Enthesitis Related Arthritis in a Longitudinal Southeast Asian Registry: High Prevalence of HLA-B27, Different Sacroiliitis Risk Factors and Less Common Drug-Free Remission

Prevalence of HLA-B27, clinical characteristics and treatment outcomes in children with enthesitis-related arthritis

BACKGROUND

Enthesitis-related arthritis (ERA) is a subtype of juvenile idiopathic arthritis with high disease burden. The objectives of this study were to explore the prevalence of HLA-B27, clinical characteristics, and treatment outcomes in children with ERA and compare the differences between HLA-B27 positive and negative patients.

METHODS

A retrospective cohort study at a pediatric rheumatology clinic in a tertiary referral hospital in Bangkok, Thailand, including ERA patients with at least 6 months of follow-up (July 2011-April 2022) was performed. Data were collected from medical records from diagnosis to recent follow-up, assessing disease activity and treatment outcomes, with an analysis comparing HLA-B27 positive and negative patients. Descriptive statistics were used for data analysis.

RESULTS

There were 59 ERA patients with mean age ± SD at diagnosis 11.2 ± 2.5 years, 53 males (89.8%), and positive HLA-B27 in 38 patients (64.4%). The HLA-B27 positive group had significantly higher levels of inflammatory markers at initial diagnosis (p = 0.001), lower baseline hemoglobin (p = 0.001) and hematocrit (p = 0.002), higher disease activity assessed by the Juvenile Spondyloarthritis Disease Activity score at 6 and 12 months of follow-up (p = 0.028 and 0.040, respectively), increased utilization of bridging systemic corticosteroids (60.5% vs. 14.3%, p = 0.001) and anti-TNF (39.5% vs. 9.5%, p = 0.018), and longer duration of methotrexate (median[IQR] 1.7[1.1-3.1] vs. 1.3[0.6-1.9] years, p = 0.040). The HLA-B27 negative group had more prevalent hip arthritis than the positive group at initial diagnosis (66.7% vs. 28.9%, p = 0.005) and during the course of the disease (71.4% vs. 36.8%, p = 0.011).

CONCLUSION

Most of the ERA patients tested positive for HLA-B27. Throughout the follow-up period, these patients demonstrated greater disease activity, greater use of corticosteroids and anti-TNF, and longer duration of methotrexate to control the disease.

Preferential involvement of the pelvis and hips along with active sacroiliitis in chronic nonbacterial osteomyelitis: MRI of 97 patients from a single tertiary referral center

OBJECTIVE

To present MRI distribution of active osteitis in a single tertiary referral center cohort of patients with chronic nonbacterial osteomyelitis (CNO).

METHODS

Two musculoskeletal radiologists retrospectively reviewed MRI examinations of all patients with a final clinical diagnosis of CNO over 15 years. Sites of active osteitis at any time during the course of disease were divided into seven groups: (A) mandible, sternum, clavicles, or scapulas; (B) upper extremities; (C) subchondral sacrum and ilium immediately subjacent to sacroiliac joints (active osteitis denoting "active sacroiliitis" here); (D) pelvis and proximal 1/3 of femurs (excluding group C); (E) bones surrounding knees including distal 2/3 of femurs and 1/2 of proximal tibias and fibulas; (F) distal legs (including distal 1/2 of tibias and fibulas), ankles, or feet; (G) spine (excluding group C). Temporal changes of lesions in response to treatment (or other treatment-related changes such as pamidronate lines) were not within the scope of the study.

RESULTS

Among 97 CNO patients (53 males [55%], 44 females; age at onset, mean ± SD, 8.5 ± 3.2 years; age at diagnosis, 10.3 ± 3.3 years), whole-body (WB) MRI was performed in 92%, mostly following an initial targeted MRI (94%). A total of 557 (346 targeted and 211 WB) MRIs were analyzed. Biopsy was obtained in 39 patients (40%), all consistent with CNO or featuring supporting findings. The most common locations for active osteitis were groups D (78%; 95% CI 69‒85%) and C (72%; 95% CI 62‒80%).

