Pre- and perinatal exposures associated with developing pediatric-onset immune-mediated inflammatory disease: A Danish nation-wide cohort study.

OBJECTIVES: We aimed to identify pre- and perinatal risk factors for developing pediatric-onset immune-mediated inflammatory (pIMID). METHODS: This nation-wide, cohort study included all children born in Denmark from 1994 to 2014 identified from the Danish Medical Birth registry. Individuals were followed through 2014 and cross-linked to the continuously updated national socioeconomic and healthcare registers to obtain data on pre- and perinatal exposures (maternal age, educational level, smoking, maternal IMID, parity, mode of conception and delivery, plurality, child's sex, and birth season). The primary outcome was a pIMID diagnosis (inflammatory bowel disease, autoimmune hepatitis, primary sclerosing cholangitis, juvenile idiopathic arthritis, or systemic lupus erythematosus) before 18 years of age. Risk estimates were calculated using Cox proportional hazards model and presented by hazard ratios (HR) with 95% confidence intervals (95%CI). RESULTS: We included 1,350,353 children with a follow-up time of 14,158,433 person-years. Among these, 2,728 were diagnosed with a pIMID. We found a higher risk of pIMID in children born to women with a preconception IMID diagnosis (HR: 3.5 [95%CI: 2.7-4.6]), children born by Caesarean section (HR: 1.2 [95%CI: 1.0-1.3]), and among females (1.5 [95%CI: 1.4-1.6]) than among children without these characteristics. Plural pregnancies were associated with a lower risk of pIMID than single pregnancies (HR: 0.7 [95%CI: 0.6-0.9]). CONCLUSIONS: Our results indicate a high genetic burden in pIMID but also identifies intervenable risk factors, such as Cesarean section. Physicians should, keep this in mind when caring for high-risk populations and pregnant women previously diagnosed with an IMID.

Risk Factors of Cancer in Pediatric-Onset Inflammatory Bowel Disease in Denmark and Finland.

OBJECTIVES: Pediatric-onset inflammatory bowel disease (pIBD) increases the risk of developing several different cancer forms. In this case-control study, we aimed to assess the impact of medical treatment and disease activity on the risk of developing disease-associated cancer (DAC) and treatment-associated cancer (TAC). METHODS: In a previous study, we identified 27 cases of DAC (colorectal cancer, small bowel cancer, and cholangiocarcinoma) and 28 TAC (lymphoma and skin cancer) in 6689 patients with pIBD in Denmark and Finland during the period 1992-2015. In this study, the patient charts were reviewed manually. Cancer-free patients from another population-based pIBD cohort were included as controls. We recorded data on phenotype, medical treatment, surgery, and relapses. Logistic regression was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals (95% CI) to estimate the relative risk. RESULTS: We included 16 cases with DAC, 21 with TAC, and 331 controls. For DAC, lower frequencies of IBD-relapses were associated with an increased risk of cancer (OR 0.2 [95% CI: 0.04-0.8]). For TAC, we found an increased risk in patients receiving thiopurines at any point during the follow-up period (aOR: 11.7 [95% CI: 2.1-116.2]) and an association with proportion of follow-up time being exposed to thiopurines (aOR 5.6 [95% CI: 1.1-31.5]). CONCLUSIONS: In this nation-wide study, covering all pIBD patients from Denmark and Finland, we found that pIBD patients treated with thiopurines had an increased risk of TAC.

Beam damage in operando X-ray diffraction studies of Li-ion batteries.

Operando powder X-ray diffraction (PXRD) is a widely employed method for the investigation of structural evolution and phase transitions in electrodes for rechargeable batteries. Due to the advantages of high brilliance and high X-ray energies, the experiments are often carried out at synchrotron facilities. It is known that the X-ray exposure can cause beam damage in the battery cell, resulting in hindrance of the electrochemical reaction. This study investigates the extent of X-ray beam damage during operando PXRD synchrotron experiments on battery materials with varying X-ray energies, amount of X-ray exposure and battery cell chemistries. Battery cells were exposed to 15, 25 or 35 keV X-rays (with varying dose) during charge or discharge in a battery test cell specially designed for operando experiments. The observed beam damage was probed by µPXRD mapping of the electrodes recovered from the operando battery cell after charge/discharge. The investigation reveals that the beam damage depends strongly on both the X-ray energy and the amount of exposure, and that it also depends strongly on the cell chemistry, i.e. the chemical composition of the electrode.

