Bulk RNA sequencing of human pediatric lung cell populations reveals unique transcriptomic signature associated with postnatal pulmonary development.

Postnatal lung development results in an increasingly functional organ prepared for gas exchange and pathogenic challenges. It is achieved through cellular differentiation and migration. Changes in the tissue architecture during this development process are well-documented and increasing cellular diversity associated with it are reported in recent years. Despite recent progress, transcriptomic and molecular pathways associated with human postnatal lung development are yet to be fully understood. In this study, we investigated gene expression patterns associated with healthy pediatric lung development in four major enriched cell populations (epithelial, endothelial, and nonendothelial mesenchymal cells, along with lung leukocytes) from 1-day-old to 8-yr-old organ donors with no known lung disease. For analysis, we considered the donors in four age groups [less than 30 days old neonates, 30 days to < 1 yr old infants, toddlers (1 to < 2 yr), and children 2 yr and older] and assessed differentially expressed genes (DEG). We found increasing age-associated transcriptional changes in all four major cell types in pediatric lung. Transition from neonate to infant stage showed highest number of DEG compared with the number of DEG found during infant to toddler- or toddler to older children-transitions. Profiles of differential gene expression and further pathway enrichment analyses indicate functional epithelial cell maturation and increased capability of antigen presentation and chemokine-mediated communication. Our study provides a comprehensive reference of gene expression patterns during healthy pediatric lung development that will be useful in identifying and understanding aberrant gene expression patterns associated with early life respiratory diseases.NEW & NOTEWORTHY This study presents postnatal transcriptomic changes in major cell populations in human lung, namely endothelial, epithelial, mesenchymal cells, and leukocytes. Although human postnatal lung development continues through early adulthood, our results demonstrate that greatest transcriptional changes occur in first few months of life during neonate to infant transition. These early transcriptional changes in lung parenchyma are particularly notable for functional maturation and activation of alveolar type II cell genes.

New insights into the natural history of bronchopulmonary dysplasia from proteomics and multiplexed immunohistochemistry.

Bronchopulmonary dysplasia (BPD) is a disease of prematurity related to the arrest of normal lung development. The objective of this study was to better understand how proteome modulation and cell-type shifts are noted in BPD pathology. Pediatric human donors aged 1-3 yr were classified based on history of prematurity and histopathology consistent with "healed" BPD (hBPD, n = 3) and "established" BPD (eBPD, n = 3) compared with respective full-term born (n = 6) age-matched term controls. Proteins were quantified by tandem mass spectroscopy with selected Western blot validations. Multiplexed immunofluorescence (MxIF) microscopy was performed on lung sections to enumerate cell types. Protein abundances and MxIF cell frequencies were compared among groups using ANOVA. Cell type and ontology enrichment were performed using an in-house tool and/or EnrichR. Proteomics detected 5,746 unique proteins, 186 upregulated and 534 downregulated, in eBPD versus control with fewer proteins differentially abundant in hBPD as compared with age-matched term controls. Cell-type enrichment suggested a loss of alveolar type I, alveolar type II, endothelial/capillary, and lymphatics, and an increase in smooth muscle and fibroblasts consistent with MxIF. Histochemistry and Western analysis also supported predictions of upregulated ferroptosis in eBPD versus control. Finally, several extracellular matrix components mapping to angiogenesis signaling pathways were altered in eBPD. Despite clear parsing by protein abundance, comparative MxIF analysis confirms phenotypic variability in BPD. This work provides the first demonstration of tandem mass spectrometry and multiplexed molecular analysis of human lung tissue for critical elucidation of BPD trajectory-defining factors into early childhood.NEW & NOTEWORTHY We provide new insights into the natural history of bronchopulmonary dysplasia in donor human lungs after the neonatal intensive care unit hospitalization. This study provides new insights into how the proteome and histopathology of BPD changes in early childhood, uncovering novel pathways for future study.

Influence of the irradiated pulmonary microenvironment on macrophage and T cell dynamics.