CONCLUSION

Pelvis and hips were preferentially involved in this cohort of CNO patients along with a marked presence of active sacroiliitis.

CLINICAL RELEVANCE STATEMENT

When suggestive findings of CNO are identified elsewhere in the body, the next targeted site of MRI should be the pelvis (entirely including sacroiliac joints) and hips, if whole-body MRI is not available or feasible.

KEY POINTS

• Heavy reliance on MRI for diagnosis of CNO underscores the importance of suggestive distribution patterns. • Pelvis and hips are the most common (78%) sites of CNO involvement along with active sacroiliitis (72%). • Pelvis including sacroiliac joints and hips should be targeted on MRI when CNO is suspected.

Drug therapy in juvenile spondyloarthritis

PURPOSE OF REVIEW

This review summarizes latest developments in treatment of juvenile spondyloarthritis (JSpA), specifically enthesitis-related arthritis (ERA) and juvenile psoriatic arthritis (JPsA).

RECENT FINDINGS

There has been addition of biologic disease modifying antirheumatic drugs (bDMARDs) beyond tumor necrosis factor inhibitors (TNFi) for JSpA such as IL-17 blockers, IL-23 blockers, and janus activating kinase inhibitors with favorable safety profile. Conducting robust clinical trials for this subpopulation of JIA remains a challenge; extrapolation studies are being used to obtain approval from regulatory agencies.

SUMMARY

Newer drug therapies have expanded the scope of treatment for patients with JSpA. bDMARDs such as adalimumab, etanercept, infliximab, and secukinumab have demonstrated clinically significant treatment efficacy in ERA and JPsA. Based on extrapolation studies, intravenous golimumab, etanercept, abatacept, and ustekinumab have gained Food and Drug Administration (FDA) approval for JPsA. Long-term follow-up studies continue to demonstrate acceptable safety profiles. There is need for more real-world data on drug efficacy from Registry studies and research on effective de-escalation strategies.

Does sacroiliitis is a mandatory criterion for enthesitis-related arthritis diagnosis?

INTRODUCTION AND OBJECTIVES

Magnetic resonance imaging (MRI) sensitivity and specificity seem to be less studied in enthesitis-related arthritis (ERA). We aimed to determine the ability of sacroiliac MRI to diagnose ERA patients.

MATERIALS AND METHODS

We conducted a retrospective study including 44 patients with juvenile idiopathic arthritis (JIA). Each patient had a sacroiliac joint MRI. We divided patients into two groups: G1 patients with ERA and G2 patients with non-ERA subtype.

RESULTS

ERA was noted in 61% of the cases. Sacroiliac joints were painful in 15 patients (34%). MRI was normal in 25 patients (57%) (G1:11 versus G2:14) and showed bone marrow edema in the sacroiliac joints in 19 patients (34%) (G1=16 versus G2=3, p=0.005). Sacroiliac joints MRI's sensitivity and specificity in the ERA diagnosis were 61.54% and 82.35%, respectively. Positive and negative predictive values were 84.21% and 58.33%, respectively. Furthermore, sacroiliac joint pain in the clinical examination was able to predict sacroiliac bone edema in MRI with an odds ratio of 6.8 (95% CI 1.68-28.09; p=0.006).

CONCLUSION

Our study showed that sacroiliac joint MRI has good specificity and positive predictive value in the diagnosis of ERA patients among JIA patients. This underlines the usefulness of sacroiliac joint MRI in the early diagnosis of ERA patients.

Profile of HLA-B27-positive enthesitis/spondylitis-related arthritis in Senegal, West Africa

BACKGROUND

Enthesitis/spondylitis-related arthritis (ERA) is a type of juvenile idiopathic arthritis (JIA) frequently associated with HLA-B27. In sub-Saharan Africa, HLA-B27-positive ERA hasn't been the subject of a specific study.

OBJECTIVES

We aimed to describe the clinical features, disease activity, functional disability and treatment of HLA-B27-positive ERA at diagnosis in Senegal and compare the findings to other populations.