Influence of Genetics, Immunity and the Microbiome on the Prognosis of Inflammatory Bowel Disease (IBD Prognosis Study): the protocol for a Copenhagen IBD Inception Cohort Study.

INTRODUCTION: Inflammatory bowel diseases (IBD), encompassing Crohn's disease and ulcerative colitis, are chronic, inflammatory diseases of the gastrointestinal tract. We have initiated a Danish population-based inception cohort study aiming to investigate the underlying mechanisms for the heterogeneous course of IBD, including need for, and response to, treatment. METHODS AND ANALYSIS: IBD Prognosis Study is a prospective, population-based inception cohort study of unselected, newly diagnosed adult, adolescent and paediatric patients with IBD within the uptake area of Hvidovre University Hospital and Herlev University Hospital, Denmark, which covers approximately 1 050 000 inhabitants (~20% of the Danish population). The diagnosis of IBD will be according to the Porto diagnostic criteria in paediatric and adolescent patients or the Copenhagen diagnostic criteria in adult patients. All patients will be followed prospectively with regular clinical examinations including ileocolonoscopies, MRI of the small intestine, validated patient-reported measures and objective examinations with intestinal ultrasound. In addition, intestinal biopsies from ileocolonoscopies, stool, rectal swabs, saliva samples, swabs of the oral cavity and blood samples will be collected systematically for the analysis of biomarkers, microbiome and genetic profiles. Environmental factors and quality of life will be assessed using questionnaires and, when available, automatic registration of purchase data. The occurrence and course of extraintestinal manifestations will be evaluated by rheumatologists, dermatologists and dentists, and assessed by MR cholangiopancreatography, MR of the spine and sacroiliac joints, ultrasonography of peripheral joints and entheses, clinical oral examination, as well as panoramic radiograph of the jaws. Fibroscans and dual-energy X-ray absorptiometry scans will be performed to monitor occurrence and course of chronic liver diseases, osteopenia and osteoporosis. ETHICS AND DISSEMINATION: This study has been approved by Ethics Committee of the Capital Region of Denmark (approval number: H-20065831). Study results will be disseminated through publication in international scientific journals and presentation at (inter)national conferences.

Mucosal microRNAs relate to age and severity of disease in ulcerative colitis.

Despite significant evidence that the expression of several microRNAs (miRNAs) impacts disease activity in patients with ulcerative colitis (UC), it remains unknown if the more severe disease phenotype seen in pediatric onset UC can be explained by an altered miRNA expression. In this study, we assessed the relationship between miRNA expression, age, and disease severity in pediatric and adult patients with UC. Using RT-qPCR, we analyzed the expression of miR-21, miR-31, miR-126, miR-142 and miR-155 in paraffin embedded rectum biopsies from 30 pediatric and 30 adult-onset UC patients. We found that lesions from adult patients had significantly higher expression levels of miR-21 compared to pediatric patients and that the expression levels of miR-31 (all patients) and miR-155 (pediatric patients only) correlated inversely with histological assessed disease severity. Using in situ hybridization followed by image analysis, the expression level estimates of miR-21 and miR-126 correlated with histological assessed disease severity. In conclusion, we found that the expression of miRNAs depends on the age of the patient and/or the severity of the disease, suggesting that miRNAs may contribute to the regulation of inflammation in UC and could be useful biomarkers in the surveillance of disease severity.

Changes in Incidence and Management of Acute Appendicitis in Children-A Population-Based Study in the Period 2000-2015.

INTRODUCTION: Recent studies suggest that the epidemiology and management of appendicitis have changed during the last decades. The purpose of this population-based study was to examine this in the pediatric population in Denmark. MATERIALS AND METHODS: Data were retrieved from the Danish National Patient Registry, the Danish Civil Registration System, and the Statbank Denmark. Patients aged 0 to 17 years diagnosed with appendicitis and appendectomized during the period 2000 to 2015 were included. The primary outcome was the annual incidences of appendicitis. Secondary outcomes were the annual percent of patients with appendicitis having a laparoscopic appendectomy, delay from admission to surgery, length of postoperative hospital stay, and 30-day postoperative mortality. RESULTS: A total of 24,046 pediatric cases of appendicitis were identified. The annual incidence steadily declined until 2008 (-29%, all ages) and then remained stable. The surgical approach of choice changed from being open appendectomy in 2000 (97%) to laparoscopic appendectomy in 2015 (94%). Simultaneously, the duration of postoperative hospital stay declined from 41 hours (median) to 17 hours. Delay from admission until surgery did not change during the period. Only one child died within the 30-day postoperative period. CONCLUSION: In accordance with other recent studies from Western countries, we found significant changes in the incidence of acute appendicitis including a decline in all age groups except those below 5 years of age, a shift toward laparoscopic appendectomy, and decreasing time spent in the hospital during the years 2000 to 2015.