BACKGROUND: The lung is sensitive to radiation, increasing normal tissue toxicity risks following radiation therapy. Adverse outcomes include pneumonitis and pulmonary fibrosis, which result from dysregulated intercellular communication within the pulmonary microenvironment. Although macrophages are implicated in these pathogenic outcomes, the impact of their microenvironment is not well understood. MATERIALS AND METHODS: C57BL/6J mice received 6Gyx5 irradiation to the right lung. Macrophage and T cell dynamics were investigated in ipsilateral right lungs, contralateral left lungs and non-irradiated control lungs 4-26wk post exposure. Lungs were evaluated by flow cytometry, histology and proteomics. RESULTS: Following uni-lung irradiation, focal regions of macrophage accumulation were noted in both lungs by 8wk, however by 26wk fibrotic lesions were observed only in ipsilateral lungs. Infiltrating and alveolar macrophages populations expanded in both lungs, however transitional CD11b + alveolar macrophages persisted only in ipsilateral lungs and expressed lower CD206. Concurrently, arginase-1 + macrophages accumulated in ipsilateral but not contralateral lungs at 8 and 26wk post exposure, while CD206 + macrophages were absent from these accumulations. While radiation expanded CD8 + T cells in both lungs, T regulatory cells only increased in ipsilateral lungs. Unbiased proteomics analysis of immune cells revealed a substantial number of differentially expressed proteins in ipsilateral lungs when compared to contralateral lungs and both differed from non-irradiated controls. CONCLUSIONS: Pulmonary macrophage and T cell dynamics are impacted by the microenvironmental conditions that develop following radiation exposure, both locally and systemically. While macrophages and T cells infiltrate and expand in both lungs, they diverge phenotypically depending on their environment.

A novel digital rectoscope for the triage of lower gastrointestinal symptoms in primary care: a prospective multicentre feasibility study.

BACKGROUND: Access to community rectoscopy might help to ease the burden on hospital services and reduce costs for the NHS. To assess this, a prospective multicentre observational phase I feasibility study of a novel digital rectoscope and telestration software for the triage of lower gastrointestinal (GI) symptoms was undertaken. AIM: To determine if digital rectoscopy is feasible, acceptable, and clinically safe. DESIGN & SETTING: Evaluation of clinician case reports and patient questionnaires from patients recruited from five primary care centres. METHOD: Adults meeting 2-week wait (2WW) criteria for suspected lower GI cancer, suspected new diagnosis, or flare-up of inflammatory bowel disease (IBD) were enrolled. Examinations were performed by primary care practitioners using the LumenEye rectoscope. The CHiP platform allowed immediate remote review by secondary care. A prospective analysis was performed of patient and clinician experiences, diagnostic accuracy, and cost. RESULTS: A total of 114 patients were recruited and 110 underwent the procedure (46 [42%] females and 64 [58%] males). No serious adverse events were reported. Eighty-two (74.5%) patients reported that examination was more comfortable than expected, while 104 (94.5%) felt the intervention was most convenient if delivered in the community. Clinicians were confident of their assessment in 100 (87.7%) examinations. Forty-eight (42.1%) patients subsequently underwent colonoscopy, flexible sigmoidoscopy, or computed tomography virtual colonoscopy (CTVC). The overall sensitivity and specificity of LumenEye in identifying rectal pathology was 90.0% and 88.9%. It was 100% and 100% for cancer, and 83.3% and 97.8% for polyps. Following LumenEye examination, 19 (17.3%) patients were discharged, with projected savings of 11 305 GBP. CONCLUSION: Digital rectoscopy in primary care is safe, acceptable, and can reduce referrals. A phase III randomised controlled trial is indicated to define its utility in reducing the burden on hospital diagnostic services.

The dietary practices and beliefs of people living with older-onset inflammatory bowel disease.

