Gerard Dijkstra

Healthcare costs of inflammatory bowel disease have shifted from hospitalisation and surgery towards anti-TNFα therapy: results from the COIN study.

Objective The introduction of anti tumour necrosis factor-α (anti-TNFα) therapy might impact healthcare expenditures, but there are limited data regarding the costs of inflammatory bowel diseases (IBD) following the introduction of these drugs. We aimed to assess the healthcare costs and productivity losses in a large cohort of IBD patients. Design Crohns disease (CD) and ulcerative colitis (UC) patients from seven university hospitals and seven general hospitals were invited to fill-out a web-based questionnaire. Cost items were derived from a 3 month follow-up questionnaire and categorised in outpatient clinic, diagnostics, medication, surgery and hospitalisation. Productivity losses included sick leave of paid and unpaid work. Costs were expressed as mean 3-month costs per patients with a 95% CI obtained using non-parametric bootstrapping. Results A total of 1315 CD patients and 937 UC patients were included. Healthcare costs were almost three times higher in CD as compared with UC, €1625 (95% CI €1476 to €1775) versus €595 (95% CI €505 to €685), respectively (p<0.01). Anti-TNFα use was the main costs driver, accounting for 64% and 31% of the total cost in CD and UC. Hospitalisation and surgery together accounted for 19% and <1% of the healthcare costs in CD and 23% and 1% in UC, respectively. Productivity losses accounted for 16% and 39% of the total costs in CD and UC. Conclusions We showed that healthcare costs are mainly driven by medication costs, most importantly by anti-TNFα therapy. Hospitalisation and surgery accounted only for a minor part of the healthcare costs.

Expression of nitric oxide synthases and formation of nitrotyrosine and reactive oxygen species in inflammatory bowel disease

Nitric oxide (NO) and reactive oxygen species (ROS) are important mediators in the pathogenesis of inflammatory bowel disease (IBD). NO in IBD can be either harmful or protective. NO can react with superoxide anions (O2.−), yielding the toxic oxidizing agent peroxynitrite (ONOO−). Peroxynitrite induces nitration of tyrosine residues (nitrotyrosine), leading to changes of protein structure and function. The aim of this study was to identify the cellular source of inducible nitric oxide synthase (iNOS) and to localize superoxide anion‐producing cells in mucosal biopsies from patients with active IBD. Additional studies were performed to look at nitrotyrosine formation as a measure of peroxynitrite‐mediated tissue damage. For this, antibodies against iNOS, endothelial NOS (eNOS), and nitrotyrosine were used. ROS‐producing cells were detected cytochemically. Inflamed mucosa of patients with active IBD showed intense iNOS staining in the epithelial cells. iNOS could not be detected in non‐inflamed mucosa of IBD patients and control subjects. eNOS was present in blood vessels, without any difference in the staining intensity between IBD patients and control subjects. ROS‐producing cells were increased in the lamina propria of IBD patients; a fraction of these cells were CD15‐positive. Nitrotyrosine formation was found on ROS‐positive cells. These results show that iNOS is induced in epithelial cells from patients with active ulcerative colitis or Crohns disease. Nitration of proteins was detected only on the ROS‐producing cells at some distance from the iNOS‐producing epithelial cells. These findings indicate that tissue damage during active inflammation in IBD patients is probably more related to ROS‐producing cells than to NO. One may speculate that NO has a protective role when during active inflammation other mucosal defence systems are impaired. Copyright