Na-Ion storage in iron hydroxide phosphate hydrate through a reversible crystalline-to-amorphous phase transition.

Iron(iii) hydroxide phosphate hydrate Fe1.13(PO4)(OH)0.39(H2O)0.61 is investigated for the first time as a Na-ion battery cathode, which reveals that the material exhibits similar storage capacities for Na- and Li-ions at relatively low current rates (i.e. C/10). Interestingly, operando X-ray diffraction shows that insertion of Na-ions induces a solid solution transition in the crystalline Fe1.13(PO4)(OH)0.39(H2O)0.61 end-member simultaneously with a major amorphization. This result adds to the series of observations of phosphate-based materials undergoing order-disorder transitions during Na-ion storage. Fe1.13(PO4)(OH)0.39(H2O)0.61 is thus ideal for enhancing our knowledge on such phenomena. To this end, using total X-ray scattering with pair distribution function analysis, we show that the amorphous phase is Na-rich NaxFe1.13(PO4)(OH)0.39(H2O)0.61 with the local [FeO6]-[PO4] motif retained but with coherence lengths of only ca. 0.6 nm. Our investigation also reveals that the crystallinity of Fe1.13(PO4)(OH)0.39(H2O)0.61 is regained upon Na-extraction (battery recharge), i.e. the order-disorder transition is reversible.

Extraintestinal Manifestations Are Associated With Disease Severity in Pediatric Onset Inflammatory Bowel Disease.

OBJECTIVES: The aim of this study was to investigate a possible association between extraintestinal manifestations (EIM) and a more severe disease course in pediatric onset inflammatory bowel disease (pIBD). METHODS: This study compares the disease course of pIBD patients (IBD diagnosis <15 years of age) with and without EIM in a population-based cohort from Denmark. Patients diagnosed with pIBD between 1998 and 2008 were included in the study and followed until December 31, 2014. Data on phenotype, treatment, relapses, and the temporal relationship between IBD relapses and activity of EIM were collected at end of follow-up by manual revision of patient charts. RESULTS: Of 333 pIBD patients, 14 (4.2%) had EIM at time of diagnosis and 47 (14.1%) developed EIM during follow-up. Median follow-up time was 9.6 years for patients with EIM and 8.8 years for patients without. In ulcerative colitis, EIM were associated with an increased risk of biological treatment and surgery (hazard ratio: 2.6; 95% confidence interval [CI]: 1.3-5.5, P = 0.008 and 2.9 [95% CI: 1.1-7.7, P = 0.03], respectively). In Crohn disease, EIM were associated with an increased relapse rate (1.3 [95% CI: 1.1-1.5], P = 0.001). Lastly, we found a positive temporal relationship between relapse of IBD and EIM activity. CONCLUSION: The presence of EIM is associated with a more severe disease course in pIBD. This should be considered when deciding treatment options, as a more aggressive treatment approach could be warranted in patients with EIM. However, prospective studies are needed to fully evaluate this.

The microbiome reflects diagnosis and predicts disease severity in paediatric onset inflammatory bowel disease.

Objectives: A microbiotic profile characterized by decreased abundance and richness has been described in inflammatory bowel disease (IBD). Recently, sequencing the microbiome to the species level has become possible, which can improve our understanding of the gut to host interaction in IBD. We aimed to describe the microbiotic profile in paediatric IBD and compare it to disease phenotype and disease course. Methods: Faecal samples were collected from a cross-sectional cohort. The microbiome analysis was performed using 16S and 18S rRNA sequencing with the miSeq instrument. Inflammatory activity was assessed by faecal calprotectin. Data regarding medical treatment and surgery in the year after faecal sampling were collected from patient charts. Results: One hundred and forty-three (143) paediatric IBD patients and 34 healthy controls (HC) were included. We found a reduced richness in IBD patients compared to HCs (controls vs. ulcerative colitis (UC), p < .001 and controls vs. Crohn's disease (CD), p = .04)). Moreover, a high degree of intestinal inflammation and extensive disease extent was associated with reduced richness in UC (p = .02 and p = .04, respectively). Nine species were significantly associated with a healthy microbiome and three species were associated with IBD. Lastly, we found that the composition of the microbiome could distinguish between CD, UC and HCs. Conclusions: In this study, we found that the microbiome could discriminate between IBD phenotypes and predict which patients were at risk of surgery. In the future, this could be included as part of the diagnostic work-up in IBD patients.

