Immune checkpoint inhibitor-related cholangiopathy: Novel clinicopathological description of a multi-centre cohort.

BACKGROUND AND AIMS: Cholestatic liver dysfunction is common in immune-related hepatitis (irH) during treatment with immune checkpoint inhibitors (CPI) for malignancy. We investigated the spectrum of bile duct injury and associated natural history in this cohort. METHOD: Clinical, laboratory, radiological and histopathological data in patients with evidence of bile duct injury during CPI treatment from 2018 to 2020 was collected in three tertiary hospitals. RESULTS: In this study, ten patients with confirmed bile duct disease were identified. Pembrolizumab was most commonly implicated (8/10). Median CPI cycles prior to bile duct injury was 6. Median alanine aminotransferase and alkaline phosphatase were 225 U/L and 1549 U/L respectively. Clinical jaundice was seen in 6/10 and radiological evidence of bile duct pathology in 8/10. Of five patients, who had liver biopsy, three cases (including two cases with normal MRCP) showed primary sclerosing cholangitis (PSC) like changes with periductal fibrosis. All patients were treated first-line with prednisolone following cessation of CPI, three with mycophenolate mofetil and one with tacrolimus, with clinical response in four patients. Five patients died after a mean follow-up of 27 weeks; cause of death was primarily related to progression of malignancy. CONCLUSION: Within this heterogeneous cohort, we identified that CPI-related cholangiopathy responded poorly to immunosuppression and potentially progressed to bile duct loss. Thorough radiological and histological assessment is recommended, as identification of the cholangiopathy-associated phenotype may permit more informed advice regarding prognosis. Further data is required to determine detailed immunological characterisation in order to identify individuals at an increased risk of developing cholangiopathy.

Improving compliance with the duty of candour: 5-year experience within an endoscopy department.

BACKGROUND AND AIMS: Duty of candour (DoC) is the requirement for timely and transparent disclosure after significant healthcare-related harm. We describe the experience of DoC following patient safety incidents (PSI) related to endoscopy, and offer reflections on improving compliance across other areas of clinical medicine. METHODS: PSI notified on an electronic reporting system (DATIX) from January 2015 to June 2021 were identified. Details of the procedure, level of harm and evidence of both verbal and written DoC were collected and analysed. RESULTS: 33 PSI were notified on DATIX. A verbal apology was documented in 23 cases (70%) and a written notification was offered or sent to in 20 (61%). Verbal apologies were timely, while written DoC was delayed. PSI reporting and verbal DoC increased over this period. Patients or families were invited to present questions for investigation in all 20 with written DoC. There were two claims for compensation during this period. CONCLUSION: DoC remains challenging for clinicians and patient safety teams 8 years after its inception. Improved compliance requires promotion by clinical leaders and high levels of awareness among clinical and nursing staff, a culture of openness and importantly, sustained administrative support to ensure that downstream actions are not overlooked.

What became of the 'eyes and the ears'?: exploring the challenges to reporting poor quality of care among trainee medical staff.

The importance of trainee medical staff in alerting Trusts to patient safety risks and low-quality care was established by the Francis Report, yet many remain hesitant about speaking up. Known barriers include lack of feedback, sceptical attitudes to the likelihood of change and fear of consequences. The author explores other factors including moral orientation in the workplace, role modelling by senior clinicians, discontinuity, 'normalisation of deviance', human reactions to burnout/moral injury, loyalty and the spectrum of motivation. The issues of absent feedback and fear are discussed in detail. Challenges met by those receiving reports are also described, such as how to collate soft intelligence, putting concerns into context (the 'bigger picture') and stewardship of resources. Initiatives to encourage reporting of trainees' concerns such as speak up guardians, 'Speak Up for Safety' campaign and simulation training are described. A proposal to embed proactive intelligence-gathering arrangements is presented.

Preclinical evaluation of the first intravenous small molecule MDM2 antagonist alone and in combination with temozolomide in neuroblastoma.

High-risk neuroblastoma, a predominantly TP53 wild-type (wt) tumour, is incurable in >50% patients supporting the use of MDM2 antagonists as novel therapeutics. Idasanutlin (RG7388) shows in vitro synergy with chemotherapies used to treat neuroblastoma. This is the first study to evaluate the in vivo efficacy of the intravenous idasanutlin prodrug, RO6839921 (RG7775), both alone and in combination with temozolomide in TP53 wt orthotopic neuroblastoma models. Detection of active idasanutlin using liquid chromatography-mass spectrometry and p53 pathway activation by ELISA assays and Western analysis showed peak plasma levels 1 h post-treatment with maximal p53 pathway activation 3-6 h post-treatment. RO6839921 and temozolomide, alone or in combination in mice implanted with TP53 wt SHSY5Y-Luc and NB1691-Luc cells showed that combined RO6839921 and temozolomide led to greater tumour growth inhibition and increase in survival compared to vehicle control. Overall, RO6839921 had a favourable pharmacokinetic profile consistent with intermittent dosing and was well tolerated alone and in combination. These preclinical studies support the further development of idasanutlin in combination with temozolomide in neuroblastoma in early phase clinical trials.

