Gastroenterology trainee experience, confidence and satisfaction in nutrition training: a cross-sectional survey in the UK.

Introduction: Nutrition is an essential part of gastroenterology specialist training. There is limited evidence of trainee experience in this area. The shorter training programme introduced in 2022 may lead to reduced exposure to this subspecialty. We aimed to explore and describe current nutrition training experiences, confidence and satisfaction to inform future improvements. Methods: Gastroenterology trainees were invited to participate in an online survey from 20 May 2022 to 18 July 2022. The questionnaire consisted of 27 questions with a range of free-text and Likert scale responses. Results: 86 responses were received. 39.5% had undertaken an advanced training programme or core placement in nutrition. 52.9% of these felt 'fairly confident' or 'very confident' in managing intestinal failure vs 5.8% of those who had not completed a nutrition placement. Obesity and eating disorders management received the lowest ratings. Nutrition training was described as 'fairly important' or 'very important' by 98.8% and 47.0% included nutrition as part of their preferred future practice. 53.1% of ST6/7 trainees were 'fairly confident' or 'very confident' their training offered adequate experience in nutrition. Participants reported barriers including a lack of education and training opportunities, and limited early rotations offering nutrition training. Conclusion: Gastroenterology trainees believe nutrition training to be important. Nutrition placements increase trainee confidence, knowledge and experiences overall, but there is variability in this. Improved structuring of placements, increased educational opportunities and exposure to this subspecialty at an earlier stage are required to ensure competency in nutrition is reliably achieved during gastroenterology training.

The host cellular immune response to cytomegalovirus targets the endothelium and is associated with increased arterial stiffness in ANCA-associated vasculitis.

BACKGROUND: Cardiovascular disease is a leading cause of death in ANCA-associated vasculitis (AAV). An expansion of CD4+CD28null T cells is seen mainly in cytomegalovirus (CMV)-seropositive individuals and has been linked to increased cardiovascular disease risk in other conditions. The aims of this study were to phenotype CD4+CD28null T cells in AAV with respect to their pro-inflammatory capacity and ability to target and damage the endothelium and to investigate their relationship to arterial stiffness, a marker of cardiovascular mortality. METHODS: CD4+CD28null T cells were phenotyped in 53 CMV-seropositive AAV patients in stable remission and 30 age-matched CMV-seropositive healthy volunteers by flow cytometry following stimulation with CMV lysate. The expression of endothelial homing markers and cytotoxic molecules was evaluated in unstimulated CD4+CD28null T cells. Arterial stiffness was measured by carotid-to-femoral pulse wave velocity (PWV) in patients with AAV. RESULTS: CD4+CD28null T cells were CMV-specific and expressed a T helper 1 (Th1) phenotype with high levels of interferon-gamma (IFN-γ) and tumour necrosis factor-alpha (TNF-α) secretion. They also co-expressed the endothelial homing markers CX3CR1, CD49d and CD11b and cytotoxic molecules perforin and granzyme B. CD4+CD28null T cells were phenotypically similar in patients with AAV and healthy volunteers but their proportion was almost twice as high in patients with AAV (11.3% [3.7-19.7] versus 6.7 [2.4-8.8]; P = 0.022). The size of the CD4+CD28null T-cell subset was independently linked to increased PWV in AAV (0.66 m/s increase per 10% increase in CD4+CD28null cells, 95% confidence interval 0.13-1.19; P = 0.016). CONCLUSION: The host cellular immune response to CMV leads to the expansion of cytotoxic CD4+CD28null T cells that express endothelial homing markers and are independently linked to increased arterial stiffness, a marker of cardiovascular mortality. Suppression of CMV in AAV may be of therapeutic value in reducing the risk of cardiovascular disease.

Valaciclovir to prevent Cytomegalovirus mediated adverse modulation of the immune system in ANCA-associated vasculitis (CANVAS): study protocol for a randomised controlled trial.