The incidence of cancer and mortality in paediatric onset inflammatory bowel disease in Denmark and Finland during a 23-year period: a population-based study.

BACKGROUND: Recent studies report increased risks of both cancer and mortality in paediatric onset inflammatory bowel disease (pIBD) but the reproducibility of this is unknown. AIM: To estimate the risk of cancer and mortality in the Danish and Finnish pIBD population in a 23-year period compared to the general population. METHODS: The pIBD population was defined as individuals registered in the national patient registries with a diagnosis of Crohn's disease (CD), ulcerative colitis (UC) or IBD-unclassified before their 18th birthday from 1992 to 2014. This cohort was cross referenced with the national cancer and mortality registries identifying all pIBD patients who subsequently developed cancer and/ or died and followed up to the end of 2014. Risk estimates are presented as standardised incidence ratios calculated based on incidence figures from the populations. RESULTS: Six thousand six hundred and eight-nine patients with pIBD were identified (median age at follow-up 22.3 years; median follow-up: 9.6 years [interquartile range: 4.8-16.0]). Seventy-two subsequently developed cancer and 65 died. The standardised incidence ratio of cancer in general was 2.6 (95% CI: 1.8-3.7) and 2.5 (95% CI: 1.8-3.4) in CD and UC, respectively. The standardised mortality ratios were 2.2 (95% CI: 1.4-3.4) and 3.7 (95% CI: 2.7-5.0) in CD and UC, respectively. The leading causes for mortality were cancer, suicide and infections. CONCLUSIONS: We found an increased risk of cancer and mortality in pIBD. This underlines the importance of cancer surveillance programs and assessment of mental health in the standard of care in adolescent pIBD patients.

Biochemical Markers, Genotype, and Inflammation in Pediatric Inflammatory Bowel Disease: A Danish Population-Based Study.

BACKGROUND: Our aim was to characterize the biochemical markers at diagnosis in patients with inflammatory bowel disease (IBD), to assess the utility of these to predict disease course and investigate if genotype influences biochemical markers of inflammation. SUMMARY: Patients were included from a population-based pediatric IBD cohort from Eastern Denmark. Data on biochemical markers and medical as well as surgical treatment were registered at diagnosis, 30 days, 6 and 12 months after diagnosis. Fifty-two single nucleotide polymorphisms (SNPs) known to be associated with IBD were selected for genotyping based on previous genetic studies. Key messages: A total of 190 IBD patients (97 ulcerative colitis [UC], 87 Crohn's disease [CD], and 6 IBD unclassified) were included. UC patients with extensive disease had higher C-reactive protein, erythrocyte sedimentation rate, and platelet count at diagnosis compared to UC patients with less extensive disease. No similar differences between disease extent groups were found in CD. Low albumin at diagnosis was associated with an increased risk of surgery in both UC (OR 1.35; 95% CI: 1.05-1.75) and CD patients (OR 1.23; 95% CI: 1.01-1.48) and increased use of azathioprine and anti-tumor necrosis factor alpha use in the total IBD cohort (OR 1.15; 95% CI: 1.04-1.27 and OR 1.19 [1.08-1.34]). One SNP (rs4986791 in the TLR-4 locus) and 2 SNPs (rs6785049 in the Pregnane-x-receptor gene and rs10500264 in the SLCA10 gene) were associated with a change in albumin and hemoglobin over time respectively in our IBD cohort. Our study confirms albumin to be a marker of severe disease course. Furthermore, the patient's genotype possibly affects the inflammatory response. Future studies in larger pediatric cohorts are needed to confirm our findings.

The sensitivity of fecal calprotectin in predicting deep remission in ulcerative colitis.

