Common and different genetic background for rheumatoid arthritis and coeliac disease.

Recent genome-wide association studies (GWAS) have revealed genetic risk factors in autoimmune and inflammatory disorders. Several of the associated genes and underlying pathways are shared by various autoimmune diseases. Rheumatoid arthritis (RA) and coeliac disease (CD) are two autoimmune disorders which have commonalities in their pathogenesis. We aimed to replicate known RA loci in a Dutch RA population, and to investigate whether the effect of known RA and CD risk factors generalize across the two diseases. We selected all loci associated to either RA or CD in a GWAS and confirmed in an independent cohort, with a combined P-value cut-off P < 5 x 10(-6). We genotyped 11 RA and 11 CD loci in 1368 RA patients, 795 CD patients and 1683 Dutch controls. We combined our results in a meta-analysis with UK GWAS on RA (1860 cases; 2938 controls) and CD (767 cases; 1422 controls). In the Dutch RA cohort, the PTPN22 and IL2/IL21 variants showed convincing association (P = 3.4 x 10(-12) and P = 2.8 x 10(-4), respectively). Association of RA with the known CD risk variant in the SH2B3 was also observed, predominantly in the subgroup of rheumatoid factor-positive RA patients (P = 0.0055). In a meta-analysis of Dutch and UK data sets, shared association with six loci (TNFAIP3, IL2/IL21, SH2B3, LPP, MMEL1/TNFRSF14 and PFKFB3/PRKCQ) was observed in both RA and CD cohorts. We confirmed two known loci and identified four novel ones for shared CD-RA genetic risk. Most of the shared loci further emphasize a role for adaptive and innate immunity in these diseases.

Novel association in chromosome 4q27 region with rheumatoid arthritis and confirmation of type 1 diabetes point to a general risk locus for autoimmune diseases.

Recently, association of celiac disease with common single-nucleotide polymorphism (SNP) variants in an extensive linkage-disequilibrium block of 480 kb containing the KIAA1109, Tenr, IL2, and IL21 genes has been demonstrated in three independent populations (rs6822844P combined=1.3 x 10(-14)). The KIAA1109/Tenr/IL2/IL21 block corresponds to the Idd3 locus in the nonobese diabetic mouse model of type 1 diabetes (T1D). This block was recently found to be associated with T1D in a genomewide association study, although this finding lacks unequivocal confirmation. We therefore aimed to investigate whether the KIAA1109/Tenr/IL2/IL21 region is involved in susceptibility to multiple autoimmune diseases. We tested SNP rs6822844 for association with disease in 350 T1D-affected and 1,047 rheumatoid arthritis (RA)-affected Dutch patients and in 929 controls. We replicated the association with T1D (P=.0006; OR 0.64 [95% CI 0.50-0.83]), and revealed a similar novel association with RA (P=.0002; OR 0.72 [95% CI 0.61-0.86]). Our results replicate and extend the association found in the KIAA1109/Tenr/IL2/IL21 gene region with autoimmune diseases, implying that this locus is a general risk factor for multiple autoimmune diseases.

Expression and regulation of HIF-1alpha in macrophages under inflammatory conditions; significant reduction of VEGF by CaMKII inhibitor.

BACKGROUND: Macrophages expressing the pro-angiogenic transcription factor hypoxia-inducible factor (HIF)-1alpha have been demonstrated in rheumatoid arthritis (RA) in the synovial tissue. Aim of the present study was to investigate intracellular signal transduction regulation of pro-inflammatory HIF-1 alpha expression in macrophages to identify possible new intervention strategies. We investigated the effects of CaMKII-inhibitors amongst other kinase inhibitors, on HIF-1 alpha expression and downstream production of pro-angiogenic factors in macrophages. METHODS: Differentiated THP-1 cells and synovial fluid (SF) macrophages were stimulated with 1 microg/ml LPS with or without pretreatment with specific inhibitors of the ERK pathway (PD98059), the PI3K pathway (LY294002), and the CaMKII pathway (KN93 and SMP-114). mRNA and protein expression of HIF-1 alpha, VEGF, MMP-9, and IL-8 was measured in cell lysates and cell supernatants. RESULTS: HIF-1 alpha protein expression in LPS-stimulated THP-1 macrophages could be blocked by ERK- and PI3K-inhibitors, but also by the CaMKII inhibitor KN93. THP-1 and SF macrophages produced high levels of VEGF, IL-8, and MMP-9, and VEGF protein production was significantly inhibited by PI3K-inhibitor, and by both CaMKII inhibitors. LPS stimulation in an hypoxic environment did not change VEGF levels, suggesting that LPS induced VEGF production in macrophages is more important than the hypoxic induction. CONCLUSIONS: Expression of HIF-1 alpha and downstream effects in macrophages are regulated by ERK-, PI3K, but also by CaMKII pathways. Inhibition of HIF-1alpha protein expression and significant inhibition of VEGF production in macrophages was found using CaMKII inhibitors. This is an unknown but very interesting effect of the CaMKII inhibitor SMP-114, which has been in clinical trial as DMARD for the treatment of RA. This effect may contribute to the anti-arthritic effects of SMP-114.