BACKGROUND: The ANCA-associated vasculitides (AAV) are systemic autoimmune inflammatory disorders characterised by necrotising inflammation affecting small to medium-sized blood vessels. Despite improvements in survival, infection and cardiovascular disease remain leading causes of morbidity and mortality. Considerable evidence suggests that CD4 + CD28null T-cell expansions, predominantly seen in Cytomegalovirus (CMV) seropositive individuals, are associated with systemic dysregulation of immune function leading to a heightened risk of infection and cardiovascular disease. In patients with AAV, CD4 + CD28null expansions are driven by CMV and are associated with an increased risk of infection and mortality. The aim of this study is to explore in detail the ways in which CMV modulates the immune system and to determine whether treatment with valaciclovir blocks subclinical CMV reactivation in CMV seropositive AAV patients and ameliorates the CMV-induced adverse effects on the immune system. METHODS/DESIGN: CANVAS is a single-centre prospective open-label randomised controlled proof-of-concept trial of 50 adult CMV seropositive patients with stable AAV. Participants will be randomly allocated to receive valaciclovir orally (2 g QDS or reduced according to renal function) or no additional treatment for 6 months with an additional 6-month follow-up period. The primary outcome is the proportion of patients with CMV reactivation, as assessed by measurable viral load on quantitative blood and urine CMV polymerase chain reaction. The secondary outcomes are safety, change in the proportion of CD4+ CMV-specific T-cell population (defined as CD4 + CD28null cells) and change in soluble markers of inflammation from baseline to 6 months. Further tertiary and exploratory outcomes include persistence of the effect of valaciclovir on the proportion of CD4 + CD28null cells at 6 months post completion of treatment, change in the immune phenotype of CD4+ T cells and change in blood pressure and arterial stiffness parameters from baseline to 6 months. DISCUSSION: The results of this study will enable larger studies to be conducted to determine whether by controlling subclinical CMV reactivation, we can improve clinical endpoints such as infection and cardiovascular disease. The potential impact of this study is not limited to AAV, as CD4 + CD28null cells have been linked to adverse outcomes in other inflammatory conditions and in the context of an ageing immune system. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01633476 (registered 29 June 2012).

CD4+CD28- T-cell expansions in ANCA-associated vasculitis and association with arterial stiffness: baseline data from a randomised controlled trial.

BACKGROUND: Cardiovascular risk is increased in the anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV). CD4+CD28- T cells are expanded in patients with AAV who are seropositive for cytomegalovirus (CMV), and are associated with increased mortality. CMV seropositivity in other conditions is associated with arterial stiffness, a marker of cardiovascular risk. We assessed whether CD4+CD28- T cells in CMV seropositive patients with AAV are associated with arterial stiffness and whether treatment with valaciclovir reduces this cell population. METHODS: In this open-label phase 2 trial, patients were randomised (1:1) by computer to valaciclovir (8 g daily) or no additional treatment for 6 months. Primary outcome was proportion of patients with CMV reactivation. Arterial stiffness (carotid to femoral pulse wave velocity [PWV]) was measured and peripheral blood CD4+CD28- T cells analysed by flow cytometry at baseline and 6 months. CD4+CD28- T-cell interferon γ (IFNγ) secretion was stimulated with CMV lysate. Data are presented as median (IQR). Between-group differences were tested by Mann-Whitney U test and correlations by Spearman's rank. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01633476. FINDINGS: Baseline data are presented from the first 28 patients enrolled, with 6 months' follow-up completed in five treatment and six control patients. More CD4+CD28- than CD4+CD28+ T cells expressed T-bet (83·5% [47·5-89·9] vs 12·9 [4·7-22·2], p<0·0001) and secreted IFNγ after stimulation (14·3% [8·4-26·0] vs 0·8 [0·2-1·3], p<0·0001). CX3CR1, a cell surface marker whose expression is associated with endothelial dysfunction, was only expressed on CD4+CD28- T cells. The proportion of CD4+CD28- T cells correlated with PWV (r=0·408, p=0·035). At 6 months, reduction in proportion of CD4+CD28- T cells was greater in the treatment than in the control group (-1·8% [-5·2 to -0·6] vs 0·5 [-0·8 to 2·5], p=0·044). INTERPRETATION: These preliminary results suggest that CD4+CD28- T cells in AAV are proinflammatory cells with high expression of the fractalkine receptor CX3CR1 that has been implicated in endothelial dysfunction. This cell population is associated with arterial stiffness, and its expansion is attenuated with valaciclovir treatment. This research has important implications, because cardiovascular disease is a major cause of mortality in AAV. FUNDING: Wellcome Trust, Vasculitis UK.

