Crosstalk within peripheral blood mononuclear cells mediates anti-inflammatory effects of n-3 PUFA-rich lipid emulsions in parenteral nutrition.

BACKGROUND AND AIMS: Parenteral nutrition (PN) rich in n-6 and n-3 long-chain fatty acids is used in clinical practice for nourishing patients who are unable to receive adequate nutrition through their digestive systems. In this study, we compare the effect on inflammation of the commonly used lipid emulsions Omegaven (n-3-rich) and Intralipid (n-6-rich) in human peripheral blood mononuclear cells (PBMCs). METHODS: PBMCs were treated with different doses of n-3-rich Omegaven and n-6-rich Intralipid and the immune cells were characterized by flow cytometry. RESULTS: We show that incubation of PBMCs with n-3-rich Omegaven leads to an increase in expression of CD1d and CD86 in CD14+monocytes. At the same time, an increased number of NKT cells expressing cytotoxic T cell antigen 4 is observed, suggesting immunological synapse formation. Both CD14+monocytes and NKT cells showed an increase in IL-10 production and a reduction in the pro-inflammatory cytokines IFN-γ, TNF-α, and IL-4, which led to an increase in the number of FOXP3+T regulatory cells. In addition, we show that n-3-rich Omegaven reduces the expression of TNFα, IFNγ and IL-4 in CD4+T and CD8+T cells independent of the presented interaction between CD14+monocytes and NKT cells. The described mechanism of n-3 rich lipid emulsions was confirmed in PBMCs from patients with inflammatory bowel disease but not in colorectal cancer patients which seem to lack the interaction between CD14+monocytes and NKT cells. CONCLUSIONS: These results show a mechanism for the beneficial effect of the n-3-rich Omegaven in patients with inflammatory conditions but questions its use in patients with cancer. Hence, our results may assist in choosing the best lipid emulsion for patients who require PN.

Association of IBD specific treatment and prevalence of pain in the Swiss IBD cohort study.

BACKGROUND: Extraintestinal manifestations (EIM) contribute significantly to the burden of disease in inflammatory bowel disease (IBD). Pain is a leading symptom in IBD and could be seen as an EIM itself. Treatment of IBD associated pain is challenging and insufficiently studied. A better knowledge on the association of pain and IBD specific treatment is warranted to improve the management of IBD patients. METHODS: All patients of the Swiss IBD Cohort Study (SIBDCS) (n = 2152) received a questionnaire regarding pain localization, pain character, and the use of IBD specific medication. RESULTS: 1263 completed questionnaires were received. Twenty-one out of 184 patients (10%) receiving anti-TNF treatment compared to 142 out of 678 patients (21%) not receiving anti-TNF medication reported elbow pain (p = 0.002) while 28 out of 198 patients (14%) receiving steroid treatment significantly more often reported elbow pain compared to 59 from 696 patients (8%) not receiving steroids (p = 0.021). Furthermore, we found significantly more female patients under anti-TNF treatment to report knee/ lower leg pain and ankle/ foot pain compared to their male counterparts (36% vs. 20% and 22% vs. 10%, respectively, p = 0.015 for both comparisons). The frequency of knee, lower leg, ankle and foot pain was especially low in male patients under anti-TNF treatment, indicating a high benefit of male patients from anti-TNF therapy regarding EIM. CONCLUSIONS: The frequency of elbow pain was lower in IBD patients treated with anti-TNF but higher in patients treated with steroids.

Malignancies in Inflammatory Bowel Disease: Frequency, Incidence and Risk Factors-Results from the Swiss IBD Cohort Study.

BACKGROUND: Malignancy may occur as long-term complication of inflammatory bowel disease (IBD) due to different risk factors. We assessed prevalence and incidence of malignancy, and predictive factors in the Swiss IBD Cohort Study (SIBDCS). METHODS: All IBD patients in the SIBDCS were analyzed from a cross-sectional and longitudinal perspective. Patients with malignancies were compared to controls. Standardized incidence ratios (SIR) were calculated based on age-specific and sex-specific background rates. RESULTS: Malignancies were identified in 122 of 3119 patients (3.9%). In a logistic regression model, age (OR 1.04 per year), intestinal surgery (OR 3.34), and treatment with steroids (OR 2.10) were the main predictors for the presence of malignancy, while treatment with 5-ASA (OR 0.57) and biologics (OR 0.38) were protective. From a longitudinal perspective, 67 out of 2580 patients (2.6%) were newly diagnosed with malignancy during a follow-up of 12,420.8 years (median 4.9 years). While there was no increased risk for malignancy overall (SIR 0.93, 95% CI 0.72-1.18) and colorectal cancer (SIR 1.55, 95% CI 0.71-2.95), IBD patients had an increased risk for lymphoma (SIR 2.98, 95% CI 1.36-5.66) and biliary cancer (SIR 6.3, 95% CI 1.27-18.41). In a Cox regression model, age and recent use of immunomodulators were the main predictors for development of malignancies, while 5-ASA, biologics were protective. CONCLUSIONS: IBD patients showed increased risk for lymphoma and biliary cancer, but not colorectal cancer and cancer overall. Age and recent use of immunomodulators were the main risk factors for malignancy, while aminosalicylates and biologics appear to be protective.