Humoral responses after influenza vaccination are severely reduced in patients with rheumatoid arthritis treated with rituximab.

OBJECTIVE: For patients with rheumatoid arthritis (RA), yearly influenza vaccination is recommended. However, its efficacy in patients treated with rituximab is unknown. The objectives of this study were to investigate the efficacy of influenza vaccination in RA patients treated with rituximab and to investigate the duration of the possible suppression of the humoral immune response following rituximab treatment. We also undertook to assess the safety of influenza vaccination and the effects of previous influenza vaccination. METHODS: Trivalent influenza subunit vaccine was administered to 23 RA patients who had received rituximab (4-8 weeks after rituximab for 11 patients [the early rituximab subgroup] and 6-10 months after rituximab for 12 patients [the late rituximab subgroup]), 20 RA patients receiving methotrexate (MTX), and 29 healthy controls. Levels of antibodies against the 3 vaccine strains were measured before and 28 days after vaccination using hemagglutination inhibition assay. The Disease Activity Score in 28 joints (DAS28) was used to assess RA activity. RESULTS: Following vaccination, geometric mean titers (GMTs) of antiinfluenza antibodies significantly increased for all influenza strains in the MTX-treated group and in healthy controls, but for no strains in the rituximab-treated group. However, in the late rituximab subgroup, a rise in GMT for the A/H3N2 and A/H1N1 strains was demonstrated, in the absence of a repopulation of CD19+ cells at the time of vaccination. Seroconversion and seroprotection occurred less often in the rituximab-treated group than in the MTX-treated group for the A/H3N2 and A/H1N1 strains, while seroprotection occurred less often in the rituximab-treated group than in the healthy controls for the A/H1N1 strain. Compared with unvaccinated patients in the rituximab-treated group, previously vaccinated patients in the rituximab-treated group had higher pre- and postvaccination GMTs for the A/H1N1 strain. The DAS28 did not change after vaccination. CONCLUSION: Rituximab reduces humoral responses following influenza vaccination in RA patients, with a modestly restored response 6-10 months after rituximab administration. Previous influenza vaccination in rituximab-treated patients increases pre- and postvaccination titers. RA activity was not influenced.

Promoting physical activity in children with juvenile idiopathic arthritis through an internet-based program: results of a pilot randomized controlled trial.

OBJECTIVE: Patients with juvenile idiopathic arthritis (JIA) are less physically active than healthy peers. Therefore, we developed an Internet-based intervention to improve physical activity (PA). The aim of this study was to examine the effectiveness of the program in improving PA. METHODS: PA was determined by activity-related energy expenditure, PA level, time spent on moderate to vigorous PA, and the number of days with > or =1 hour of moderate to vigorous activity, and was assessed with a 7-day activity diary. Aerobic exercise capacity was assessed by means of a Bruce treadmill test and was recorded as maximum endurance time. Disease activity was assessed by using the JIA core set. Adherence was electronically monitored. RESULTS: Of 59 patients, 33 eligible patients were included and randomized in an intervention (n = 17, mean +/- SD age 10.6 +/- 1.5 years) or control waiting-list group (n = 16, mean +/- SD age 10.8 +/- 1.4 years). All patients completed baseline and T1 testing. PA significantly improved in both groups. Maximum endurance time significantly improved in the intervention group but not in the control group. In a subgroup analysis for patients with low PA (intervention: n = 7, control: n = 5), PA improved in the intervention group but not in the control group. The intervention was safe, feasible, and showed a good adherence. CONCLUSION: An Internet-based program for children with JIA ages 8-12 years directed at promoting PA in daily life effectively improves PA in those patients with low PA levels. It is also able to improve endurance and it is safe, feasible, and has good adherence.

Role for CaMKII inhibition in rheumatoid arthritis: effects on HIF-1-induced VEGF production by rheumatoid synovial fibroblasts.

