Rheumatoid Arthritis: Nielsen S

Ruperto N, Ravelli A, Castell E, Gerloni V, Haefner R, Malattia C, Kanakoudi-Tsakalidou F, Nielsen S, Bohnsack J, Gibbas D, Rennebohm R, Voygioyka O, Balogh Z, Lepore L, Macejkova E, Wulffraat N, Oliveira S, Russo R, Buoncompagni A, Hilário MO, Alpigiani MG, Passo M, Lovell DJ, Merino R, Martini A, Giannini EH, Anonymous00431, Anonymous00432. · IRCCS G. Gaslini, Pediatria II-Reumatologia, PRINTO, Genova, Italy. · Clin Exp Rheumatol. · Pubmed #17181934 No free full text.

Abstract: OBJECTIVE: To investigate the clinical use patterns, clinical effect and safety of cyclosporine A (CSA) in juvenile idiopathic arthritis (JIA) in the setting of routine clinical care. METHODS: An open-ended, phase IV post marketing surveillance study was conducted among members of the Pediatric Rheumatology Collaborative Study Group (PRCSG) and of the Paediatric Rheumatology International Trials Organisation (PRINTO) to identify patients with polyarticular course JIA who had received CSA during the course of their disease. RESULTS: A total of 329 patients, half of whom had systemic JIA, were collected in 21 countries. Data were collected during 1240 routine clinic visits. CSA was started at a mean of 5.8 years after disease onset and was given at a mean dose of 3.4 mg/kg/day. The drug was administered in combination with MTX in 61% and along with prednisone in 65% of the patients who were still receiving CSA. Among patients who were still receiving CSA therapy at the last reported visit, remission was documented in 9% of the patients, whereas in 61% of the patients the disease activity was rated as moderate or severe. The most frequent reason for discontinuation of CSA was insufficient therapeutic effect (61% of the patients); only 10% of the patients stopped CSA because of remission. In 17% of the patients, side effects of therapy was given as the primary reason for discontinuation. CONCLUSION: This survey suggests that CSA may have a less favourable efficacy profile than MTX and etanercept, whereas the frequency of side effects may be similar. The exact place of CSA in the treatment of JIA can only be established via controlled clinical trial.

Gudbrandsdottir S, Larsen R, Sørensen LK, Nielsen S, Hansen MB, Svenson M, Bendtzen K, Müller K. · Paediatric Department, Institute of Inflammation Research, Rigshospitalet, Copenhagen, Denmark. · Clin Exp Rheumatol. · Pubmed #15005015 No free full text.

Abstract: BACKGROUND: Etanercept (Enbrel) induces a rapid and sustained decline in disease activity in the majority of patients with refractory juvenile idiopathic arthritis (JIA). For unknown reasons, however, a number of JIA patients fail to respond to this therapy. During this treatment neutralisation of tumour necrosis factor (TNF, previously termed TNF alpha) and lymphotoxin (LT, previously termed TNF beta) may be mediated by etanercept itself as well as by naturally occurring soluble TNF receptors. In light of this, it was of interest to study the total TNF neutralizing capacity in plasma before and during treatment with etanercept. RESULTS: In initial experiments plasma samples from healthy individuals were incubated with etanercept, and spiked with TNF or LT to a final concentration of 1000 pg/mL. Detection of TNF and LT by ELISA was found to be reduced by approximately 50% and 80% respectively, at a concentration of etanercept of 5-500 ng/mL, which is close to the pharmacological plasma concentrations. Plasma samples (n = 80) were then collected from 12 JIA patients (5 with pauciarticular, 5 with polyarticular and 2 with the systemic onset type) during treatment with etanercept (0.4 mg/kg twice weekly) for a period of 20.8 (15.6-23.9) months (median, range). The plasma samples were spiked with LT, and the inhibition of LT detection in ELISA was measured. In samples obtained 3 months after the start of etanercept, the inhibition of LT detection was augmented [72% (60-85)] compared with pre-treatment samples [16% (0.32)] (p = 0.0039). These findings were confirmed in binding assays using radiolabelled TNF. Among patients who responded insufficiently to therapy, reduced LT binding capacity, coinciding with flares of disease activity, was observed. CONCLUSION: We have developed an assay by which LT binding capacity, reflecting the level of free, pharmacologically active etanercept, may be monitored in the blood of patients treated with etanercept. This assay may prove to be useful in guiding dose adjustments in patients with an incomplete response to etanercept.

