Aluminum enhances inflammation and decreases mucosal healing in experimental colitis in mice

The increasing incidence of inflammatory bowel diseases (IBDs) in developing countries has highlighted the critical role of environmental pollutants as causative factors in their pathophysiology. Despite its ubiquity and immune toxicity, the impact of aluminum in the gut is not known. This study aimed to evaluate the effects of environmentally relevant intoxication with aluminum in murine models of colitis and to explore the underlying mechanisms. Oral administration of aluminum worsened intestinal inflammation in mice with 2,4,6-trinitrobenzene sulfonic acid- and dextran sodium sulfate-induced colitis and chronic colitis in interleukin 10-negative (IL10(-/-)) mice. Aluminum increased the intensity and duration of macroscopic and histologic inflammation, colonic myeloperoxidase activity, inflammatory cytokines expression, and decreased the epithelial cell renewal compared with control animals. Under basal conditions, aluminum impaired intestinal barrier function. In vitro, aluminum induced granuloma formation and synergized with lipopolysaccharide to stimulate inflammatory cytokines expression by epithelial cells. Deleterious effects of aluminum on intestinal inflammation and mucosal repair strongly suggest that aluminum might be an environmental IBD risk factor.Mucosal Immunology advance online publication, 16 October 2013; doi:10.1038/mi.2013.78

Cancer incidence in Behçet's disease

Background: Previous studies demonstrated an increased cancer risk in autoimmune diseases. Behçet's disease (BD) was also reported to be associated with an increased risk of cancer, although the data is limited. Aims: In this study, we aimed to assess cancer incidence in a large cohort of BD patients and to compare with the data of the same age and gender groups. Methods: The study cohort consisted of BD patients of > 18 years of age who were prospectively recorded in the Hacettepe University Vasculitis Center. Data on any cancer was collected from the patient files. Cancer incidence was compared with age- and gender-specific cancer incidence rates of the normal population retrieved from the 2014 Turkish National Cancer Registry (TNCR) data using standardized incidence rates (SIR). Results: Totally, 451 adult cases with BD were included. The median age of the cohort was 43 (20-75), and 52.5% of the patients were males. Eleven cancer cases were observed during a median of 124 months follow-up. Behçet's disease was associated with an increase in cancer risk compared with expected counts in the corresponding age and sex group (SIR 2.84, 95% CI 1.50-4.94, p < 0.001). Patients with papulopustular lesions had a trend toward a decreased risk of cancer (p = 0.060), and patients using azathioprine had a significantly decreased cancer risk (p = 0.031). Conclusion: This study revealed BD patients had approximately three times increased cancer risk compared with corresponding age and sex groups. Besides the routine care, increased attention for cancer surveillance is required in the follow-up of BD patients.PubMe

Identification of possible pathogenic pathways in Behçet's disease using genome-wide association study data from two different populations

Behçet's disease (BD) is a multi-system inflammatory disorder of unknown etiology. Two recent genome-wide association studies (GWASs) of BD confirmed a strong association with the MHC class I region and identified two non-HLA common genetic variations. In complex diseases, multiple factors may target different sets of genes in the same pathway and thus may cause the same disease phenotype. We therefore hypothesized that identification of disease-associated pathways is critical to elucidate mechanisms underlying BD, and those pathways may be conserved within and across populations. To identify the disease-associated pathways, we developed a novel methodology that combines nominally significant evidence of genetic association with current knowledge of biochemical pathways, protein-protein interaction networks, and functional information of selected SNPs. Using this methodology, we searched for the disease-related pathways in two BD GWASs in Turkish and Japanese case-control groups. We found that 6 of the top 10 identified pathways in both populations were overlapping, even though there were few significantly conserved SNPs/genes within and between populations. The probability of random occurrence of such an event was 2.24E-39. These shared pathways were focal adhesion, MAPK signaling, TGF-β signaling, ECM-receptor interaction, complement and coagulation cascades, and proteasome pathways. Even though each individual has a unique combination of factors involved in their disease development, the targeted pathways are expected to be mostly the same. Hence, the identification of shared pathways between the Turkish and the Japanese patients using GWAS data may help further elucidate the inflammatory mechanisms in BD pathogenesis