Incidence of juvenile idiopathic arthritis in children in Estonia: a prospective population-based study

Disease characteristics of HLA-B27 positive and negative finnish patients with juvenile idiopathic arthritis - results of the 18-year cohort follow-up study

BACKGROUND

The aim of this long-term follow-up study was to compare the disease characteristics of HLA-B27 positive and negative patients with juvenile idiopathic arthritis (JIA).

METHODS

The study is a cohort study with consecutive cases of newly diagnosed Finnish patients with JIA according to the International League of Associations for Rheumatology (ILAR) criteria [1]. Patients were enrolled between 1997 and 2000 from a defined area of Southern Finland. Clinical data including disease activity and serology were registered during a mean period of 17.5 years.

RESULTS

159 patients completed the 18-year follow-up study. HLA-B27 was available for 151 patients, of which 25% were HLA-B27 positive. Chronic uveitis was diagnosed in 30% of HLA-B27 positive and 29% of HLA-B27 negative patients. HLA-B27 positive patients had a lower prevalence of temporomandibular (TMJ) involvement than the antigen negative ones, 19% versus 28%. None of the HLA-B27 positive patients had cervical spine affected compared to 11% of antigen negative patients (p = 0.022). Of the HLA-B27 positive patients, 54% had had biological medication at some point during follow-up versus 25% in the negative group (p = 0.003). At last follow-up, 32% of antigen positive patients were not in remission compared to 18% of the antigen negative (p = 0.017).

CONCLUSIONS

The use of biological medication was more common in HLA-B27 positive patients with JIA. At the 18-year follow-up, more antigen positive patients had active disease compared HLA-B27 negative patients. This real-world follow-up study indicates that the prospects for worse outcome with HLA-B27 positivity in long-term should be taken into consideration.

Systemic Juvenile Idiopathic Arthritis and Secondary Macrophage Activation Syndrome in Latvia from 2009 to 2020: A Nationwide Retrospective Study

Background and Objectives: Systemic juvenile idiopathic arthritis (sJIA) is a distinctive JIA subtype with mostly nonspecific systemic clinical features, which can be a diagnostic challenge. This study aimed to analyze our experience with sJIA in Latvia for twelve years: assessing clinical and epidemiological characteristics, the efficacy of therapy, and disease outcomes, including the development of macrophage activation syndrome (MAS). Materials and methods: This is a descriptive study in which we conducted a retrospective case review of all patients with sJIA diagnosis admitted to the only pediatric tertiary centre in Latvia during the period 2009-2020. Results: sJIA was diagnosed in 35 patients with a mean annual incidence rate of 0.85 patients per 100,000 children. Major clinical signs at the first visit were: fever, rash, arthritis, and lymphadenopathy. Almost half of the patients, 48.5%, had a monocyclic disease course, and only 20% of patients had persistent disease. MAS developed in 28.6% of patients. Biological therapy was administered to 48.6% of patients, mostly by tocilizumab, which induced remission in 75% after one year, and in 81.2% after two years without any serious therapy-related complications. In our study, none of the patients had interstitial lung disease, drug reaction with eosinophilia and systemic symptoms (DRESS)-like syndrome, or fatal disease. Conclusions: The incidence and clinical characteristics of sJIA correlate with the literature findings, although MAS was more common than described in other studies. There is a tendency for the persistent disease to decrease with the use of biological therapy. Tocilizumab is an efficient choice of treatment with a good safety profile.

Antibiotic exposures and the development of pediatric autoimmune diseases: a register-based case-control study

BACKGROUND

Antibiotics have been associated with several individual autoimmune diseases (ADs). This study aims to discover whether pre-diagnostic antibiotics are associated with the onset of ADs in general.

METHODS

From a cohort of 11,407 children, 242 developed ADs (type 1 diabetes, autoimmune thyroiditis, juvenile idiopathic arthritis (JIA), or inflammatory bowel diseases) by a median age of 16 years. Antibiotic purchases from birth until the date of diagnosis (or respective date in the matched controls n = 708) were traced from national registers.

RESULTS

Total number of antibiotic purchases was not related to the onset of ADs when studied as a group. Of specific diagnoses, JIA was associated with the total number of antibiotics throughout the childhood and with broad-spectrum antibiotics before the age of 3 years. Intriguingly, recent and frequent antibiotic use (within 2 years before diagnosis and ≥3 purchases) was associated with the onset of ADs (OR 1.72, 95% CI 1.08-2.74). Regardless of frequent use in childhood (40% of all antibiotics), penicillin group antibiotics were not related to any ADs.

