Clinical, functional, and radiographic differences among juvenile-onset, adult-onset, and late-onset ankylosing spondylitis

Comparison of clinical characteristics between adult-onset and juvenile-onset non-radiographic axial spondyloarthritis in Chinese patients: results from the COCAS cohort

BACKGROUND

Axial spondyloarthritis (axSpA) is a chronic inflammatory rheumatic disease predominantly affecting the axial skeleton. We aimed to describe the clinical characteristics of patients with non-radiographic axSpA (nr-axSpA) in China and compare the differences between adult- and juvenile-onset cases.

METHODS

A cross-sectional study was conducted using data from 776 patients with nr-axSpA in the Clinical Characteristic and Outcome in Chinese Axial Spondyloarthritis (COCAS) study cohort. Patients were divided into two groups including the adult-onset group (n = 662) and the juvenile-onset group (n = 114) according to age at disease onset. Baseline demographics and clinical characteristics were compared between patients with adult-onset and juvenile-onset nr-axSpA.

RESULTS

Overall, the male-to-female ratio was 1.26:1, the prevalence of HLA-B27 positivity was 72.2%, and the median age at disease onset of nr-axSpA was 22 years. Nearly 75% of nr-axSpA patients had peripheral arthritis in the disease course, and the prevalence of extra-articular manifestations was 10.4%. The juvenile-onset group contained a higher proportion of men (66.7% vs. 53.9%, P = 0.011) and a longer baseline disease duration (4.0 [4.0] vs. 1.6 [3.5], P < 0.001) than the adult-onset group. A family history of spondyloarthritis was more frequent in the juvenile-onset group than in the adult-onset group (23.7% vs. 15.4%, P = 0.028), but no significant difference in the prevalence of HLA-B27 positivity was observed between the two groups (P = 0.537). Regarding initial symptoms, peripheral arthritis occurred more often in patients with juvenile-onset nr-axSpA, whereas patients with adult-onset nr-axSpA presented more frequently with axial involvement. The prevalence of inflammatory back pain (IBP) was higher in the adult-onset group than in the juvenile-onset group (85.0% vs. 75.4%, P = 0.010), whereas the juvenile-onset group showed a higher prevalence of peripheral arthritis and enthesitis than the adult-onset group (67.5% vs. 48.5%, P < 0.001; 35.1% vs. 23.3%, P = 0.007, respectively).

CONCLUSIONS

Compared with adult-onset nr-axSpA, juvenile-onset nr-axSpA was more common in men and those with a family history of spondyloarthritis. Juvenile-onset nr-axSpA presents with a "peripheral predominant" mode at disease onset and a higher frequency of peripheral arthritis and enthesitis during the disease course.

The frequency of sacroiliitis on MRI in subjects over 55 years of age

OBJECTIVE

To evaluate the frequency of sacroiliitis in older subjects.

MATERIALS AND METHODS

Consecutive MRI examinations of the sacroiliac joints (SIJs) performed for suspected sacroiliitis (2005-2019) in patients ≥ 18 years were retrospectively evaluated for the presence of active/structural lesions and were categorized for the presence/absence of sacroiliitis. Clinical and imaging parameters were compared between subjects with sacroiliitis according to age groups < 40 years, 40-55, and > 55 years. Clinical parameters including inflammatory back pain (IBP) and other spondyloarthritis (SpA) features were retrieved from the medical records.

RESULTS

A total of 431 patients with SIJs MRI were evaluated: median age, 44 [IQR 35-54]; female:male 267(62%):164(38%). Sacroiliitis was diagnosed in 89 (20.6%) subjects-median age, 41 years [IQR 32-54], 52% females- and was equally prevalent among the different age groups: > 40 years old, 23.6%; 40-55, 20%; and > 55 years old, 17%, p = 0.43, with active/structural lesions equally dispersed. Older patients (> 55) started suffering from back pain at an older age and had a longer delay in diagnosis. Gender distribution, the presence of IBP, and other SpA features were no different in patients < 45 and > 55 years of age.

CONCLUSIONS

The frequency of sacroiliitis on SIJs-MRI in subjects > 55 years is similar to its frequency in younger subjects and is associated with the same type and magnitude of active and structural MRI lesions. Clinical parameters such as IBP and additional SpA features are similarly prevalent in older and younger subjects suggesting they suffer from the same disease and differing only in age of presentation.

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

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

Spectrum of Spondyloarthritis Among Chinese Populations

Purpose of Review

This review aims to emphasize interesting and important new findings with a focus on the spectrum of spondyloarthritis (SpA) in China.

Recent Findings

Over the past decade, significant advances have been made in the investigation of SpA epidemiology, the exploration of genetic and environmental risk factors, the identification of clinical features, and the updating of treatment protocols in the Chinese population. The prevalence of ankylosing spondylitis (AS) in China is 0.20–0.42%, and the prevalence of HLA-B27 in AS patients is 88.8–89.4%. HLA-B*2704 is the most common subtype in Chinese AS patients, followed by HLA-B*2705. HLA-A*01, more precisely HLA-A*01:01, may be associated with psoriatic arthritis (PsA). Tumor necrosis factor inhibitors and IL-17A inhibitors have been shown to be effective and safe for AS patients in China. Juvenile-onset AS is relatively rare, accounting for only 9.1% of the AS population. The prevalence of arthritis related to inflammatory bowel disease is 6.9 to 7.2%. A Chinese study showed that the most frequently prescribed medication was methotrexate (66.4%). Biological agents were prescribed in only16.4% of patients with PsA.