BACKGROUND AND OBJECTIVES: The role of diet in inflammatory bowel disease (IBD) remains incompletely understood. Studies have previously examined dietary practices in IBD, but none have specifically focused on older-onset disease. IBD may put vulnerable groups at risk of nutritional deficiency and associated complications, potentially heightened by comorbidities, frailty and polypharmacy. Our objective was to describe dietary practices and beliefs in older-onset IBD. METHODS: A questionnaire exploring dietary practices and beliefs was prospectively administered to 137 people with older-onset IBD attending gastroenterology clinics. RESULTS: Thirty-two percent believed diet was the initiating factor for their IBD. This was significantly more likely in people with Crohn's disease than ulcerative colitis (P = 0.05) and in those who felt limited in their dietary choices due to cost (P = 0.008). Forty-three percent believed diet could trigger IBD relapse and 68% avoided dietary components to avoid relapse. Most frequently avoided were spicy and fatty foods, carbonated drinks, red meat, alcohol and raw fruit and vegetables. Twenty-two percent of participants had tried a whole food exclusion diet, most frequently gluten- or lactose-free. Almost a third avoided eating out (29%) or eating the same meal as their family (32%) to prevent relapse. Respondents rarely relied upon healthcare professionals or patient support organisations for their dietary information. CONCLUSION: Individuals with older-onset IBD report dietary practices with a high degree of consistency. Dietary avoidance may impact upon both nutritional and psychosocial wellbeing in this more vulnerable group and, as such, early dietetic assessment could help improve outcomes.

E-cigarette exposures, respiratory tract infections, and impaired innate immunity: a narrative review.

Electronic cigarettes (e-cigarettes) are commonly used devices by adolescents and young adults. Since their introduction, the popularity of e-cigarettes has increased significantly with close to twenty percent of United States high school students reporting current use in 2020. As the number of e-cigarette users has increased, so have reports of vaping related health complications. Overall, respiratory tract infections remain one of the top ten leading causes of death in the US for every age group. Specific to the pediatric population, lower respiratory tract infections are the leading cause for hospitalization. This review highlights the current evidence behind e-cigarette exposure and its association with impaired innate immune function and the risk of lower respiratory tract infections. To date, various preclinical models have evaluated the direct effects of e-cigarette exposure on the innate immune system. More specifically, e-cigarette exposure impairs certain cell types of the innate immune system including the airway epithelium, lung macrophage and neutrophils. Identified effects of e-cigarette exposure common to the lung's innate immunity include abnormal mucus composition, reduced epithelial barrier function, impaired phagocytosis and elevated systemic markers of inflammation. These identified impairments in the lung's innate immunity have been shown to increase adhesion of certain bacteria and fungi as well as to increase virulence of common respiratory pathogens such as influenza virus, Staphylococcus aureus or Streptococcus pneumoniae. Information summarized in this review will provide guidance to healthcare providers, policy advocates and researchers for making informed decisions regarding the associated respiratory health risks of e-cigarette use in pediatric and young adults.

The use of 5-aminosalicylate for patients with Crohn's disease in a prospective European inception cohort with 5 years follow-up - an Epi-IBD study.

BACKGROUND: The lack of scientific evidence regarding the effectiveness of 5-aminosalicylate in patients with Crohn's disease is in sharp contrast to its widespread use in clinical practice. AIMS: The aim of the study was to investigate the use of 5-aminosalicylate in patients with Crohn's disease as well as the disease course of a subgroup of patients who were treated with 5-aminosalicylate as maintenance monotherapy during the first year of disease. METHODS: In a European community-based inception cohort, 488 patients with Crohn's disease were followed from the time of their diagnosis. Information on clinical data, demographics, disease activity, medical therapy and rates of surgery, cancers and deaths was collected prospectively. Patient management was left to the discretion of the treating gastroenterologists. RESULTS: Overall, 292 (60%) patients with Crohn's disease received 5-aminosalicylate period during follow-up for a median duration of 28 months (interquartile range 6-60). Of these, 78 (16%) patients received 5-aminosalicylate monotherapy during the first year following diagnosis. Patients who received monotherapy with 5-aminosalicylate experienced a mild disease course with only nine (12%) who required hospitalization, surgery, or developed stricturing or penetrating disease, and most never needed more intensive therapy. The remaining 214 patients were treated with 5-aminosalicylate as the first maintenance drug although most eventually needed to step up to other treatments including immunomodulators (75 (35%)), biological therapy (49 (23%)) or surgery (38 (18%)). CONCLUSION: In this European community-based inception cohort of unselected Crohn's disease patients, 5-aminosalicylate was commonly used. A substantial group of these patients experienced a quiescent disease course without need of additional treatment during follow-up. Therefore, despite the controversy regarding the efficacy of 5-aminosalicylate in Crohn's disease, its use seems to result in a satisfying disease course for both patients and physicians.