Kristensen K, Nielsen S, Karup Pedersen F, Zak M. · Paediatric Clinic 2, the Juliane Marie Centre, the National University Hospital Rigshospitalet, Copenhagen, Denmark. · Scand J Rheumatol. · Pubmed #10898073 No free full text.

Abstract: The concentration of methotrexate (MTX) in erythrocytes (E-MTX) was measured twice with three months interval in 21 children suffering from juvenile chronic arthritis (JCA). At the same time joint score, visual analogue scale (VAS), and laboratory parameters (CRP, WBC, PMNs, and ALAT) were obtained. There was only a weak insignificant correlation between the dose of MTX/m2 and E-MTX (r=0.24, p=0.11). No significant relations between the clinical or laboratory parameters and E-MTX was found. However, ALAT above normal range was associated with a lower dose of MTX (p=0.02) and lower VAS (p=0.02), indicating that toxicity may be associated with less articular discomfort. At present we consider routine determination of E-MTX in children with JCA of limited value.

Nielsen S, Ruperto N, Gerloni V, Simonini G, Cortis E, Lepore L, Alpigiani MG, Zulian F, Corona F, Alessio M, Barcellona R, Gallizzi R, Rossi F, Magni-Manzoni S, Lombardini G, Filocamo G, Raschetti R, Martini A, Ravelli A, Anonymous00024. · Istituto di Ricovero e Cura a Carattere Scientifico G. Gaslini, Genova, Italy. · Clin Exp Rheumatol. · Pubmed #18799107 No free full text.

Abstract: OBJECTIVE: To investigate the rate of radiographic progression, as measured with the carpo-metacarpal ratio (Poznanski score), during etanercept (ETN) therapy in children with polyarticular juvenile idiopathic arthritis (JIA). METHODS: Patients included in the Italian ETN registry who had a standard radiograph of both hands and wrists in the posteroanterior view made at start of treatment and after 1 year were included in the study. The clinical response was assessed by means of the ACR Pediatric definition of improvement. Radiographic progression was determined by calculating the change in the Poznanski score between the baseline and the 1-year radiographs. RESULTS: A total of 40 patients were studied. The frequency of ACR pediatric 30, 50, and 70 response at 1 year was 77%, 72%, and 50%, respectively. The median change in the Poznanski score between baseline and 1 year was + 0.3 units, meaning that, on average, patients experienced improvement in radiographic progression. CONCLUSION: Our pilot study provides evidence that ETN is potentially capable of reducing the progression of radiographic joint damage in JIA. This finding deserves confirmation in a controlled trial.

Berntson L, Damgård M, Andersson-Gäre B, Herlin T, Nielsen S, Nordal E, Rygg M, Zak M, Fasth A, Anonymous00028. · Department of Women's and Children's Health, Uppsala University Children's Hospital, Uppsala, Sweden. · J Rheumatol. · Pubmed #18785306 No free full text.

Abstract: OBJECTIVE: Juvenile idiopathic arthritis (JIA) is a heterogeneous condition with very few clinical and laboratory signs that can help predict the course and severity of the disease in the individual patient. The cell-surface antigen HLA-B27 is well known to be associated with spondyloarthropathies, reactive arthritis, and enthesitis. HLA-B27 plays an important role in the classification of JIA, since evidence of sacroiliitis most often evolves after years of arthritis in other joints. We investigated the associations of HLA-B27 and the clinical manifestations of JIA using a method as close to a population-based study as possible. METHODS: We studied an incidence-based cohort of 305 patients collected prospectively in 3 Nordic countries (Sweden, Norway, Denmark). Clinical and serological data of the first 3 years of the disease were collected. RESULTS: HLA-B27 was found to be positive in 25.5% of the patients, and we found a higher proportion of HLA-B27-positive boys with older age at disease onset (p=0.034). Regression analysis showed a correlation of 0.7 in the HLA-B27-positive boys, pointing to a higher risk of more joint involvement with older age at disease onset. By Fisher's exact test, involvement of small joints in the lower extremities was associated with HLA-B27 in boys (p=0.011), but not in girls (p=0.687). HLA-B27 was associated with inflammatory back pain in both sexes (p=0.041 in boys, p=0.042 in girls), but with enthesitis only in boys (p<0.001 in boys, p=0.708 in girls). CONCLUSION: HLA-B27 is of increasing importance with older age at disease onset in boys with JIA, predicting more active joints within the first 3 years of disease, and also involving small joints in the lower extremity to a greater degree than in HLA-B27-negative boys. During the first 3 years of disease the occurrence of HLA-B27 is associated with inflammatory back pain in both sexes, but with enthesitis only in boys. Our data present new challenges for the ILAR classification of JIA.