Summary

This review summarizes the latest research in the epidemiology, pathogenesis, clinical manifestations, and management of SpA among Chinese populations. Multiple HLA associations with SpA have also been described, and it is hoped that discoveries of such ethnic-specific risk factor(s) and understanding of their pathological mechanisms may potentially lead to newer targeted therapies for the Chinese populations worldwide.

Profiling Behavioral and Psychological Symptoms in Children Undergoing Treatment for Spondyloarthritis and Polyarthritis

OBJECTIVE

Few studies examine psychopathology in different juvenile idiopathic arthritis (JIA) subtypes and disease activity states. We aimed to (1) evaluate emotional and behavioral symptoms in children with juvenile spondyloarthritis (SpA) and polyarticular arthritis (PolyA) as compared to a national normative population using the Child Behavior Checklist (CBCL), and (2) evaluate the relationship between CBCL scores and disease activity.

METHODS

Patients with JIA aged 6-17 years with SpA or PolyA were recruited from our pediatric rheumatology clinic from April 2018 to April 2019 and the CBCL and clinical Juvenile Arthritis Disease Activity Score in 10 joints (cJADAS10) were completed. Primary outcome measures were CBCL total competence, internalizing, externalizing, and total problems raw scores. We compared outcomes from each group to national CBCL normative data. To investigate the relationship between CBCL scores and disease activity, we ran a generalized linear regression model for all patients with arthritis with cJADAS10 as the main predictor.

RESULTS

There were 111 patients and 1753 healthy controls (HCs). Compared to HCs, patients with SpA or PolyA had worse total competence and internalizing scores. Higher cJADAS10 scores were associated with worse total competence, worse internalizing, and higher total problems scores. Most of these differences reached statistical significance (P < 0.01). Self-harm/suicidality was almost 4-fold higher in patients with PolyA than HCs (OR 3.6, 95% CI 1.3-9.6, P = 0.011).

CONCLUSION

Our study shows that patients with SpA and PolyA with more active disease have worse psychological functioning in activities, school, and social arenas, and more internalized emotional disturbances, suggesting the need for regular mental health screening by rheumatologists.

Enthesitis-related arthritis: monitoring and specific tools

OBJECTIVES

In this article, the authors aimed to review the different tools used in the monitoring of enthesitis-related arthritis.

SOURCES

The authors performed a literature review on PubMed, Google Scholar, and Scopus databases. The dataset included the original research and the reviews including patients with enthesitis-related arthritis or juvenile spondylarthritis up to October 2020.

SUMMARY OF FINDING

Enthesitis-related arthritis is a category of juvenile idiopathic arthritis. It is characterized by the presence of enthesitis, peripheral arthritis, as well as axial involvement. The only validated tool for disease activity measurement in juvenile idiopathic arthritis is the Disease Activity Score: It has proven its reliability and sensitivity. Nevertheless, due to an absence of validated evaluation tools, the extent of functional impairment, as well as the children and parents' perception of the disease, could not be objectively perceived. Despite the great progress in the field of imaging modalities, the role they play in the evaluation of disease activity is still controversial. This is partially due to the lack of validated scoring systems.

CONCLUSIONS

Further work is still required to standardize the monitoring strategy and validate the outcome measures in enthesitis-related arthritis.

[Midterm follow-up outcomes of total hip arthroplasty in treatment for patients with juvenile-onset ankylosing spondylitis]

OBJECTIVE

To assess the midterm follow-up outcomes of total hip arthroplasty (THA) for the treatment of patients with juvenile-onset ankylosing spondylitis (JAS).

METHODS

The clinical data of 81 patients (127 hips) with JAS (age≤16 years, JAS group) and 267 patients (391 hips) with adult onset ankylosing spondylitis (AAS) (age>16 years, AAS group) between January 2004 and March 2018 were retrospectively analysed. The baseline demographics, clinical, radiographic, and laboratory parameters were collected. Before operation and at last follow-up, the overall disease activity [Bath ankylosing spondylitis disease activity index (BASDAI)] and function status [Bath ankylosing spondylitis functional index (BASFI)], hip subjective score [Harris hip score (HHS)] and objective score [12-item short form health survey (SF-12), including physical component score (PCS) and mental component score (MCS)], and patient satisfaction for THA were reviewed. The major orthopedic complications, including periprosthetic infection, dislocation, periprosthetic fractures, and poor incision healing, were also recorded during the follow-up period.

RESULTS

The comparison of preoperative baseline parameters showed that the body mass, body mass index, age of onset, age of surgery, disease duration, and the proportion of combined smoking history in the JAS group were significantly lower than those in the AAS group ( P<0.05), the proportion of bilateral surgeries, proportion of uveitis, proportion of combined family history, C-reactive protein, albumin, and preoperative BASFI were significantly higher than those in the AAS group ( P<0.05). Both groups were followed up. The follow-up time in the JAS group was 29-199 months, with an average of 113 months; in the AAS group was 35-199 months, with an average of 98 months. Incisions in both groups healed by first intention. During the follow-up period, there were 1 case of periprosthetic fracture, 1 case of dislocation, and 1 case of ceramic fragmentation in the JAS group, 1 case of periprosthetic infection and 6 cases of periprosthetic fracture in the AAS group. There was no significant difference in the incidence of complications between the two groups ( P>0.05). At last follow-up, the BASDAI, BASFI, SF-12 MCS, SF-12 PCS, and HHS score of the two groups were significantly improved when compared with those before operation ( P<0.05); but there was no significan difference in the difference of the above parameters before and after operation and the patient satisfaction between the two groups ( P>0.05).

CONCLUSION

The midterm follow-up outcomes of THA for the treatment of JAS patients were reliable. A low age at disease onset did not exert a significant negative effect on THA reconstruction for the treatment of ankylosing spondylitis.