BACKGROUND AND AIMS: The present study was designed to investigate the effects of a novel CaMKII inhibitor SMP-114, which was effective in a collagen-induced arthritis model in rats, on rheumatoid synovial fibroblasts. METHODS: Rheumatoid synovial fibroblasts (RSF) were cultured under pro-inflammatory (IL-1beta stimulation) and hypoxic conditions. Protein and mRNA expression of HIF-1alpha and the effects of inhibitors of the CaMKII-, PI3K-, and ERK pathway on VEGF and IL-6 production were analyzed. RESULTS: Stimulation under hypoxic conditions induced higher expression of HIF-1alpha and VEGF mRNA than treatment with either IL-1beta or hypoxia alone. However, incubation with a specific CaMKII inhibitor did not result in reduced VEGF production in RSF. CONCLUSIONS: CaMKII activation has been reported to be involved in HIF-1alpha stabilization, but incubation with SMP-114, a specific CaMKII inhibitor, had no effect on HIF-1-induced VEGF production by rheumatoid synovial fibroblasts.

Physical activity in adolescents with juvenile idiopathic arthritis.

OBJECTIVE: To explore physical activity (PA) in adolescents with juvenile idiopathic arthritis (JIA) compared with a healthy population and to examine associations between PA and disease-related factors. METHODS: Total energy expenditure (TEE), activity-related energy expenditure (AEE), PA level, and PA pattern were assessed with a 3-day activity diary. Aerobic capacity was assessed using a Symptom Limited Bicycle Ergometry test. Functional ability was assessed with the Childhood Health Assessment Questionnaire. Disease activity was assessed using Paediatric Rheumatology International Trials Organisation core set criteria. Overall well-being was measured using a visual analog scale, and time since diagnosis was assessed by retrospective study from patients' charts. We used a cross-sectional study design. Reference data were collected from healthy Dutch secondary school children. RESULTS: Thirty patients and 106 controls were included (mean+/-SD age 17.0+/-0.6 and 16.7+/-0.9 years, respectively). TEE, AEE, and PA level were significantly lower in the JIA group. The JIA group spent more time in bed and less time on moderate to vigorous PA. Only 23% of the JIA patients met public health recommendations to perform >or=1 hour daily moderate to vigorous PA compared with 66% in the reference group. Higher PA was associated with higher levels of well-being and maximal oxygen consumption. CONCLUSION: Adolescents with JIA have low PA levels and are at risk of losing the benefits of PA. Low PA is not related to disease activity, and control over the disease does not restore previous PA levels. Interventions by pediatric rheumatologists are needed to increase PA levels in patients with JIA.

Association of STAT4 with rheumatoid arthritis: a replication study in three European populations.

OBJECTIVE: This study was undertaken to investigate the previously reported association of the STAT4 polymorphism rs7574865 with rheumatoid arthritis (RA) in 3 different European populations from Spain, Sweden, and The Netherlands, comprising a total of 2,072 patients and 2,474 controls. METHODS: Three different cohorts were included in the study: 923 RA patients and 1,296 healthy controls from Spain, 273 RA patients and 285 healthy controls from Sweden, and 876 RA patients and 893 healthy controls from The Netherlands. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the STAT4 single-nucleotide polymorphism rs7574865 using a TaqMan 5'-allele discrimination assay. The chi-square test was performed to compare allele and genotype distributions. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: We observed a significantly increased frequency of the minor T allele in RA patients compared with healthy controls in the Spanish population (24.8% versus 20.8%; P = 0.001, OR 1.26 [95% CI 1.09-1.45]). This association was confirmed in both the Swedish population (P = 0.03, OR 1.35 [95% CI 1.03-1.77]) and the Dutch population (P = 0.03, OR 1.45 [95% CI 1.21-1.73]). The overall P value for all 3 populations was 9.79 x 10(-6) (OR 1.25 [95% CI 1.13-1.37]). No association between rs7574865 and the presence of rheumatoid factor or anti-cyclic citrullinated peptide autoantibodies was observed. A meta-analysis of all published STAT4 associations revealed an OR of 1.25 (95% CI 1.19-1.33) (P = 1 x 10(-5)). CONCLUSION: Our findings indicate an association between the STAT4 polymorphism rs7574865 and RA in 3 different populations, from Spain, Sweden, and The Netherlands, thereby confirming previous data.

Aerobic and anaerobic exercise capacity in adolescents with juvenile idiopathic arthritis.

