Anti-infliximab antibody concentrations can guide treatment intensification in patients with Crohn's disease who lose clinical response.

BACKGROUND: The presence of antibodies towards infliximab (ATI) is associated with lower infliximab (IFX) trough concentrations and loss of response. IFX treatment intensification is effective for restoring response in most, but not all patients with Crohn's disease (CD). AIM: To compare outcome, pharmacokinetics and immunogenicity of treatment intensification strategies in patients with CD who lost clinical response to IFX. METHODS: A retrospective cohort study was conducted, including 103 patients with CD who lost clinical response during IFX maintenance therapy and therefore received a double dose IFX (10 mg/kg) and/or a next infusion after a shortened interval. IFX and ATI concentrations were measured in consecutive trough samples, just before (T0) and after (T+1) treatment intensification. RESULTS: Clinical response (physicians' global assessment) and biological response and remission (CRP) were restored in 63%, 42% and 24% of patients (evaluated at T+1). Treatment intensification increased IFX trough concentrations from 1.2 µg/mL [0.3-3.6] at T0 to 3.6 µg/mL [0.5-10.2] at T+1 (P < .0001). Using a drug tolerant assay, ATI were detected in the T0 sample of 47% of patients. ATI negatively impacted the achieved IFX trough concentration (Spearman r -0.57, P < .0001) and the probability of clinical response (P = 0.034) at T+1. When ATI were quantifiable but <282 ng/mL eq. at T0, combined interval shortening and dose doubling was more effective for restoring therapeutic IFX trough concentrations (≥3 µg/mL at T+1) than dose doubling alone, which in turn was more effective than interval shortening alone (P < .001). CONCLUSION: Antibodies towards infliximab can guide clinical decision-making on treatment intensification.

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.

Smoking behaviour and knowledge of the health effects of smoking in patients with inflammatory bowel disease.

BACKGROUND: The detrimental effect of smoking on development and progression of Crohn's disease (CD) is generally accepted. AIM: To evaluate the awareness of smoking risks in a Belgian inflammatory bowel disease (IBD) population. METHODS: In the out-patient clinic of a tertiary referral centre, 625 consecutive patients with CD, 238 patients with ulcerative colitis (UC) and 289 non-IBD controls, filled out a simple questionnaire. This questionnaire included data on smoking behaviour and awareness of smoking-related health effects, including effects on IBD. RESULTS: At diagnosis, more CD patients were active smokers compared to UC (40% vs. 17%, P < 0.001). Remarkably, smoking cessation rates after diagnosis were similar for CD and UC (both 56%, P = 0.997). The great majority recognised a detrimental influence of smoking on general health (98-99%), lung cancer (95-97%), myocardial infarction (89-92%) and stroke (78-87%). Although CD patients more frequently acknowledged risks of smoking on their disease, only 37% were aware of a link with CD development, 30% of increased surgical rates and 27% of increased post-operative CD recurrence. Active smokers more frequently denied an increased risk of surgery and higher post-operative CD recurrence. Intriguingly, within the active smokers with CD, those not willing to quit smoking most often denied a potential bad influence of smoking. Taking into account disease duration, previous surgery, education level, working status and nicotine dependence, we were unable to define specific subgroups of patients requiring extra education. CONCLUSION: Although patients with Crohn's disease were better informed on the detrimental effects of smoking, the awareness rate was still low.

Efficacy and safety of anti-TNF therapy in elderly patients with inflammatory bowel disease.

BACKGROUND: The general increased life expectancy is reflected in the age of patients with inflammatory bowel disease (IBD). The knowledge about efficacy and safety of anti-tumour necrosis factor (TNF) therapy in elderly is scarce and conflicting. AIM: To assess the efficacy and safety of anti-TNF therapy in elderly patients taking into account eventual comorbidity. METHODS: Observational and retrospective single-centred study where 66 IBD patients initiating anti-TNF treatment at age ≥65 years (cases: ≥65 anti-TNF) were compared with 112 IBD patients initiating anti-TNF <65 years (controls <65 anti-TNF) and 61 anti-TNF naïve IBD patients treated with immunosuppressants (IMS) and/or corticosteroids (CS) ≥65 years (controls ≥65 IMS/CS). Controls were matched to cases for IBD type, follow-up, disease duration and anti-TNF type. Comorbidity was assessed by using the Charlson Comorbidity Index (CCI). Both efficacy and safety of treatment were adjusted for comorbidity. RESULTS: The short-term clinical response to anti-TNF at 10 weeks was significantly lower in cases: ≥65 anti-TNF (68% vs. 89%; P < 0.001), whereas at ≥6 months, differences were not significant (79.5% vs. 82.8%; P = 0.639). The risk for any severe adverse events was higher in cases: ≥65 anti-TNF than in controls <65 anti-TNF (RR = 4.7; P < 0.001) or controls ≥65 IMS/CS (RR = 3.09; P = 0.0008). Age older than 65 and CCI > 0 were independent risk factors for malignancy and mortality regardless of the medication. CONCLUSION: Elderly patients treated with anti-TNF have a lower rate of short-term clinical response and a higher rate of severe adverse events than the younger patients under the same treatment.

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.