[Spondyloarthritis in childhood and adulthood]

Axial spondylarthritis in adulthood (SpAA) is frequently initially manifested as a sacroiliitis, whereas this not true for enthesitis-related arthritis (EAA), which begins in childhood and adolescence. Classically, EAA begins with peripheral arthritis and only a part transitions into a juvenile SpA (jSpA) or SpAA. The criteria used for classification of SpAA and EAA are currently being validated and revised. For the first time imaging is included for EAA. For both diseases nonsteroidal anti-inflammatory drugs (NSAID) are initially used therapeutically, followed by biologicals or synthetic targeted disease-modifying drugs in refractory courses. Steroids should be avoided in long-term treatment. For optimal transition and further care in adulthood, a close cooperation between internistic and pediatric rheumatologists is necessary.

Spondyloarthritides: Theories and beyond

Spondyloarthritides (SpA) are a family of interrelated rheumatic disorders with a typical disease onset ranging from childhood to middle age. If left untreated, they lead to a severe decrease in patients' quality of life. A succesfull treatment strategy starts with an accurate diagnosis which is achieved through careful analysis of medical symptoms. Classification criterias are used to this process and are updated on a regular basis. Although there is a lack of definite knowledge on the disease etiology of SpA, several studies have paved the way for understanding plausible risk factors and developing treatment strategies. The significant increase of HLA-B27 positivity in SpA patients makes it a strong candidate as a predisposing factor and several theories have been proposed to explain HLA-B27 driven disease progression. However, the presence of HLA-B27 negative patients underlines the presence of additional risk factors. The current treatment options for SpAs are Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), TNF inhibitors (TNFis), Disease-Modifying Anti-Rheumatic Drugs (DMARDs) and physiotherapy yet there are ongoing clinical trials. Anti IL17 drugs and targeted synthetic DMARDs such as JAK inhibitors are also emerging as treatment alternatives. This review discusses the current diagnosis criteria, treatment options and gives an overview of the previous findings and theories to clarify the possible contributors to SpA pathogenesis with a focus on Ankylosing Spondylitis (AS) and enthesitis-related arthritis (ERA).

Changes over time in inflammatory and structural lesions at the sacroiliac joint in children with spondyloarthritis exposed and unexposed to tumor necrosis factor inhibitor

BACKGROUND

The objective of this work was to describe magnetic resonance imaging (MRI) changes over time in inflammatory and structural lesions at the sacroiliac joint (SIJ) in children with spondyloarthritis (SpA) exposed and unexposed to tumor necrosis factor inhibitor (TNFi).

METHODS

This was a retrospective, multicenter study of SpA patients with suspected or confirmed sacroiliitis who underwent at ≥2 pelvic MRI scans. Images were reviewed independently by 3 radiologists and scored for inflammatory and structural changes using the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ inflammation score (SIS) and structural score (SSS). Longitudinal, quantitative changes in patient MRI scans were measured using descriptive statistics and stratified by TNFi exposure. We used an average treatment effects (ATE) regression model to explore the average effect of TNFi exposure over time on inflammatory and structural lesions, adjusting for baseline lesion scores.

RESULTS

Forty-six subjects were evaluated using the SIS (n = 45) and SSS (n = 18). Median age at baseline imaging was 13.6 years, 63% were male and 71% were white. Twenty-three subjects (50%) were TNFi exposed between MRI studies. The median change in SIS in TNFi exposed and unexposed subjects with a baseline SIS ≥0 was - 20.7 and - 14.3, respectively (p = 0.09). Eleven (85%) TNFi exposed and 8 (89%) unexposed subjects with a baseline SIS ≥0 met the SIS minimal clinically important difference (MCID; ≥2.5). Using the ATE model adjusted for baseline SIS, the average effect of TNFi on SIS in patients with a baseline SIS ≥2 was - 14.5 (p < 0.01). Unadjusted erosion change score was significantly worse in TNFi unexposed versus exposed subjects (p = 0.03) but in the ATE model the effect of TNFi was not significant.

CONCLUSION

This study quantitatively describes how lesions in the SIJs on MRI change over time in patients exposed to TNFi versus unexposed. Follow-up imaging in TNFi exposed patients showed greater improvement than the unexposed group by most metrics, some of which reached statistical significance. Surprisingly, a majority of TNFi unexposed children with a baseline SIS≥2 met the SIS MCID. Additional studies assessing the short and long-term effects of TNFi on inflammatory and structural changes in juvenile SpA are needed.

Enthesitis-related arthritis and spondylarthritis: the same disease or disparate entities?

OBJECTIVES

The aim of this study is to compare the clinical features, disease activity and physical impairment, between enthesitis-related arthritis, adult and late-onset spondylarthritis in Tunisian patients.

METHODS

This study included 190 patients divided into three groups according to their age at the onset of symptoms: ERA (onset of symptoms ≤ 16 years of age), AOSpA (16 < onset of symptoms < 50 years of age) and LOSpA (onset of symptoms ≥ 50 years of age). AOSpA and LOSpA patients fulfilled the ASAS criteria for SpA. Whereas, ERA patients were classified according to the ILAR criteria.

RESULTS

Among 190 patients, 21% had ERA, 70.5% had AOSpA, and 8.5% had LOSpA. There were no differences in gender ratio between ERA and AOSpA groups. Regarding the clinical presentation, ERA and LOSpA groups had more peripheral symptoms than AOSpA in whom the axial manifestation pattern continued throughout the course of the disease. HLA-B27 was more associated with ERA (p = 0,007). Extra-articular manifestations were more observed in the ERA group (p = 0.004). Disease activity, functional status and anthropometric parameters were similar between groups. Nevertheless, health-related quality-of-life assessed by ASQoL and SF-36 scores were better in the AOSpA group but with no significant differences. Regarding the treatment option, methotrexate was widely used in the ERA group (p < 0.001).