Berntson L, Wernroth L, Fasth A, Aalto K, Herlin T, Nielsen S, Nordal E, Rygg M, Zak M. · Department of Women's and Children's Health, Uppsala University Children's Hospital, Uppsala, Sweden. · J Rheumatol. · Pubmed #17896798 No free full text.

Abstract: OBJECTIVE: Variables for assessment of disease activity of juvenile idiopathic arthritis (JIA) were studied, in order to develop a disease activity score for children with JIA. METHODS: One randomly chosen hospital visit was studied for each of 312 patients with JIA, with regard to disease activity variables. The physician global assessment score visual analog scale (physician GA) was used as a dependent variable in comparisons between potential disease activity variables. Previous studies have shown this variable to be the most sensitive to changes in JIA disease activity and to be comparable between patients. RESULTS: Based on Spearman's rank order correlation the number of active joints had a strong association with the physician GA. The median physician GA score rose markedly for each active large joint, but less for small joints, although small joints were also statistically important in assessing disease activity. Among the laboratory data, the erythrocyte sedimentation rate, C-reactive protein level, and platelet count showed weak correlations to the physician GA. CONCLUSION: In preparation of a disease activity score for children with JIA the importance of both the number and size of joints involved needs further evaluation.

Foeldvari I, Nielsen S, Kümmerle-Deschner J, Espada G, Horneff G, Bica B, Olivieri AN, Wierk A, Saurenmann RK. · Department of Pediatric Rheumatology, Hamburger Zentrum für Kinder und Jugendrheumatologie, Klinikum Eilbek, Hamburg, Germany. · J Rheumatol. · Pubmed #17343318 No free full text.

Abstract: OBJECTIVE: Uveitis occurs in 10%-15% of patients with juvenile idiopathic arthritis (JIA). If topical treatment fails, second-line agents are used to control the disease. However, some patients need the addition of tumor necrosis factor-alpha (TNF-alpha) antagonist (anti-TNF). We organized a cross-sectional cohort to investigate use and efficacy of anti-TNF treatment in patients with JIA-associated uveitis. METHODS: The international pediatric rheumatology community was queried about the use and efficacy of anti-TNF in treatment of JIA-associated uveitis using an E-mail survey. RESULTS: Of the 33 responding centers following 884 patients with uveitis, only 15 centers, following 404 patients, were using anti-TNF for this indication. A total of 47 patients with JIA-related uveitis treated with anti-TNF because of an insufficient response to previous therapy were reported. The mean age of the patients was 12.5 years. The mean duration from onset of uveitis to start of anti-TNF treatment was 45.1 months. Three different anti-TNF agents were used: etanercept in 34 cases, infliximab in 25 cases, and adalimumab in 3 cases. In 12 of the 34 patients etanercept was inefficacious and patients were switched to infliximab. The final response was rated according to a composite index as 53%/12%/32%, and according to physician rating as 47%/12%/38% representing good, moderate, and poor, respectively, in the etanercept group; and 70%/30%/0% and 68%/24%/0% in the infliximab group. All 3 patients taking adalimumab were responders. Infliximab was statistically significantly more efficacious for the treatment of JIA-associated uveitis than etanercept (chi-square p = 0.004). CONCLUSION: Anti-TNF seems to be an effective treatment for refractory JIA-associated uveitis. In this cohort infliximab was more efficacious than etanercept.

Gutiérrez-Suárez R, Pistorio A, Cespedes Cruz A, Norambuena X, Flato B, Rumba I, Harjacek M, Nielsen S, Susic G, Mihaylova D, Huemer C, Melo-Gomes J, Andersson-Gare B, Balogh Z, De Cunto C, Vesely R, Pagava K, Romicka AM, Burgos-Vargas R, Martini A, Ruperto N, Anonymous00034. · IRCCS G. Gaslini, Università di Genova, Pediatria II - Reumatologia, Largo Gaslini, 5 16147 Genova, Italy. · Rheumatology (Oxford). · Pubmed #16877459 links to  free full text

Abstract: 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.

Ring T, Kallenbach M, Praetorius J, Nielsen S, Melgaard B. · Department of Nephrology, Aalborg Hospital, Hobrovej 18-22, 9100, Aalborg, Denmark. · Clin Rheumatol. · Pubmed #16283417 No free full text.

