Prevalence Of HLA-B27 Research Articles

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

BackgroundEnthesitis-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.MethodsA 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.ResultsThere 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).ConclusionMost 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.

Differences between radiographic and non-radiographic axial spondyloarthritis patients in a Mexican cohort

To compare the demographic, clinical, and laboratory characteristics, disease onset, and clinical features of radiographic axial Spondyloarthritis (r-axSpA) and non-radiographic axial Spondyloarthritis (nr-axSpA) patients. All patients who attended outpatient spondylarthritis (SpA) clinics at Hospital General de Mexico and the Instituto Nacional de la Nutrición from 1998 to 2005 and met the rheumatologist diagnostic criteria for SpA were selected. Then the SpA patients were classified by European Spondyloarthropathy Study Group criteria (ESSG). We selected SpA patients with axial presentation as axial SpA (axSpA), and they were classified as r-axSpA if they met modified New York (mNY) criteria for sacroiliitis and as nr-axSpA if they did not meet mNY criteria; to compared clinical, demographic, and laboratory test between the subgroups. It included 148 SpA patients; 55 (37.2%) patients had r-axSpA, and 70 (47.3%) had nr-axSpA. The nr-axSpA patients had a lower proportion of males (58.6% vs 78.2%, P < 0.05), lower HLA-B27 frequency (54.3%. vs. 92.7%, P < 0.05), were older at disease onset (21 vs 16 years; P < 0.01) and had a higher frequency of infections at disease onset (9.1% vs 32.9, P < 0.05) than r-axSpA. BASFI (2.9 vs 4.8; P < 0.0001), Dougados functional index (7 vs. 14; P < 0.05), and BASDAI (4.1 vs. 5.2; P < 0.001) were lower in patients with nr-axSpA than r-axSpA, respectively. The factors that most influenced the presentation of r-axSpA were history of uveitis (OR 14, 95% CI 2.3–85), HLA-B27 (OR 7.97, 95% CI, 2.96–122), male sex (OR 6.16, 95% CI, 1.47–25.7), axial enthesopathy count (OR 1.17 95% CI, 1.03–1.33). This study provides insight into the differences between nr-axSpA and r-axSpA in Mexico. Patients with r-axSpA were mainly male, with a younger presentation age, a higher prevalence of HLA-B27, more history of uveitis, fewer episodes of dactylitis, more axial enthesopathy, and higher disease activity than nr-axSpA.

Comparing clinical profiles in spondyloarthritis with Crohn's disease or ulcerative colitis: insights from the ASAS-PerSpA study.

Assuming SpA manifestations may vary among patients with different inflammatory bowel disease (IBD) subtypes, we explored the clinical characteristics associated with the presence of Crohn's disease (CD) or ulcerative colitis (UC) in patients with spondyloarthritis (SpA). We included 3152 patients of ASAS-PerSpA study diagnosed with either axial SpA or peripheral SpA, according to their treating rheumatologist. Of these, 146 (4.6%) had confirmed IBD by endoscopy and were categorized into CD or UC groups. Demographics, clinical characteristics, treatments and patient-reported outcomes were compared between the two subgroups. From 146 patients included in the current analysis, 87 (59.6%) had CD [75 (86.2%) axial SpA and 12 (13.8%) peripheral SpA], and 39 (26.7%) had UC [34 (87.2%) axial SpA and 5 (12.8%) peripheral SpA]. CD and UC groups had similar age with average of 44.9 (13.5) vs 44.0 (13.0) years, respectively, and a slight male predominance in CD (63.2%) compared with UC (51.3%). Diagnostic delay for SpA was 7.0 (6.9) years for CD and 8.8 (8.1) years for UC. Chronic back pain was the most reported symptom present in 95.4% of CD patients and 89.7% of UC patients. Both groups had similar musculoskeletal phenotyping, with higher frequency of psoriasis (15.4%) and uveitis 28.2% in UC; and higher tendency to be HLA-B27 positive in CD (51.9% in CD vs.s 39.4% in UC). In our analysis patients with SpA and concurrent CD or UC had mainly similar musculoskeletal phenotypes. However, they differ slightly in extra-musculoskeletal manifestations and HLA-B27 prevalence.

Exploring the unifying concept of Spondyloarthritis: a latent class analysis of the REGISPONSER registry.