Bacteroides thetaiotaomicron-derived outer membrane vesicles promote regulatory dendritic cell responses in health but not in inflammatory bowel disease.

BACKGROUND: Bacteroides thetaiotaomicron (Bt) is a prominent member of the human intestinal microbiota that, like all gram-negative bacteria, naturally generates nanosized outer membrane vesicles (OMVs) which bud off from the cell surface. Importantly, OMVs can cross the intestinal epithelial barrier to mediate microbe-host cell crosstalk involving both epithelial and immune cells to help maintain intestinal homeostasis. Here, we have examined the interaction between Bt OMVs and blood or colonic mucosa-derived dendritic cells (DC) from healthy individuals and patients with Crohn's disease (CD) or ulcerative colitis (UC). RESULTS: In healthy individuals, Bt OMVs stimulated significant (p < 0.05) IL-10 expression by colonic DC, whereas in peripheral blood-derived DC they also stimulated significant (p < 0.001 and p < 0.01, respectively) expression of IL-6 and the activation marker CD80. Conversely, in UC Bt OMVs were unable to elicit IL-10 expression by colonic DC. There were also reduced numbers of CD103+ DC in the colon of both UC and CD patients compared to controls, supporting a loss of regulatory DC in both diseases. Furthermore, in CD and UC, Bt OMVs elicited a significantly lower proportion of DC which expressed IL-10 (p < 0.01 and p < 0.001, respectively) in blood compared to controls. These alterations in DC responses to Bt OMVs were seen in patients with inactive disease, and thus are indicative of intrinsic defects in immune responses to this commensal in inflammatory bowel disease (IBD). CONCLUSIONS: Overall, our findings suggest a key role for OMVs generated by the commensal gut bacterium Bt in directing a balanced immune response to constituents of the microbiota locally and systemically during health which is altered in IBD patients. Video Abstract.

Lymphocyte-Specific Biomarkers Associated With Preterm Birth and Bronchopulmonary Dysplasia.

Many premature babies who are born with neonatal respiratory distress syndrome (RDS) go on to develop Bronchopulmonary Dysplasia (BPD) and later Post-Prematurity Respiratory Disease (PRD) at one year corrected age, characterized by persistent or recurrent lower respiratory tract symptoms frequently related to inflammation and viral infection. Transcriptomic profiles were generated from sorted peripheral blood CD8+ T cells of preterm and full-term infants enrolled with consent in the NHLBI Prematurity and Respiratory Outcomes Program (PROP) at the University of Rochester and the University at Buffalo. We identified outcome-related gene expression patterns following standard methods to identify markers for oxygen utilization and BPD as outcomes in extremely premature infants. We further identified predictor gene sets for BPD based on transcriptomic data adjusted for gestational age at birth (GAB). RNA-Seq analysis was completed for CD8+ T cells from 145 subjects. Among the subjects with highest risk for BPD (born at <29 weeks gestational age (GA); n=72), 501 genes were associated with oxygen utilization. In the same set of subjects, 571 genes were differentially expressed in subjects with a diagnosis of BPD and 105 genes were different in BPD subjects as defined by physiologic challenge. A set of 92 genes could predict BPD with a moderately high degree of accuracy. We consistently observed dysregulation of TGFB, NRF2, HIPPO, and CD40-associated pathways in BPD. Using gene expression data from both premature and full-term subjects (n=116), we identified a 28 gene set that predicted the PRD status with a moderately high level of accuracy, which also were involved in TGFB signaling. Transcriptomic data from sort-purified peripheral blood CD8+ T cells from 145 preterm and full-term infants identified sets of molecular markers of inflammation associated with independent development of BPD in extremely premature infants at high risk for the disease and of PRD among the preterm and full-term subjects.

A novel in vitro model of primary human pediatric lung epithelial cells.