Abstract: We report the course of a 55-year-old woman, the first patient with primary Sjögren's syndrome and distal renal tubular acidosis but without lymphoma to be treated with B-cell depletion using Rituximab. Rapidly after B-cell depletion, remarkable improvement in xerostomia occurred, while serological findings and tubular acidosis have been unchanged. In labial salivary gland biopsy, lymphocyte infiltration and particularly CD20-positive cells decreased strikingly. Aquaporin 1 (AQP-1) expression in myoepithelial cells was very low before treatment and increased noticeably. Apical AQP-5 in acinus cells likewise increased following Rituximab. In contrast, basolateral NKCC1 was expressed at unchanged intensity before and following Rituximab. The improvement has been sustained and still is most gratifying 10 months after treatment. B-cell depletion may be effective treatment in Sjögren's syndrome. Likewise, it may now be possible to separate the immunologic phenomena in Sjögren's syndrome from the consequences of prolonged hyposalivation when studying the pathophysiology of xerostomia.

Bjørnhart B, Svenningsen P, Gudbrandsdottir S, Zak M, Nielsen S, Bendtzen K, Müller K. · Institute for Inflammation Research, Rigshospitalet National University Hospital, Copenhagen, Denmark. · Int Immunopharmacol. · Pubmed #15589462 No free full text.

Abstract: INTRODUCTION: Tumour necrosis factor (TNF)-alpha and TNF-beta, also called lymphotoxin (LT), are bound by soluble truncated TNF receptors (sTNFRI and II) that are released from cell surfaces and act as natural inhibitors of TNF-induced inflammation. We investigated the plasma levels of sTNFRI and II in parallel with LT binding capacity (LTBC) in 44 patients with juvenile chronic arthritis (JIA). METHODS: LTBC was determined by spiking diluted plasma samples with 1000 pg/ml of human recombinant LT. Detectable LT was measured by an in-house ELISA and LTBC was expressed in arbitrary units (AU) as the percentage value of bound LT to added LT. The levels of sTNFRI and-II were measured by ELISA (R&D). RESULTS: We found slightly reduced sTNFRI and II levels in JIA patients (n=44) compared with healthy controls sTNFRI: 1118 pg/ml (656-2074) [mean (range)] vs. 1262 pg/ml (819-2280) p=0.015; sTNFRII: 1953 pg/ml (889-4476) vs. 2311 pg/ml (1309-4186) p=0.008. The sTNFRI levels correlated positively with morning stiffness (r=0.30, p=0.044), physician's global assessment (r=0.39; p=0.009) and CRP (r=0.43; p=0.0048). sTNFRII did not correlate with measures of disease activity. In contrast, patient LTBC values were elevated compared to controls: 44 AU (36-52) vs. 31 AU (13-41) [mean (range)], p<0.0001, but did not correlate with disease activity. CONCLUSION: Despite overall slightly reduced plasma levels of sTNFRI and II, the capacity to bind TNF appeared to be increased in plasma samples from JIA patients.

Berntson L, Andersson Gäre B, Fasth A, Herlin T, Kristinsson J, Lahdenne P, Marhaug G, Nielsen S, Pelkonen P, Rygg M, Anonymous00387. · Department of Pediatrics, Falun Hospital, SE-791 82 Falun, Sweden. · J Rheumatol. · Pubmed #14528529 No free full text.

Abstract: OBJECTIVE: To find the incidence of juvenile arthritis according to the ILAR and EULAR criteria within defined areas in the Nordic countries, and to study the validity of the ILAR and EULAR criteria from this perspective. METHOD: A longitudinal, prospective, population based study with patients enrolled according to the ILAR and EULAR criteria. Twenty doctors in Iceland, Norway, Sweden, Denmark, and Finland collected data from the incidence cases within their catchment areas over a period of 1.5 years, beginning July 1, 1997. Clinical and serological data from the first year of the disease were collected. RESULTS: In the whole group of 315 patients, the incidence rate was 15 per 100,000 children/year (95% CI 13-17) according to the ILAR criteria, varying from 7 (1-13) in Iceland, 19 (7-31) and 23 (10-36) from 2 different regions in Norway, and 9 (5-12) and 16 (9-23) from 2 different areas in Denmark, to 15 (12-18) in Sweden and 21/100,000/year (15-26) in the Helsinki region in Finland. An early peak in distribution for age of onset was found in girls but not in boys. The number of antinuclear antibody (ANA) positive children in the whole group, made up of children who had undergone at least one analyzed ANA test, was 123/315 (39%). Girls were ANA positive in 83/197 (42%) and boys in 40/118 (34%). Uveitis developed in 27/315 (8.6%) children during the first 6 months of the disease. CONCLUSION: Incidence rates of juvenile arthritis for areas within the Nordic countries were in accord with previous data. The ILAR criteria present slightly higher incidence rates, with a shorter disease duration for inclusion, compared to the EULAR criteria. Patients in one subgroup in either of the criteria sets do not necessarily belong to the expected subgroup in the other set of criteria; e.g., for juvenile ankylosing spondylitis (EULAR) and enthesitis related arthritis (ILAR). Our epidemiological findings are a reminder to be aware of possible new subgroups in children with juvenile arthritis.

