Sustainability of biologic treatment in paediatric patients with Crohn's disease: population-based registry analysis.

BACKGROUND: We aimed to evaluate the predictors of sustainability of biologic drugs for paediatric patients with Crohn's disease (CD). METHODS: The Czech National Prospective Registry of Biologic and Targeted Therapy of Inflammatory Bowel Disease (CREdIT) was used to identify the biologic treatment courses in paediatric patients with CD. Mixed-effects Cox models and propensity score analyses were employed to evaluate predictors of treatment sustainability. RESULTS: Among the 558 observations of 473 patients, 264 were treated with adalimumab (47%), 240 with infliximab (43%), 41 with ustekinumab (7%), and 13 with vedolizumab (2%). Multivariable analysis revealed higher discontinuation risk with infliximab compared to adalimumab (HR = 0.600, 95%CI 0.389-0.926), both overall and in first-line treatment (HR = 0.302, 95%CI 0.103-0.890). Infliximab versus adalimumab was associated with shorter time to escalation (HR = 0.094, 95%CI 0.043-0.203). Propensity-score analysis demonstrated lower sustainability of infliximab (HR = 0.563, 95%CI 1.159-2.725). The time since diagnosis to treatment initiation (HR = 0.852, 95%CI 0.781-0.926) was the most important predictor. Baseline immunosuppressive therapy prolonged sustainability with infliximab (HR = 2.899, 95%CI 1.311-6.410). CONCLUSIONS: Given the results suggesting shorter sustainability, the need for earlier intensification and thus higher drug exposure, and the greater need for immunosuppression with infliximab than with adalimumab, the choice of these drugs cannot be considered completely equitable. IMPACT: Our study identified predictors of sustainability of biologic treatment in paediatric patients with Crohn's disease, including adalimumab (versus infliximab), early initiation of biologic treatment, and normalised baseline haemoglobin levels. Infliximab treatment was associated with earlier intensification, higher drug exposure, and a greater need for immunosuppression. Parents and patients should be fully informed of the disadvantages of intravenous infliximab versus adalimumab during the decision-making process. This study emphasises the importance of not delaying the initiation of biologic therapy in paediatric patients with Crohn's disease.

The CTLA4 variants may interact with the IL23R- and NOD2-conferred risk in development of Crohn's disease.

BACKGROUND: The CTLA4 (cytotoxic T-lymphocyte antigen 4) gene is associated with several immunopathologic diseases and because of its important immuno-regulatory role it may be considered also a plausible candidate for a genetic association with inflammatory bowel diseases. Previously published studies found no association of CTLA4 with Crohn's disease itself, but some indicated an association with its subphenotypes. The aim of this study was to assess the association in the Czech population, using a set of markers shown to associate with other diseases. METHODS: Six polymorphisms within the CTLA4 region were investigated in 333 patients with Crohn's disease and 482 unrelated healthy controls, all Caucasians of Czech origin. The genotypes of the SNPs were determined using the TaqMan SNP genotyping assays. Haplotypes were reconstructed using an expectation-maximization algorithm, and their association with the condition was assessed using log-linear modeling. Then, potential interactions were tested between the CTLA4 variants and other genetic factors known to confer the disease susceptibility. RESULTS: No crude associations with Crohn's disease were found for the tested CTLA4 variants under the log-additive or dominant models. However, when stratified for the genetic risk conferred by the variants in the NOD2 (the p.Leu1007fsX1008, rs5743293) or the IL23R (p.R381Q, rs11209026), a significant negative association emerged for the minor alleles of CTLA4 CT60 (rs3087243), JO31 (rs11571302), JO27-1 (rs11571297) polymorphisms. This negative association with CTLA4 was apparent only in the strata defined by presence minor alleles at the NOD2 rs5743293 (here the CTLA4 CT60 A coffered an OR = 0.43, 95%CI 0.19 - 0.95 for the presence of CT60 A), or IL23R rs11209026 (here the OR for presence of CT60 A was 0.23, 95%CI 0.07 - 0.71). We observed this effect also for the haplotype consisting of minor alleles of the three tightly linked CTLA4 markers. Furthermore, this haplotype was associated with the younger age at diagnosis (OR 1.52, 95%CI 1.09 - 2.11, p = 0.014). CONCLUSIONS: A protective effect of a CTLA4 haplotype was unmasked after stratification for the risk variants in the NOD2 and IL23R genes, and may point towards the biological relevance of the molecule in the pathogenesis of the disease.

Incidence of Crohn disease in the Czech Republic in the years 1990 to 2001 and assessment of pediatric population with inflammatory bowel disease.

BACKGROUND: The aim of this study was to assess the pediatric population that suffered from inflammatory bowel disease (IBD) in the Czech Republic and to determine the incidence of Crohn disease (CD) in children up to 15 years age between 1990 and 2001. METHODS: Diagnostic criteria for CD, ulcerative colitis (UC), and indeterminate colitis (IC) were defined. Medical records provided a source of basic information about the children. A standardized protocol was filled out and sent to the coordinator of the study. All protocols were checked to see whether the data corresponded to the defined criteria and then were processed further. The study was retrospective in character for the years 1990 to 1999 and prospective for the years 2000 and 2001. RESULTS: Diagnostic criteria were met in 470 patients with IBD; 201 of them turned 18 years old during the study period. CD was diagnosed in 223 patients. The incidence of CD in children up to 15 years of age increased from 0.25/100,000 in 1990 to 1.25/100,000 in 2001. Eighty-two percent of children with CD were treated with aminosalicylates in combination with corticosteroids; 29% of patients received azathioprine. Severe growth retardation was recorded in 6.4% of adolescents with CD at the age of 18. UC was diagnosed in 202 patients. Therapy with aminosalicylates only was sufficient for control of the disease in 23% patients; 68% children were treated with corticosteroids, 15 of them (23% of the whole group) received additional azathioprine. Criteria for IC were met in 9.8% of all patients with IBD. CONCLUSION: This study confirmed an increase in incidence of CD in children younger than 15 years in the Czech Republic.