METHODS

We conducted a retrospective study by reviewing the medical records of patients diagnosed with ERA with an age of symptom onset < 18 years according to the 2019 PRINTO provisional criteria for ERA from January 2012 to December 2022. We collected demographic, clinical, paraclinical and therapeutic data. Disease activity score was assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Functional disability was assessed using Bath Ankylosing Spondylitis Functional Index (BASFI).

RESULTS

A total of 31 patients with HLA-B27-positive ERA were included. Twenty of 31 (64.5%) were males. Twenty-seven (87%) were Fula (ethnicity). The median age at symptom onset and at diagnosis was 12 years and 19 years, respectively. Seven patients had a family history of Spondyloarthritis. Peripheral arthritis and enthesitis were the most common presenting features at disease onset. Peripheral arthritis was present in 29 (93.5%) and located in the lower limbs in 27/29 (93.1%) patients. Heel enthesitis was present in 26 (83.8%) patients. Axial involvement was present in 27 (87%) patients, dominated by low back pain and sacroiliac pain/ buttock pain in 24 (88.8%) and 22 (81.5%) patients, respectively. Seven (22.5%) patients had anterior uveitis. The ESR and CRP were elevated in 65.5% and 57.1% of cases, respectively. On imaging, sacroiliitis was found in 22 patients. The mean BASDAI was 5.5/10 (77.2% of patients had a high active disease; BASDAI ≥ 4/10). The mean ASDAS-ESR/CRP was 3.8. The mean BASFI was 5.4/10 (80% of patients had high functional disability; BASFI ≥ 4/10). Twenty-seven (87%) patients were treated with methotrexate and non-steroidal anti-inflammatory drugs. After 6 months of treatment, mean BASDAI was 3/10 and mean BASFI was 2.5/10.

CONCLUSION

In our study, HLA-B27-positive ERA was found in our Senegalese cohort mainly in adolescents of the Fula ethnic group. 22 (70.9%) patients developed ankylosing spondylitis at adulthood. The disease was very active at the time of diagnosis with significant functional disability. Treatment was mainly based on methotrexate and NAISDs.

Advances in the Diagnosis and Treatment of Enthesitis-Related Arthritis

Enthesitis-related arthritis (ERA) represents 5-30% of all cases of juvenile idiopathic arthritis (JIA) and belongs to the spectrum of the disorders included in the group of juvenile spondyloarthritis. In the last decade, there have been considerable advances in the classification, diagnosis, monitoring, and treatment of ERA. New provisional criteria for ERA have been recently proposed by the Paediatric Rheumatology INternational Trials Organisation, as part of a wider revision of the International League of Associations for Rheumatology criteria for JIA. The increased use of magnetic resonance imaging has shown that a high proportion of patients with ERA present a subclinical axial disease. Diverse instruments can be used to assess the disease activity of ERA. The therapeutic recommendations for ERA are comparable to those applied to other non-systemic JIA categories, unless axial disease and/or enthesitis are present. In such cases, the early use of a TNF-alpha inhibitor is recommended. Novel treatment agents are promising, including IL-17/IL-23 or JAK/STAT pathways blockers.

Predictors of long-term functional outcomes of juvenile idiopathic arthritis-enthesitis-related arthritis: a single centre experience

OBJECTIVES

Long-term functional outcomes in enthesitis-related arthritis (ERA) is limited from developing countries. We assessed the clinical and genetic factors that predicted the long-term functional outcome in ERA.

METHODS

Patients with ERA having ≥5 years of disease and >16 years of age were included in this cross-sectional study. Data on clinical features within 6 months of disease onset was collected from hospital records. Bath indices, HAQ Disability Index (HAQ-DI) and World Health Organization's Quality of Life (WHO-QOL) were assessed at last visit. Poor functional outcome (PFO) was defined as BASFI > 1.5 or HAQ-DI > 1. Persistent disease activity (PDA) was defined as BASDAI ≥ 4. Endoplasmic reticulum aminopeptidase 1 (ERAP1) and IL-23 receptor single nucleotide polymorphism genotyping was performed with the TaqMan method and HLA-B27 by PCR.

