Increased abundance of proteobacteria in aggressive Crohn's disease seven years after diagnosis.

Intestinal dysbiosis in inflammatory bowel disease (IBD) patients depend on disease activity. We aimed to characterize the microbiota after 7 years of follow-up in an unselected cohort of IBD patients according to disease activity and disease severity. Fifty eight Crohn's disease (CD) and 82 ulcerative colitis (UC) patients were included. Disease activity was assessed by the Harvey-Bradshaw Index for CD and Simple Clinical Colitis Activity Index for UC. Microbiota diversity was assessed by 16S rDNA MiSeq sequencing. In UC patients with active disease and in CD patients with aggressive disease the richness (number of OTUs, p = 0.018 and p = 0.013, respectively) and diversity (Shannons index, p = 0.017 and p = 0.023, respectively) were significantly decreased. In the active UC group there was a significant decrease in abundance of the phylum Firmicutes (p = 0.018). The same was found in CD patients with aggressive disease (p = 0.05) while the abundance of Proteobacteria phylum showed a significant increase (p = 0.03) in CD patients. We found a change in the microbial abundance in UC patients with active disease and in CD patients with aggressive disease. These results suggest that dysbiosis of the gut in IBD patients is not only related to current activity but also to the course of the disease.

Hepatoblastoma in the Nordic countries.

Little is known about the etiology of hepatoblastoma. Because of the young age at diagnosis, several studies have looked at various birth characteristics. The purpose of our study was to investigate the incidence of hepatoblastoma in the Nordic countries and the association between selected birth characteristics and hepatoblastoma. Data from national cancer registries and birth registries in Denmark, Sweden, Norway and Finland 1985-2006 was used. Overall, 155 children with hepatoblastoma aged 0-14 years were included and individually matched to five controls drawn randomly from national population registries. The incidence rate of hepatoblastoma was 1.7 per million person-years with a predominance of boys (1.5:1). Incidence rate was highest before the age of 1 year (8.3 per million person-years). A higher risk of hepatoblastoma was found in children with birth weight <1,500 g [odds ratio (OR) = 9.5; 95% confidence interval (CI): 2.3-38.2], born preterm in week 22-32 (OR = 4.5; CI: 1.8-11.5) and Apgar scores <7 after 1 min (OR = 3.1; CI: 1.3-7.1) and 5 min (OR = 7.5; CI: 1.8-32.4). A doubling in risk was found in children who were large for gestational age (OR = 2.3; CI: 1.0-5.3). No associations were found with birth order, maternal age or maternal smoking. Our study indicates that intrauterine and/or neonatal factors are associated with increased risk of hepatoblastoma. These may include low birth weight and asphyxia leading to neonatal intensive care. Alternatively, the factors may be a consequence of hepatoblastoma developing in utero.

Infectious exposure in the first years of life and risk of central nervous system tumours in children: analysis of birth order, childcare attendance and seasonality of birth.

BACKGROUND: An infective, mostly viral basis has been found in different human cancers. To test the hypothesis of a possible infectious aetiology for central nervous system (CNS) tumours in children, we investigated the associations with proxy measures of exposure to infectious disease. METHODS: In a large case-control study nested in the populations of Denmark, Norway, Sweden, and Finland of 4.4 million children, we studied the association of birth order and seasonal variation of birth with subsequent risk for CNS tumours. We identified 3983 children from the national cancer registries, and information on exposure was obtained from the high-quality national administrative health registries. We investigated the association between childcare attendance during the first 2 years of life and the risk for CNS tumours in a subset of Danish children with CNS tumours, using information from the Danish Childcare database. RESULTS: We observed no association between birth order and risk of CNS tumours overall (odds ratio (OR) for second born or later born vs first born, 1.03; 95% confidence interval (CI), 0.96-1.10) or by histological subgroup, and children with CNS tumours did not show a seasonal variation of birth that was distinct from that of the background population. Childcare attendance compared with homecare showed a slightly increased OR (1.29; 95% CI, 0.90-1.86) for CNS tumours, with the highest risk observed in children attending a crèche. The strongest association was observed for embryonal CNS tumours. We found no effect of age at enrolment or duration of enrolment in childcare. CONCLUSION: These results do not support the hypothesis that the burden of exposure to infectious disease in early childhood has an important role in the aetiology of paediatric CNS tumours.