BACKGROUND: Mucosal healing is proposed as treat-to-target in ulcerative colitis (UC), even though the definition of mucosal healing remains contested as it has been suggested to be assessed by either endoscopy, histology or both. However, all definitions require an endoscopic evaluation of the mucosa. As endoscopies are invasive and uncomfortable to the patient we aimed to calibrate noninvasive predictors of mucosal inflammatory status defined by both endoscopy and histology. METHODS: UC patients (n = 106) undergoing a sigmoid-/colonoscopy were prospectively included. Feces (fecal calprotectin, FC), blood samples (hemoglobin, C-reactive protein, orosomucoid, erythrocyte sedimentation rate, albumin) and symptom scores (Simple Clinical Colitis Activity Index, SSCAI) were collected and analyzed. The colonic mucosa was assessed by the Mayo endoscopic sub score and biopsies were obtained for a histologic grading by Geboes score. Predictive cutoff values were analyzed by receiver operating characteristics (ROC). A combined endoscopic and histologic assessment defined deep remission (Mayo =0 and Geboes ≤1) and activity (Mayo ≥2 and Geboes >3). RESULTS: Only FC showed a significant ROC curve (p < .05). We suggest FC (mg/kg) cutoffs for detection of following: Deep remission: FC ≤25; Indeterminate: FC 25-230 - an endoscopy is recommended if a comprehensive status of both endoscopic and histologic assessed activity is needed; Active disease: FC >230. The complete ROC data is presented, enabling extraction of an FC cutoff value's sensitivity and specificity. CONCLUSIONS: FC predicts endoscopic and histologic assessed deep remission and inflammatory activity of colon mucosa. Neither the markers in blood nor the SCCAI performed significant ROC results.

Individualized Infliximab Treatment Guided by Patient-managed eHealth in Children and Adolescents with Inflammatory Bowel Disease.

BACKGROUND: To individualize timing of infliximab (IFX) treatment in children and adolescents with inflammatory bowel disease (IBD) using a patient-managed eHealth program. METHODS: Patients with IBD, 10 to 17 years old, treated with IFX were prospectively included. Starting 4 weeks after their last infusion, patients reported a weekly symptom score and provided a stool sample for fecal calprotectin analysis. Based on symptom scores and fecal calprotectin results, the eHealth program calculated a total inflammation burden score that determined the timing of the next IFX infusion (4-12 wk after the previous infusion). Quality of Life was scored by IMPACT III. A control group was included to compare trough levels of IFX antibodies and concentrations and treatment intervals. Patients and their parents evaluated the eHealth program. RESULTS: There were 29 patients with IBD in the eHealth group and 21 patients with IBD in the control group. During the control period, 94 infusions were provided in the eHealth group (mean interval 9.5 wk; SD 2.3) versus 105 infusions in the control group (mean interval 6.9 wk; SD 1.4). Treatment intervals were longer in the eHealth group (P < 0.001). Quality of Life did not change during the study. Appearance of IFX antibodies did not differ between the 2 groups. Eighty percent of patients reported increased disease control and 63% (86% of parents) reported an improved knowledge of the disease. CONCLUSIONS: Self-managed, eHealth-individualized timing of IFX treatments, with treatment intervals of 4 to 12 weeks, was accompanied by no significant development of IFX antibodies. Patients reported better control and improved knowledge of their IBD.

Vedolizumab in Paediatric Inflammatory Bowel Disease: A Retrospective Multi-Centre Experience From the Paediatric IBD Porto Group of ESPGHAN.

Background: Vedolizumab, an anti-integrin antibody, has proven to be effective in adults with inflammatory bowel disease [IBD], but the data in paediatrics are limited. We describe the short-term effectiveness and safety of vedolizumab in a European multi-centre paediatric IBD cohort. Method: Retrospective review of children [aged 2-18 years] treated with vedolizumab from 19 centres affiliated with the Paediatric IBD Porto group of ESPGHAN. Primary outcome was Week 14 corticosteroid-free remission [CFR]. Results: In all, 64 children were included (32 [50%] male, mean age 14.5 ± 2.8 years, with a median follow-up 24 weeks [interquartile range 14-38; range 6-116]); 41 [64%] cases of ulcerative colitis/inflammatory bowel disease unclassified [UC/IBD-U] and 23 [36%] Crohn's disease [CD]. All were previously treated with anti-tumour necrosis factor [TNF] [28% primary failure, 53% secondary failure]. Week 14 CFR was 37% in UC, and 14% in CD [P = 0.06]. CFR by last follow-up was 39% in UC and 24% in CD [p = 0.24]. Ten [17%] children required surgery, six of whom had colectomy for UC. Concomitant immunomodulatory drugs did not affect remission rate [42% vs 35%; p = 0.35 at Week 22]. There were three minor drug-related adverse events. Only 3 of 16 children who underwent endoscopic evaluation had mucosal healing after treatment (19%). Conclusions: Vedolizumab was safe and effective in this cohort of paediatric refractory IBD. These data support previous findings of slow induction rate of vedolizumab in CD and a trend to be less effective compared with patients with UC.