Three Faces of Mercaptopurine Cytotoxicity In Vitro: Methylation, Nucleotide Homeostasis, and Deoxythioguanosine in DNA.

Mercaptopurine (MP) is a cytotoxic thiopurine important for the treatment of cancer and autoimmune diseases. MP and other thiopurine drugs undergo extensive intracellular metabolism, but the mechanisms of action are poorly characterized. In particular, it is unknown how different metabolites contribute to cytotoxicity and incorporation of thiopurine bases into DNA. The aim of this study was to ask whether cytotoxicity results from the incorporation of thioguanosine nucleotides into DNA, an alternative thiopurine metabolite, or a combination of factors. Therefore, we measured the cytotoxicity, metabolism, and incorporation of thioguanosine into DNA in response to MP or MP metabolites. Thiopurine metabolites varied in cytotoxicity, with methyl-thioinosine-mono-phosphate and thioguanosine-tri-phosphate the most toxic, and the methyl-thioguanosine nucleotides the least. We show, using liquid chromatography-tandem mass spectrometry, how different metabolites may perturb biochemical pathways, particularly disrupting guanosine nucleotide homeostasis, that may contribute to the mechanism of action of thiopurines. Although there was no correlation between metabolite cytotoxicity and the levels of 6-methylthioinosine-mono-phosphate or thioguanosine incorporation into DNA as individual factors, a combined analysis suggested that these factors together had a major influence on cytotoxicity. This study emphasizes the importance of enzymes of nucleotide homeostasis, methylation, and demethylation in thiopurine effects. These results will facilitate the development of dynamic biochemical models of thiopurine biochemistry that will improve our understanding of mechanisms of action in relevant target tissues.

Cancer-related health behaviours of young people not in education, employment or training ('NEET'): a cross-sectional study.

BACKGROUND: Links between participating in unhealthy behaviours, e.g. smoking, and an increased risk of developing some cancers are well established. Unemployed adults are more likely to participate in cancer-related health behaviours than their employed counterparts. However, evidence of whether this is true in young adults not in education, employment or training (NEET) compared to their 'non-NEET' peers is either limited or inconclusive. Using cross-sectional health data from across the UK, this study aims to investigate whether participation in cancer-related health behaviours varies by NEET status. METHODS: Data for 16-24 year olds were extracted from the 2010-12 Health Surveys for England (HSE) and Scottish Health Surveys (SHeS). Information on economic activity in the last week was used to determine NEET status. Data on whether respondents had been seeking employment within the last four weeks and availability to start within the next two weeks allowed NEETs to be further identified as unemployed (UE) or economically inactive (EI). Logistic regression modelled the effect of being NEET on odds of being a current smoker; heavy drinker; not participating in sport; having eaten less than five portions of fruit or vegetables the day before survey interview and having an unhealthy body mass index (BMI). Analyses were performed before and after exclusion of EI NEETs. RESULTS: Data were extracted for 4272 individuals, of which 715 (17%) were defined as NEET with 371 (52%) and 342 (48%) further classified as UE and EI respectively. Two NEETs could not be further defined as UE or EI due to missing information. Relative to non-NEETs, NEETs were significantly more likely to be current smokers, not participate in sport and have an 'unhealthy' BMI. These results held after adjustment for socio-demographic characteristics both before and after exclusion of EI NEETs. Before exclusion of EI NEETs, NEETs were significantly less likely to be heavy drinkers than non-NEETs. There was no significant difference in likelihood of heavy drinking between NEETs and non-NEETs when excluding EI NEETs. CONCLUSIONS: NEETs were generally at an increased risk of participating in cancer-related health behaviours than non-NEETs. As the likelihood of becoming NEET is greater in socioeconomically-disadvantaged groups, interventions to discourage unhealthy behaviours in NEETs may contribute to a reduction in health inequalities.

A Retinol Isotope Dilution Equation Predicts Both Group and Individual Total Body Vitamin A Stores in Adults Based on Data from an Early Postdosing Blood Sample.