CONCLUSION

ERA is characterized mainly by marked peripheral arthritis, more extra-articular manifestations, and a higher frequency of hip involvement.

Effectiveness and drug retention of biologic disease modifying antirheumatic drugs in Korean patients with late onset ankylosing spondylitis

The clinical data on the biologic disease-modifying antirheumatic drug (bDMARD) use in late-onset ankylosing spondylitis (LOAS) is limited. Thus, this study aimed to evaluate the drug efficacy and retention rate of bDMARDs in LOAS and compare it to young-onset ankylosing spondylitis (YOAS). Data of patients with AS receiving bDMARDs were extracted from the Korean College of Rheumatology Biologics and Targeted Therapy registry. Patients whose age of onset was > 50 years and ≤ 50 years were classified as having LOAS and YOAS, respectively. Their baseline characteristics and disease-associated parameters were evaluated. Drug efficacy [Ankylosing Spondylitis Disease Activity Score (ASDAS)-clinically important improvement (CII), ASDAS-major improvement (MI), Assessment of SpondyloArthritis International Society (ASAS) 20, and ASAS 40] at 1-year follow-up and drug retention rates were assessed. A total of 1708 patients (comprising 1472 patients with YOAS and 236 patients with LOAS) were included in this analysis. The LOAS group had a lower prevalence among males, lower HLA-B27 positivity and a higher prevalence of peripheral arthritis. Patients with LOAS were more likely to have higher disease-associated parameters (inflammatory reactants, patient global assessment, ASDAS-erythrocyte sedimentation rate, and ASDAS-C-reactive protein). LOAS was negatively associated with achieving ASDAS-CII, ASAS 20, and ASAS 40. The drug retention rate was lower in LOAS; however, the propensity score-matched and covariate-adjusted hazard ratios for bDMARD discontinuation were comparable to YOAS. There were no differences in the drug retention rates based on the type of bDMARD used in LOAS. Inferior clinical efficacy and shorter drug retention time were found in patients with LOAS receiving bDMARDs using real-world nationwide data. There were no differences among each bDMARD type.

Risk factors for radiological hip involvement in patients with ankylosing spondylitis

OBJECTIVE

Our study aimed to explore the potential risk factors for radiological hip joint involvement in patients with ankylosing spondylitis (AS).

METHODS

This cross-sectional convey collected the clinical data, laboratory indicators, and radiographic data of patients with AS. Radiographic hip joint involvement was defined as a Bath Ankylosing Spondylitis Radiology Hip Index (BASRI-hip) score ≥2. Multivariate logistic regression analyses were conducted to explore the potential risk factors for radiological hip involvement in patients with AS.

RESULTS

Based on BASRI-hip score, all enrolled 386 patients with AS were classified as patients involving with radiological hip joint involvement (BASRI-hip ≥2; n=203) and those without it (BASRI-hip ≤1; n=183). Mean age of enrolled patients with AS were 36.7±11.9 years, and 320 (82.9%) patients were male. Mean course of disease was 10.7±8.3 years, and 349 (90.4%) patients were with a positive HLAB27. Multivariate analyses indicated that Juvenile onset (onset age ≤16 years) (odds ratio [OR]=4.159, 95% confidence interval [CI], 1.779-9.721, p<0.001), body mass index (BMI) <18.5 kg/m2 (OR=1.986, 95%CI 1.187-3.323, p=0.009), continuous nonsteroidal anti-inflammatory drug (NSAID) use (OR=0.351, 95%CI 0.155-0.794, p=0.012), and bone mass below the expected range for age (Z score ≤-2) (OR=2.791, 95%CI 1.456-5.352, p=0.002) were independently associated with radiological hip joint involvement in patients with AS.

CONCLUSIONS

The potential risk factors for radiological hip joint involvement were juvenile onset, lower BMI, and bone mass below the expected range for age. Furthermore, continuous NSAID use was the protective factor for radiological hip joint involvement in these population.

Axial spondyloarthritis: emerging drug targets

INTRODUCTION

Axial spondyloarthritis (AxSpA) is an inflammatory disorder that affects the joints, entheses, and bone tissues and is sometimes associated with psoriasis, anterior uveitis, and gut inflammation. Its pathogenesis is not wholly understood and treatment strategies require optimization. Data concerning AxSpA pathogenesis support a critical role of abnormal CD4⁺ T cell differentiation and exacerbated type 3 immune response. This knowledge boosted the development of interleukin (IL)-17 and Janus kinase inhibitors for AxSpA treatment beyond tumor necrosis factor-α inhibition.

AREAS COVERED

Emerging drug targets in animal and cellular models and with phase-II clinical trials have been evaluated. We also reflect on key issues for preclinical and clinical research going forward.

EXPERT OPINION

Some of the most promising approaches include: (i) modulation of transforming growth factor-β family that could exert a specific role on bone formation; (ii) blockade of granulocyte-macrophage colony-stimulating factor that could reduce type 3 immune responses, and (iii) rebalancing of biased immune response by cytokines such as IL-2 or IL-27 that could favor anti-inflammatory response and sustained drug-free remission. Multiomics tools and artificial intelligence could contribute to identification of optimal targets and help stratify patients for the most appropriate treatment options.

Age at onset in axial spondyloarthritis around the world: data from the ASAS-PerSpA study

Objective

Age at onset is useful in identifying chronic back patients at an increased risk of axial SpA (axSpA). However, the majority of data on which the criterion of age at onset <45 years is based originates from Europe. Therefore it is unknown if this criterion applies in other parts of the world. We aimed to assess the age at onset of axSpA and its relationship with HLA-B27 and gender across the world.