CONCLUSIONS

Use of antibiotics was relatively safe regarding the overall development of ADs. However, broad-spectrum antibiotics should be used considerately as they may associate with an increased likelihood of JIA.

IMPACT

Increasing numbers of antibiotic purchases before the age of 3 years or throughout childhood were not associated with the development of pediatric autoimmune diseases. Broad-spectrum antibiotics were related to the development of autoimmune diseases, especially juvenile idiopathic arthritis in children, while penicillin group antibiotics were not. The use of broad-spectrum antibiotics in children should be cautious as they may carry along a risk for autoimmune disease development.

An Economic Comparison of Treatment Strategies with Anakinra in Systemic Juvenile Idiopathic Arthritis (sJIA)

Introduction

Systemic juvenile idiopathic arthritis (sJIA) is a rare, complex autoinflammatory disease with substantial morbidity, often characterized by fever, rash, and muscle pain, amongst other symptoms. Biologic agents, such as anakinra, have been successfully used to treat patients internationally, but their usage in some regions is limited to patients that have failed to achieve clinically inactive disease with corticosteroids and conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs). Use of anakinra early in the disease course leads to better clinical outcomes; however, longer-term costs for this treatment strategy have not been established. This study compares the economic implications of first-line versus later-line availability of anakinra for patients with sJIA.

Methods

Data for patients treated with first-line anakinra were identified from a single-center, prospective study and compared to a combination of published trial and economic evaluation information to facilitate a comparison to later-line anakinra (ie, following corticosteroids + csDMARDs). Costs were estimated for product acquisition and medical resource utilization (MRU), including planned outpatient visits and unplanned hospital admissions. Total costs over a 5-year horizon were compared.

Results

Total 5-year product acquisition cost for the first-line anakinra strategy was €24,021, and for later-line anakinra was €20,471. The corresponding MRU costs were €19,197 (first-line) versus €25,425 (later-line). Overall 5-year costs (product acquisition and MRU) were lower for the first-line strategy (€43,218 versus €45,896).

Conclusion

The use of anakinra for patients with sJIA in the first-line setting is efficacious to induce and sustain inactive disease, and the findings of this study show that this treatment strategy leads to cost savings through reduced medical expenditure.

Uveitis in Juvenile Idiopathic Arthritis: 18-Year Outcome in the Population-based Nordic Cohort Study

PURPOSE

To assess the long-term outcome of uveitis in juvenile idiopathic arthritis (JIA).

DESIGN

Population-based, multicenter, prospective JIA cohort, with a cross-sectional assessment of JIA-associated uveitis (JIA-U) 18 years after the onset of JIA.

PARTICIPANTS

A total of 434 patients with JIA, of whom 96 had uveitis, from defined geographic areas of Denmark, Finland, Norway, and Sweden.

METHODS

Patients with onset of JIA between January 1997 and June 2000 were prospectively followed for 18 years. Pediatric rheumatologists and ophthalmologists collected clinical and laboratory data.

MAIN OUTCOME MEASURES

Cumulative incidence of uveitis and clinical characteristics, JIA and uveitis disease activity, ocular complications, visual outcome, and risk factors associated with the development of uveitis-related complications.

RESULTS

Uveitis developed in 96 (22.1%) of 434 patients with JIA. In 12 patients (2.8%), uveitis was diagnosed between 8 and 18 years of follow-up. Systemic immunosuppressive medication was more common among patients with uveitis (47/96 [49.0%]) compared with patients without uveitis (78/338 [23.1%]). Active uveitis was present in 19 of 78 patients (24.4%) at the 18-year visit. Ocular complications occurred in 31 of 80 patients (38.8%). Short duration between the onset of JIA and the diagnosis of uveitis was a risk factor for developing ocular complications (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.8). Patients with a diagnosis of uveitis before the onset of JIA all developed cataract and had an OR for development of glaucoma of 31.5 (95% CI, 3.6-274). Presence of antinuclear antibodies (ANAs) was also a risk factor for developing 1 or more ocular complications (OR, 3.0; 95% CI, 1.2-7.7). Decreased visual acuity (VA) <6/12 was found in 12 of 135 eyes (8.9%) with uveitis, and 4 of 80 patients (5.0%) with JIA-U had binocular decreased VA <6/12.

CONCLUSIONS

Our results suggest that uveitis screening should start immediately when the diagnosis of JIA is suspected or confirmed and be continued for more than 8 years after the diagnosis of JIA. Timely systemic immunosuppressive treatment in patients with a high risk of developing ocular complications must be considered early in the disease course to gain rapid control of ocular inflammation.