BACKGROUND: Retinol isotope dilution (RID) is used to determine vitamin A total body stores (TBS) after an oral dose of a vitamin A stable isotope. The generally accepted prediction equation proposed by Olson's group in 1989 (Furr et al. Am J Clin Nutr 1989;49:713-6) includes factors related to dose absorption and retention, isotope equilibration in plasma compared with stores, catabolism during the mixing period, and the optimal time for measuring plasma isotope enrichment. OBJECTIVES: The objectives were 1) to develop a modified RID equation and identify an earlier sampling time for predicting TBS and 2) to improve prediction in individuals as well as groups. METHODS: To develop a modified RID equation, we used results of model-based compartmental analysis [the Simulation, Analysis and Modeling software (WinSAAM version 3.0.8; http://www.WinSAAM.org)] of plasma [13C10]retinol kinetic data from 32 previously studied, healthy young adults of European ancestry who had moderate vitamin A intakes and who ingested 2.95 µmol [13C10]retinyl acetate. RESULTS: We examined the time dependence of factors in the prediction equation related to absorption/retention (Fa) and isotope equilibration (S) and determined that 4 or 5 d postdosing was the optimal sampling time. TBS calculated by the equation TBS = Fa x S x (1/SAp), where SAp is plasma retinol specific activity (fraction of dose/µmol), were highly correlated with model-predicted TBS (r = 0.95 and 0.96 for 4 and 5 d, respectively; P < 0.001); predictions for individuals were also highly correlated (Rs = 0.94 and 0.94; P < 0.001). CONCLUSION: The equation TBS ≈ 0.5 × (1/SAp) accurately predicted vitamin A TBS in this group of 32 healthy young adults and its individual members with the use of data from 1 blood sample taken 4 d after isotope administration.

Plasma Retinol Kinetics and ß-Carotene Bioefficacy Are Quantified by Model-Based Compartmental Analysis in Healthy Young Adults with Low Vitamin A Stores.

BACKGROUND: Model-based compartmental analysis of data on plasma retinol kinetics after administration of labeled retinol provides unique information about whole-body vitamin A metabolism. If labeled ß-carotene is coadministered, its bioefficacy relative to the retinol reference dose can also be estimated. OBJECTIVES: The objectives were to model plasma retinol kinetics after administration of labeled preformed vitamin A and provitamin A ß-carotene and to determine relative ß-carotene bioefficacy. METHODS: We used the Simulation, Analysis and Modeling software (WinSAAM version 3.0.8; http://www.WinSAAM.org) to analyze previously collected data on plasma [13C10]- and [13C5]retinol kinetics for 14 d after oral administration of 1 mg [13C10]retinyl acetate and 2 mg [13C10]ß-carotene in oil to 30 healthy young adults of European ancestry [13 men, 17 women; mean ± SD age: 24.5 ± 4.2 y; mean ± SD body weight: 65.2 ± 10 kg; mean ± SD body mass index (in kg/m2): 22.5 ± 1.9] with moderate vitamin A intakes. RESULTS: A 6-component model provided the best fit to the data, including compartments for initial metabolism of vitamin A, plasma retinol, and extravascular vitamin A storage. The disposal rate was 6.7 ± 3.1 µmol/d, fractional catabolic rate was 6.0% ± 2.3%/d, and vitamin A stores were 123 ± 71 µmol. Relative ß-carotene bioefficacy, based on the ratio of the areas under the fraction of dose curves calculated by WinSAAM, averaged 13.5% ± 6.02% (retinol activity equivalents = 7.7:1.0 µg). Interindividual variation in relative ß-carotene bioefficacy was high (CV: 44%). CONCLUSIONS: Vitamin A kinetics in these young adults were best described by essentially the same model that had been previously developed by using data for older adults with higher vitamin A stores; differences in parameter values reflected differences in vitamin A status. Estimated ß-carotene bioefficacy was relatively low but similar to previously reported estimates obtained by graphical methods. This trial was registered at the UK Clinical Research Network as UKCRN 7413.

An LC/MS/MS method for stable isotope dilution studies of ß-carotene bioavailability, bioconversion, and vitamin A status in humans.

Isotope dilution is currently the most accurate technique in humans to determine vitamin A status and bioavailability/bioconversion of provitamin A carotenoids such as ß-carotene. However, limits of MS detection, coupled with extensive isolation procedures, have hindered investigations of physiologically-relevant doses of stable isotopes in large intervention trials. Here, a sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS) analytical method was developed to study the plasma response from coadministered oral doses of 2 mg [(13)C10]ß-carotene and 1 mg [(13)C10]retinyl acetate in human subjects over a 2 week period. A reverse phase C18 column and binary mobile phase solvent system separated ß-carotene, retinol, retinyl acetate, retinyl linoleate, retinyl palmitate/retinyl oleate, and retinyl stearate within a 7 min run time. Selected reaction monitoring of analytes was performed under atmospheric pressure chemical ionization in positive mode at m/z 537→321 and m/z 269→93 for respective [(12)C]ß-carotene and [(12)C] retinoids; m/z 547→330 and m/z 274→98 for [(13)C10]ß-carotene and [(13)C5] cleavage products; and m/z 279→100 for metabolites of [(13)C10]retinyl acetate. A single one-phase solvent extraction, with no saponification or purification steps, left retinyl esters intact for determination of intestinally-derived retinol in chylomicrons versus retinol from the liver bound to retinol binding protein. Coadministration of [(13)C10]retinyl acetate with [(13)C10]ß-carotene not only acts as a reference dose for inter-individual variations in absorption and chylomicron clearance rates, but also allows for simultaneous determination of an individual's vitamin A status.