Berntson L, Fasth A, Andersson-Gäre B, Herlin T, Kristinsson J, Lahdenne P, Marhaug G, Nielsen S, Pelkonen P, Rygg M. · Department of Pediatrics, Falun Hospital and Göteborg University, Göteborgm, Sweden. · J Rheumatol. · Pubmed #12415608 No free full text.

Abstract: OBJECTIVE: To evaluate how heredity for psoriasis influences classification according to the International League of Associations for Rheumatology (ILAR). Heredity for psoriasis is currently both an exclusion and an inclusion criterion for different types of childhood arthritis according to ILAR classification criteria. METHODS: Twenty physicians in 5 Nordic countries prospectively collected data from the incident cases in their catchment areas over an 18 month period beginning July 1, 1997. Clinical and serological data from the first year of disease were collected. RESULTS: Of the 321 patients included who could be classified according to ILAR criteria for childhood arthritis, 50 (15.6%) patients were excluded from 55 classification events and fulfilled criteria for "other arthritis 1" i.e., did not fulfill criteria for any of the other classification categories, primarily because of heredity for psoriasis. If psoriasis in second degree relatives was disregarded as an exclusion criterion, only 8.7% of the patients remained in the "other arthritis 1" subgroup. For 20.6% of the whole group, heredity for psoriasis in a first or second degree relative (or both) and its distribution among arthritis subgroups did not differ except for juvenile psoriatic arthritis. CONCLUSION: We suggest that second degree heredity for psoriasis be withdrawn as an exclusion criterion from the ILAR criteria.

Berntson L, Fasth A, Andersson-Gäre B, Kristinsson J, Lahdenne P, Marhaug G, Nielsen S, Pelkonen P, Svensson E, Anonymous00091. · Department of Pediatrics, Hospital of Falun, Sweden. · J Rheumatol. · Pubmed #11764226 No free full text.

Abstract: OBJECTIVE: New classification criteria (ILAR) have been proposed for juvenile idiopathic arthritis (JIA). They are more descriptive than those formerly used [American College of Rheumatology (ACR), European League Against Rheumatism (EULAR)], but require validation against classifications already in use. We validated the ILAR criteria in relation to the EULAR criteria in a prospective, incidence, and population based setting, and analyzed their feasibility. METHODS: Construct validity of ILAR and EULAR classification criteria refers to how closely the 2 instruments are related and how each of them operates in classifying subgroups/categories. Twenty doctors in 5 Nordic countries collected data from the incidence cases within their catchment areas during an 18 month period beginning July 1, 1997. Clinical and serological data from the first year of disease were collected. RESULTS: A total of 322 patients were included. Classification according to the ILAR criteria was possible in 321 patients; 290 patients had a disease duration > or = 3 months and were classified according to the EULAR criteria. One child could only be classified according to the EULAR criteria. Thus, 31/322 (9.6%) children were classified according to the ILAR criteria only. Forty-eight of 321 (15%) patients did not fit into any category and 6% (20/321) fulfilled criteria for2 categories. In the ILAR classification 5 out of 7 categories/subgroups have 2 to 5 specified exclusion criteria that highly discriminate the definition of each patient. In our study the exclusion criteria were fulfilled to only a small extent. CONCLUSION: The EULAR and ILAR criteria differ concerning the operational definitions of the subvariables involved, which complicates their comparison. By using ILAR rather than EULAR criteria the number of cases with juvenile arthritis increased by 10%, considering the first half-year after onset. The validity of the ILAR criteria is low since they often exclude patients from subgroup classification and the possibility of having more than one diagnosis is not negligible. The specified exclusion criteria for some of the subgroups are difficult to fulfill in clinical work and variables involved could be questioned with regard to their consistency.