OBJECTIVE: To examine the aerobic and anaerobic exercise capacity in adolescents with juvenile idiopathic arthritis (JIA) compared with age- and sex-matched healthy individuals, and to assess associations between disease-related variables and aerobic and anaerobic exercise capacity. METHODS: Of 25 patients enrolled in a JIA transition outpatient clinic, 22 patients with JIA were included in this study (mean +/- SD age 17.1 +/- 0.7 years, range 16-18 years). Aerobic capacity was examined using a Symptom Limited Bicycle Ergometry test. Anaerobic capacity was assessed with the Wingate Anaerobic Test. Functional ability was assessed with the Childhood Health Assessment Questionnaire. Pain and overall well-being were measured using a visual analog scale. Disease duration and disease activity were also assessed. RESULTS: Absolute and relative maximal oxygen consumption in the JIA group were significantly impaired (85% and 83% for boys, respectively; 81% and 78% for girls, respectively) compared with healthy controls. Mean power was also significantly impaired (88% for boys and 74% for girls), whereas peak power was significantly impaired for girls and just failed significance for boys (67% for girls and 92% for boys). A post hoc analysis correcting for underweight and overweight demonstrated that body composition did not influence the results substantially. CONCLUSION: This study demonstrated that adolescents with JIA have an impaired aerobic and anaerobic exercise capacity compared with healthy age- and sex-matched peers. The likely cause for this significant impairment is multifactorial and needs to be revealed to improve treatment strategies.

Longitudinal echocardiographic follow-up in children with congenital complete atrioventricular block.

BACKGROUND: Due to a low heart rate (HR) in children with congenital complete atrioventricular block (CCAVB), a larger stroke volume of the left ventricle (LV) may be expected. If so, end-diastolic (LVEDD) and end-systolic (LVESD) diameters may be enlarged and even dilated cardiomyopathy (DCM) may occur. The aim of this study was to answer the question if children with CCAVB develop LV dilatation. Furthermore, we investigated whether LV dilatation would decrease after pacing. METHODS: We longitudinally evaluated echocardiographic data (LVEDD, LVESD, shortening fraction [SF]) in 36 children with CCAVB. Age at the first visit was 2.5 +/- 3.3 years (mean +/- SD); follow-up 10.6 +/- 7.3 years. RESULTS: Three children had DCM, already at 1st visit. LVEDD and LVESD Z scores in all children with CCAVB were larger than in normal controls (LVEDD Z score 1.38 +/- 1.80; LVESD Z score 0.64 +/- 1.35). Both Z scores were larger when HR was lower. Both Z scores increased over time in children who met criteria for pacing, but did not change in non-paced children. Physiologic pacing decreased both Z scores. SF of all children was normal and remained normal during follow-up (0.39 +/- 0.05 1st visit vs 0.39 +/- 0.06 last visit). CONCLUSIONS: We conclude that children with CCAVB have LV dilatation, which is progressive in children who met criteria for pacing. LV dilatation regressed by physiologic pacing. LV dilatation was larger when HR was lower. SF does not deteriorate over time. DCM occurs early in the disease and does not develop during childhood, not even in children with LV dilatation.

Standardised assessment of membrane proteinase 3 expression. Analysis in ANCA-associated vasculitis and controls.

OBJECTIVES: Increased numbers of neutrophils expressing proteinase 3 on their membrane (mPR3) have been reported in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) and are suggested to be involved in AAV immunopathogenesis. In most studies, neutrophils were analysed for mPR3 expression without priming with TNFalpha, suggesting that mPR3 expression on neutrophils is dependent on other priming events, such as isolation procedures . These priming events can be variable. Therefore, we analysed mPR3 expression on neutrophils before and after priming with TNFalpha to assess whether standardised assessment of mPR3 expression requires priming. Using neutrophils before and after priming with TNFalpha, we assessed percentages of mPR3(+) neutrophils in patients with AAV and in disease and healthy controls. METHODS: Neutrophils from patients with PR3-AAV and MPO-AAV, systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), and from healthy controls were analysed before and after priming with TNFalpha for mPR3 expression. RESULTS: 42% of all individuals analysed showed minimal expression for mPR3 on all neutrophils before priming with TNFalpha, whereas after priming a clear mPR3(+) subset was observed next to mPR3(-) neutrophils, corresponding to bimodal mPR3 expression. In patients with PR3-AAV or MPO-AAV, the percentage of mPR3(+) neutrophils after priming with TNFalpha was significantly increased (p<0.01 and p<0.05, respectively) compared with healthy controls. Percentages of mPR3(+) PMN were also increased in patients with SLE (p<0.01) but not in RA. CONCLUSION: Standardised assessment of proteinase 3 on the membrane of neutrophils requires priming with TNFalpha. Percentages of mPR3(+) PMN are increased in AAV and SLE, but not in RA.

Serum matrix metalloproteinase 3 levels during treatment with sulfasalazine or combination of methotrexate and sulfasalazine in patients with early rheumatoid arthritis.