BACKGROUND: Current in vitro human lung epithelial cell models derived from adult tissues may not accurately represent all attributes that define homeostatic and disease mechanisms relevant to the pediatric lung. METHODS: We report methods for growing and differentiating primary Pediatric Human Lung Epithelial (PHLE) cells from organ donor infant lung tissues. We use immunohistochemistry, flow cytometry, quantitative RT-PCR, and single cell RNA sequencing (scRNAseq) analysis to characterize the cellular and transcriptional heterogeneity of PHLE cells. RESULTS: PHLE cells can be expanded in culture up to passage 6, with a doubling time of ~4 days, and retain attributes of highly enriched epithelial cells. PHLE cells can form resistant monolayers, and undergo differentiation when placed at air-liquid interface. When grown at Air-Liquid Interface (ALI), PHLE cells expressed markers of airway epithelial cell lineages. scRNAseq suggests the cultures contained 4 main sub-phenotypes defined by expression of FOXJ1, KRT5, MUC5B, and SFTPB. These cells are available to the research community through the Developing Lung Molecular Atlas Program Human Tissue Core. CONCLUSION: Our data demonstrate that PHLE cells provide a novel in vitro human cell model that represents the pediatric airway epithelium, which can be used to study perinatal developmental and pediatric disease mechanisms.

CX3CR1 as a respiratory syncytial virus receptor in pediatric human lung.

BACKGROUND: Data on the host factors that contribute to infection of young children by respiratory syncytial virus (RSV) are limited. The human chemokine receptor, CX3CR1, has recently been implicated as an RSV receptor. Here we evaluate a role for CX3CR1 in pediatric lung RSV infections. METHODS: CX3CR1 transcript levels in the upper and lower pediatric airways were assessed. Tissue localization and cell-specific expression was confirmed using in situ hybridization and immunohistochemistry. The role of CX3CR1 in RSV infection was also investigated using a novel physiological model of pediatric epithelial cells. RESULTS: Low levels of CX3CR1 transcript were often, but not always, expressed in both upper (62%) and lower airways (36%) of pediatric subjects. CX3CR1 transcript and protein expression was detected in epithelial cells of normal human pediatric lung tissues. CX3CR1 expression was readily detected on primary cultures of differentiated pediatric/infant human lung epithelial cells. RSV demonstrated preferential infection of CX3CR1-positive cells, and blocking CX3CR1/RSV interaction significantly decreased viral load. CONCLUSION: CX3CR1 is present in the airways of pediatric subjects where it may serve as a receptor for RSV infection. Furthermore, CX3CR1 appears to play a mechanistic role in mediating viral infection of pediatric airway epithelial cells in vitro.

Ethnic differences in inflammatory bowel disease: Results from the United Kingdom inception cohort epidemiology study.

BACKGROUND: The current epidemiology of inflammatory bowel disease (IBD) in the multi-ethnic United Kingdom is unknown. The last incidence study in the United Kingdom was carried out over 20 years ago. AIM: To describe the incidence and phenotype of IBD and distribution within ethnic groups. METHODS: Adult patients (> 16 years) with newly diagnosed IBD (fulfilling Copenhagen diagnostic criteria) were prospectively recruited over one year in 5 urban catchment areas with high South Asian population. Patient demographics, ethnic codes, disease phenotype (Montreal classification), disease activity and treatment within 3 months of diagnosis were recorded onto the Epicom database. RESULTS: Across a population of 2271406 adults, 339 adult patients were diagnosed with IBD over one year: 218 with ulcerative colitis (UC, 64.3%), 115 with Crohn's disease (CD, 33.9%) and 6 with IBD unclassified (1.8%). The crude incidence of IBD, UC and CD was 17.0/100000, 11.3/100000 and 5.3/100000 respectively. The age adjusted incidence of IBD and UC were significantly higher in the Indian group (25.2/100000 and 20.5/100000) compared to White European (14.9/100000, P = 0.009 and 8.2/100000, P < 0.001) and Pakistani groups (14.9/100000, P = 0.001 and 11.2/100000, P = 0.007). The Indian group were significantly more likely to have extensive disease than White Europeans (52.7% vs 41.7%, P = 0.031). There was no significant difference in time to diagnosis, disease activity and treatment. CONCLUSION: This is the only prospective study to report the incidence of IBD in an ethnically diverse United Kingdom population. The Indian ethnic group showed the highest age-adjusted incidence of UC (20.5/100000). Further studies on dietary, microbial and metabolic factors that might explain these findings in UC are underway.