RESULTS

One hundred and eighty-one patients [170 male, median (interquartile range) age of disease onset 12.5 (10-15) years, disease duration 7 (5-11) years] were recruited. There was a delay in diagnosis of 3 (1-5) years. The median Ankylosing Spondylitis Disease Activity Score (ASDAS)-ESR, BASDAI, HAQ-DI and BASFI at inclusion were 2.6 (1.8-3.6), 2.6 (1-5.2), 0.5 (0-0.5) and 1.6 (0.3-3.2), respectively. BASFI and HAQ-DI correlated with ASDAS-ESR, ASDAS-CRP and WHO-QOL-BREF. Those with PFO (n = 98) had a longer delay in diagnosis (4 vs 2 years, P < 0.001), lower prevalence of arthritis at onset [odds ratio (OR) = 0.3; 95% CI: 0.1, 0.8], higher prevalence of ERAP1 (rs27044) allele C (OR = 7.2; 95% CI: 1.5, 33.7) and higher disease activity currently. Delay in diagnosis (OR = 1.2; 95% CI: 1.08, 1.4) was the sole predictor of PFO in multivariate analysis. One-third of patients had PDA. Tarsitis at disease onset was the sole predictor of PDA (OR = 2.3; 95% CI: 1.009, 5.4).

CONCLUSIONS

PFO was seen in one-half of JIA-ERA in the long-term and was associated with active disease with delay in diagnosis as its sole predictor.

High prevalence of sacroiliitis and early structural changes in the sacroiliac joint in children with enthesitis-related arthritis: findings from a tertiary centre in Hong Kong

BACKGROUND

Epidemiological studies have demonstrated a wide, unexplained disparity in the prevalence of juvenile idiopathic arthritis (JIA) subtypes depending on geographical location, ethnicity and other factors. Enthesitis-related arthritis (ERA) is more prevalent in Southeast Asia. Axial involvement in ERA patients is increasingly recognised to occur early in the disease course. Inflammation in the sacroiliac joint (SIJ) observed on MRI seems highly predictive of subsequent structural radiographic progression. The resulting structural damage can have significant impacts on both functional status and spinal mobility. This study aimed to evaluate the clinical characteristics of ERA in a tertiary centre in Hong Kong. The primary objective of the study was to provide a comprehensive description of the clinical course and radiological findings of the SIJ among ERA patients.

METHOD

Paediatric patients diagnosed with JIA attending the paediatric rheumatology clinic from January 1990 to December 2020 were recruited from our registry based at the Prince of Wales Hospital.

RESULTS

In our cohort, 101 children were included. The median age of diagnosis was 11 years, interquartile range (IQR) 8-15 years. The median follow-up duration was 7 years (IQR 2-11.5 years). ERA was the most prevalent subtype (40%), followed by oligoarticular JIA (17%). Axial involvement was frequently reported in our cohort of ERA patients. 78% demonstrated radiological evidence of sacroiliitis. Among those, 81% had bilateral involvement. The median duration from disease onset to confirmation of radiological sacroiliitis was 17 months (IQR 4-62 months). Among the ERA patients, 73% had structural changes of the SIJ. Alarmingly, 70% of these patients had already developed radiological structural changes when sacroiliitis was first detected on imaging (IQR 0-12 months). Erosion was the most common finding (73%), followed by sclerosis (63%), joint space narrowing (23%), ankylosis (7%) and fatty change (3%). The duration from symptom onset to diagnosis was significantly longer in ERA patients with SIJ structural changes (9 vs 2 months, p = 0.009), comparing with those without.

CONCLUSION

We found that a high proportion of ERA patients had sacroiliitis and a significant number of them had radiological structural changes during early disease. Our findings illustrate the importance of prompt diagnosis and early treatment in these children.