Protocol for a prospective, controlled, observational study to evaluate the influence of hypoxia on healthy volunteers and patients with inflammatory bowel disease: the Altitude IBD Study.

INTRODUCTION: Inflammatory bowel disease (IBD) is a chronic intestinal disorder, often leading to an impaired quality of life in affected patients. The importance of environmental factors in the pathogenesis of IBD, including their disease-modifying potential, is increasingly recognised. Hypoxia seems to be an important driver of inflammation, as has been reported by our group and others. The aim of the study is to evaluate if hypoxia can alter disease activity of IBD measured by Harvey-Bradshaw Activity Index in Crohn's disease (increase to ≥5 points) and the partial Mayo Score for ulcerative colitis (increase to ≥2 points). To test the effects of hypoxia under standardised conditions, we designed a prospective and controlled investigation in healthy controls and patients with IBD in stable remission. METHODS AND ANALYSIS: This is a prospective, controlled and observational study. Participants undergo a 3-hour exposure to hypoxic conditions simulating an altitude of 4000 metres above sea level (m.a.s.l.) in a hypobaric pressure chamber. Clinical parameters, as well as blood and stool samples and biopsies from the sigmoid colon are collected at subsequent time points. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethics Committee of the Kanton Zurich (reference KEK-ZH-number 2013-0284). The results will be published in a peer-reviewed journal and shared with the worldwide medical community. TRIALS REGISTRATION NUMBER: NCT02849821; Pre-results.

Risk Factors for the Development of Fistulae and Stenoses in Crohn Disease Patients in the Swiss Inflammatory Bowel Disease Cohort.

BACKGROUND: Fistulae and stenoses represent frequent and severe complications in patients with Crohn disease (CD). Our study aimed to identify risk factors for fistula and stenosis formation in CD patients. SUMMARY: We retrieved data of 1,600 CD patients from the nationwide Swiss Inflammatory Bowel Disease Cohort Study (SIBDCS). The risk for fistulae and stenoses in relation to gender, age at diagnosis, smoking status at diagnosis, and ileal involvement at diagnosis were analyzed. In the multivariate analysis, female gender showed a lower risk for developing perianal and any fistula (risk ratio [RR] 0.721, 95% confidence interval [CI] 0.582-0.893, p = 0.003 and RR 0.717, 95% CI 0.580-0.888, p = 0.002, respectively), and older age at diagnosis showed a lower risk for developing perianal fistula (RR 0.661, 95% CI 0.439-0.995, p = 0.047). Furthermore, ileal involvement was associated with a lower risk for perianal fistula (RR 0.713, 95% CI 0.561-0.906, p = 0.006), a lower risk for any fistula (RR 0.709, 95% CI 0.558-0.901, p = 0.005), and a higher risk for stenosis (RR 2.170, 95% CI 1.728-2.725, p < 0.001). KEY MESSAGES: In the nationwide SIBDCS, younger age at diagnosis and male gender were risk factors for developing perianal and nonperianal fistulae. Additionally, ileal involvement was revealed to be a potent risk factor (RR 2.170) for developing a stenosis.

Patients' views on fecal microbiota transplantation: an acceptable therapeutic option in inflammatory bowel disease?

