Juvenile idiopathic arthritis and future risk for cardiovascular disease: a multicenter study.

OBJECTIVES: To evaluate the frequency of cardiovascular disease (CVD) and CVD risk factor development in adult patients previously diagnosed with juvenile idiopathic arthritis (JIA). METHOD: A cohort study was conducted utilizing patients at two academic institutions (cohorts 1 and 2). Each institution evaluated the common endpoint of CVD outcomes and CVD risk factor development in adults aged ≥ 30 years and at the 29-year follow-up from disease onset in cohorts 1 and 2, respectively, with comparison to control groups of similar age and sex. RESULTS: Cohort 1 included 41 patients with JIA and follow-up ≥ 30 years of age with comparison to 41 controls. Three patients (7%) had CVD, compared to one control (2%; p = 0.31). Cohort 2 included 170 patients with JIA and a median of 29 years of follow-up from disease onset with comparison to 91 controls. Two patients (2%) had CVD, compared to none of the controls (p = 0.29). The presence of CVD risk factors was found to be increased in the JIA group compared to the controls in three categories: family history of CVD (cohort 1), hypertension (cohort 2), and ever smokers (cohorts 2). CONCLUSIONS: There is no increase in CVD events in patients with JIA 29 years following disease onset when compared to the general population. As these cohorts age, it will be informative to evaluate whether this baseline risk remains present or a trend towards increasing CVD emerges. Continued longitudinal follow-up of these cohorts and larger population-based studies are needed to establish a definitive relationship between JIA and CVD.

The association of PTPN22 rs2476601 with juvenile idiopathic arthritis is specific to females.

A preponderance of females develop autoimmune disease, including juvenile idiopathic arthritis (JIA), yet the reason for this bias remains elusive. Evidence suggests that genetic risk of disease may be influenced by sex. PTPN22 rs2476601 is associated with JIA and numerous other autoimmune diseases, and has been reported to show female-specific association with type 1 diabetes. We performed main effect and sex-stratified association analyses to determine whether a sex-specific association exists in JIA. As expected, rs2476601 was associated with JIA in our discovery (413 cases and 690 controls) and replication (1008 cases and 9284 controls) samples. Discovery sample sex-stratified analyses demonstrated an association specifically in females (odds ratio (OR)=2.35, 95% confidence interval (CI)=1.52-3.63, P=0.00011) but not males (OR=0.91, 95% CI=0.52-1.60, P=0.75). This was similarly observed in the replication sample. There was evidence for genotype-by-sex interaction (Pinteraction=0.009). The association between rs2476601 and JIA appears restricted to females, partly accounting for the predominance of females with this disease.

CIITA gene variants are associated with rheumatoid arthritis in Scandinavian populations.

Expression of the major autoimmune risk loci DRB1 and DQB1 is regulated by the class II MHC (major histocompatibility complex) transactivator (CIITA), making the CIITA gene a strong autoimmune risk locus candidate. A CIITA promoter single-nucleotide polymorphism (SNP), rs3087456 (-168 A/G), has indeed been associated with several autoimmune diseases, including rheumatoid arthritis (RA). Recently, an intronic SNP rs8048002 has been suggested as a better susceptibility marker in Addison's disease. Therefore, we tested both SNPs in a panel of autoimmune diseases, consisting of Norwegian patients with RA (n=819), juvenile idiopathic arthritis (JIA; n=524), or type 1 diabetes (T1D; n=1211), and 2149 controls. We also included an independent Swedish RA cohort (n=2503) and controls (n=1416). Both rs3087456 and rs8048002 were significantly associated with RA (combined Norwegian and Swedish patients P(corrected)=0.012 and P(corrected)=0.0016, respectively), but not with JIA or T1D. Meta-analysis of 16 RA cohorts confirmed rs3087456 with only marginal significance (P=0.016). However, results were stronger in the Scandinavian subgroup (4 cohorts, P=3.8 × 10(-4)), indicating a population-dependent effect. A similar pattern was observed in a meta-analysis of rs8048002. Our results support involvement of CIITA in RA, but imply that this is population dependent and that the aetiological variant is yet to be discovered.

Craniofacial growth disturbance is related to temporomandibular joint abnormality in patients with juvenile idiopathic arthritis, but normal facial profile was also found at the 27-year follow-up.