Recent updates in enthesitis-related arthritis

Enthesitis-related arthritis (ERA) is a category of juvenile idiopathic arthritis which belongs to the spectrum of diseases that are included in juvenile spondyloarthropathy. In recent years, there have been significant advances in understanding pathogenesis, tools to assess disease activity, early recognition of the axial disease, and targeted therapy using IL-17 inhibitors and small molecule inhibitors. The current narrative review highlights these new advances. Among many hypotheses linking HLA B27 to ERA, one of them is the effect of HLA B27 on gut dysbiosis. However, recent data suggest that gut dysbiosis is probably not determined by HLA B27. Though children present with arthritis and enthesitis, axial disease is present in 50-60% on MRI. Using data-driven approach, discriminative MRI finding for active and chronic diseases has been defined for children. This will help in the early recognition of disease. An abridged version of juvenile spondyloarthropathy disease activity (JSpADA) score without the need for acute phase reactants and Schober test performed as well as the original score may increase its acceptance in routine practice. Secukinumab (anti-IL-17 antibody) has shown a more than 75% response rate in children with ERA and may be a good alternative to anti-TNF therapy. Initial data with tofacitinib also look promising. All these will translate into better outcomes for children with ERA.

Enthesitis-related arthritis: the clinical characteristics and factors related to MRI remission of sacroiliitis

Background

To describe the clinical characteristics and explore the factors related to the MRI remission of sacroiliitis in patients with enthesitis-related arthritis (ERA).

Methods

Patients with ERA from 2018–2022 in our medical center were retrospectively reviewed, which identified according to Pediatric Rheumatology International Trials Organization (PRINTO) criteria. Demographics, clinical characteristics, examinations, and treatments were described. Univariate and multivariate logistic regression models were used to analyze the factors related to MRI remission of sacroiliitis in ERA.

Results

This retrospective study included 160 ERA patients (51.9% male) with a mean onset age of 9.2 ± 3.0 years. There were 144 cases (81.9%) with peripheral arthritis, and the hip, knee, and ankle joints were the most commonly involved joints. Enthesitis occurred in 48 cases (30.0%), and sacroiliitis occurred in 142 cases (88.5%) at diagnosis. Human leukocyte antigen (HLA)-B27 was positive in 33 cases (17.1%), and acute uveitis occurred in 3 cases (1.9%). The majority of patients (93.7%) were treated with disease-modifying anti-rheumatic drugs (DMARDs), and 60% with biologics. Among 62 patients with MRI-defined sacroiliitis, 27 (43.5%) cases showed improvement in the sacroiliac joint lesion after treatment. Multivariate logistic regression analysis showed that duration from onset to diagnosis of less than 3 months (OR = 3.609, 95% CI: 1.068–12.192) and active joints of more than 4 (OR = 4.916, 95% CI: 1.006–24.037) were independent factors.

Conclusion

We highlighted differences in ERA clinical characteristics. Patients with a shorter diagnosis time and more joint involvement improved more significantly in sacroiliac joint lesions after treatment.

Comparison of the outcomes between early and late anti-tumor necrosis factor therapy in patients with enthesitis-related subcategory of juvenile idiopathic arthritis: a multi-center study in Southeast Asia

BACKGROUND

Little is known about the impact of delayed initiation of anti-tumor necrosis factor (TNF) therapy in patients with enthesitis-related arthritis (ERA). Here, we compared the impact of delayed treatment on disease outcomes of ERA patients in Southeast Asia.

RESEARCH DESIGN AND METHODS

This retrospective study enrolled 149 ERA patients from Thailand and Singapore. Early (e-aTNF) and late (l-aTNF) treatment groups received anti-TNF therapy starting at ≤6 months and >6 months, respectively, after diagnosis. Outcomes included mean differences in disease activity parameters, Juvenile Spondyloarthritis Disease Activity (JSpADA) score, Juvenile Arthritis Diseases Activity (JADAS)-10 score, and American College of Rheumatology Pediatric (ACR Pedi) criteria, and the frequency of clinically inactive disease and first flare event.

RESULTS

The mean changes in JSpADA (p = 0.002) and JADAS-10 (p < 0.001) scores over time were significantly higher in the e-aTNF group than in the l-aTNF group. A significantly higher proportion of patients in the e-aTNF group than l-aTNF group satisfied ACR Pedi 100 criteria at 2 years (p = 0.042). All other long-term outcomes were not significantly different between the groups.

CONCLUSIONS

Although early anti-TNF treatment improved disease activity parameters somewhat better than delayed anti-TNF therapy, there was no significant difference in long-term outcomes.