High frequency of early colorectal cancer in inflammatory bowel disease

Background and aim: To detect precancerous dysplasia or asymptomatic cancer, patients suffering from inflammatory bowel disease often undergo colonoscopic surveillance based on American or British guidelines. It is recommended that surveillance is initiated after 8–10 years of extensive colitis, or after 15–20 years for left-sided disease. These starting points, however, are not based on solid scientific evidence. Our aim was to assess the time interval between onset of inflammatory bowel disease (IBD) and colorectal carcinoma (CRC), and subsequently evaluate how many patients developed cancer before their surveillance was recommended to commence. Methods: A nationwide automated pathology database (PALGA) was consulted to identify patients with IBD-associated colorectal carcinoma in seven university medical centres in The Netherlands between January 1990 and June 2006. Data were collected retrospectively from patient charts. Time intervals between onset of disease and cancer diagnosis were calculated in months. Results: 149 patients were identified with confirmed diagnoses of IBD and CRC (ulcerative colitis n = 89/Crohn’s disease n = 59/indeterminate colitis n = 1). Taking date of diagnosis as the entry point, 22% of patients developed cancer before the 8 or 15 year starting points of surveillance, and 28% if surveillance was commenced 10 or 20 years after diagnosis for extensive or left-sided disease, respectively. Using onset of symptoms to calculate the time interval, 17–22% of patients would present with cancer prior to the surveillance starting points. Conclusions: These results show that the diagnosis of colorectal cancer is delayed or missed in a substantial number of patients (17–28%) when conducting surveillance strictly according to formal guidelines.

Molecular prediction of disease risk and severity in a large Dutch Crohn's disease cohort

Background: Crohn’s disease and ulcerative colitis have a complex genetic background. We assessed the risk for both the development and severity of the disease by combining information from genetic variants associated with inflammatory bowel disease (IBD). Methods: We studied 2804 patients (1684 with Crohn’s disease and 1120 with ulcerative colitis) and 1350 controls from seven university hospitals. Details of the phenotype were available for 1600 patients with Crohn’s disease and for 800 with ulcerative colitis. Genetic association for disease susceptibility was tested for the nucleotide-binding and oligomerisation domain 2 gene (NOD2), the IBD5 locus, the Drosophila discs large homologue 5 and autophagy-related 16-like 1 genes (DLG5 and ATG16L1) and the interleukin 23 receptor gene (IL23R). Interaction analysis was performed for Crohn’s disease using the most associated single nucleotide polymorphism (SNP) for each locus. Odds ratios were calculated in an ordinal regression analysis with the number of risk alleles as an independent variable to analyse disease development and severity. Results: Association with Crohn’s disease was confirmed for NOD2, IBD5, DLG5, ATG16L1 and IL23R. Patients with Crohn’s disease carry more risk alleles than controls (p = 3.85 × 10−22). Individuals carrying an increasing number of risk alleles have an increasing risk for Crohn’s disease, consistent with an independent effects multiplicative model (trend analysis p = 4.25 × 10−23). Patients with Crohn’s disease with a more severe disease course, operations or an age of onset below 40 years have more risk alleles compared to non-stricturing, non-penetrating behaviour (p = 0.0008), no operations (p = 0.02) or age of onset above 40 years (p = 0.028). Conclusion: Crohn’s disease is a multigenic disorder. An increase in the number of risk alleles is associated with an increased risk for the development of Crohn’s disease and with a more severe disease course. Combining information from the known common risk polymorphisms may enable clinicians to predict the course of Crohn’s disease.

Detection of infliximab levels and anti-infliximab antibodies: a comparison of three different assays

Formation of antibodies to infliximab (ATI) inversely correlates with functional drug levels and clinical outcome. Comparison of drug levels and anti‐drug antibody monitoring is hampered by lack of standardisation.

Inflammatory Bowel Disease After Liver Transplantation: Risk Factors for Recurrence and De Novo Disease

Inflammatory bowel disease (IBD) is associated with primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) and can recur or develop de novo after orthotopic liver transplantation (OLT). The aim of this study was to investigate the incidence and severity of IBD after liver transplantation and to perform a multivariate analysis for possible risk factors. In this retrospective study, 91 patients transplanted for PSC or AIH, without prior colectomy, were included. Sixty patients were transplanted for PSC, 31 for AIH. IBD activity before and after OLT and other possible risk factors were analysed in a multivariate model. Forty‐nine patients (54%) had IBD before OLT. Forty patients (44%) had active IBD after transplantation: recurrence in 32 and de novo in 8. Cumulative risk for IBD after OLT was 15, 39 and 54% after 1, 5 and 10 years, respectively. In 59% of patients with IBD prior to OLT the disease was more active after transplantation. Risk factors for recurrent disease were: symptoms at time of OLT, short interval of IBD before OLT and use of tacrolimus. 5‐aminosalicylates were protective. A cytomegalovirus positive donor/negative recipient combination increased the risk for de novo IBD.