Low Serum IGF-1 in Boys with Recent Onset of Juvenile Idiopathic Arthritis

Background

Liver-derived insulin-like growth factor-1 (IGF-1) contributes bone formation. Decreased IGF-1 levels are common in juvenile idiopathic arthritis (JIA), but whether IGF-1 is related to sex and differ during the pathogenic progress of JIA is unknown.

Objective

The aim of this study was to examine IGF-1 levels in boys and girls with newly diagnosed JIA, with established JIA and in controls.

Methods

The study group included 131 patients from the Estonian population-based prevalence JIA study. Blood samples were obtained from 27 boys and 38 girls with early JIA (≤1 month from the diagnosis), 29 boys and 36 girls with established JIA (mean disease duration 18 months), and from 47 age- and sex-matched controls.

Results

IGF-1 levels in boys were significantly decreased in early JIA compared to male controls, while IGF-1 levels in girls were comparable between JIA and controls. In early JIA, IGF-1 levels were 12-fold lower in boys relative to girls. In controls, IGF-1 levels correlated with both age and height, while these correlations were lost in boys with early JIA.

Conclusion

We report a sex-dependent deficiency in serum IGF-1 in boys with early JIA, which argues for sex-related differences in biological mechanisms involved in the disease pathogenesis.

Epidemiology and risk of juvenile idiopathic arthritis among children with allergic diseases: a nationwide population-based study

BACKGROUND

Epidemiological research reveals that the incidence of allergic diseases and that of autoimmune diseases have been increasing in parallel, raising an interest in a potential link between the two disorders. However, the relationship between Th2-mediated allergic disease and Th1-mediated juvenile idiopathic arthritis (JIA) remains unclear. This population-based case-control study was aimed at investigating the development of childhood-onset allergic diseases and the subsequent risks of JIA.

METHODS

We included 329 children with JIA diagnosed between 2000 and 2008, and 1316 age- and sex-matched controls. The odds ratios of developing JIA were calculated to determine an association with preexisting allergic diseases.

RESULTS

The incidence rate of JIA in Taiwan between 2000 and 2008 was 1.33 cases per 100,000 children/year according to the International League of Associations for Rheumatology (ILAR) criteria. The children with a single allergic disease had an increased risk of JIA, with adjusted odds ratios of developing JIA of 1.44 for allergic conjunctivitis (95 % confidence interval [CI], 1.07-1.95), 1.50 for allergic rhinitis (1.15-1.96), and 1.44 for asthma (1.00-2.10). The adjusted odds ratios increased with the number of concurrent allergic diseases from 1.50 (95 % CI, 1.12-2.01) for those with only one allergic disease to 1.72 (1.24-2.38) for those with at least two allergic diseases. The adjusted odds ratios of those with at least two allergic diseases increased to 1.84 (95 % CI, 1.19-2.86) for boys and 2.54 (1.42-4.54) for those older than 12 years. The children who made two or more medical visits for associated allergic diseases per year had an increased risk of JIA.

CONCLUSION

Children with onset of allergic diseases were at increased risk of developing JIA. The increased risk was associated with the cumulative effect of concurrent allergic diseases and frequency of seeking medical care. Further study to investigate the role of Th2-mediated allergic diseases that contribute to the development of Th1-mediated JIA is warranted.

Fever as an initial manifestation of enthesitis-related arthritis subtype of juvenile idiopathic arthritis: retrospective study

Objective

We wished to determine the prevalence of fever as one of the first symptoms of the enthesitis-related arthritis (ERA) subtype of juvenile idiopathic arthritis. Also, we wished to ascertain if ERA patients with fever at disease onset differed from those without fever.

Methods

Consecutive cases of ERA were diagnosed and followed in a retrospective observational study from 1998 to 2013. Information about clinical/laboratory data, medications, magnetic resonance imaging (MRI), and disease activity during the study period was also recorded.