The aim of our study is to identify the potential distinct phenotypes within a broad Spondyloarthritis (SpA) population. We conducted a cross-sectional study using the REGISPONSER registry with data from 31 specialist centres in Spain including patients with SpA who fulfilled the European Spondyloarthropathy Study Group (ESSG) criteria. A latent class analysis (LCA) was performed to identify the latent classes underlying SpA according to a set of predefined clinical and radiographic features, independently of expert opinion. In a population of 2319 SpA patients, a 5 classes LCA model yielded the best fit. Classes named 'axial with spine involvement' and 'axial with isolated SIJ involvement" show a primarily axial SpA phenotype defined by inflammatory back pain and high HLA-B27 prevalence. Patients in class 'axial + peripheral' show similar distribution of manifest variables to previous classes but also have a higher likelihood of peripheral involvement (peripheral arthritis/dactylitis) and enthesitis, therefore representing a mixed (axial and peripheral) subtype. Classes 'Peripheral + psoriasis' and 'Axial + peripheral + psoriasis' are indicative of peripheral SpA (and/or PsA) with high likelihood of psoriasis, peripheral involvement, dactylitis, nail disease, and low HLA-B27 prevalence, while class 'Axial + peripheral + psoriasis' also exhibits increased probability of axial involvement both clinically and radiologically. The identification of 5 latent classes in the REGISPONSER registry with significant overlap between axial and peripheral phenotypes is concordant with a unifying concept of SpA. Psoriasis and related features (nail disease and dactylitis) influence the phenotype of both axial and peripheral manifestations.

The Impact of Spondyloarthritis on Health-Related Quality of Life and Healthcare Resource Utilization in Saudi Arabia: A Narrative Review and Directions for Future Research.

Spondylarthritis (SpA) is an umbrella term that encompasses a wide range of rheumatological disorders. Several studies demonstrated that SpA is associated with increased healthcare resource utilization (HCRU) and a lower health-related quality of life (HRQoL). This review aimed to summarize the current literature regarding the multidimensional impact of SpA on HRQoL and HCRU in Saudi Arabia and explore the correlation of the extent of severity of SpA with HRQoL and HCRU. Although the prevalence of SpA varies across different populations and is correlated with HLA-B27 prevalence, the magnitude of SpA in the Saudi population has not been extensively evaluated. Few studies have investigated the impact of SpA on HRQoL and HCRU in Saudi Arabia and the Middle East. There is a need to study the cost-effectiveness of various SpA treatment strategies, including biologic disease-modifying anti-rheumatic drugs (bDMARDs), to prioritize healthcare spending in the Saudi healthcare system. Data on SpA in Saudi Arabia and the Middle East region are mainly based on expert views, with few population-based studies compared to other regions. Therefore, there is an imperative need to develop high-quality, national-level epidemiological studies that assess the following: (1) more accurate estimates of the current prevalence of SpA in Saudi Arabia, including the prevalence of axial SpA and psoriatic arthritis; (2) the phenotypes/clinical characteristics of SpA, including disease severity and extra-articular involvement; (3) the impact of SpA on the HRQoL of the patients and the factors that can predict the extent of impaired HRQoL in such population, which can represent the first step in developing psychological interventions that should be personalized to this patient population; (4) the impact of implementing formal assessment of disease activity on the management of the patients and, subsequently, their HRQoL; and (5) the HCRU and costs for patients with SpA, and how treatment patterns can affect this cost.

Correlation of Interleukin-17 and 23 Inflammatory Markers with Genetically Transmitted Spondyloarthritis Patients at a Tertiary Care Facility, South India

Human leukocyte antigens (HLA) are genetically derived proteins in the major histocompatibility complex. They help distinguish “self” and “non-self” antigens and are essential in interacting with the immune cells inside the body. The present research work examines the prevalence of HLA-B27 among patients suspected of Spondyloarthritis (SpA), which has also been correlated with Interleukin-17/23 Inflammatory Markers and other clinical manifestations and was carried out between August 2017 to January 2021. The patient’s blood samples were collected and tested for HLA-B27 and Interleukin-17/23 inflammatory markers. Among 289 SpA patients, 60% (172) were males, and 40% (117) were females, with a ratio of 1.5:1. Ankylosing Spondylitis (65.1%) was found to be the most prevalent subgroup of SpA among the patients, closely followed by reactive arthritis (21%), psoriatic arthritis (10.7%), undifferentiated spondyloarthritis (2.1%), and inflammatory bowel disease with associated arthritis (1%). HLA-B27 was found to be positive in 54% (156) out of 289 patients. Normal IL-17 ranges were seen in 42% of HLA-B27- positive patients, while increased IL-17 was seen in 58% of the population with positive HLA-B27 cases. IL-23 was found within normal ranges in 40% of positive HLA-B27 cases, while it was found to be increased in 60% of the positive HLA-B27 positive subjects. We concluded that HLA-B27 was found to be positive among more than half of the patient population with SpA. The early detection of HLA-B27 may aid in changing lifestyle to prevent Spondyloarthritides.

Genetic and Molecular Distinctions Between Axial Psoriatic Arthritis and Radiographic Axial Spondyloarthritis: Post Hoc Analyses from Four Phase3 Clinical Trials.