Methods

Analyses were applied to patients from 24 countries across the world with an axSpA diagnosis and known age at onset of axial complaints. Cumulative probability plots were used to display the cumulative distribution of age at onset of axial symptoms. Linear regression models were built to assess the effect of HLA-B27 and gender on age at onset of axial symptoms.

Results

Of 2579 axSpA patients, 92% had an age at onset of axial symptoms <45 years, with only small variations across the geographical regions [Asia, n = 574 (94%); Europe and North America, n = 988 (92%); Latin America, n = 246 (89%); Middle East and North Africa, n = 771 (91%)]. Age at onset of axial symptoms was consistently lower in HLA-B27-positive patients {median 25 years [interquartile range (IQR) 19–32] vs 31 [IQR 22–39]} and male patients [median 25 years (IQR 19–33) vs 28 (IQR 21–37)], but in multivariable models an additional statistically significant effect of male gender independent of HLA-B27 was only found in Asia.

Conclusion

Around the world, the great majority of axSpA patients had an age at onset of axial disease of <45 years, with HLA-B27 and male gender associated with earlier disease onset.

Similarities and Differences Between Juvenile and Adult Spondyloarthropathies

Spondyloarthritis (SpA) encompasses a broad spectrum of conditions occurring from childhood to middle age. Key features of SpA include axial and peripheral arthritis, enthesitis, extra-articular manifestations, and a strong association with HLA-B27. These features are common across the ages but there are important differences between juvenile and adult onset disease. Juvenile SpA predominantly affects the peripheral joints and the incidence of axial arthritis increases with age. Enthesitis is important in early disease. This review article highlights the similarities and differences between juvenile and adult SpA including classification, pathogenesis, clinical features, imaging, therapeutic strategies, and disease outcomes. In addition, the impact of the biological transition from childhood to adulthood is explored including the importance of musculoskeletal and immunological maturation. We discuss how the changes associated with adolescence may be important in explaining age-related differences in the clinical phenotype between juvenile and adult SpA and their implications for the treatment of juvenile SpA.

Root Joint Involvement in Spondyloarthritis: A Post-hoc Analysis from the International ASAS-PerSpA Study

OBJECTIVES

Primary objective was to compare the clinical characteristics of spondyloarthritis (SpA) patients with and without root joint disease (RJD+ and RJD-). Secondary objectives were to compare the prevalence of RJD across various SpA subtypes and in different world regions, to compare the SpA axial severity and SpA burden between RJD+ and RJD-.

METHODS

This is a post-hoc analysis of the ASAS-PerSpA study (PERipheral involvement in SpondyloArthritis), which included 4,465 patients with SpA (axial (axSpA), peripheral (pSpA), psoriatic (PsA), inflammatory bowel disease, reactive and juvenile) according to the rheumatologist's diagnosis. RJD was defined as the "ever" presence of hip or shoulder involvement related to SpA, according to the rheumatologist. The patient's characteristics were compared between RJD+ and RJD-. Multivariable stepwise binary logistic regression analyses were conducted to identify factors associated with "RJD", "hip" and "shoulder" involvement.

RESULTS

RJD was significantly associated with the SpA main diagnosis (highest in pSpA), a higher prevalence of HLA-B27 positivity, enthesitis, tender and swollen joints, CRP, cs-DMARDs, loss of lumbar lordosis and occiput-wall distance > 0. RJD was more prevalent in Asia, and occurred in 1,503 patients (33.7%), with more hip (24.2%) than shoulder (13.2%) involvement. Hip involvement had a distinct phenotype, similar to axSpA (including younger age at onset, HLA-B27 positivity), whereas shoulder involvement was associated with features of pSpA (including older age at onset).

CONCLUSION

RJD+ SpA patients had a distinctive clinical phenotype compared with RJD-. Hip involvement, based on the rheumatologist's diagnosis, was more prevalent than shoulder involvement and was clinically distinct.

Uveitis as the first symptom in spondyloarthritis and its association with the evolution of the disease. Results from the REGISPONSER registry

OBJECTIVES

To describe the time of onset of acute anterior uveitis (AAU) relative to the appearance of rheumatic symptoms and to determine its association with the evolution of the spondyloarthritis (SpA) in terms of activity, structural damage, functional ability and treatment.

METHODS

This was a cross-sectional study with data extracted from the REGISPONSER (SpA Registry of the Spanish Rheumatology Society). Thirty-one centres participated, and patients with SpA according to the ESSG criteria were included from 2004 to 2007. Patients were classified according to the time of uveitis appearance with regard to rheumatic symptom onset (before, concomitant with, or after rheumatic symptom onset). We compared the clinical characteristics, disease activity, radiographic damage and functional ability between "AAU before or concomitant with rheumatic symptoms" and "AAU after rheumatic symptoms onset". Finally, we compared whether the time of appearance of AAU had an impact on the use of conventional and biological disease-modifying antirheumatic drugs (csDMARDs and bDMARDs, respectively).

RESULTS

A total of 2367 patients were included in REGISPONSER, with an AAU prevalence of 16.2% (379 patients). Patients with AAU before/concomitant with rheumatic symptom onset (n=59) exhibited better functional ability (BASFI, OR 0.85 [0.73-0.99]) and less structural damage (spinal BASRI, OR 0.88 [0.79-0.99]). Additionally, this group of patients was older at SpA symptom onset (OR 1.05 [1.02-1.09]) and had a shorter diagnosis delay (OR 0.90 [0.84-0.96]) compared patients with AAU after rheumatic symptom onset (n=229). No statistically significant differences in the use of DMARDs were noted (27.9% vs 23.2% for csDMARD use and 15.3% vs 20.3% for bDMARD use in patients with AAU before or concomitant with rheumatic symptom onset vs after rheumatic symptom onset, respectively).