Results

A total of 146 consecutive ERA patients were assessed. Among them, 52 patients (35.6%) had fever as one of the first symptoms at disease onset. Compared with ERA patients without fever at disease onset, patients with fever had significantly more painful joints (3.5 vs. 2.8), more swollen joints (1.1 vs. 0.8), and more enthesitis (1.0 vs. 0.4) (p<0.05 for all comparisons). Patients with fever had significantly higher mean values of erythrocyte sedimentation rate, C-reactive protein, platelet count, and child health assessment questionnaire (CHAQ) scores (40.8 vs. 26.4 mm/h; 20.7 vs. 9.7 mg/dL; 353.2×10⁹/L vs. 275.6×109/L; 1.0 vs. 0.8, respectively; all p<0.05). During two-year follow-up, CHAQ score, number of flares, as well as the number of patients treated with oral non-steroidal anti-inflammatory drugs, corticosteroids and combination therapy with disease-modifying anti-rheumatic drugs, were significantly higher in ERA patients with fever.

Conclusions

Fever was a frequent manifestation of ERA. ERA patients with fever had more active disease at disease onset and poorer outcomes than ERA patients without fever.

Prevalence of juvenile idiopathic arthritis in children aged 6 to 12 years in Embu das Artes, state of Sao Paulo, Brazil

The aim of the study was to study the prevalence of juvenile idiopathic arthritis (JIA) in school children in the city of Embu das Artes in São Paulo State. 2880 school children from seven public schools, aged between 6 and 12 years, were evaluated (clinical findings) by a pediatric rheumatologist. A board certified Pediatric Rheumatologist evaluated the subjects with suspected inflammatory arthropathy. Children with higher suspicion were referred to a specialized service. One hundred and forty-one children have presented abnormalities on examination of musculoskeletal system, with isolated pain on palpation the most common finding in the first evaluation (60.9%), with improvement in almost all cases in the second examination. Most of the abnormalities were related to recent injuries or congenital malformations. Six children have clinical findings suggestive of chronic arthropathy and were referred to a specialized pediatric rheumatology clinic. Of these, a 12 year-old girl fulfilled the criteria for JIA. The other diagnoses were aseptic necrosis of the hip (P = 1) of and post-trauma synovitis (P = 4). The prevalence of JIA in children aged between 6 and 12 years was 1/2.880 (or 0.34/1.000).

Prevalence of HLA-B27 antigen in patients with juvenile idiopathic arthritis

Introduction

Human leukocyte antigen B27 (HLA-B27) is considered as a risk factor for development of juvenile idiopathic arthritis (JIA).

The aim of this study was to analyse the prevalence of HLA-B27 antigen in JIA categories and its influence on disease onset and response to conventional therapy.

Material and methods

The retrospective analysis included 461 unselected children with JIA hospitalized in a single reference rheumatology centre between July 2007 and June 2012. The diagnosis was based on criteria by the International League of Association for Rheumatology. HLA-B27 was determined in 387 of all patients (84%) by hybridization of the amplified, labelled product to immobilize it on the microarray probe.

Results

HLA-B27 antigen was found in 104 of 383 affected children (27.2%), 48 of 206 girls (23.3%), and 56 of 177 boys (31.6%) – most frequently in patients with enthesitis-related arthritis (71%), psoriatic arthritis (50%) and unclassified cases (86.7%). The age of JIA onset was slightly (by 1 year) but significantly different in patients with and without HLA-B27 antigen [11 (8.5–14) vs. 10 (5–13.5) years.; p < 0.001].

The use of disease-modifying antirheumatic drugs (DMARDs) and corticosteroids was more frequently clinically ineffective in HLA-B27 positive than negative patients (23.1% vs. 15.2%; p = 0.09). Patients with polyarthritis, systemic, and psoriatic arthritis more frequently received biological therapy. HLA-B27 positive patients with enthesitis-related arthritis received biological therapy more frequently than HLA-B27 negative ones (20.4% vs. 0, respectively; p = 0.09).

Conclusions

HLA-B27 antigen is a strong risk factor for the development of enthesitis-related arthritis, and to a lesser extent for psoriatic arthritis and extended course of oligoarthritis. The presence of this antigen does not affect the disease onset but seems to predict resistance to therapy with disease-modifying drugs and corticosteroids.

Polyarticular juvenile idiopathic arthritis - epidemiology and management approaches

Juvenile idiopathic arthritis (JIA) is a group of disorders characterized by arthritis persisting for at least 6 weeks with onset before the age of 16 years. Within this cluster of conditions, the polyarticular form (involving more than four joints within the first 6 months) is further divided based on the presence of rheumatoid factor. Children with polyarticular JIA pose unique diagnostic and therapeutic challenges compared to children with involvement of fewer joints. Polyarticular JIA patients tend to have a more refractory course and therefore are at increased risk for joint damage, resulting in poorer functional outcomes and decreased quality of life. Although the ability to treat this disorder continues to improve, especially with the advent of biologic agents, there is still much about the epidemiology and pathogenesis of polyarticular JIA that is unknown. The epidemiology of polyarticular JIA varies worldwide with a vast difference in reported cases between different global regions as well as within individual countries. Several genetic risk loci have been identified conferring increased susceptibility to JIA, many within the human leukocyte antigen region. Beyond the genome, environmental factors also seem to contribute to the etiology of polyarticular JIA. This review article will focus on the epidemiology and current treatments of polyarticular JIA and briefly discuss genetic and environmental influences on the pathogenesis of JIA as well as new and emerging therapies.