Emerging evidence suggests psoriatic arthritis (PsA)with axial involvement (axPsA) and radiographic axial spondyloarthritis (r-axSpA) maypossibly represent distinct disorders, with some differing clinical manifestations, genetic associations, and radiographic findings. Moreover, axPsA and r-axSpA may respond differently to therapies: guselkumab (interleukin [IL]-23p19 subunit inhibitor [i]) and ustekinumab (IL-12/23p40i) demonstrated improvements in axial symptoms in patients with PsA; however, neither risankizumab (IL-23p19i) nor ustekinumab demonstrated efficacy versus placebo in patients with r-axSpA. Current analyses aim to further understand potential molecular distinctions between axPsA and r-axSpA and examine the pharmacodynamic effects of guselkumab in patients with axPsA and those with PsA without axial involvement (non-axPsA). Posthoc analyses utilized biomarker data from blood and serum samples collected from a subset of participants in phase3 studies of ustekinumab in r-axSpA and guselkumab in PsA (DISCOVER-1 and DISCOVER-2). Participants with axPsA were identified by investigator-verified sacroiliitis (imaging-confirmed)and axial symptoms. HLA mapping, serum cytokine analysis, and whole-blood RNA sequencing were conducted. Relative to r-axSpA, patients with axPsA had a lower prevalence of HLA-B27, HLA-C01, and HLA-C02 alleles and a higher prevalence of HLA-B13, HLA-B38, HLA-B57, HLA-C06, and HLA-C12 alleles. Compared with r-axSpA, patients with axPsA had elevated baseline levels of serum IL-17A and IL-17F cytokines, enrichment of IL-17 and IL-10 pathway-associated genes, and neutrophil gene markers. Across axPsA and non-axPsA cohorts, reductions in cytokine levels and normalization ofpathway-associated gene expressionwith guselkumab treatment were comparable. The differences in HLA genetic associations, serum cytokines, and enrichment scores support the concept that axPsA and r-axSpA may be distinct disorders. The comparable pharmacodynamic effects of guselkumab on cytokine levels and pathway-associated genes observed in patients with axPsA and non-axPsA are consistent with demonstrated clinical improvements across PsA cohorts. These findings contribute to the understanding of potential genetic and molecular distinctions between axPsA and r-axSpA. ClinicalTrials.gov identifiers, NCT03162796, NCT0315828, NCT02437162, and NCT02438787.

Heterogeneity of axial spondyloarthritis: genetics, sex and structural damage matter

ObjectiveAxial spondyloarthritis (axSpA) comprises both radiographic and non-radiographic disease. However, the paucity of specific objective measures for the disease and current classification criteria showing suboptimal specificity contribute to disease heterogeneity...

Axial Spondyloarthritis in Japan.

The differences in the epidemiology and management of patients with axial spondyloarthritis (axSpA) among regions and countries largely depend on the positivity of human leukocyte antigen (HLA)-B27 and the health care system. This review article focused on axSpA in Japan, where the prevalence of HLA-B27 is extremely low (0.3%) and the universal health insurance system typically provides a 70% or more copayment by the government. A nationwide survey was conducted in Japan in 2018, which estimated that there were 3200 patients (95% confidence interval [CI]: 2400-3900) with ankylosing spondylitis (AS), a term interchangeable with radiographic axSpA (r-axSpA), and 800 patients (95% CI: 530-1100) had non-radiographic (nr)-axSpA. These data indicate a prevalence of 2.6/100,000 or 0.0026% for AS and 0.6/100,000 or 0.0006% for nr-axSpA. Patients with AS, but not those with nr-axSpA, are designated as suffering from intractable diseases in Japan; thus, their medical expenses are reduced by grant under the Act on Medical Care for Patients with Intractable Diseases. As of February 2022, infliximab, adalimumab, secukinumab, ixekizumab, and brodalumab have been approved for AS, and secukinumab, ixekizumab, and brodalumab have been approved for nr-axSpA. An algorithm for nr-axSpA in Japan has been developed for the proper diagnosis and use of these therapeutic agents. A low prevalence of axSpA, especially that of nr-axSpA, was found in Japan. Early referral and the resultant diagnosis and appropriate treatment of these patients by rheumatologists are crucial issues in Japan, as in other countries.