CONCLUSION

Patients presenting with a first episode of AAU before/concomitant with the onset of rheumatic symptoms had less severe disease (better functional ability and less structural damage) and a shorter diagnosis delay; however, the time of AAU onset did not impact the treatments received.

Juvenile-Versus Adult-Onset Spondyloarthritis: Similar, but Different

This article provides an overview of juvenile spondyloarthritis and important differences in the classification criteria, clinical presentation, outcomes, and pathology in juvenile versus adult-onset disease. Key differences in classification criteria between children and adults with spondyloarthritis are important to understand, as they can make transition from pediatric to adult care challenging. MRI and ultrasonography are increasingly relied on for the assessment of adult-onset disease activity and change over time in the pediatric population. The unique features of the maturing axial and peripheral skeleton are described for each modality, as they are key to understand for accurate interpretation of pathology in the pediatric population.

Evaluating low back pain in adolescents

Low back pain in adolescents is a common complaint in primary care. With an average prevalence rate of 40%, adolescent low back pain correlates with greater healthcare use, higher incidences of adult back pain, and negative effects on overall well-being. A thorough history and physical examination can increase early detection and accurate diagnosis while ensuring the judicious use of diagnostic modalities. Although underlying serious pathology is rare in adolescents with low back pain, clinicians should recognize specific signs and symptoms that necessitate urgent evaluation and intervention. This article emphasizes the value of using a thorough history and physical examination to guide the initial diagnostic workup and to enhance the early detection and accurate diagnosis of adolescents who present with low back pain.

Radiographic progression in non-radiographic axial spondyloarthritis

INTRODUCTION

Non-radiographic axial spondyloarthritis (nr-axSpA) represents a subtype of axial spondyloarthritis (axSpA) with no significant structural damage in sacroiliac joints and spine. In addition, patients with nr-axSpA demonstrate a substantial burden of illness, and a considerable share of them might progress to radiographic axSpA (r-axSpA) over time. The amount and quality of published data allows crude estimation of progression rate and factors related to a higher risk of progression. Areas covered: This review discusses the available data reporting the rates and predictors of radiographic progression in the sacroiliac joints and in the spine in patients with nr-axSpA as well as predisposing factors for such a progression. Expert commentary: Most of the studies report about 10-40% of patients with nr-axSpA to progress to r-axSpA over a period of 2-10 years. Multiple risk factors for the radiographic sacroiliitis progression are outlined and explored. There are not enough data to presume that any treatment modality may influence progression from nr-axSpA to r-axSpA, with TNFi showing some promising results. Radiographic progression in the spine is in general low in nr-axSpA; thus, long-term studies are required to investigate the natural course of the progression and possible treatment effects.

Conventional radiography in juvenile idiopathic arthritis: Joint recommendations from the French societies for rheumatology, radiology and paediatric rheumatology

BACKGROUND

Juvenile idiopathic arthritis (JIA) can cause structural damage. However, data on conventional radiography (CR) in JIA are scant.

OBJECTIVE

To provide pragmatic guidelines on CR in each non-systemic JIA subtype.

METHODS

A multidisciplinary task force of 16 French experts (rheumatologists, paediatricians, radiologists and one patient representative) formulated research questions on CR assessments in each non-systemic JIA subtype. A systematic literature review was conducted to identify studies providing detailed information on structural joint damage. Recommendations, based on the evidence found, were evaluated using two Delphi rounds and a review by an independent committee.

RESULTS

74 original articles were included. The task force developed four principles and 31 recommendations with grades ranging from B to D. The experts felt strongly that patients should be selected for CR based on the risk of structural damage, with routine CR of the hands and feet in rheumatoid factor-positive polyarticular JIA but not in oligoarticular non-extensive JIA.

CONCLUSION

These first pragmatic recommendations on CR in JIA rely chiefly on expert opinion, given the dearth of scientific evidence. CR deserves to be viewed as a valuable tool in many situations in patients with JIA.

KEY POINTS

• CR is a valuable imaging technique in selected indications. • CR is routinely recommended for peripheral joints, when damage risk is high. • CR is recommended according to the damage risk, depending on JIA subtype. • CR is not the first-line technique for imaging of the axial skeleton.

Performance of the classification criteria in patients with late-onset axial spondyloarthritis

AIM

To evaluate the performance of four different classification criteria for spondyloarthritis (SpA) in patients with late-onset symptoms and to compare the clinical, laboratory and radiographic outcomes among the patients with symptoms before and after 45 years of age.

PATIENTS AND METHODS

A total of 329 patients with SpA were enrolled in this prospective cohort. Patients with psoriatic arthritis, reactive arthritis, colitis associated arthritis and peripheral or undifferentiated SpA were excluded. The remaining individuals were divided into two groups based on their ages at the time of onset of symptoms: from 16 to 45 years of age (adult-onset, A-O) and after 45 years of age (late-onset, L-O). The clinical data were collected, including BASDAI, BASFI, BASMI, mSASSS, ASDAS, as were concomitant diseases and medications, efficacy and safety data. The performance of four SpA classification criteria, including modified New York, ESSG, Amor and ASAS, was evaluated in both groups. p value <.05 was considered as significant.

RESULTS

Thirty-two patients (9.72%) had L-O axial SpA. Mean age of diagnosis and symptoms were 57.6 (8.0) years and 7.6 (5.1) years, respectively. L-O patients had statistically worse functional impairment and higher disease activity. However, they had lower radiographic sacroiliac and spine damage (p < .001).