Nielsen S, Ruperto N, Herlin T, Pedersen FK, Anonymous00064. · Juliane Marie Centret, Rigshospitalet, Pediatrisk Klinik II, Afsnit 4064, Blegdamsvej 9, 2100 Copenhagen, Denmark. · Clin Exp Rheumatol. · Pubmed #11510331 No free full text.

Abstract: We report herein the results of the cross-cultural adaptation and validation into the Danish 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 Danish CHAQ-CHQ were fully validated with 3 forward and 3 backward translations. A total of 139 subjects were enrolled: 76 patients with JIA (25% systemic onset, 30% polyarticular onset, 19% extended oligoarticular subtype, and 26% persistent oligoarticular subtype) and 63 healthy children. The CHAQ clinically discriminated between healthy subjects and JIA patients, with the systemic, polyarticular and extended oligoarticular subtypes having a higher degree of disability, pain, and a lower overall well-being when compared to their healthy peers. 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 Danish version of the CHAQ-CHQ is a reliable, and valid tool for the functional, physical and psychosocial assessment of children with JIA.

Nielsen HE, Dørup J, Herlin T, Larsen K, Nielsen S, Pedersen FK. · Paediatric Department, Gentofte Hospital, Rigshospitalet, Copenhagen, Denmark. · J Rheumatol. · Pubmed #10405951 No free full text.

Abstract: OBJECTIVE: We studied the socioeconomic background of children with juvenile chronic arthritis (JCA) diagnosed during the years 1988-91 in Denmark. The working hypothesis is that JCA may be triggered by one or several different infectious agents and that the amount of exposure to infectious agents in infancy and childhood affects the risk of JCA. METHODS: In this case-control study, we investigated socioeconomic variables prior to disease onset from national registers, primarily the Fertility Database of Statistics Denmark, in a national cohort of all 220 known cases of JCA fulfilling the EULAR criteria incident during the years 1988-91, identified from national and local diagnosis registers. There were 4 controls per case, matched for sex, age, and county of residence. Socioeconomic variables as risk factors were quantified by odds ratios, which are equivalent to relative risks of contracting JCA if exposed to a risk factor. RESULTS: Three socioeconomic variables were significantly and mutually independently associated with the risk of developing JCA during the following year. An only child had a risk of JCA 1.6 times that of a child with siblings. Children whose parents had a high income had a relative risk of 1.9. Children living in an urban flat had a risk 2.7 times that of children living on a farm. We found no space-time clustering of cases and no cyclical variations of incidence rates. CONCLUSION: The absence of clustering and of seasonal variation does not support a theory of triggering by infection. The hitherto unreported effects of the socioeconomic variables on the risk of JCA are of the same order of magnitude as reported for certain HLA alleles. Our findings do not lend full support to either of the 2 mechanisms, that growing up under either hygienic or unhygienic conditions increases the risk of JCA, and lack an obvious biological explanation.

Zak M, Hassager C, Lovell DJ, Nielsen S, Henderson CJ, Pedersen FK. · University Clinic of Pediatrics II, Rigshospitalet, Copenhagen, Denmark. · Arthritis Rheum. · Pubmed #10211895 links to  free full text

Abstract: OBJECTIVE: To assess bone mineral density (BMD) and bone turnover in adults with a history of juvenile chronic arthritis (JCA) or persistent JCA, and to identify predictors of reduced BMD. METHODS: Sixty-five white patients (mean age 32.2 years) with a history of JCA and 65 age-, sex-, height-, and weight-matched healthy control subjects participated in the study. Densitometry of the left hip and the lumbar spine was performed, and osteocalcin (bone formation marker) and crosslinks (bone resorption marker) were measured. In addition, bone-related clinical parameters were assessed in the JCA group. RESULTS: BMD in the hip and lumbar spine was significantly lower in the JCA group than in the controls. Levels of osteocalcin and crosslinks were significantly increased in the JCA group. According to WHO definitions, significantly more subjects in the JCA group had "osteopenia" and "osteoporosis" than would be expected in a normal population sample. Active disease at the time of the study (1996-1997), baseline erosions evaluated in 1979, Steinbrocker functional class in 1996-1997, polyarticular course of JCA, and history of systemic steroid treatment for more than 1 year were significantly associated with reduced BMD. In linear regression analysis including both the JCA and control groups, presence of JCA proved to be the factor most strongly associated with reduced BMD, explaining approximately 20% of its variation. CONCLUSION: Reduced BMD and evidence of increased bone turnover suggest that JCA patients may be at risk of developing premature osteoporosis and associated fractures later in life. The data are consistent with the concept that BMD in JCA is determined by many factors.