O001. Juvenile-onset spondyloarthritis: a study of 54 cases in Senegal

Abstract Background Juvenile onset spondyloarthritis (JoSpA), also known as enthesitis-related arthritis (ERA), accounts for approximately 10-20% of all juvenile idiopathic arthritis (JIA) and affects four times more boys than girls. It’s characterized by frequent arthritis of the lower limbs and strongly associated with presence of HLA-B27. In sub-Saharan Africa, SpA is considered as a rare disease where the frequency of HLA-B27 is &amp;lt; 1% in the population. However, an interesting exception is found in the Fula ethnic group of Gambia, where the prevalence of HLA-B27 was estimated at 6% to 7.8%. This ethnic group is also present in Senegal Aims: To determine the epidemiological, clinical, Para clinical, therapeutic and disease course aspects of JoSpA in Senegal. Methods A retrospective observational study, was conducted in rheumatology department of Aristide Le Dantec Hospital, between January 2012 and December 2020. Two hundred and fifteen JIA cases were collated, 54 were JoSpA fulfilling the ILAR classification criteria of ERA, with age of onset of symptoms ≤ 16 years. Exclusion criteria were: psoriasis or history of psoriasis, presence of rheumatoid factor and presence of systemic arthritis. Disease activity was assessed by activity indexes (BASDAI and ASDAS), functional impact by BASFI, and Quality of Life by Nottingham Health Profile (NHP). Results A total of 54 patients (29 males and 25 females with a sex ratio M/F of 1.16) were included in the study. The mean age at onset of symptoms was 12.4 years, mean age at diagnosis was 23.2 years. 34 (63%) patients were of Fula ethnicity. The inaugural symptomatology was exclusively peripheral in 33 cases (61.1%), axial and peripheral in 23 cases (42.6%). At the time of diagnosis, arthritis was located in the lower limbs in 92.1% of cases, where knee involvement was predominant in 30 (55.6%) cases, followed by hip involvement in 17 (31.5%) cases. Axial involvement was present in 46 cases (85.2%), dominated by sacroiliac pain/ buttock pain in 73.9%, followed by low back pain in 52.1%. Entheseal involvement was present in 30 cases, dominated by Achilles enthesitis and plantar fasciitis in 83.3%. Involvement of the anterior chest wall was found in 12 patients. Uveitis was present in 3 patients. Biological inflammatory syndrome was found in 55.5% of cases, with a mean CRP level of 17.1mg/l. Search for HLA-B27 was carried out in 34 patients, 25 were HLA-B27 positive (73.5%). Among HLA-B27 positive patients, 21 (84%) were of Fula ethnicity. On radiography, sacroiliitis was present in 29 patients, and 8 had coxitis. On admission, the mean BASDAI and ASDAS-CRP were 4.66/10 and 2.98 respectively, mean BASFI was 4.36/10. NHP showed impairment of all items, especially the concepts of energy, pain, sleep and physical mobility. Treatment was based on: NSAIDs (42 patients, 79.6%), methotrexate (30 patients, 55.5%), sulfasalazine (8 patients, 14.8%), oral steroids (15 patients, 27.7%), intra-articular joint steroid injections (6 patients), hip replacement surgery (2 patients), and functional rehabilitation (5 patients). The evolution was favorable, after 6 months of treatment, mean BASDAI and BASFI were 2.47/10 and 2.19/10 respectively. Conclusion In our study, JoSpA affects both girls and boys. The prevalence of HLA-B27 was 73.5% of cases, especially in the Fula ethnic group. The disease is considered as a source of significant functional impact and impairment of quality of life. The treatment was based mainly on conventional treatment. Evolution was globally favorable after treatment. Further epidemiological studies are needed to obtain reliable prevalence rates and to better understand our findings.