Complex host genetics influence the microbiome in inflammatory bowel disease

BackgroundHuman genetics and host-associated microbial communities have been associated independently with a wide range of chronic diseases. One of the strongest associations in each case is inflammatory bowel disease (IBD), but disease risk cannot be explained fully by either factor individually. Recent findings point to interactions between host genetics and microbial exposures as important contributors to disease risk in IBD. These include evidence of the partial heritability of the gut microbiota and the conferral of gut mucosal inflammation by microbiome transplant even when the dysbiosis was initially genetically derived. Although there have been several tests for association of individual genetic loci with bacterial taxa, there has been no direct comparison of complex genome-microbiome associations in large cohorts of patients with an immunity-related disease.MethodsWe obtained 16S ribosomal RNA (rRNA) gene sequences from intestinal biopsies as well as host genotype via Immunochip in three independent cohorts totaling 474 individuals. We tested for correlation between relative abundance of bacterial taxa and number of minor alleles at known IBD risk loci, including fine mapping of multiple risk alleles in the Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene exon. We identified host polymorphisms whose associations with bacterial taxa were conserved across two or more cohorts, and we tested related genes for enrichment of host functional pathways.ResultsWe identified and confirmed in two cohorts a significant association between NOD2 risk allele count and increased relative abundance of Enterobacteriaceae, with directionality of the effect conserved in the third cohort. Forty-eight additional IBD-related SNPs have directionality of their associations with bacterial taxa significantly conserved across two or three cohorts, implicating genes enriched for regulation of innate immune response, the JAK-STAT cascade, and other immunity-related pathways.ConclusionsThese results suggest complex interactions between genetically altered host functional pathways and the structure of the microbiome. Our findings demonstrate the ability to uncover novel associations from paired genome-microbiome data, and they suggest a complex link between host genetics and microbial dysbiosis in subjects with IBD across independent cohorts.

Associations with tight junction genes PARD3 and MAGI2 in Dutch patients point to a common barrier defect for coeliac disease and ulcerative colitis.

Background: Coeliac disease (gluten-sensitive enteropathy; GSE) and inflammatory bowel disease (IBD) are common gastrointestinal disorders. Both display enhanced intestinal permeability, initiated by gluten exposure (GSE) or bacterial interactions (IBD). Previous studies showed the association of both diseases with variants in MYO9B, presumably involved in epithelial permeability. Aim: It was hypothesised that genetic variants in tight junction genes might affect epithelial barrier function, thus contributing to a shared pathogenesis of GSE and IBD. Methods: This hypothesis was tested with a comprehensive genetic association analysis of 41 genes from the tight junction pathway, represented by 197 tag single nucleotide polymorphism (SNP) markers. Results: Two genes, PARD3 (two SNPs) and MAGI2 (two SNPs), showed weak association with GSE in a Dutch cohort. Replication in a British GSE cohort yielded significance for one SNP in PARD3 and suggestive associations for two additional SNPs, one each in PARD3 and MAGI2. Joint analysis of the British and Dutch data further substantiated the association for both PARD3 (rs10763976, p = 6.4×10−5; OR 1.23, 95% CI 1.11 to 1.37) and MAGI2 (rs6962966, p = 7.6×10−4; OR 1.19, 95% CI 1.08 to 1.32). Association was also observed in Dutch ulcerative colitis patients with MAGI2 (rs6962966, p = 0.0036; OR 1.26, 95% CI 1.08 to 1.47), and suggestive association with PARD3 (rs4379776, p = 0.068). Conclusions: These results suggest that coeliac disease and ulcerative colitis may share a common aetiology through tight junction-mediated barrier defects, although the observations need further replication.