Duplex Ratio Tests as Diagnostic Biomarkers in Malignant Melanoma.

Chromosomal instability is a well-described feature of malignant tumors. Melanomas have typical patterns of chromosomal instability compared with benign nevi, which have minimal DNA copy number change. A few malignant melanomas and their benign counterparts, nevi, prove difficult to diagnose on histopathologic analysis alone, which is currently the gold standard. Quantitative PCR-based assays called duplex ratio tests (DRTs) have been developed by our laboratory for application using DNA from FFPE samples of melanomas and nevi. The reproducibility and accuracy of the DRTs were demonstrated and appropriate correction factors for DNA quality calculated for each assay, based on the results of 108 diploid samples. As a panel, seven DRTs were able to differentiate unambiguous cases of melanoma and nevi with a sensitivity of 87% (95% CI, 83%-91%) and a specificity of 88% (95% CI, 84%-92%) in a series of 145 melanomas and 123 nevi. The DRT scores for 20 nonmetastasizing primary melanomas and 20 metastasizing primary melanomas revealed that DRTs had a marginal benefit as prognostic markers. DRTs have early potential to act as molecular biomarkers of melanoma on FFPE specimens pending validation, and DRTs may have applicability as prognostic markers in melanoma or other tumor types if new DRTs to relevant loci are developed.

Accurate detection of copy number changes in DNA extracted from formalin-fixed, paraffin-embedded melanoma tissue using duplex ratio tests.

A minority of melanocytic lesions cannot confidently be classified as benign or malignant on histopathological examination, causing diagnostic uncertainty. DNA copy number changes can be used to distinguish nevi from melanoma, although the use of FFPE tissue can pose technical challenges. DNA copy number assays, called duplex ratio tests, have been developed with duplex real-time PCR, using a simple method with potential for high throughput. Five duplex ratio test assays targeting loci with common DNA copy number changes in melanoma were designed and tested using DNA extracted from FFPE samples microdissected from melanoma, common nevi, benign tonsil (10 each), and two melanoma cell lines. The assays proved accurate when DNA extracted from fresh and FFPE melanoma cell lines were compared (intraclass correlation coefficient, 0.99) and gave precise results when repeated on DNA from FFPE tissue (intraclass correlation coefficient range, 0.90 to 0.96). In combination, duplex ratio test values from three of the assays distinguished between the nevi and melanomas with 100% sensitivity (95% CI, 69.1% to 100%) and 100% specificity (95% CI, 69.1% to 100%). Duplex ratio test assays have been shown to be accurate and precise and can distinguish melanomas from common nevi using DNA from FFPE tissue. Appropriately designed assays could have value in assessment of other cancers.

Detection of copy number changes in DNA from formalin fixed paraffin embedded tissues using paralogue ratio tests.

The purpose of this study was to evaluate whether paralogue ratio tests (PRT) using real-time PCR can accurately determine the DNA copy number (CN) using formalin fixed paraffin embedded (FFPE) tissue. Histopathology diagnostic archives are an enormous resource of FFPE tissue, but extracted DNA is of poor quality and may be unsuitable for CN assessment, thus representing a missed opportunity for studies of genetic association and somatic change in cancer in large cohorts of easily accessible samples. Assays with paralogues on chromosomes 18 and 20 (18|20 PRT) and chromosomes 13 and X (13|X PRT) were tested using archived FFPE pathology samples with known CN, including tonsil, placentae, and FFPE melanoma cell lines. The assay proved accurate over the dynamic range from 1:1 to 1:3 and gave precise results when repeated four times over several weeks. The precision of the assay was marginally reduced once the CT value for 10 ng of FFPE DNA increased above 30 cycles, reflecting importance of DNA quality. The assays distinguished changes in CN ratio with high sensitivity and specificity. The 13|X PRT could detect cells with distinct genotypes microdissected from within the same FFPE sample. Therefore, PRTs are suitable for analyzing CN in FFPE tissues.