P24 Ankylosing spondylitis &amp; uveitis - challenges in management

Case report - IntroductionAnkylosing spondylitis is a chronic inflammatory condition involving spine, chest and sacroiliac joints. It can be associated with extra spinal manifestations which include uveitis and enthesitis, as well as other features of an inflammatory spondyloarthropathy including psoriasis and inflammatory bowel disease. It is characterised by the presence of inflammatory back pain, limited range of spinal movement, sacroiliitis on imaging, excess spinal bone formation and a high prevalence of HLA-B27. The main aims of treatment are to improve symptoms and retain function as well as to prevent disease complications.Case report - Case descriptionA 49-year-old male diagnosed with ankylosing spondylitis at the age of 23 (HLA-B27 positive, classical radiographic features on plain radiographs and MRI), with background of meningitis and subsequent epilepsy (not on treatment since the age of 13), severe hip osteoarthritis and osteoporosis. He has peripheral elbow and knee synovitis. At the age of 27 he developed sight-threatening bilateral recurrent anterior uveitis complicated by cystoid macular oedema (causing central vision loss). Initial management included anti-inflammatories and steroids. He progressed to biologics but developed a rash on adalimumab. He was switched to infliximab in 2010. In 2015 it was switched due to reduced response to golimumab which was non-beneficial. Subsequently he was switched to etanercept but after 3 months it was discontinued due to eye flare. The patient’s therapy was switched to certolizumab, which was non-beneficial for spine and discontinued. In 2016, infliximab was retried as the patient thought it worked best. Unfortunately, in 2018 patient developed Infliximab antibodies and treatment was changed to secukinumab. After 9 months this was stopped owing to ongoing active eye and spine disease. Adalimumab was re-tried; however, it was discontinued as it was showing no benefit. In 2020 Eeanercept (Benepali) was re-tried; however, only for 4 months because of severe flare of joint and eye disease. Tofacitinib was commenced but was non-beneficial and hence it was discontinued. Currently he continues on ixekizumab, oral prednisolone and also receives steroid eye and joint injections. On commencing biologics he was on methotrexate; however, the patient stopped. He was switched to mycophenolate mofetil which he remained on for 10 years. It was switched to methotrexate to try and control peripheral inflammatory joint disease better (re-tried for the second time) which the patient has recently discontinued as he felt it was non-beneficial.Case report - DiscussionThe case is very challenging. The patient’s disease continues to flare despite changing therapies. He continues to get flares in his back disease, eye disease and peripheral synovitis. His latest BASDI was 5.1 and VAS was 9/10. Measurements: intermalleolar distance 15cm, modified Schober’s 4cm, right lateral flexion 3.8cm and left lateral flexion 11cm. His latest MRI of whole spine and SI joints (in 2020) showed signs of previously active seronegative spondyloarthropathy with established cervical and thoracic ankyloses as well as bilateral sacroiliac joint ankylosis. There is a need for repeated steroid injections to the knees as well as the eyes. He continues on oral prednisolone which was first started in 2006. This is associated with multiple side effects, i.e., osteoporosis. The patient has already completed 8 years of bisphosphonate therapy. He is under regular review with the osteoporosis clinic. His bone density scan showed worsening bone mineral density and bisphosphonates had to be restarted. The patient adjusted medications depending on his symptoms. Recently he also discontinued methotrexate as he felt it was of no benefit to him at all. We are very limited at present to find combined medications to manage both the patient’s inflammatory back disease and inflammatory eye disease.Case report - Key learning pointsThis patient was diagnosed with ankylosing spondylitis 26 years ago. To date he has tried 5 different anti-TNF agents (two of which have also been re-tried at a different time point). This failed to control his disease as he continued to experience flares in either inflammatory back or eye disease. The biologic classes were also changed – he has tried one IL-17A agent as well as a JAK-I. Unfortunately, they both failed to control his disease. He currently continues on a second IL-17A; however, he still requires steroid eye and joint injections as well as systemic steroids. Throughout the years he has tried different DMARDs – most recently methotrexate. Unfortunately, the patient decided to discontinue it as he felt it was of no benefit to him. All of the above indicates that there is still a need to find a collaborative treatment option that will control the patient’s inflammatory back disease, inflammatory eye disease and peripheral synovitis. The aim would be, if possible, to decrease the steroid dose as well (currently on prednisolone 15mg daily) in order to prevent the steroid-associated side effects.

Worldwide Differences in Clinical Phenotype of Axial Spondyloarthritis.

This review aims to describe the variations in the clinical presentation of axial spondyloarthritis (axSpA) across the globe. We searched the PubMed database and screened more than 1360 articles; 60 of them were selected based on relevance to the topic being discussed and the goals of the review. Most of the clinical manifestations, including IBP, peripheral arthritis, and extra-articular involvement are seen in different regions of the world, but with appreciable clinical heterogeneity, possibly related to a smaller number of patients from some countries, and global variation in the prevalence of HLA-B27. For example, HLA-B27-positive patients have an earlier age of onset, higher prevalence of acute anterior uveitis, and greater familial occurrence. Peripheral arthritis and enthesitis are most commonly seen among axSpA patients from Latin America and Asia, whereas IBD appears to be slightly more common among Middle Eastern and North African patients. The main weakness encountered while reviewing these data is that some studies were small, and others were cross-sectional and retrospective; hence the inferences may have a selection bias. AxSpA is a very heterogenous disease with varied presentation across the globe, in part related to HLA-B27 positivity. It is imperative to further investigate the key regional differences as they impact timely disease recognition and initiation of early treatment. Therefore, there is a need for a large worldwide systematic study to capture the clinical picture of AxSpA in a more uniform manner.

A cross-sectional study on clinical characteristics of Saudi axial spondylarthritis: preliminary results.