OBJECTIVES: To assess the long-term outcome of craniofacial morphology related to disease variables and temporomandibular joint (TMJ) involvement as demonstrated with computed tomography (CT) and magnetic resonance imaging (MRI) in adult patients with juvenile idiopathic arthritis (JIA). METHODS: Sixty of 103 patients participated in a re-examination on average 27 years after baseline. Craniofacial morphology, with emphasis on size and position of the mandible, was assessed in lateral cephalographic images and related to disease variables and TMJ involvement by CT and MRI. Definitions of craniofacial growth disturbances were based on measurements outside 2 SD from the mean of healthy adult controls. RESULTS: Sagittal craniofacial growth disturbances were found in 57% and micrognathia in 27% of the 60 patients. Of those with JIA TMJ involvement, 70% had some form of growth disturbance. Micrognathia occurred only in patients with bilateral TMJ involvement. The bilateral TMJ group had significantly different craniofacial morphology than healthy controls and patients without TMJ involvement. Growth disturbances and TMJ involvement were present in all subtypes of JIA, except for one subtype comprising one patient. Patients with growth disturbances had more severe disease than patients with normal craniofacial growth, regarding both present and previous disease activity. Unexpectedly, half of the patients without craniofacial growth disturbances also had TMJ involvement, many from before the age of 12. CONCLUSIONS: Craniofacial growth disturbances were found to be frequent in adult JIA patients, especially in those with bilateral TMJ involvement. However, growth disturbances did not always follow TMJ involvement, not even when affected early.

Self-rated physical and psychosocial health in a cohort of young adults with juvenile idiopathic arthritis.

OBJECTIVE: To explore self-rated physical and psychosocial health in a cohort of young adults with juvenile idiopathic arthritis (JIA) 18.3 years after symptom onset, make comparisons with population-based data, and illuminate possible predictors of self-rated health. METHODS: Of a baseline cohort of 84 patients with JIA, 55 (65.5%) answered the self-administered questionnaires of the Health Assessment Questionnaire (HAQ), the Visual Analogue Scale (VAS) of pain, fatigue, and illness, the Medical Outcomes Study 36-item Short Form Health Survey (SF-36), and the General Health Questionnaire (GHQ-30). Telephone interviews were conducted with 51/55 patients. Population-based norm-data of SF-36 were used for comparison. RESULTS: Significantly impaired physical health but no difference in psychosocial health was found as compared to the general Norwegian population. The level of education was significantly higher whereas no difference was found in employment status as compared to norm-data. Pain was a significant correlate of the education level. Predictors of physical impairment were physical disability and pain, whereas psychiatric distress and female sex were predictors of mental ill-health. CONCLUSION: Physical disability does not seem to have a negative influence on the patients' functioning psychosocially.

Relationship between disease course in the temporomandibular joints and mandibular growth rotation in patients with juvenile idiopathic arthritis followed from childhood to adulthood.

OBJECTIVE: To investigate the relationship between radiographic JIA disease course in the TMJs and mandibular growth rotation, compared with growth in healthy individuals. METHODS: From a larger series of JIA patients followed from childhood to adulthood, 26 were included; 11 without and 15 with bilateral radiographic TMJ involvement. Joint morphology and function were assessed at baseline, 2-, 4-, 6- and 27 years follow-up. Mandibular growth rotation (anterior, posterior or none) was assessed from cephalometric evaluations at childhood and adulthood, with observations from 16 healthy individuals as controls. TMJ disease course and mandibular growth rotation were assessed independently and their relationship analysed. Non-parametric statistical methods were applied to test differences between groups. RESULTS: In the normal TMJ group of JIA patients the joint morphology was similar at the follow-ups and all patients had good function both in childhood and in adulthood. The mandibular growth rotation was similar to that of healthy controls, i.e. predominantly in anterior direction. In the abnormal TMJ group different JIA TMJ disease courses were observed and associated with changes in the mandibular growth rotation (p = 0.007).Progressing JIA TMJ disease course was related to posterior mandibular growth rotation and improving disease course to anterior mandibular growth rotation. CONCLUSION: A relationship was found between JIA disease course in the TMJs and mandibular growth rotation, suggesting that a favourable growth could be regained in patients with improvement in TMJ morphology and/or TMJ function. To confirm this, further research on larger patient series is needed.

The efficacy of rehabilitation for patients with rheumatoid arthritis: comparison between a 4-week rehabilitation programme in a warm and cold climate.