Effects of active and passive smoking on disease course of Crohn's disease and ulcerative colitis

Background: Smoking is a remarkable risk factor for inflammatory bowel disease (IBD), aggravating Crohns disease (CD) while having beneficial effects on ulcerative colitis (UC). We studied the effects of active and passive smoking in Dutch IBD patients. Methods: A questionnaire focusing on cigarette smoke exposure was sent to 820 IBD patients. Returned questionnaires were incorporated into a retrospective chart review, containing details about disease behavior and received therapy. Results: In all, 675 IBD patients (380 [56%] CD and 295 [44%] UC) responded. At diagnosis there were 52% smokers in CD, 41% in the general population, and 28% in UC. The number of present smokers in CD is lower than in the general population (26% versus 35%). No detrimental effects of active smoking on CD were observed, but passive smokers needed immunosuppressants and infliximab more frequently than nonpassive smokers. Active smoking had beneficial effects on UC, indicated by reduced rates of colectomy, primary sclerosing cholangitis, and backwash‐ileitis in active smokers compared to never smokers, and higher daily cigarette dose correlated with less extensive colitis and a lower need for therapy. Furthermore, smoking cessation after diagnosis was detrimental for UC patients, indicated by increased needs for steroids and hospitalizations for patients that stopped smoking after compared to before the diagnosis. Conclusions: Active smoking is a risk factor for CD, but does not affect the outcome; passive smoking is detrimental for the outcome of CD patients. In UC, active smoking shows dose‐dependent beneficial effects. Our data suggest that passive smoking is a novel risk factor for CD. (Inflamm Bowel Dis 2009)

Confirmation of Multiple Crohn's Disease Susceptibility Loci in a Large Dutch–Belgian Cohort

OBJECTIVES:Inflammatory bowel diseases (IBD)—Crohns disease (CD) and ulcerative colitis (UC)—are chronic gastrointestinal inflammatory disorders with a complex genetic background. A genome-wide association scan by the Wellcome Trust Case Control Consortium (WTCCC) recently identified several novel susceptibility loci.METHODS:We performed a large replication study in 2,731 Dutch and Belgian IBD patients (1,656 CD and 1,075 UC) and 1,086 controls. In total, 40 single nucleotide polymorphisms (SNPs) that showed moderate or strong association in the WTCCC study, along with SNPs in the previously identified genes IL23R, ATG16L1, and NELL1, were studied.RESULTS:We confirmed the associations with IL23R (rs11209026, P=2.69E-12), ATG16L1 (rs2241880, P=4.82E-07), IRGM (rs4958847, P=2.26E-05), NKX2-3 (rs10883365, P=5.91E-06), 1q24 (rs12035082, P=1.51E-05), 5p13 (rs17234657, P=2.62E-05), and 10q21 (rs10761659, P=8.95E-04). We also identified associations with cyclin Y (CCNY; rs3936503, P=2.09 E-04) and Hect domain and RCC1-like domain 2 (HERC2; rs916977, P=1.12E-04). Pooling our data with the original WTCCC data substantiated these associations. Several SNPs were also moderately associated with UC. Two genetic risk profiles based on the number of risk alleles and based on a weighted score were created. On the basis of these results, we calculated sensitivities, specificities, positive and negative predictive values, and likelihood ratios for CD.CONCLUSIONS:We replicated genetic associations for CD with IL23R, ATG16L1, IRGM, NKX2-3, 1q24, 10q21, 5p13, and PTPN2 and report evidence for associations with HERC2 and CCNY. Pooling our data with the results of the WTCCC strengthened the results, suggesting genuine genetic associations. We show that a genetic risk profile can be constructed that is clinically useful and that can aid in making treatment decisions.