CONCLUSION

Our data showed that almost 10% of the patients with SpA had late-onset of symptoms. Moreover, they had higher disease activity, worse physical function and lower spine radiographic damage than A-O SpA patients. Additionally, the ASAS classification criteria had the best performance and might be used in clinical practice.

Assessment of Sacroiliitis at Diagnosis of Juvenile Spondyloarthritis by Radiography, Magnetic Resonance Imaging, and Clinical Examination

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.

Juvenile spondyloarthritis

PURPOSE OF REVIEW

This article provides a comprehensive update of the pathogenesis, diagnostic imaging, treatments, and disease activity measurements of juvenile spondyloarthritis (JSpA).

RECENT FINDINGS

Genetic and microbiome studies have provided new information regarding possible pathogenesis of JSpA. Recent work suggests that children with JSpA have decreased thresholds for pain in comparison to healthy children. In addition, pain on physical examination and abnormalities on ultrasound of the entheses are not well correlated. Treatment guidelines for juvenile arthritis, including JSpA, were published by the American College of Rheumatology and are based on active joint count and presence of sacroiliitis. Recent studies have established the efficacy of tumor necrosis factor inhibitors in the symptomatic treatment of axial disease, although their efficacy for halting progression of structural damage is less clear. Newly developed disease activity measures for JSpA include the Juvenile Arthritis Disease Activity Score and the JSpA disease activity index. In comparison to other categories of juvenile arthritis, children with JSpA are less likely to attain and sustain inactive disease.

SUMMARY

Further microbiome and genetic research may help elucidate JSpA pathogenesis. More randomized therapeutic trials are needed and the advent of new composite disease activity measurement tools will hopefully allow the design of these greatly needed trials.

Demographic, clinical, and laboratory features of Turkish patients with late onset ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease, which typically begins in early decades of life with primarily axial joints involvement. This disease rarely affects patients older than 50 years of age. The aim of this study was to compare and evaluate the demographic, clinical, and laboratory features of late onset and early onset AS patients who were followed up in a single rheumatology center. A total of 339 patients who have been diagnosed with AS according to modified New York criteria were included in the study. The patients whose initial symptoms were observed after 50 years of age were accepted as late onset AS. Out of 339 patients, 27 (7.9%) were diagnosed as late onset AS and 312 (92.3%) patients were evaluated as early onset AS. Of 27 late onset patients, 10 were male and 17 were female. Delay in the diagnosis was 5.8 years for early onset AS, while it was 3.8 years for late onset AS (p = 0.001). Higher levels of acute phase reactants and more methotrexate (MTX) use were detected in early onset AS patients compared to late onset AS (p = 0.001, p = 0.007, respectively). Statistically, there was no difference between these two groups, with regard to disease clinical activity indexes, anthropometric measurement parameters, uveitis and peripheral joint involvement. In this study, we showed that early and late onset AS patients may present with different clinical, genetic, and laboratory features. Late onset AS patients are characterized with lower human leukocyte antigen-B27 sequence, less inflammatory sign, delayed diagnosis, and less MTX and anti-tumor necrosis factor alpha drug usage.

Clinical outcomes and progression to orthopedic surgery in juvenile- versus adult-onset ankylosing spondylitis

OBJECTIVE

Juvenile- and adult-onset ankylosing spondylitis (AS) are subtypes of AS that may have different clinical outcomes. We compared cohorts of juvenile-onset AS and adult-onset AS in terms of clinical characteristics, clinical outcomes, proceeding to AS-related orthopedic surgery, and type of orthopedic surgery.

METHODS

A retrospective cohort study was conducted of all AS patients attending a teaching hospital. Demographics, clinical parameters, and history of AS-related orthopedic surgery to the spine, root, or peripheral joints were recorded. Differences between surgery for juvenile- and adult-onset AS patients, and effects of covariates were assessed using logistic regression and survival analyses.

RESULTS

A total of 553 AS patients were studied: 162 juvenile-onset AS and 391 adult-onset AS cases. After adjusting for significant covariates, adult-onset AS cases were less likely to proceed to surgery (odds ratio [OR] 0.31, P < 0.001), have a hip procedure (resurfacing or arthroplasty; OR 0.374, P = 0.001), and have hip arthroplasty (OR 0.43, P = 0.01). Significant differences were also observed when comparing Kaplan-Meier survival curves (P = 0.001) and using Cox proportional hazards regression (P = 0.002). A history of smoking was not associated with surgery. AS cases with older age at symptom onset were far less likely to have surgery than those with younger onset, in a nonlinear manner.

CONCLUSION

Juvenile-onset AS cases are more likely than adult-onset AS cases to proceed to hip arthroplasty, but equally likely to have hip resurfacing and hip arthroplasty revision/re-revisions. Smoking was not associated with the risk of orthopedic surgery. Orthopedic surgery was unlikely after 40 years of disease in both subsets.

Enthesitis-related arthritis: time to re-define?

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. Enthesitis-related arthritis (ERA) is one of the seven JIA subtypes classified by the International League of Associations for Rheumatology (ILAR). Due to inclusion and exclusion criteria, a pitfall of the ERA category is that it does not include all subsets of juvenile spondyloarthropathy, with many children ending up in the undifferentiated category. The ERA nomenclature also does not have a method for distinguishing between axial and peripheral disease, two phenotypes which vary in presentation and treatment requirements. This distinction is very important given the overall poor prognosis seen in ERA patients, specifically in those with axial involvement. Since axial involvement is more common and presents earlier than previously thought in ERA, the pediatric rheumatology community should develop more accurate and sensitive classification criteria based on disease course to assist in improving timely diagnosis and appropriate management.

