBD controls. We found records of pyoderma gangrenosum (OR = 29.24), erythema nodosum (OR = 5.95), primary sclerosing cholangitis (OR = 188.25), uveitis (OR = 2.81), ankylosing spondylitis (OR = 7.07), sacroiliitis (OR = 2.79) and non-rheumatoid inflammatory arthritides (OR = 2.66) to be associated with IBD. One or more of these was recorded in 8.1 % of IBD patients and 2.3 % of controls. Non-specific arthritides were present in many more patients, affecting 30 % of IBD patients and 23.8 % of controls overall. We also found weaker associations with a number of conditions not generally considered to be extra-intestinal manifestations including psoriasis, ischemic heart disease, multiple sclerosis and hay fever. CONCLUSION: Although "classical" extra-intestinal manifestations are strongly associated with IBD, most IBD patients remain unaffected. Arthropathies, perceived to be the commonest extra-intestinal manifestation, are not strongly associated with IBD, and the proportion of arthropathies attributable to IBD is likely to be small.

Radiographic progression is associated with increased cardiovascular risk in patients with axial spondyloarthritis.

OBJECTIVES: To compare the cardiovascular disease (CVD) risk between axial spondyloarthritis (axSpA) patients and matched controls, and to identify factors associated with increased CVD risk in axSpA patients. METHODS: This cross-sectional study enrolled 185 axSpA patients who fulfilled the Assessment for Spondyloarthritis (ASAS) criteria and 925 age- and sex-matched controls. None of the subjects had a previous history of CVD or diabetes mellitus. Traditional CVD risk factors were assessed and the 10-year CVD risk was calculated using the Framingham risk score (FRS). Estimated 10-year CVD risk was compared between axSpA patients and matched controls. Disease activity and radiographic progression in the sacroiliac joint and spine of axSpA patients were evaluated at the time of CVD risk assessment. RESULTS: High-density lipoprotein (HDL) cholesterol levels were lower in axSpA patients than in the matched controls (p = 0.004); however, systolic blood pressure was higher (p < 0.001). The FRS was 5.0 ± 6.6% for controls and 6.3 ± 8.7% for axSpA patients (p = 0.046). Both the grade of sacroiliitis on X-ray and the number of syndesmophytes correlated with the FRS (p = 0.009 and p = 0.001, respectively), but disease activity variables did not. The FRS was significantly higher in axSpA patients with a greater number of syndesmophytes (p = 0.035). Multivariate analysis identified the number of syndesmophytes as being independently associated with the FRS (p < 0.001). CONCLUSIONS: The FRS was higher in axSpA patients than in a matched general population. Radiographic progression in the spine was associated with a high estimated 10-year CVD risk.