OBJECTIVES: To investigate the long-term effect (week 16) of a 4-week rehabilitation programme for patients with rheumatoid arthritis (RA) and to compare the effect of this intervention given in a Mediterranean or a Norwegian climate. METHODS: A randomized, controlled, parallel group design, where 124 RA patients applying for rehabilitation were randomized to a rehabilitation programme either in Norway or in a Mediterranean climate. The participants were examined clinically immediately before (week 0) and after (week 4) the rehabilitation period as well as in week 16 and answered a mailed questionnaire in week 28. The 28-Joint Disease Activity Score (DAS28), American College of Rheumatology (ACR) response and physical tests were used to measure clinical response. RESULTS: The baseline DAS28 value 4.45 (1.16) was reduced by -0.95 (1.05) in the Mediterranean climate and the baseline DAS28 value 4.18 (1.17) was reduced by -0.37 (0.92) in the Norwegian climate at week 16 (p = 0.003). An ACR20 improvement was achieved in 25% of the patients treated in the Mediterranean climate and in 15% of those treated in the Norwegian climate. Sustained improvement in all ACR core components at week 16 and in patient's assessment of health status at week 28 was found in the patients treated in the Mediterranean climate only. Tests of physical function, the 6-Minute Walk Test (6MWT) and the Timed Up and Go (TUG), showed comparable improvements in patients treated in both climates. CONCLUSIONS: RA patients showed immediate positive effects with regard to disease activity, physical function, and symptoms during a 4-week rehabilitation programme. The effects on disease activity and symptoms were larger and better maintained at least 3 months after rehabilitation in a warm rather than in a cold climate.

A longitudinal follow-up study of physical and psychosocial health in young adults with chronic childhood arthritis.

OBJECTIVE: The aim was to describe physical and psychosocial health status in a second follow-up of a cohort of patients with chronic childhood arthritis, to compare results from the present study with the first follow-up, and to explore the course of physical and psychosocial functioning from baseline. METHODS: At a median of 18.3 years after symptom onset 55 patients answered the self-administered questionnaires Health Assessment Questionnaire Disability Index (HAQ-DI), Visual Analogue Scales (VAS) of pain, fatigue and illness, and General Health Questionnaire (GHQ) 30-item version. Results from the current study were compared to first follow-up median 8.7 years after symptom onset, and the course of physical and psychosocial function from baseline was discussed. RESULTS: At second follow-up, 38% reported HAQ-DI above 0 indicating physical disability, 22% had a GHQ-30 score in the clinical range indicating psychiatric distress, and fatigue seemed to be an overarching aspect of the health status. Pain was an important correlate of physical disability at first and second follow-up. At second follow-up psychiatric distress was a significant correlate of pain and fatigue, indicating a relation to disease severity. The association between psychosocial functioning and chronic family difficulties observed at first follow-up is not evident at second follow-up. CONCLUSIONS: The favourable physical and psychosocial outcome reported at first follow-up seems to persist. However, arthritis-related ill-health is still evident in a considerable proportion of the patients, indicating a constant impact of the disease on every-day life of the individual.

Recent-onset childhood arthritis--association with Streptococcus pyogenes in a population-based study.

OBJECTIVES: To assess the frequency of Streptococcus pyogenes in children with early arthritis, compare the characteristics in patients with post-streptococcal ReA (PSReA) with those in patients with other types of arthritis, and describe the occurrence of carditis in PSRA. PATIENTS: In a population-based Norwegian study, the physicians were asked to refer all children with suspected arthritis. The arthritis patients were followed up at 6 weeks, 6 months and 18 months. The presence of S. pyogenes was based on throat smear or antibodies. Echocardiography was performed in the patients with ARF or PSRA. RESULTS: Thirty-two (18%) of the 173 children with arthritis tested positive for S. pyogenes. The percentage of positive tests rose steadily with age and peaked at ages 8-11 (35%). Six weeks after admission arthritis was present in 33% of the PSRA patients, which was less frequent than in the juvenile idiopathic arthritis (JIA) patients (P < 0.001), but more frequent than in the transient arthritis patients (P = 0.012). Hip arthritis was more frequent and knee/ankle arthritis, ANA and HLA-B27 were less frequent in PSRA than in JIA (P < 0.001, P = 0.009 and P = 0.029, respectively). The PSRA patients were older than those with transient arthritis (P = 0.007). One child with ARF had carditis. CONCLUSIONS: Streptococcus pyogenes was present in 18% of children with arthritis. The patient characteristics, clinical presentation and early disease course in PSRA was different from that of JIA and transient arthritis.