Natural disease course of Crohn's disease during the first 5 years after diagnosis in a European population-based inception cohort: an Epi-IBD study.

OBJECTIVE: The Epi-IBD cohort is a prospective population-based inception cohort of unselected patients with inflammatory bowel disease from 29 European centres covering a background population of almost 10 million people. The aim of this study was to assess the 5-year outcome and disease course of patients with Crohn's disease (CD). DESIGN: Patients were followed up prospectively from the time of diagnosis, including collection of their clinical data, demographics, disease activity, medical therapy, surgery, cancers and deaths. Associations between outcomes and multiple covariates were analysed by Cox regression analysis. RESULTS: In total, 488 patients were included in the study. During follow-up, 107 (22%) patients received surgery, while 176 (36%) patients were hospitalised because of CD. A total of 49 (14%) patients diagnosed with non-stricturing, non-penetrating disease progressed to either stricturing and/or penetrating disease. These rates did not differ between patients from Western and Eastern Europe. However, significant geographic differences were noted regarding treatment: more patients in Western Europe received biological therapy (33%) and immunomodulators (66%) than did those in Eastern Europe (14% and 54%, respectively, P<0.01), while more Eastern European patients received 5-aminosalicylates (90% vs 56%, P<0.05). Treatment with immunomodulators reduced the risk of surgery (HR: 0.4, 95% CI 0.2 to 0.6) and hospitalisation (HR: 0.3, 95% CI 0.2 to 0.5). CONCLUSION: Despite patients being treated early and frequently with immunomodulators and biological therapy in Western Europe, 5-year outcomes including surgery and phenotype progression in this cohort were comparable across Western and Eastern Europe. Differences in treatment strategies between Western and Eastern European centres did not affect the disease course. Treatment with immunomodulators reduced the risk of surgery and hospitalisation.

Natural Disease Course of Ulcerative Colitis During the First Five Years of Follow-up in a European Population-based Inception Cohort-An Epi-IBD Study.

BACKGROUND AND AIMS: Few population-based cohort studies have assessed the disease course of ulcerative colitis [UC] in the era of biological therapy and widespread use of immunomodulators. The aim of this study was to assess the 5-year outcome and disease course of patients with UC in the Epi-IBD cohort. METHODS: In a prospective, population-based inception cohort of unselected patients with UC, patients were followed up from the time of their diagnosis, which included the collection of their clinical data, demographics, disease activity, medical therapy, and rates of surgery, cancers, and deaths. Associations between outcomes and multiple covariates were analysed by Cox regression analysis. RESULTS: A total of 717 patients were included in the study. During follow-up, 43 [6%] patients underwent a colectomy and 163 [23%] patients were hospitalised. Of patients with limited colitis [distal to the left flexure], 90 [21%] progressed to extensive colitis. In addition, 92 [27%] patients with extensive colitis experienced a regression in disease extent, which was associated with a reduced risk of hospitalisation (hazard ratio [HR]: 0.5 95% CI: 0.3-0.8]. Overall, patients were treated similarly in both geographical regions; 80 [11%] patients needed biological therapy and 210 [29%] patients received immunomodulators. Treatment with immunomodulators was found to reduce the risk of hospitalisation [HR: 0.5 95% CI: 0.3-0.8]. CONCLUSIONS: Although patients in this population-based cohort were treated more aggressively with immunomodulators and biological therapy than in cohorts from the previous two decades, their disease outcomes, including colectomy rates, were no different. However, treatment with immunomodulators was found to reduce the risk of hospitalisation.

Disease course of inflammatory bowel disease unclassified in a European population-based inception cohort: An Epi-IBD study.