To describe Spondyloarthritis (SpA) patients in a single center (preliminary phase), Build connections to establish local cohorts, Saudi Registry, and publication in Gulf and Arab database. This prospective observational cohort consists of patients with spondylarthritis (SpA) diagnosed by a rheumatologist. Patients with AS were defined as those who met the modified New York criteria for Ankylosing Spondylitis (AS) 1984. All other patients with axial SpA who did not meet the radiology criteria of modified New York criteria for Ankylosing Spondylitis were classified as having non-radiographic axial SpA based on Assessment of SpondyloArthritis International Society (ASAS) diagnostic criteria for axial spondyloarthropathy. The study group comprised 106 patients with SpA (49 patients with AS and 57 patients with non-radiographic axial SpA). Patients with non-radiographic axial SpA and patients with AS who had previously been treated with biologic disease-modifying drugs (DMARDs) were 66.67 percent and 83.67 percent, respectively. In patients with AS, CRP and age significantly impact disease activities (p<0.05). The overall mean ASDAS score was 2.3 ± 0.7. This study has shown a more detailed description of the largest Saudi cohort reported yet. Interestingly, both disease groups, Ankylosing spondylitis and non-radiographic spondyloarthritis showed a lower prevalence of HLA-B27 is lower in the general Saudi population compared to other nations including Caucasians, thus, limiting its use as a diagnostic tool. The majority of both groups, nearly three-quarters of all patients (74.53%) in biologic DMARD treatment, and only (22.64%) used csDMARD treatment, which may help control disease activity and showing easier access and availability of these therapies to the patient. Patients with non-radiographic axial SpA showed slightly higher Extra-articular Manifestations comparing with AS patients.

POS1297 HOW HLA B27 PREVALENCE IN THE POPULATION INFLUENCE ON FEATURES OF JUVENILE IDIOPATHIC ARTHRITIS: DATA FROM SAKHA REPUBLIC (YAKUTIA)

Background:Sakha Republic (Yakutia) - SR(Y) is a bid arctic region of Russia with high proportion of aboriginals - Yakutians (50%), intra-national marriages, increased level of inbreeding and high distribution of HLAB27 among aboriginals – 33%, according the epidemiological studies. The main type of arthritis is ankylosing spondylitis in adults and enthesytis-related arthritis (ERA) of juvenile idiopathic arthritis (JIA) in children. The pattern of arthritis distribution in adults and children in SR(Y) is differ from Caucasians and similar to Native Americans.Objectives:Our study aimed to evaluate the features of JIA in aboriginals of SR(Y), associated with high prevalence of HLAB27 antigen.Methods:In the retrospective study we included 144 Yakutians who were admitted in the rheumatology department of Yakutsk in 2007-2016 years and 753 JIA patients Caucasian origin in Saint-Petersburg in the same years. We evaluated routine clinical and laboratorial features. HLA B27 was evaluated according the clinical judgement of the attending physicians.Results:ERA is a main JIA category in Yakutians. The main features the male predominance, higher onset age, high inflammatory activity, lower number of active joints, high incidence of hip and sacroiliac joints involvement, lower levels of psoriasis and uveitis. Yakutians have rare the involvement of cervical spine (6% vs 14%, p=0.0000001), TMJ (1% vs 6%, p=0.027), elbow (8% vs 16%, p=0.012), wrist (18% vs 28%, p=0.017), MCP (7% vs 21%, p=0.00005), PIP (8% vs 25%, p=0.00005). The treatment rates of methotrexate and biologics were similar between groups, but in Yakutians the biologics were administered earlier, because methotrexate failed and often was ineffective. The cumulative probability to receive biologics was higher in Yakutians compare to Caucasians: HR=3.4 [2.6; 4.4], p=0.000001 (Figure 1). The main biologic in Yakutians was etanercept (49/70; 70%). Yakutians received corticosteroids and cyclosporine A rarely, due to low incidence of systemic onset JIA and oligoarthritis with uveitis. It was observed, that the HLA B27 as a risk factors had different significance in Yakutians and Caucasians. HLA B27 presence increased the risk of ERA OR=2.72 (1.3; 5.6) p=0.01 in Yakutians and OR=69.2 (29.5; 162.3), p=0.00001 for Caucasians; for biologic administration: 0,86 (0,4; 1,8), p=0.529 and 2,45 (1,5; 4,0), p=0.0003, respectively.Figure 1.Cumulative probability to leave without biologics between Yakutian and Caucasian JIA patients.Conclusion:High distribution of HLA B27 antigene in Yakutians, lead to different pattern of JIA categories distributions and patient’s management.This work was supported by the Project of the Ministry of Science and Higher Education of the Russian Federation (basic part of funding to M.K. Ammosov North-Eastern Federal University #FSRG-2020-0016) and by the RFBR grant #18-05-600035_Arctika.Table 1.Differences between Yakutian and Caucasian JIA patients.JIA featuresYakutians, n=144 (%)Caucasians, n=723 (%)рGender, boys, n (%)85 (59.0)279 (38.6)0.000006Onset age, years10.6 (6.0; 13.4)6.0 (3.0; 10.3)0.0000001JIA categories, n (%)Oligoarthritis36 (25.0)188 (26.0)0.0000001Poly, RF (-)21 (14.6)248 (34.3)Poly, RF (+)1 (0.7)22 (3.0)Systemic onset4 (2.8)53 (7.3)ERA76 (52.8)171 (23.7)Psoriatic arthritis6 (4.2)41 (5.7)Active joints4.0 (3.0; 6.0)6.0 (3.0; 12.0)0.0000001Uveitis, n (%)16 (11.1)114/503 (22.7)0.002Psoriasis, n(%)3/143 (2.1)46/719 (6.4)0.043Hip involvement50 (34.7)146 (20.2)0.0001Sacroiliitis46 (31.9)69 (9.6)0.0000001HLA B27, n (%)76/131 (58.0)105/301 (34.8)0.00001ANA, n (%)4/46 (8.7)204/444 (46.0)0.00001RF, n (%)3/141 (2.1)22/403 (5.5)0.104Biologics, primary, n (%)70/144 (48.6)347 (48.0)0.892Time before first biologics, years0.6 (0.3; 1.4)2.6 (1.0; 5.4)0.0000001Disclosure of Interests:None declared