The FCRL3 -169T>C polymorphism is associated with rheumatoid arthritis and shows suggestive evidence of involvement with juvenile idiopathic arthritis in a Scandinavian panel of autoimmune diseases.

BACKGROUND AND OBJECTIVES: The Fc receptor-like 3 (FCRL3) gene -169T>C single nucleotide polymorphism (SNP) has been reported to be associated with several autoimmune diseases (AIDs) in Japanese populations. However, association results in other populations have been conflicting. Therefore, we investigated this SNP in a Scandinavian panel of AIDs. METHODS: We genotyped patients with rheumatoid arthritis (RA; n = 708), juvenile idiopathic arthritis (JIA; n = 524), systemic lupus erythaematosus (SLE; n = 166), ulcerative colitis (UC; n = 335), primary sclerosing cholangitis (PSC; n = 365), Crohn disease (CD; n = 149), a healthy control group (n = 1030) and 425 trio families with type 1 diabetes (T1D). Statistical analysis consisted of case-control and family-based association tests. RESULTS: RA was associated with the C allele (odds ratio (OR) = 1.16, 95% CI 1.01 to 1.33) and the CC genotype (OR = 1.30, 95% CI 1.01 to 1.67) of the FCRL3 -169T>C SNP in our material. Suggestive evidence for association was also found for JIA (CC genotype: OR = 1.30, 95% CI 0.99 to 1.70), and clinical subgroup analysis indicated that this was connected to the polyarticular subgroup. No significant association was found with SLE, UC, CD, PSC or T1D. In patients with RA, we found no significant interaction between the FCRL3 -169T>C and PTPN22 1858C>T SNPs, nor between the FCRL3 -169CC genotype and IgM-rheumatoid factor or anti-cyclic citrullinated peptide titre levels. CONCLUSION: We found an association between the FCRL3 -169T>C SNP and RA, and suggestive evidence for involvement with JIA, in a Norwegian population. These findings lend support for a role for this SNP in RA across ethnically diverse populations, and warrant follow-up studies in JIA.

Health-related quality of life of patients with juvenile idiopathic arthritis coming from 3 different geographic areas. The PRINTO multinational quality of life cohort study.

OBJECTIVES: To compare health-related quality of life (HRQL) and to identify clinical determinants for poor HRQL of patients with juvenile idiopathic arthritis (JIA) coming from three geographic areas. METHODS: The HRQL was assessed through the Child Health Questionnaire (CHQ). A total of 30 countries were included grouped in three geographic areas: 16 countries in Western Europe; 10 in Eastern Europe; and four in Latin America. Potential determinants of poor HRQL included demographic data, physician's and parent's global assessments, measures of joint inflammation, disability as measured by Childhood Health Assessment Questionnaire (CHAQ) and erythrocyte sedimentation rate. Poor HRQL was defined as a CHQ physical summary score (PhS) or psychosocial summary score (PsS) <2 S.D. from that of healthy children. RESULTS: A total of 3167 patients with JIA, younger than 18 yrs, were included in this study. The most affected health concepts (<2 S.D. from healthy children) that differentiate the three geographic areas include physical functioning, bodily pain/discomfort, global health, general health perception, change in health with respect to the previous year, self-esteem and family cohesion. Determinants for poor HRQL were similar across geographic areas with physical well-being mostly affected by the level of disability while the psychosocial well-being by the intensity of pain. CONCLUSION: We found that patients with JIA have a significant impairment of their HRQL compared with healthy peers, particularly in the physical domain. Disability and pain are the most important determinants of physical and psychosocial well-being irrespective of the geographic area of origin.

Disease duration, hypertension and medication requirements are associated with organ damage in childhood-onset systemic lupus erythematosus.

OBJECTIVE: To investigate the frequency of organ damage in childhood-onset systemic lupus erythematosus (SLE) and to identify disease variables and patient characteristics related to organ damage. METHODS: A cohort of 71 patients was examined in a cross-sectional study after a mean disease duration of 10.8+/-8.2 years (mean age 26.4+/-9.8 years). The occurrence of organ damage was measured by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Factors analysed as possible explanatory variables of organ damage were the following: demographic variables, clinical variables at diagnosis and during disease course, as well as medication use. Growth and self-reported health status were also measured. RESULTS: The most frequent areas of organ damage were in the neuropsychiatric (28%), renal (13%) and musculoskeletal (13%) organ systems. Forty-three patients (61%) had evidence of damage. The mean SDI score was 1.3 for the whole study population. Hypertension, longer disease duration and use of cyclophosphamide were factors significantly related to an increasing SDI score in multiple linear regression analyses. Furthermore, patients with damage (SDI > or =1) compared to those without damage (SDI = 0) had a significantly higher cumulative corticosteroid dose (24.7 g versus 10.6 g) and more frequently required high-dose prednisolone at diagnosis (68% versus 43%). CONCLUSION: Evidence of organ damage was found in 61% of all patients. Long disease duration, known hypertension and use of cylophosphamide were significantly associated with an increasing SDI score. Furthermore high-dose prednisolone at diagnosis and cumulative prednisolone dose were significantly related to the presence of organ damage.

