Immunomodulator comedication promotes the reversal of anti-drug antibody-mediated loss of response to anti-TNF therapy in inflammatory bowel disease.

PURPOSE: Loss of therapeutic response (LOR) due to anti-drug antibodies (ADA) against tumor necrosis factor (TNF) inhibitors is common in patients with inflammatory bowel disease (IBD). We aimed to investigate whether immunomodulator comedication can reverse the immunogenic LOR to TNF inhibitors in IBD. METHODS: In this real-world retrospective cohort study, 123 IBD patients with neutralizing ADA to infliximab or adalimumab and concomitant subtherapeutic trough levels were screened for clinical LOR. Subsequent ADA and trough level measurements and clinical outcomes were analyzed for patients who received either immunomodulator comedication or dose intensification of infliximab or adalimumab to overcome LOR. RESULTS: Following immunogenic LOR, the initial anti-TNF regimen was optimized in 33 patients. In univariable and multivariable logistic regression analyses, immunomodulator comedication was identified as the crucial factor for regaining clinical remission and ADA clearance. Detectable trough levels (≥ 0.98 or ≥ 1.00 mg/L, respectively) had optimal predictive performance for both endpoints in receiver operating characteristics curves [area under the curve 0.86 (95% confidence interval 0.68-1.00) for regaining clinical remission, 0.87 (0.71-1.00) for ADA clearance]. Furthermore, 11/20 patients (55%) on a comedication with azathioprine or methotrexate and 2/13 patients (15%) receiving anti-TNF dose intensification exclusively (P = 0.032) exhibited ADA elimination, regain of therapeutic trough levels, and clinical remission. Regain of clinical remission alone was achieved in 17/20 (85%) patients receiving comedication and 2/13 (15%) patients receiving anti-TNF dose intensification (P = 1.6 × 10-4). CONCLUSION: Immunogenic LOR to infliximab or adalimumab in IBD can be successfully reversed using immunomodulator comedication.

Perceived Versus Real Swimming Skills of Adolescents Under Standard and Challenging Conditions: Exploring Water Competencies as an Approach to Drowning Prevention.

In this study, we compared adolescents' actual (expert assessed) front crawl swimming skills to their self-assessment in two conditions: in standard swimming (wearing a swimsuit and goggles) and in a simulated risk scenario (swimming in plain clothes without goggles). We postulated that education focused on water competencies is fundamental in preventing drownings. Experts evaluated the skills of 21 female and 21 male adolescents in both standard and challenging conditions. All were low-skilled swimmers aged 14-15 years. Participants were asked to self-assess their skills before and after each trial. Boys and girls covered the same distance in both trials. Their self-assessment did not change regardless of the difficulty of the conditions. Girls assessed themselves more accurately than boys. However, boys who underestimated their skills showed greater ability to utilise the experience gained from performing the task for a more accurate self-assessment. In conclusion, adolescents should be educated in total water competencies, and not merely in swimming skills. For girls, "water readiness" is thought to broaden their ability to adapt their swimming skills to nonstandard conditions. Aquatic education for boys should focus on developing self-reflection in order to create a long-lasting responsibility using their own swimming skills.

Global genetic analyses reveal strong inter-ethnic variability in the loss of activity of the organic cation transporter OCT1.

BACKGROUND: The organic cation transporter OCT1 (SLC22A1) mediates the uptake of vitamin B1, cationic drugs, and xenobiotics into hepatocytes. Nine percent of Caucasians lack or have very low OCT1 activity due to loss-of-function polymorphisms in OCT1 gene. Here we analyzed the global genetic variability in OCT1 to estimate the therapeutic relevance of OCT1 polymorphisms in populations beyond Caucasians and to identify evolutionary patterns of the common loss of OCT1 activity in humans. METHODS: We applied massively parallel sequencing to screen for coding polymorphisms in 1,079 unrelated individuals from 53 populations worldwide. The obtained data was combined with the existing 1000 Genomes data comprising an additional 1,092 individuals from 14 populations. The identified OCT1 variants were characterized in vitro regarding their cellular localization and their ability to transport 10 known OCT1 substrates. Both the population genetics data and transport data were used in tandem to generate a world map of loss of OCT1 activity. RESULTS: We identified 16 amino acid substitutions potentially causing loss of OCT1 function and analyzed them together with five amino acid substitutions that were not expected to affect OCT1 function. The variants constituted 16 major alleles and 14 sub-alleles. Six major alleles showed improper subcellular localization leading to substrate-wide loss in activity. Five major alleles showed correct subcellular localization, but substrate-specific loss of activity. Striking differences were observed in the frequency of loss of OCT1 activity worldwide. While most East Asian and Oceanian individuals had completely functional OCT1, 80 % of native South American Indians lacked functional OCT1 alleles. In East Asia and Oceania the average nucleotide diversity of the loss-of-function variants was much lower than that of the variants that do not affect OCT1 function (ratio of 0.03) and was significantly lower than the theoretically expected heterozygosity (Tajima's D = -1.64, P < 0.01). CONCLUSIONS: Comprehensive genetic analyses showed strong global variations in the frequency of loss of OCT1 activity with selection pressure for maintaining OCT1 activity in East Asia and Oceania. These results not only enable pharmacogenetically-based optimization of drug treatment worldwide, but may help elucidate the functional role of human OCT1.