OBJECTIVE: To determine the effects of treatment with sulfasalazine (SSZ) or the combination of methotrexate (MTX) and SSZ on serum matrix metalloproteinase 3 (MMP-3) levels in patients with early rheumatoid arthritis (RA). METHODS: Eighty-two patients with early RA (symptoms < 1 year and DMARD-naive at presentation) were selected who had been treated with SSZ (2000 mg/day) or with the combination of MTX (7.5-15 mg/week) and SSZ. Serum MMP-3 levels, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), swollen joint count (SJC), tender joint count (TJC), Ritchie articular index (RAI), and the Disease Activity Score (DAS) were determined at 4 week intervals during a followup of 28 weeks for each treatment group. Response was based on clinical grounds and CRP at 12, 20, and 28 weeks. RESULTS: SSZ responders (n = 52) had lower baseline values of serum MMP-3, CRP, and ESR, compared to partial/nonresponders (n = 30), but did not differ in joint scores and DAS. In the SSZ responder group all variables decreased. In the SSZ partial/nonresponders, CRP, ESR, and SJC decreased in contrast to serum MMP-3, TJC. RAI, and DAS-3. After addition of MTX all variables decreased in 24 of the 30 patients who had shown a partial or no response taking SSZ. In the SSZ responders there was a delayed decrease in serum MMP-3 compared to CRP. CONCLUSION: Serum MMP-3 levels decrease in patients with early RA who respond to SSZ or to the combination of MTX and SSZ. In patients who respond to SSZ the changes in serum MMP-3 levels indicate a delayed response compared to CRP.

Prognostic factors for joint destruction in rheumatoid arthritis: a prospective longitudinal study of 318 patients.

OBJECTIVE: To quantify articular damage and to investigate prognostic factors for joint damage progression in rheumatoid arthritis (RA). METHODS: RA patients satisfying the 1987 American College of Rheumatology criteria and with disease duration under 5 years were sampled from the EURIDISS longitudinal cohort study in Norway, The Netherlands, and France. Hand radiographs were assessed at baseline and at 2 to 3 year followup using Sharp score modified by van der Heijde. Assessment of erosion and joint space narrowing, performed in sequential order by a single reader blinded to patients' characteristics, had high intraobserver reproducibility (intraclass correlation coefficient 0.98-0.99). Baseline prognostic factors were analyzed in a multivariate linear regression model. RESULTS: A total of 318 patients with RA aged 52.4 years (70.4% were female) and with a mean 2 years' disease duration at baseline were followed over 30 months. Median (quartiles) baseline and followup modified Sharp scores were 3 (0-11) and 9 (1-27), respectively, with 35.8% and then 22.3% of patients with no radiological damage. Controlling for age, sex, and country, the final joint damage was predicted by baseline modified Sharp score, rheumatoid factor positivity, time from disease diagnosis, patient global health assessment, and erythrocyte sedimentation rate, and by followup duration, explaining 76.8% of the outcome variance. CONCLUSION: This multinational study confirmed the prognostic role in RA of a set of features previously identified in smaller cohorts. It indicates which disease characteristics should be focused on in the early years of RA to identify patients at higher risk of developing severe disease and who are candidates for aggressive therapy.

Strong inhibition of TNF-alpha production and inhibition of IL-8 and COX-2 mRNA expression in monocyte-derived macrophages by RWJ 67657, a p38 mitogen-activated protein kinase (MAPK) inhibitor.

In inflammatory processes, the p38 mitogen-activated protein kinase (MAPK) signal transduction route regulates production and expression of cytokines and other inflammatory mediators. Tumor necrosis factor alpha (TNF-alpha) is a pivotal cytokine in rheumatoid arthritis and its production in macrophages is under control of the p38 MAPK route. Inhibition of the p38 MAPK route may inhibit production not only of TNF-alpha, but also of other inflammatory mediators produced by macrophages, and indirectly of inflammatory mediators by other cells induced by TNF-alpha stimulation. Here we investigate the effects of RWJ 67657, a p38 MAPK inhibitor, on mRNA expression and protein production of TNF-alpha and other inflammatory mediators, in monocyte-derived macrophages. A strong inhibition of TNF-alpha was seen at pharmacologically relevant concentrations of RWJ 67657, but also inhibition of mRNA expression of IL-1beta, IL-8, and cyclooxygenase-2 was shown. Furthermore, it was shown that monocyte-derived macrophages have a high constitutive production of matrix metalloproteinase 9, which is not affected by p38 MAPK inhibition. The results presented here may have important implications for the treatment of rheumatoid arthritis.