PRINTO/PRES international website for families of children with rheumatic diseases: www.pediatric-rheumatology.printo.it.

OBJECTIVE: To prepare a website for families and health professionals containing up to date information about paediatric rheumatic diseases (PRD). METHODS: Firstly, paediatric rheumatology centres and family self help associations were surveyed to characterise current clinical practice of physicians providing care for children with PRD, research activities, and training facilities of each centre. Secondly, international consensus was reached on the content of the website. Finally, the website was developed and the texts translated. RESULTS: The web page contains three main sections: (a) description for families of the characteristics of 15 PRD; (b) list of paediatric rheumatology centres; (c) contact information for family self help associations. A version for 45 countries in 52 languages (with another three in progress) is now available on the web. 291 surveys from 171 centres and 102 family associations were received from 42 countries. The median proportion of time spent in paediatric practice in the centres examined was 100%, with 70% of this time dedicated to paediatric rheumatology. 90% of the centres were willing to perform clinical trials in the future. CONCLUSIONS: The PRINTO/PRES website provides a well defined and competent set of information about PRD, with appropriate multiple translated versions and easy web navigational direction.

Genetic association between juvenile rheumatoid arthritis and polymorphism in the SH2D2A gene.

T-cell-specific adapter protein (TSAd) involved in the negative control of T-cell activation is encoded by the SH2D2A gene. Our recent studies indicate that homozygosity for short (ie GA(13) and GA(16)) alleles of the SH2D2A gene promoter is associated with development of multiple sclerosis. To study whether the same SH2D2A promoter polymorphism also contributes to the genetic susceptibility to develop juvenile rheumatoid arthritis (JRA), we examined 210 JRA patients and 558 healthy unrelated controls from Norway. The frequency of the short allele GA(13) was increased among the JRA patients compared to control (0.098 vs 0.05; P(n=8)=0.042). There was a significant increased frequency of HLA-DRB1(*)08-positive patients carrying two copies of 'short' alleles GA(13) and/or GA(16) compared to healthy controls (16% vs 6%; P(n=4)=0.016). Our data indicate that the 'short' alleles of the SH2D2A promoter could contribute to the genetic susceptibility to JRA.

Juvenile idiopathic arthritis (JIA) is primarily associated with HLA-DR8 but not DQ4 on the DR8-DQ4 haplotype.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is strongly associated with the DR8-DQ4 haplotype. The genes encoding DR8 and DQ4 are in strong linkage disequilibrium (LD) and occur together on the same HLA haplotype in almost all patients and controls. Because of the strong LD it is not clear whether DR8, DQ4, or both, are primarily associated with JIA. OBJECTIVE: To unveil the primary association of JIA--that is, with DR8 or DQ4. METHODS: DRB1, DQA1, and DQB1 alleles of 585 Norwegian and 47 Polish unrelated patients with JIA (categorised as pauciarticular and rheumatoid factor negative polyarticular JIA), and of 3155 Norwegian and 158 Polish unrelated controls, were typed using a polymerase chain reaction or oligonucleotide hybridisation and sequence-specific primers method. RESULTS: Several haplotypes which encoded DR8 (that is, carried DRB1*08) and which did not encode DQ4 (that is, did not carry DQA1*0401) were found. Such haplotypes were found in three Norwegian patients and two controls (p=0.029). In the Polish population such haplotypes were found among four patients with JIA and two controls (p=0.025). No haplotypes which carried DQA1*0401 and DQB1*0402 in the absence of DRB1*08 were found, either among patients with JIA (Polish and Norwegian) or among the controls (Polish). CONCLUSION: On the DR8-DQ4 haplotype the DRB1*08 allele is primarily associated with JIA.