Spondyloarthritis in North Africa: an update.

Spondyloarthritis (SpA) has been less well studied than rheumatoid arthritis in North Africa, due to a belief that it is rare and benign in certain populations. The main genetic trait of SpA is its association with human leukocyte antigen (HLA)-B27. The distribution of this allele largely explains the prevalence and severity of SpA. The prevalence of HLA-B27 in the general population of North Africa is estimated at about 4%, and rises to about 60% among people affected with SpA. Coxitis is one of the main features of North African SpA, but the response to treatment is comparable to the literature from the West. The major challenge in North Africa remains accessibility to specialized care and means of early diagnosis. Prevalent infections in North Africa do not seem to be a major obstacle to optimal treatment strategies.

Do geography and ethnicity play a role in juvenile Spondyloarthritis? A multi-center binational retrospective study

BackgroundObservations among Israeli pediatric rheumatologists reveal that pediatric Juvenile Spondyloarthritis (JSpA) may present differently compared to patients from the United States (US). This study is aimed to compare the demographic and clinical variables of Israeli and US JSpA patients upon presentation.MethodsWe performed a retrospective, cross-sectional, multicenter comparison of JSpA patients among 3 large Israeli pediatric rheumatology centers and a large US pediatric rheumatology center. Patients with diagnosis of Juvenile Ankylosing Spondylitis (JAS) and/or Enthesitis-related Arthritis (ERA) were included. The demographic, clinical and radiologic features were compared.ResultsOverall 87 patients were included (39 Israeli, 48 US patients). Upon presentation, inflammatory back pain, sacroiliac joint tenderness and abnormal modified Schober test, were significantly more prevalent among Israeli patients (59% vs. 35.4, 48.7% vs. 16.7, and 41.2% vs. 21.5%, respectively, all p < 0.05), whereas peripheral arthritis and enthesitis were significantly more prevalent among US patients (43.6% vs. 91.7 and 7.7% vs. 39.6% in Israeli patients vs. US patients, p < 0.05). In addition, 96.7% of the Israeli patients versus 29.7% of the US patients demonstrated sacroiliitis on MRI (p < 0.001, N = 67). Less than one-third of the Israeli patients (32%) were HLA-B27 positive vs. 66.7% of US patients (p = 0.007).ConclusionIsraeli children with JSpA presented almost exclusively with axial disease compared to US patients who were more likely to present with peripheral symptoms. HLA B27 prevalence was significantly lower in the Israeli cohort compared to the US cohort. Further studies are needed to unravel the genetic and possibly environmental factors associated with these findings.

Prevalence of HLA-B27 in Turkish Patients with Ankylosing Spondylitis and Non-radiographic Axial Spondyloarthritis

Prevalence of HLA-B27 in Turkish Patients with Ankylosing Spondylitis and Non-radiographic Axial Spondyloarthritis

Prevalence of Juvenile Idiopathic Arthritis in the Alaska Native Population.

To determine the prevalence and clinical characteristics of juvenile idiopathic arthritis (JIA) in Alaska Native children. Potential cases of JIA were identified by querying administrative data from hospitals and clinics in the Alaska Tribal Health System for codes possibly identifying JIA. Medical record abstraction was performed to confirm criteria met for JIA, demographic and clinical characteristics, and treatment patterns. Individuals age ≤18 years with a confirmed diagnosis of JIA were included. The denominator for prevalence was the 2015 Alaska Area Indian Health Service user population age of ≤18 years. The unadjusted prevalence of JIA in Alaska Native children was 74.6 per 100,000 (age-adjusted 79.0 per 100,000). JIA was more common in females than males (unadjusted prevalence 105.8 versus 45.0 per 100,000). Oligoarthritis was the most common subtype (31% of cases), but polyarthritis and enthesitis-related arthritis were also common (26% and 24% of cases, respectively), with a notably high prevalence of enthesitis-related arthritis. The median age at diagnosis was 9 years. Of the combined cohort with results available, 56% were antinuclear antibody positive, 23% were rheumatoid factor positive, 19% were anti-cyclic citrullinated peptide antibody positive, and 57% had the presence of HLA-B27. Uveitis had been diagnosed in 16% of cases. The prevalence of JIA in Alaska Native children may be higher than the general US population. Enthesitis-related arthritis makes up a higher proportion of cases than in other populations described likely because of the high prevalence of HLA-B27 in this population.

