Prognostic factors for long-term infliximab treatment in Crohn's disease patients: a 20-year single centre experience.

BACKGROUND: The long-term efficacy of infliximab in patients with Crohn's disease is suboptimal. AIM: To study prognostic factors for real-life long-term effcacy of infliximab in Crohn's disease. METHODS: All consecutive Crohn's disease patients treated with infliximab at a tertiary centre were retrospectively analysed. Only patients who received scheduled infliximab maintenance treatment were considered. Patient- and disease-related factors were used to identify independent predictors of infliximab failure-free survival using Cox proportional hazards regression. RESULTS: Of 1031 patients with Crohn's disease, 261 were eligible for inclusion. Median time on infliximab was 2.4 [IQR 1.4-4.7] years, and 65 (24.9%) patients experienced infliximab failure. Estimated 5-year infliximab failure-free survival was 65.9% (95% CI 58.3-73.5). Multivariate Cox regression identified disease duration ≥1 year (HR 2.5 (95% CI 1.2-5.2), P = 0.02), L1 disease location [HR 2.0 (1.1-3.5), P = 0.02], prior anti-TNF use [HR 2.3 (1.1-4.8), P = 0.03], haemoglobin <13.5 g/dL [HR 2.3 (1.2-4.4), P = 0.02], not using therapeutic drug monitoring [HR 8.0 (4.1-15.6), P = 1 × 10(-9) ], and first dose optimisation within first year [HR 3.7 (2.1-6.6), P = 5 × 10(-6) ] as independent predictors of infliximab failure-free survival. Stratifying patients into risk groups resulted in estimated 3-year infliximab failure-free survival rates ranging from 95.3% (94.2-96.4) to 26.3% (8.6-44.0) depending on the number of risk factors (P = 8 × 10(-13) ). CONCLUSIONS: This study identified several easy to obtain predictors of infliximab failure in patients with Crohn's disease, and these are in line with previous reports. Those with a high-risk profile for infliximab failure in whom infliximab initiation is considered, should be treated as early as possible making use of therapeutic drug monitoring.

Genetic susceptibility and genotype-phenotype association in 588 Danish children with inflammatory bowel disease.

AIM: To investigate the association between known inflammatory bowel disease (IBD)-associated genetic variants and development of paediatric IBD, and specific clinical sub-phenotypes. MATERIAL AND METHODS: In this case-control study we included IBD patients <18 years of age at diagnosis from the Danish National Patient Registry and healthy children <18 years of age were randomly selected from the Danish Central Office of Civil Registration. The latter had filled out a questionnaire regarding health status, and DNA was obtained from blood samples and the buccal mucosa. Patient files were retrieved and clinical information was extracted. DNA was obtained from Guthrie cards from the Danish National Neonatal Screening Biobank (PKU-biobanken) at Statens Serum Institut and from blood samples. RESULTS: A total of 588 IBD patients (244 Crohn's disease (CD), 318 ulcerative colitis (UC) and 26 IBD-unclassified (IBDU)) and 543 healthy controls were included. We found an association between CD and rs22411880 (ATG16L1, odds ratio (OR)=1.7 [1.1-1.7], p=0.003), rs5743289 (NOD2, OR=1.4 [1.1-1.9], p=0.009) and the paediatric specific rs1250550 (ZMIZ1, OR=0.7 [0.5-0.9], p=0.01). None of the investigated 41 SNPs were associated with disease localisation, medical treatment or surgery after correcting for multiple analyses. CONCLUSION: We found an association between CD and three previously published genetic variants and replicated the association with the paediatric specific ZMIZ1 gene. No Bonferroni corrected significant genotype-phenotype associations were found. For future studies aimed at finding predictors for disease course in (paediatric) IBD, it will be worthwhile to include a combination of genetic, clinical and serological markers.

Effects of haptoglobin polymorphisms and deficiency on susceptibility to inflammatory bowel disease and on severity of murine colitis.

BACKGROUND: Haptoglobin (Hp) is a haemoglobin-binding protein with immunomodulatory properties. Its gene (16q22) harbours a common polymorphism with two different alleles: Hp1 and Hp2. Genotype Hp22 has been shown to be over-represented in different immune diseases. Results in Crohn's disease (CD) are contradictory. AIMS: To determine whether Hp plays a role in inflammatory bowel disease, both genetically and functionally. METHODS: 1061 patients with CD, 755 with ulcerative colitis (UC) and 152 with primary sclerosing cholangitis, as well as 452 healthy controls, were genotyped using touch-down PCR. To confirm association results, 464 CD trios and 151 UC trios were genotyped. Serum Hp concentrations were determined in 62 individuals of different genotype. Colitis was induced in mice with dextran sulphate sodium (DSS) and oxazolone (Oxa). Cytokine production was evaluated by mRNA quantification in colonic tissue and ELISA on supernatants of mesenteric lymph node cells. RESULTS: Prevalence of Hp2 was higher in CD and UC than in controls. In the confirmatory cohorts, Hp2 was over-transmitted to the affected offspring. Serum Hp concentrations were higher in individuals with genotypes Hp11 and Hp21 than in those with Hp22 (1.38 vs 0.89 g/l). DSS- and Oxa-induced colitis were more severe in Hp-deficient mice than in control mice and accompanied by higher concentrations (although not statistically significantly different) of tissue mRNA for cytokines. Interleukin-17 production was significantly higher in the presence of Hp-deficient serum compared with wild-type serum. CONCLUSIONS: The Hp gene may play a role in susceptibility to inflammatory bowel disease. Its implication in other immune diseases underscores the common pathways between these diseases. Experimental models of colitis showed that Hp has a protective role in inflammatory colitis, most likely by inhibiting the production of Th1 and Th17 cytokines.

Evidence that glioma-associated oncogene homolog 1 is not a universal risk gene for inflammatory bowel disease in Caucasians.

The transcription factor glioma-associated oncogene homolog 1 (GLI1) has a central function in gastrointestinal tract development and homeostasis. A non-synonymous single-nucleotide polymorphism (SNP) (rs2228226; Q1100E) in GLI1, which impairs GLI1 function in vitro, has been proposed as a risk factor for inflammatory bowel disease (IBD). In this study, we assessed the cumulative evidence for association of GLI1 with IBD. New genotype data for rs2228226 from New Zealand (907 controls, 990 IBD patients) and Belgian Caucasian case-control data sets (312 controls, 1214 IBD patients) were combined with data from the National Institute of Diabetes and Digestive and Kidney Diseases and three previously studied Caucasian case-control data sets. Meta-analysis of rs2228226 did not detect any association with ulcerative colitis (UC) (P=0.09, odds ratio (OR)=1.07, 95% confidence interval (CI)=0.92-1.24), Crohn's disease (CD) (P=0.29, OR=1.06, 95% CI=0.93-1.21) or overall IBD (P=0.15, OR=1.05, 95% CI=0.92-1.19). Our analyses of rs2228226 suggest that GLI1 is not a significant risk factor for IBD in Caucasians.