BACKGROUND AND AIM: A definitive diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) is not always possible, and a proportion of patients will be diagnosed as inflammatory bowel disease unclassified (IBDU). The aim of the study was to investigate the prognosis of patients initially diagnosed with IBDU and the disease course during the following 5 years. METHODS: The Epi-IBD study is a prospective population-based cohort of 1289 IBD patients diagnosed in centers across Europe. Clinical data were captured prospectively throughout the follow-up period. RESULTS: Overall, 476 (37%) patients were initially diagnosed with CD, 701 (54%) with UC, and 112 (9%) with IBDU. During follow-up, 28 (25%) IBDU patients were changed diagnoses to either UC (n = 20, 71%) or CD (n = 8, 29%) after a median of 6 months (interquartile range: 4-12), while 84 (7% of the total cohort) remained IBDU. A total of 17 (15%) IBDU patients were hospitalized for their IBD during follow-up, while 8 (7%) patients underwent surgery. Most surgeries (n = 6, 75%) were performed on patients whose diagnosis was later changed to UC; three of these colectomies led to a definitive diagnosis of UC. Most patients (n = 107, 96%) received 5-aminosalicylic acid, while 11 (10%) patients received biologicals, of whom five remained classified as IBDU. CONCLUSIONS: In a population-based inception cohort, 7% of IBD patients were not given a definitive diagnosis of IBD after 5 years of follow-up. One in four patients with IBDU eventually was classified as CD or UC. Overall, the disease course and medication burden in IBDU patients were mild.

Vitamin D deficiency in a European inflammatory bowel disease inception cohort: an Epi-IBD study.

BACKGROUND: Serum vitamin D level is commonly low in patients with inflammatory bowel disease (IBD). Although there is a growing body of evidence that links low vitamin D level to certain aspects of IBD such as disease activity and quality of life, data on its prevalence and how it varies across disease phenotype, smoking status and treatment groups are still missing. MATERIALS AND METHODS: Patients diagnosed with IBD between 2010 and 2011 were recruited. Demographic data and serum vitamin D levels were collected. Variance of vitamin D level was then assessed across different treatment groups, disease phenotype, disease activity and quality of life scores. RESULTS: A total of 238 (55.9% male) patients were included. Overall, 79% of the patients had either insufficient or deficient levels of vitamin D at diagnosis. Patients needing corticosteroid treatment at 1 year had significantly lower vitamin D levels at diagnosis (median 36.0 nmol/l) (P=0.035). Harvey-Bradshaw Index (P=0.0001) and Simple Clinical Colitis Activity Index scores (P=0.0001) were significantly lower in patients with higher vitamin D level. Serum vitamin D level correlated significantly with SIBQ score (P=0.0001) and with multiple components of SF12. Smokers at diagnosis had the lowest vitamin D levels (vitamin D: 34 nmol/l; P=0.053). CONCLUSION: This study demonstrates the high prevalence of low vitamin D levels in treatment-naive European IBD populations. Furthermore, it demonstrates the presence of low vitamin D levels in patients with IBD who smoke.

Epidemiology of inflammatory bowel disease in racial and ethnic migrant groups.

AIM: To summarise the current literature and define patterns of disease in migrant and racial groups. METHODS: A structured key word search in Ovid Medline and EMBASE was undertaken in accordance with PRISMA guidelines. Studies on incidence, prevalence and disease phenotype of migrants and races compared with indigenous groups were eligible for inclusion. RESULTS: Thirty-three studies met the inclusion criteria. Individual studies showed significant differences in incidence, prevalence and disease phenotype between migrants or race and indigenous groups. Pooled analysis could only be undertaken for incidence studies on South Asians where there was significant heterogeneity between the studies [95% for ulcerative colitis (UC), 83% for Crohn's disease (CD)]. The difference between incidence rates was not significant with a rate ratio South Asian: Caucasian of 0.78 (95%CI: 0.22-2.78) for CD and 1.39 (95%CI: 0.84-2.32) for UC. South Asians showed consistently higher incidence and more extensive UC than the indigenous population in five countries. A similar pattern was observed for Hispanics in the United States. Bangladeshis and African Americans showed an increased risk of CD with perianal disease. CONCLUSION: This review suggests that migration and race influence the risk of developing inflammatory bowel disease. This may be due to different inherent responses upon exposure to an environmental trigger in the adopted country. Further prospective studies on homogenous migrant populations are needed to validate these observations, with a parallel arm for in-depth investigation of putative drivers.