Sacroiliitis at diagnosis as a protective predictor against disease flare after stopping medication: outcomes of a Southeast Asian enthesitis-related arthritis (ERA) longitudinal cohort

OBJECTIVES

To assess short- and long-term outcomes of ERA in a large monocentric cohort in Singapore.

METHODS

Children diagnosed with ERA according to ILAR criteria from 2002 to 2021 were recruited. Nonparametric statistics were used to describe the data. Outcomes were defined according to modified Wallace criteria, and probabilities and predictors were determined using Kaplan-Meier survival and logistic regression analyses.

RESULTS

One hundred fifty-one ERA patients (male 86%; Chinese 81%) were included. The median age at onset was 11.9 years (IQR: 9.4-13.9), and disease duration was 5.3 years (IQR: 2.9-8.4). At diagnosis, 39% of the patients had sacroiliitis. HLA-B27 was positive in 83%, and biologics were used in 72% of the patients. Clinical inactive disease (CID) was achieved in 92% of the patients, of which 27% achieved within 6 months. Sacroiliitis at diagnosis is an unfavorable predictor of early CID at 6 months. Medication was discontinued in one-third of the patients. Favorable predictor of medication withdrawal includes male gender, while unfavorable predictors include positive HLA-B27 and ANA. Two-thirds of the patients with CID had at least one disease flare. Sacroiliitis at diagnosis is a protective predictor of flare after stopping medication.

CONCLUSION

Despite a high proportion of ERA patients achieving CID, only one-third could stop medication with high rates of disease flare. Unfavorable predictors include older age at onset, HLA-B27, and ANA positivity. While sacroiliitis at diagnosis is a negative predictor of CID at 6 months, it is associated with less disease flare after discontinuing medication.

Tapering of Biological Agents in Juvenile ERA Patients in Daily Clinical Practice

Objectives: We aim to evaluate the proportion and characteristics of enthesitis-related arthritis (ERA) patients in whom medications can be withdrawn in daily practice and to analyze the factors associated with flare-ups during medication tapering of these patients.

Methods: We retrospectively reviewed records of patients under 16 years old diagnosed with ERA from April 2001 to March 2020 in one tertiary medical center in Taiwan. Patients were categorized by different medication uses: conventional disease modifying anti-rheumatic drugs (cDMARDs) only and cDMARDs plus biologics. Demographics, laboratory data, presence of uveitis, and medication withdrawal rate were analyzed. Subgroup analysis was performed in the patients with cDMARDs plus biologics to identify factors associated with flare-ups during medication tapering of these patients. Statistical analysis was performed using R (v3.6.0).

Results: There were 75 juvenile ERA patients with a median onset age of 10.28 years old. Nineteen (25.3%) patients used cDMARDs for disease control; 56 (74.7%) patients depended on cDMARDs plus biologics. Poly-articular involvement was noted in 29 (38.7%) patients, and it occurred more frequently in the cDMARDs plus biologics subgroup (cDMARDs only, 5.3%; cDMARDs plus biologics, 53.6%; P = 0.0001). ANA positivity was observed in 18 (24.0%) patients, and it occurred more frequently in the cDMARDs plus biologics subgroup (cDMARDs, 0%; cDMARDs plus biologics, 32.1%; P = 0.0038). The overall medication withdrawal rate was 34.7%, and it occurred more frequently in patients with cDMARDs only (cDMARDs only, 84.2%; cDMARDs plus biologics, 17.9%; P < 0.001). In the subgroup analysis of patients with cDMARDs plus biologics, patients on biologics tapering with flare-up had a significantly longer time interval between disease onset and initiation of cDMARDs (biologics tapering without flare-up: 0.27 (0.11–0.73) years; biologics tapering with flare-up: 1.14 (0.39–2.02) years; ever withdrawing biologics: 0.26 (0.18–0.42) years, P = 0.0104).

Conclusion: Juvenile ERA patients with polyarticular involvement had a higher risk of developing cDMARDs refractory and progressing to biologics use. Patients with a long time interval between disease onset and initiation of cDMARDs were prone to experience flare-up during tapering of biologics.