[Epidemiologic profile of juvenile-onset compared to adult-onset spondyloarthritis in a large Brazilian cohort]

OBJECTIVE

To analyze the clinical and epidemiologic characteristics of juvenile-onset spondyloarthritis (SpA) (< 16 years) and compare them with a group of adult-onset (≥ 16 years) SpA patients.

PATIENTS AND METHODS

Prospective, observational and multicentric cohort with 1,424 patients with the diagnosis of SpA according to the European Spondyloarthropathy Study Group (ESSG) submitted to a common protocol of investigation and recruited in 29 reference centers participants of the Brazilian Registry of Spondyloarthritis (RBE - Registro Brasileiro de Espondiloartrites). Patients were divided in two groups: age at onset<16 years (JOSpA group) and age at onset ≥ 16 years (AOSpA group).

RESULTS

Among the 1,424 patients, 235 presented disease onset before 16 years (16.5%). The clinical and epidemiologic variables associated with JOSpA were male gender (p<0.001), lower limb arthritis (p=0.001), enthesitis (p=0.008), anterior uveitis (p=0.041) and positive HLA-B27 (p=0.017), associated with lower scores of disease activity (Bath Ankylosing Spondylitis Disease Activity Index - BASDAI; p=0.007) and functionality (Bath Ankylosing Spondylitis Functional Index - BASFI; p=0.036). Cutaneous psoriasis (p<0.001), inflammatory bowel disease (p=0.023), dactylitis (p=0.024) and nail involvement (p=0.004) were more frequent in patients with adult-onset SpA.

CONCLUSIONS

Patients with JOSpA in this large Brazilian cohort were characterized predominantly by male gender, peripheral involvement (arthritis and enthesitis), positive HLA-B27 and lower disease scores.

Prevalence and risk factors of low bone mineral density in juvenile onset ankylosing spondylitis

The objective of this study is to assess the prevalence and risk in patients with juvenile onset ankylosing spondylitis (JoAS) complicated with low bone mineral density (BMD). A total of 112 children and adolescents with JoAS were enrolled in the study. Bone mass was measured from the lumbar spine and the left proximal femur using dual-energy X-ray absorptiometry. According to the 2007 International Society of Clinical Densitometry definitions, a Z score of less than -2 was termed as "low BMD." Stepwise regression analysis was used to investigate associations between low BMD and disease-related factors including gender, age, weight, height, body mass index, disease duration, HLA-B27 antigen, grades of sacroiliitis, Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), patient global assessment (PGA), spine pain, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Low BMD was found in 18 (16.1 %) cases in at least one of the two measured regions. Lumbar spine BMD had negative correlations with BASDAI, BASFI, spine pain, ESR, and CRP (P < 0.05). Hip BMD significantly negatively correlated with BASDAI and PGA (P < 0.05). In conclusion, patients with JoAS are likely to develop low BMD, which may be related to high disease activity.

Association of HLA-B27 status and gender with sacroiliitis in patients with ankylosing spondylitis

Objective: To observe the influence of human leucocyte antigen B27 (HLA-B27) status and gender on sacroiliitis on computed tomography (CT) in ankylosingspondylitis (AS).

Methods: We reviewed the archived medical records of the AS inpatients admitted in the Rheumatology Department of the First Affiliated Hospital of Wenzhou Medical University during the period from January 2007 through January 2013 and finally 386 patients were included in the study. The severity of sacroiliitis on CT was evaluated according to the grading used in the modified New York criteria for AS. Two-way classification analysis of variance (ANOVA) was employed to examine the effect of HLA-B27 status and gender on age at disease onset. The impact of HLA-B27 and gender on sacroiliitis on CT was tested by univariate and multivariate logistic regression analyses.

Results: There were 350 HLA-B27 positive patients (90.7%) and 36 HLA-B27 negative patients (9.3%). The ANOVA test indicated that HLA-B27 positive patients and male patients respectively had an earlier age at disease onset than HLA-B27 negative patients and female patients. The logistic regression analysis indicated that positive HLA-B27 status (OR 2.601, p=0.004) and male gender (OR 1.923, p=0.004) were significant predictors of worse sacroiliitis. In addition, elevated ESR (OR 2.181, p=0.013) and longer disease duration (OR 1.100, p<0.001) contributed to worse sacroiliitis likewise.

Conclusion: Positive HLA-B27 status and male gender are associated with worse sacroiliitis on CT, acting as predictors of sacroiliitis. Elevated ESR and longer disease duration also contribute to worse sacroiliitis. Meanwhile, positive HLA-B27 status and male gender are associated with earlier age at disease onset.

Juvenile Versus Adult-onset Ankylosing Spondylitis — Clinical, Radiographic, and Social Outcomes. A Systematic Review

Ankylosing spondylitis (AS) has 2 main modes of onset: juvenile-onset AS (JoAS) and adult-onset AS (AoAS). It is not known whether JoAS is a subtype of AS, or AS modulated by early age of onset and longer disease duration. We performed a systematic review of the literature, identifying 12 articles and 1 abstract directly comparing JoAS and AoAS cohorts, with observational study design. Patients with JoAS appear to have more peripheral joint involvement both clinically and radiographically (especially knees and ankles) and more root joint involvement (hips and shoulders); they are more likely to proceed to hip arthroplasty and often initially present with peripheral rather than axial symptoms. Patients with AoAS appear to have more axial symptoms and radiographic disease, particularly in the lumbar spine, and worse axial metrology. In terms of other characteristics, more evidence is needed to confidently state whether JoAS and AoAS are different.