Juvenile idiopathic arthritis in Southeast Asia: the Singapore experience over two decades.

To examine the clinical characteristics, treatment and outcomes of juvenile idiopathic arthritis (JIA) patients evaluated in Singapore and compare those with reports elsewhere. Patients with JIA were recruited from our Singapore pediatric rheumatology registry from January 1997 to December 2015. Demographic, clinical, treatment, and outcome data were retrospectively collected. Nonparametric statistics were used to describe the data. Chi-squared, Mann-Whitney U, or Kruskal-Wallis tests were applied to compare differences between groups where appropriate. Multivariate logistic regression analyses were used to identify predictors for clinical parameters. Two hundred eighty-seven JIA patients with 60.6% males of predominantly Chinese descent were included in the study. The median onset age was 9years (IQR 5.3-12.6), and the median follow-up duration was 30.1months (IQR 9.1-61.7). Enthesitis-related arthritis (ERA, 32.8%) followed by persistent oligoarthritis (31.0%) was the most common. Elbow or ankle involvement predicted oligoarthritis extension (OR 15.8 (95% CI: 2.3-108.3, p = 0.005), 8.1 (95% CI: 1.5-45.3, p = 0.017)). JIA-associated uveitis was rare (2.8%) which paralleled the less common positive-ANA rate. Majority of our ERA patients had HLA-B27 (79.8%), together with older age predicted sacroiliitis (OR 4.7 (95% CI: 2.0-11.1, p < 0.05), OR 1.2 (95% CI: 1.1-1.3, p = 0.002)). TMJ involvement was under-reported. Methotrexate remained the most common DMARD used, but 36% of patients required biologics for which ERA and polyarthritis were the majority. Joint damage was rare. This study highlights geographical and ethnic differences in JIA epidemiology. Compared with reports elsewhere, our JIA population had many unique findings and good functional outcomes requiring regional study validation. Key points • ERA is the most prominent JIA subtype in Singapore with high prevalence of HLA-B27. • JIA-associated uveitis is rare in SEA and is not associated with ANA or JIA-subtypes. • Elbow and/or ankle involvement at presentation is associated with oligoarthritis extension in our JIA cohort.

Added Value of Anti-CD74 Autoantibodies in Axial SpondyloArthritis in a Population With Low HLA-B27 Prevalence.

Axial spondyloarthritis (axSpA) is often diagnosed late due to the non-specific nature of its main symptom [chronic back pain (CBP)] and to the paucity of diagnostic markers, particularly in regions with low HLA-B27 prevalence, such as the Middle-East. We tested the performance of IgG4 and IgA anti-CD74 antibodies as an early diagnostic marker for axSpA, compared with the performance of HLA-B27, in Lebanon. Sera of axSpA patients diagnosed by the rheumatologist and also fulfilling the imaging arm of the ASAS criteria (patients) and of blood donors (BD) (controls) were analyzed for HLA-B27, IgG4 and IgA anti-CD74, blinded to clinical characteristics. Receiver Operating Characteristic curves were constructed to identify an optimal cut-off point for anti-CD74 antibodies. Diagnostic properties were calculated (sensitivity, specificity, positive, and positive predictive values (PPV, NPV), Likelihood ratios) for each marker. Forty-nine axSpA patients and 102 BD were included in the final analysis. IgA anti-CD74 correlated poorly with axSpA (Area Under the Curve (AUC) 0.657), whereas IgG4 anti-CD74 had a good discriminative value (AUC 0.837). Respectively, for HLA-B27, IgG4 anti-CD74, and the combination of both, we found a sensitivity of 33-92-33%, specificity of 96-79-98%, PPV 80-68-89%, NPV 75-95-75%, and LR+ 8.2-4.4-16.5. IgG4 anti-CD 74 were positive in 88% of HLA-B27 negative axSpA patients, and correlated with BASDAI. In this first study in a population with low HLA-B27 prevalence, IgG4 anti-CD74 antibodies combined with HLA-B27 showed higher diagnostic value than HLA-B27 alone for early axSpA. IgG4 anti-CD74 should be considered for further evaluation as an early axSpA diagnostic marker in future dedicated research, particularly in patients with CBP.