The Norwegian version of the Childhood Health Assessment Questionnaire (CHAQ) and the Child Health Questionnaire (CHQ).

We report herein the results of the cross-cultural adaptation and validation into the Norwegian language of the parent's version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children independently from the underlying disease. The Norwegian CHAQ and CHQ have already been published and therefore they were fully revalidated in this study. A total of 148 subjects were enrolled: 88 patients with JIA (6% systemic onset, 45% polyarticular onset, 10% extended oligoarticular subtype, and 39% persistent oligoarticular subtype) and 60 healthy children. The CHAQ clinically discriminated between patients with various JIA subtypes, with the systemic, polyarticular and extended oligoarticular subtypes having a higher degree of disability, pain, and a lower overall well-being when compared to those with persistent oligoarticular arthritis. Also the CHQ clinically discriminated between healthy subjects and JIA patients, with the systemic onset, polyarticular onset and extended oligoarticular subtypes having a lower physical and psychosocial well-being when compared to their healthy peers. In conclusion the Norwegian version of the CHAQ-CHQ is a reliable, and valid tool for the functional, physical and psychosocial assessment of children with JIA.

Young adults with juvenile arthritis in remission attain normal peak bone mass at the lumbar spine and forearm.

OBJECTIVE: To assess the impact of disease activity on acquired peak bone mass and bone turnover in young adult patients with either persistent juvenile arthritis (JA) or a history of JA (JA in remission). METHODS: Two hundred twenty-nine patients with JA were studied after a mean +/- SD of 15.6 +/- 2.4 years in women and 14.9 +/- 2.1 years in men since disease onset. One hundred forty-five women and 84 men were over the age of 20 at the time of examination (mean +/- SD age 24.9 +/- 2.9 years for women and 25.2 +/- 3.1 years for men). Forty-one healthy women (mean +/- SD age 27.4 +/- 3.1 years) and 55 healthy men (mean +/- SD age 25.7 +/- 3.1 years) served as a reference group. Bone mineral density (BMD) was analyzed by dual x-ray absorptiometry. Serum osteocalcin concentrations and urinary concentrations of deoxypyridium (D-Pyd) were measured. Linear regression analyses were performed to evaluate the impact of disease on BMD. RESULTS: Patients with persistent disease had significantly lower BMD compared with healthy subjects (P < 0.001 for women at all measured sites and for men at the femoral neck and total body; P < 0.05 for men at the radius and lumbar spine). Of the patients with a history of JA, only women had significantly lower BMD at the femoral neck and total body (P < 0.05). Patients with persistent JA had significantly more osteopenia and osteoporosis than healthy subjects, while patients with a history of JA had more frequent osteopenia only in the total body. Weight, urinary concentration of D-Pyd, and belonging to the patient group significantly affected BMD at all measured sites in the entire study population, while analysis of all patients found that only the number of months taking corticosteroids significantly affected BMD at all measured sites. However, the impact of the variables differed from site to site. CONCLUSION: Our findings imply that most young adults with JA attain the same BMD as healthy subjects if the disease goes into remission, while young adults with active disease have increased risk for osteopenia and osteoporosis.

[Classification of idiopathic juvenile arthritis]. / Klassifisering av idiopatiske juvenile artritter.

We present a review of the criteria for the classification of juvenile arthritides. Historical aspects, the present situation and proposals for new criteria are outlined. The most commonly used classification criteria today are the European juvenile chronic arthritis criteria (JCA), the European League Against Rheumatism (EULAR) criteria, and the American juvenile rheumatoid arthritis (JRA), the American Rheumatoid Association (ARA) criteria. They differ in nomenclature and have different inclusion and exclusion demands. This has made it difficult to compare studies using different criteria. Neither of them can define homogeneous subgroups of disease. The most recent proposal for new classification criteria of juvenile arthritides is that of the International League Against Rheumatism, ILAR. They are primarily designed to define homogeneous subgroups of disease. The goal is also to obtain an international consensus. Advantages and disadvantages are discussed in this article. The criteria have not yet been validated, and should not be used by clinicians until they have been approved by the international scientific society. We also present guidelines recommended for the classification of juvenile arthritis in Norway today. We recommend using the term juvenile arthritis. Disease duration of arthritis must be at least six weeks. A diagnosis of arthritis should not be made on painful and restricted joint movement alone, as is the case in both the EULAR and ARA criteria today, but at least be based on definite swelling of joints verified by either clinical examination and/or by imaging techniques such as ultrasound, X-ray or EMR.