BACKGROUND: Fecal microbiota transplantation (FMT) represents a new therapeutic option that has been studied in two randomized-controlled trials in ulcerative colitis patients. Our study aimed to identify patients' views on the use of this novel therapeutic approach. METHODS: Using an anonymous questionnaire, we obtained data from 574 inflammatory bowel disease (IBD) patients on their knowledge and willingness to undergo FMT. RESULTS: A large proportion of IBD patients (53.5%) are unaware that FMT is a therapeutic option in Clostridium difficile infection and potentially IBD. More responders preferred FMT (31.5%) to a study with a new medication (28.9%), although the difference was not significant (P=0.37), and the preferred way of transplantation was colonoscopy (49.7%). In all, 38.3% preferred a family member as a donor, but there was fear about the procedure (41.5% mentioned fear of infectious diseases, 26.5% expressed disgust). The knowledge of successful FMT treatment in other patients was important for 82.2% of responders and for 50.7%, a discussion with a specialist would likely change their opinion about FMT. CONCLUSION: FMT represents a therapeutic procedure that is of interest for IBD patients. As FMT has been receiving increasing interest as an alternative treatment in IBD and more studies on FMT in IBD are being carried out, it is important to learn about the knowledge, attitude, and preferences of patients to provide better education to patients on this topic. However, there are reservations because of the fact that data on the benefits of FMT in IBD are controversial and several limitations exist on the use of FMT in IBD.

Genotype-Phenotype Associations of the CD-Associated Single Nucleotide Polymorphism within the Gene Locus Encoding Protein Tyrosine Phosphatase Non-Receptor Type 22 in Patients of the Swiss IBD Cohort.

BACKGROUND: Protein tyrosine phosphatase non-receptor type 22 (PTPN22) plays an important role in immune cell function and intestinal homeostasis. The single nucleotide polymorphism (SNP) rs2476601 within the PTPN22 gene locus results in aberrant function of PTPN22 protein and protects from Crohn's disease (CD). Here, we investigated associations of PTPN22 SNP rs2476601 in inflammatory bowel disease (IBD) patients in the Swiss IBD Cohort Study (SIBDCS). METHODS: 2'028 SIBDCS patients (1173 CD and 855 ulcerative colitis (UC) patients) were included. The clinical characteristics were analysed for an association with the presence of the PTPN22 SNP rs2476601 genotypes 'homozygous variant' (AA), 'heterozygous' (GA) and 'homozygous wild-type' (GG). RESULTS: 13 patients (0.6%) were homozygous variant (AA) for the PTPN22 polymorphism, 269 (13.3%) heterozygous variant (GA) and 1'746 (86.1%) homozygous wild-type (GG). In CD, AA and GA genotypes were associated with less use of steroids and antibiotics, and reduced prevalence of vitamin D and calcium deficiency. In UC the AA and GA genotype was associated with increased use of azathioprine and anti-TNF antibodies, but significantly less patients with the PTPN22 variant featured malabsorption syndrome (p = 0.026). CONCLUSION: Our study for the first time addressed how presence of SNP rs2476601 within the PTPN22 gene affects clinical characteristics in IBD-patients. Several factors that correlate with more severe disease were found to be less common in CD patients carrying the A-allele, pointing towards a protective role for this variant in affected CD patients. In UC patients however, we found the opposite trend, suggesting a disease-promoting effect of the A-allele.

Malignancies in Patients with Inflammatory Bowel Disease: A Single-Centre Experience.

BACKGROUND: Gastrointestinal and extraintestinal malignancies are long-term complications in patients with inflammatory bowel disease (IBD), likely as a result of chronic inflammation and the use of immunosuppressive medications used to control inflammation. Here, we assessed the frequency of malignancies in a large tertiary IBD centre at the University Hospital Zurich. METHODS: We performed a retrospective analysis of data from 1,026 patients from our IBD clinic treated between 2007 and 2014. RESULTS: Twenty two of the 1,026 patients developed 28 cases of malignancies, 14 patients were male and 8 patients female. The median latency between IBD diagnosis and first malignancy was 13 years (range 2-27 years). Most common malignancies were non-Hodgkin lymphoma, colorectal cancer (CRC), urothelial carcinoma, cholangiocellular carcinoma (CCC) and prostate cancer. The most common tumour type in Crohn's disease patients (13/22) was lymphoma (5 cases), in ulcerative colitis patients (9/22) CCC (2 cases) and CRC (2 cases). The observed incidence of lymphoma (32.5/100,000), bladder carcinoma (21.7/100,000) and CCC (10.8/100,000) was higher than expected and known from general population. All of the patients that developed a malignancy had received immunosuppressive therapy. Compared to a cohort of 927 IBD patients without malignancies there were no statistical differences regarding gender, antibodies targeting tumour necrosis factor and thiopurine use. CONCLUSION: Our data support the assumption that a long-standing disease course and immunosuppressive therapy increase the risk for developing malignancies in IBD patients.

NLRP3 tyrosine phosphorylation is controlled by protein tyrosine phosphatase PTPN22.