Analysis of Clinical Symptoms and Laboratory Profiles in Children with Juvenile Idiopathic Arthritis in Malopolska Region (Poland) in the Years 2007-2010

Background: Juvenile idiopathic arthritis (JIA) is a heterogenic group of chronic inflammatory connective tissue diseases of unknown aetiology in children up to 16 years of age.Aim: The aim of this study was to analyse the incidence, clinical presentation and laboratory findings in children with JIA in Malopolska region.Materials and methods: A retrospective analysis included all children with JIA (N=251) hospitalized in the two reference rheumatology centres covering Malopolska region (Poland), between July 2007 and December 2010.Results: The annual incidence of JIA in Malopolska region was estimated at 9.5 per 100 000 children. Oligoarthritis (54.9%) was the most common category in all age groups with a tendency to decrease with age; from 71.4 % in children aged 1-6 years; 55.7% in aged 7-12 years to 39.3 % in aged 13-16 years. The frequency of polyarthritis and enthesitis-related arthritis was greater in adolescents (29.2 % and 22.5 %, respectively). HLA-B27 antigen and uveitis were most frequently found in children with enthesitis-related arthritis (58% and 18.5 %, respectively).Conclusions: The study suggests the improvement of diagnostic capacity of JIA during the last decade in Poland. In accordance with the existing data diverse clinical presentation of JIA categories and laboratory characteristics were proven.

The role of gender in juvenile idiopathic arthritis-associated uveitis

Uveitis is a common complication of juvenile idiopathic arthritis (JIA) affecting up to 30% of patients with JIA. Although the typical bilateral chronic anterior uveitis associated with the persistent and extended oligoarticular and polyarticular, rheumatoid factor negative variants of JIA occurs predominantly in girls, boys may be more commonly affected in the HLA-B27 positive, enthesitis variant of JIA. While female gender has been associated with the development of the chronic anterior uveitis in children with JIA, the clinical course of JIA-associated uveitis may be worse in boys than in girls. The purpose of this paper is to review the available published literature to determine the role of gender in the clinical presentation and outcomes of patients with JIA-associated uveitis.

Prevalence and incidence of juvenile idiopathic arthritis: a systematic review

OBJECTIVES

To conduct a systematic literature review on incidence and prevalence of juvenile idiopathic arthritis and to estimate these figures in Europe for 2010.

METHODS

Articles on incidence or prevalence of juvenile idiopathic arthritis were searched in Medline. Pooled incidence and prevalence were calculated overall, by gender, age, classification and arthritis categories. We used the available age and gender pooled rates to standardize the incidence and prevalence on the 2010 European population and estimate the number of cases in Europe in 2010.

RESULTS

Forty-three articles (33 on incidence, 29 on prevalence) were included. Incidence rates varied from 1.6 to 23 and prevalence from 3.8 to 400/100,000. Pooled incidence and prevalence were higher for girls (10.0 [9.4-10.7] and 19.4 [18.3-20.6]/100,000) than boys (5.7 [5.3-6.2] and 11.0 [10.2-11.9]/100,000). Oligoarthritis was the most frequent form (pooled incidence rate 3.7 [3.5-3.9] and prevalence 16.8 [15.9-17.7]/100,000). The direct standardized incidence rate was 8.2 [7.5-9.0] and prevalence 70.2 [62.9-78.1]/100,000. In Europe in 2010, the estimated number of incident cases was 6896 [5481-8578] and 59,175 [44,256-76,983] prevalent cases.

CONCLUSIONS

Incidence and prevalence varied greatly among published reports of juvenile idiopathic arthritis, which may be explained by methodological issues, classification used, and time. Estimating the number of affected children can be useful, especially with the new treatment possibilities.

Juvenile idiopathic arthritis-associated uveitis: a nationwide population-based study in Taiwan

OBJECTIVE

The incidence and prevalence of juvenile idiopathic arthritis (JIA) vary widely across the world but data in East Asia is lacking. Uveitis is a serious cause of morbidity in JIA. This study aimed to analyze the incidence and prevalence of JIA, and the characteristics of JIA-associated uveitis in Taiwan.