Impact of a new distal attachment on colonoscopy performance in an academic screening center.

BACKGROUND AND AIMS: Distal attachments placed on the colonoscope tip may positively affect performance by assisting insertion and polyp detection. The original Endocuff (ARC Medical Design, Leeds, United Kingdom) appears to improve adenoma detection rate (ADR), but no data assess the performance of the second-generation Endocuff Vision. METHODS: A pilot service evaluation study (April 2013 to September 2014) was conducted on patients with positive fecal occult blood tests within the National Bowel Cancer Programme during 3 consecutive periods: precuff/no device used, during-cuff/device used, and postcuff/no device used. During the middle period the use of the Endocuff Vision by the 4 screening-accredited colonoscopists was discretional (nonrandomized design). Data were analyzed using pairwise comparisons during the 3 designated periods to examine key performance indicators: adenoma detection, procedural time, sedation requirements, and patient comfort. RESULTS: Four hundred ten complete colonoscopies were performed (137 precuff, 136 cuff, and 137 postcuff period). Overall, there was a notable increase in the mean ADR of 16% (P < .03) and in the mean number adenoma per procedure (MAP) of 83% (P = .007) from precuff to cuff period. The mean cecal intubation time was statistically lower during the cuff period (7 minutes) in relation to the precuff period (8 minutes; reduction of 12.5%, P = .002) and the postcuff period (9 minutes; increase of 28.6%, P = .002). The mean negative colonoscopy withdrawal time was also significantly lower during the cuff period (8 minutes, 30 seconds) when compared with the precuff (12 minutes) or postcuff period (9 minutes, 45 seconds; P ≤ .001). Multivariate regression analysis showed that the use of the Endocuff Vision was not associated with sedation requirements or patient discomfort scores. No adverse events were reported from the use of the Endocuff Vision, although it was electively removed in 6 patients where severe sigmoid colon diverticulosis was encountered and 2 patients because of discomfort during anal insertion. CONCLUSIONS: In this pilot service evaluation study, the use of the Endocuff Vision appears to be associated with an improvement in overall colonoscopy operator performance. We found increased ADR and MAP as well as decreased time for colonoscope insertion and withdrawal time with no increase in sedation requirements or patient discomfort.

Effects of IL-4 on pulmonary fibrosis and the accumulation and phenotype of macrophage subpopulations following thoracic irradiation.

PURPOSE: Thoracic irradiation injures lung parenchyma, triggering inflammation and immune cell activation, leading to pneumonitis and fibrosis. Macrophage polarization contributes to these processes. Since IL-4 promotes pro-fibrotic macrophage activation, its role in radiation-induced lung injury was investigated. MATERIALS AND METHODS: Lung macrophage subpopulations were characterized from 3-26 weeks following exposure of WT and IL-4-/- mice to 0 or 12.5 Gray single dose thoracic irradiation. RESULTS: Loss of IL-4 did not prevent fibrosis, but blunted macrophage accumulation within the parenchyma. At 3 weeks following exposure, cell numbers and expression of F4/80 and CD206, an alternative activation marker, decreased in alveolar macrophages but increased in infiltrating macrophages in WT mice. Loss of IL-4 impaired recovery of these markers in alveolar macrophages and blunted expansion of these populations in infiltrating macrophages. CD206+ cells were evident in fibrotic regions of WT mice only, however Arg-1+ cells increased in fibrotic regions in IL-4-/- mice only. Radiation-induced proinflammatory Ly6C expression was more apparent in alveolar and interstitial macrophages from IL-4-/- mice. CONCLUSIONS: IL-4 loss did not prevent alternative macrophage activation and fibrosis in irradiated mice. Instead, a role is indicated for IL-4 in maintenance of macrophage populations in the lung following high single dose thoracic irradiation.