F-calprotectin and Blood Markers Correlate to Quality of Life in Pediatric Inflammatory Bowel Disease.

OBJECTIVES: Our aim was to investigate predictors of health-related quality of life (HRQoL) with respect to changes in disease parameters over time in children with inflammatory bowel disease. METHODS: This was a prospective longitudinal study examining the association between HRQoL (IMPACT III) and symptom scores (Pediatric Crohn Disease Activity Index, abbreviated Pediatric Ulcerative Colitis Activity Index), fecal calprotectin measures and blood analyses (C-reactive protein, erythrocyte sedimentation rate, orosomucoid, albumin, hemoglobin, and vitamin-D) in a cohort of 10- to 17-year-old patients with inflammatory bowel disease. Data were collected prospectively at 3-month intervals during a 2-year period. Associations were analyzed using linear mixed-effect models. Patients were divided into 2 groups, which received nonbiological oral treatment or biological parenteral treatment. RESULTS: From 79 patients (39 Crohn disease/40 ulcerative colitis), representing a total of 43,132 days of observation, 572 IMPACT measurements were paired with variables. A decrease in the IMPACT III score was significantly associated with increased ulcerative colitis-symptom score in the biological group (P = 0.005), and a similar inverse tendency was found in the nonbiological group and for Crohn disease symptoms in both groups. We found in both treatment groups overall a significant (P < 0.05) inverse association between the IMPACT III and the levels of fecal calprotectin, erythrocyte sedimentation rate, and orosomucoid, whereas albumin, hemoglobin, and vitamin-D were directly significantly associated. CONCLUSIONS: The IMPACT score, already known to correlate with disease activity, has now been shown to be associated with disease markers in feces and blood. This emphasizes that objective markers of disease activity indirectly can predict the patient's HRQoL.

Self-managed eHealth Disease Monitoring in Children and Adolescents with Inflammatory Bowel Disease: A Randomized Controlled Trial.

BACKGROUND: To evaluate the impact of eHealth on disease activity, the need for hospital contacts, and medical adherence in children and adolescents with inflammatory bowel disease (IBD). Furthermore, to assess eHealth's influence on school attendance and quality of life (QoL). METHODS: Patients with IBD, 10 to 17 years attending a public university hospital, were prospectively randomized to a 2-year open label case-controlled eHealth intervention. The eHealth-group used the web-application young.constant-care.com (YCC) on a monthly basis and in case of flare-ups, and were seen at one annual preplanned outpatient visit. The control-group continued standard visits every third month. Every 3 months, both groups had blood and fecal calprotectin tested and the following were assessed: escalation in medication, disease activity, hospital contacts, medical adherence, school absence, and QoL. RESULTS: Fifty-three patients in nonbiological treatment were included (27 eHealth/26 control). We found no differences between the groups regarding escalation in treatment and disease activity (symptoms, fecal calprotectin, and blood). The number of total outpatient visits (mean: eHealth 3.26, SEM 0.51; control 7.31, SEM 0.69; P < 0.0001) and IBD-related school absence (mean days: eHealth 1.6, SEM 0.5; control 16.5, SEM 4.4; P < 0.002) was significantly lower in the eHealth-group. No differences in medical adherence and QoL were found. Adherence to YCC was 81% (384 of the 475 expected entries). None of the patients or parents felt unsafe using the eHealth system. CONCLUSIONS: The use of eHealth in children and adolescents with IBD is feasible, does not lead to impaired disease control, and can be managed by the patients without risk of increased disease activity.

Hollow-core fibers for high power pulse delivery.

We investigate hollow-core fibers for fiber delivery of high power ultrashort laser pulses. We use numerical techniques to design an anti-resonant hollow-core fiber having one layer of non-touching tubes to determine which structures offer the best optical properties for the delivery of high power picosecond pulses. A novel fiber with 7 tubes and a core of 30µm was fabricated and it is here described and characterized, showing remarkable low loss, low bend loss, and good mode quality. Its optical properties are compared to both a 10µm and a 18µm core diameter photonic band gap hollow-core fiber. The three fibers are characterized experimentally for the delivery of 22 picosecond pulses at 1032nm. We demonstrate flexible, diffraction limited beam delivery with output average powers in excess of 70W.