METHODS

A population-based cohort study was conducted using the Taiwan National Health Insurance Research Database. Each patient was individually tracked from 1999 to 2009 to identify the diagnosis of JIA and uveitis using the International Classification of Diseases diagnostic codes. Multivariate logistic regression was used to determine the risk factors and complications of uveitis in patients with JIA.

RESULTS

The study cohort had 2636 cases of JIA and included juvenile rheumatoid arthritis (57.7%), enthesitis-related arthritis (ERA) (39.2%), and psoriatic arthritis (3.1%). The average annual incidence of JIA and JIA-associated uveitis were 4.93 (range, 3.93-6.23) and 0.25 (range, 0.12-0.37) cases per 100,000 population, respectively. The average period prevalence of JIA was 33.8 cases per 100,000 population. Uveitis occurred in 4.7% of patients with JIA, while JIA-associated uveitis was complicated by cataract (11.2%) and glaucoma (24.8%). Enthesitis-related arthritis was significantly associated with uveitis (OR: 3.47; 95% CI: 2.24-5.37) (p<0.0001). Uveitis diagnosed before JIA was the most significant risk factor for complications of glaucoma or cataract (OR: 3.54; 95% CI: 1.44-8.72) (p = 0.006).

CONCLUSIONS

The incidence of JIA is low but that of JIA-associated uveitis is increasing. Higher percentage of males in patients with ERA and the strong association between ERA and uveitis are unique for children with JIA in Taiwan. Uveitis diagnosed before arthritis is an important risk factor for complications. Continuous ophthalmologic follow-up is needed for children with JIA or uveitis of unknown etiology.

Incidence and prevalence of juvenile idiopathic arthritis among children in a managed care population, 1996-2009

OBJECTIVE

Few studies based in well-defined North American populations have examined the occurrence of juvenile idiopathic arthritis (JIA), and none has been based in an ethnically diverse population. We used computerized healthcare information from the Kaiser Permanente Northern California membership to validate JIA diagnoses and estimate the incidence and prevalence of the disease in this well-characterized population.

METHODS

We identified children aged ≤ 15 years with ≥ 1 relevant International Classification of Diseases, 9th edition, diagnosis code of 696.0, 714, or 720 in computerized clinical encounter data during 1996-2009. In a random sample, we then reviewed the medical records to confirm the diagnosis and diagnosis date and to identify the best-performing case-finding algorithms. Finally, we used the case-finding algorithms to estimate the incidence rate and point prevalence of JIA.

RESULTS

A diagnosis of JIA was confirmed in 69% of individuals with at least 1 relevant code. Forty-five percent were newly diagnosed during the study period. The age- and sex-standardized incidence rate of JIA per 100,000 person-years was 11.9 (95% CI 10.9-12.9). It was 16.4 (95% CI 14.6-18.1) in girls and 7.7 (95% CI 6.5-8.9) in boys. The peak incidence rate occurred in children aged 11-15 years. The prevalence of JIA per 100,000 persons was 44.7 (95% CI 39.1-50.2) on December 31, 2009.

CONCLUSION

The incidence rate of JIA observed in the Kaiser Permanente population, 1996-2009, was similar to that reported in Rochester, Minnesota, USA, but 2 to 3 times higher than Canadian estimates.

HLA-B27 predicts a more chronic disease course in an 8-year followup cohort of patients with juvenile idiopathic arthritis

OBJECTIVE

We investigated associations of HLA-B27 with clinical manifestations and longterm outcome in a near population-based setting among patients with juvenile idiopathic arthritis (JIA).

METHODS

We studied clinical and serological data from 410 patients with HLA-B27 results among 440 prospectively collected patients with JIA with 8-year followup data in a Nordic database. The study was structured to be as close to a population-based study as possible.

RESULTS

HLA-B27 was analyzed in 93% of patients, and was positive in 21% of the cohort, in 18.4% of the girls and in 25.9% of the boys. Boys who were HLA-B27-positive had significantly higher age at onset compared to HLA-B27-negative boys and compared to both HLA-B27-negative and positive girls. This difference in onset age in relation to HLA-B27 was not found in girls. HLA-B27 was associated with clinical signs of sacroiliitis, enthesitis, and tenosynovitis in boys, but not in girls. After 8 years of disease, 46 children (11.2%) were classified as having enthesitis-related arthritis (ERA). Boys with ERA had clinical signs of sacroiliitis more often than girls with ERA. HLA-B27-positive children, as well as children with clinical signs of sacroiliitis, enthesitis, and hip arthritis, had higher odds of not being in remission off medication after 8 years of disease.