Inflammasomes form as the result of the intracellular presence of danger-associated molecular patterns and mediate the release of active IL-1ß, which influences a variety of inflammatory responses. Excessive inflammasome activation results in severe inflammatory conditions, but physiological IL-1ß secretion is necessary for intestinal homeostasis. Here, we have described a mechanism of NLRP3 inflammasome regulation by tyrosine phosphorylation of NLRP3 at Tyr861. We demonstrated that protein tyrosine phosphatase non-receptor 22 (PTPN22), variants in which are associated with chronic inflammatory disorders, dephosphorylates NLRP3 upon inflammasome induction, allowing efficient NLRP3 activation and subsequent IL-1ß release. In murine models, PTPN22 deficiency resulted in pronounced colitis, increased NLRP3 phosphorylation, but reduced levels of mature IL-1ß. Conversely, patients with inflammatory bowel disease (IBD) that carried an autoimmunity-associated PTPN22 variant had increased IL-1ß levels. Together, our results identify tyrosine phosphorylation as an important regulatory mechanism for NLRP3 that prevents aberrant inflammasome activation.

The Clinical Relevance of the IBD-Associated Variation within the Risk Gene Locus Encoding Protein Tyrosine Phosphatase Non-Receptor Type 2 in Patients of the Swiss IBD Cohort.

BACKGROUND/AIMS: The single nucleotide polymorphism (SNP) rs1893217 within the gene locus encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) results in a dysfunctional PTPN2 protein is associated with Crohn's disease (CD) and exists in perfect linkage disequilibrium with the CD- and ulcerative colitis (UC)-associated PTPN2 SNP rs2542151. We investigated associations of PTPN2 SNP rs1893217 and clinical characteristics of inflammatory bowel disease (IBD) patients. METHODS: One thousand seventy three patients with CD and 734 patients with UC from the Swiss IBD Cohort Study (SIBDCS) were included. Epidemiologic, disease and treatment characteristics were analysed for an association with the presence of one of the rs1893217 genotypes 'homozygous wild-type' (TT), 'heterozygous' (CT) and 'homozygous variant' (CC). RESULTS: About 2.88% of IBD patients were identified with CC, 26.8% with CT and 70.4% with TT genotype. The CC-genotype was associated with the existence of gallstones in CD and pancolitis in UC patients. The presence of the C-allele (i.e. either CC or CT genotype) was associated with the onset of uveitis, but protected from aphthous oral ulcers in CD patients. UC patients carrying a C-allele were diagnosed at an older age but required intestinal surgery more often. The presence of the C-allele was associated with a successful treatment with anti-TNF antibodies in both CD and UC patients. CONCLUSION: IBD patients carrying the C-allele of PTPN2 SNP rs1893217 are at greater risk for developing a severe disease course but are more likely to respond to treatment with anti-TNF antibodies. These findings demonstrate a clinical relevance of this PTPN2 risk variant in IBD patients.

Patients' perceptions on the impact of coffee consumption in inflammatory bowel disease: friend or foe?--a patient survey.

BACKGROUND: Environmental factors are an integral component in the pathogenesis of inflammatory bowel disease (IBD). There is an increasing interest in nutritive components. While the potential disease-modifying role of coffee has been intensively investigated in a variety of gastrointestinal diseases, the data on the potential impact on IBD is very limited. We aimed to determine the patients' perspective on coffee consumption in IBD. METHODS: We conducted a questionnaire among IBD patients in Switzerland, assessing key questions regarding coffee consumption. Descriptive statistics including chi square testing were used for analysis of questionnaire data. RESULTS: Among a total of 442 patients 73% regularly consume coffee. 96% of patients attributing a positive and 91% of patients attributing no impact of coffee intake on IBD regularly drink coffee and surprisingly even 49% of those patients that assign a negative impact on disease symptoms. Among those patients refraining from regular coffee intake 62% are convinced that coffee adversely influences intestinal symptoms, significantly more in Crohn's disease (CD) than in ulcerative colitis (UC) (76% vs. 44%, p = 0.002). In total, 38% of all study subjects suppose that coffee has an effect on their symptoms of disease, significantly more in CD (54%) compared to UC patients (22%, p < 0.001). Moreover, while 45% of CD patients feel that coffee has a detrimental influence, only 20% of UC patients share this impression (p < 0.001). CONCLUSION: Two thirds of IBD patients regularly consume coffee. More than twice as many CD compared to UC patients attribute a symptom-modifying effect of coffee consumption, the majority a detrimental one. However, this negative perception does not result in abstinence from coffee consumption.