CONCLUSION

In this near population-based Nordic JIA cohort we found significant differences between HLA-B27-positive boys and girls in age at disease onset, clinical signs of sacroiliitis, and ERA classification. HLA-B27 was negatively associated with longterm remission status, possibly because of its association with clinical disease characteristics, such as sacroiliitis, rather than being a general marker of persistent disease.

Clinical features of children with juvenile idiopathic arthritis using the ILAR classification criteria: a community-based cohort study in Taiwan

BACKGROUND/PURPOSE

The aim of the study was to describe the clinical features of children affected by juvenile idiopathic arthritis (JIA) under the International League of Associations for Rheumatology-derived classification criteria in a community-based setting.

METHODS

Consecutive cases of JIA from defined geographic areas of Taiwan were diagnosed and followed in an observational cohort from 1995 to 2010. In addition to the clinical and laboratory data required for the International League of Associations for Rheumatology system, information about the medication and disease activity during the study period was also recorded.

RESULTS

Out of 292 children with chronic joint pain, 195 were diagnosed as JIA: systemic arthritis (19%), oligoarthritis (persistent 16.4%; extended 6.7%), polyarthritis rheumatoid factor-negative (11.8%), polyarthritis rheumatoid factor-positive (4.6%), psoriatic arthritis (1.5%), enthesitis-related arthritis (ERA; 37.4%), and undifferentiated arthritis (2.6%). Human leukocyte antigen-B27 was positive in 82.2% of patients with ERA. Uveitis was observed in 6.7% of patients. Disease-modifying anti-rheumatic drugs, including biologic medications, were used in 73.3% of children during the observational period. At the last follow-up, 40% of patients experienced a continuously active or relapsing course.

CONCLUSION

Compared with previous reports on Western populations, a remarkably high prevalence was found in the ERA of the Chinese cohort, but a relatively low rate of uveitis. Ongoing disease activity was evident in a substantial number of children. These results provided a good starting point in understanding the epidemiology of this serious disease in the Chinese population.

Systemic arthritis in children: a review of clinical presentation and treatment

Systemic juvenile idiopathic arthritis (sJIA) constitutes a small part of juvenile idiopathic arthritis (JIA), yet has a disproportionally higher rate of mortality. Despite being grouped under JIA, it is considered to be a multifactorial autoinflammatory disease. The objective of this paper is to review the epidemiology, pathogenesis, genetics, clinical manifestations, complications, therapy, prognosis, and outcome of sJIA. The presentation and clinical manifestations of sJIA have not changed much in the past several decades, but the collective understanding of the pathogenesis and the development of new targeted therapies (particularly the biologic agents) have transformed and improved the disease outcome for children with sJIA.

Simultaneous Juvenile Idiopathic Arthritis and Diabetes Mellitus Type 1 — A Finnish Nationwide Study

Objective.

To describe the occurrence and main clinical and laboratory findings of patients having both juvenile idiopathic arthritis (JIA) and diabetes mellitus type 1 (DM-1) in a period of 30 years.

Methods.

Eighty-two patients having simultaneous JIA and DM-1 were identified in the reimbursement registers of the Finnish National Institute of Insurance during the period 1976–2005. Data on their clinical histories were collected from patient files.

Results.

Occurrence of simultaneous JIA and DM-1 increased 4.5-fold between the first (1976-85) and the last (1996–2005) decade. Prevalence of uveitis was 7%, of rheumatoid factor seropositivity 15%; 22% of patients had a third autoimmune disease [autoimmune disease (AID)], and 16% had serious psychiatric problems.

Conclusion.

The occurrence of patients with the 2 diseases, JIA and DM-1, increased over 3 decades. The prevalence of uveitis was low, the number of seropositive patients was high, and further cases of AID were frequent. Patients had multiple additional problems necessitating multiprofessional care.

HLA B27 allele types in homogeneous groups of juvenile idiopathic arthritis patients in Latvia

Juvenile idiopathic arthritis (JIA) is a heterogeneous condition and therapeutic strategies vary in different JIA types. The routinely accepted practice to start with Sulphasalazine (SS) as the first line treatment in patients with HLA B27 positive JIA proves to be ineffective in a large proportion of children.

OBJECTIVE

to investigate HLA B27 positive JIA patients clinical characteristics, determined HLA B27 allele types and their connection with antirheumatic treatment in homogenous patient groups.

MATERIALS AND METHODS

56 patients diagnosed with JIA and observed over the period 2006 to 2009 included in the study. HLAB27 allele types were determined using PCR method.

RESULTS

In HLA B27 positive JIA patients mean disease onset was 12.34 ± 3.3 years. Most common (44%) JIA type was enthesitis related arthritis. Positive response to the treatment with SS was found in 32% of patients, Methotrexate (MTX) - in 43%, combined treatment - SS with MTX was effective in 12.5%. 12.5% of patients required combination MTX with Enbrel.Eight HLA B27 allele types were found in JIA patients in Latvia: *2702, *2703, *2704, *2705, *2710, *2715, *2717, *2728. The most common was *2705 - in 55% of cases. Among all the patients enthesitis related arthritis most commonly occurred in patients with HLAB*2705 allele (OR = 2.01, p < 0.02), oligoarthritis in patients with *2710 allele (OR = 3.0, p < 0.04) and polyarthritis with *2717 allele (OR = 3.0, p < 0.05). In patients with *2705 allele effective treatment was MTX (OR = 1.13, p < 0.03) and MTX with SS (OR = 2.02, p < 0.05), but in patients having *2703 allele - MTX with Enbrel (OR = 2.94, p < 0.02).

CONCLUSIONS

There are 8 different HLA B27 alleles in JIA patients in Latvia and the most common is *2705, but in order to assert them to be disease associated alleles, more extensive studies are needed, including control group of HLA B27 positive healthy individuals. Standard treatment approach with SS proves to be unsatisfactory in the majority of JIA patients. To improve children's quality of life achieving rapid disease control, the first line treatment in HLA B27 positive patients should be MTX. In order to start with the most appropriate drug it is necessary to determine HLAB 27 type at the onset of disease.

Incidence and prevalence of juvenile idiopathic arthritis in Catalonia (Spain)

OBJECTIVE

To ascertain the incidence and prevalence of juvenile idiopathic arthritis (JIA) in Catalonia (autonomous region in northeast Spain), examined according to the currently established disease subtypes.

METHODS

Before initiating the study, we conducted an educational programme on paediatric rheumatology, addressed to all general paediatricians in Catalonia. A 2-year (2004-2006), prospective, population-based study was then carried out to determine the incidence of JIA. Prospective and retrospective data retrieval was performed to calculate prevalence. The International League of Associations for Rheumatology (ILAR, Edmonton revision) classification criteria were applied.

RESULTS

Over the study period, 145 new cases of JIA were diagnosed. The mean annual incidence was 6.9/10⁵ children aged less than 16 years (range 5.8-8.1 years; 9.0 years for girls and 4.8 years for boys). On separate analysis of patients ≤ 6 and > 6 years, the distribution in younger children was found to be similar for both girls and boys, whereas in older children, most girls belonged to the oligoarthritis and polyarthritis subgroups, and boys to the enthesitis-related arthritis and undifferentiated subgroups. The calculated prevalence of JIA (31 October 2006) was 39.7 (36.1-43.7)/10⁵ children younger than 16. The relative risk of girls having JIA was 2.1 [95% confidence interval (CI) 1.7-2.7, p < 0.001]. In 70% of patients, the diagnosis was established before the age of 7. Subgroup distribution of prevalent cases mirrored that of incident cases.

CONCLUSION

This is the first population-based study on the epidemiology of JIA in Catalonia. Incidence and prevalence rates are lower than those reported for several areas in Nordic countries of Europe. Oligoarthritis was the most common subtype.

The incidence of juvenile rheumatoid arthritis in Quebec: a population data-based study

OBJECTIVE

To determine the population incidence of juvenile rheumatoid arthritis (JRA) in Quebec.

METHODS

We obtained data from Quebec's physician claims database. Incident cases were defined as having a visit for JRA in 2000, no visit in the previous 3 years, a confirmed diagnosis by an arthritis specialist, or having >/= 2 visits to any physician for JRA, >/= 2 months apart but within 2 years.

RESULTS

Cumulative incidence of JRA was 17.8/100,000. Mean age at diagnosis was 9.8 +/- 4.6 years, 68% were female and more persons were diagnosed in winter. Subjects had a median of 10 medical visits over the first year.

CONCLUSION

Our population based incidence estimate was similar to others. Children and adolescents with JRA are heavy users of medical care. Additional study of environmental or climate- related triggers may be warranted.