Can regulatory T cells improve outcomes of sensitised patients after HLA-Ab incompatible renal transplantation: study protocol for the Phase IIa GAMECHANgER-1 trial

BACKGROUND

Kidney transplantation is the gold-standard treatment for patients with kidney failure. However, one-third of patients awaiting a kidney transplant are highly sensitized to human leukocyte antigens (HLA), resulting in an increased waiting time for a suitable kidney, more acute and chronic rejection, and a shorter graft survival compared to non-highly sensitised patients. Current standard immunosuppression protocols do not adequately suppress memory responses, and so alternative strategies are needed. Autologous polyclonally expanded regulatory T cells (Tregs) have been demonstrated to be safe in transplant settings and could be a potential alternative to modulate memory immune alloresponses.

METHODS

The aim of this trial is to determine whether adoptive transfer of autologous Tregs into HLA sensitised patients can suppress memory T and B cell responses against specific HLA antigens. This is a two-part, multi-centre, prospective clinical trial, comprising an observational phase (Part 1) aiming to identify patients with unregulated cellular memory responses to HLA (Pure HLA Proteins) followed by an interventional phase (Part 2). The first 9 patients identified as being eligible in Part 1 will undergo baseline immune monitoring for 2 months to inform statistical analysis of the primary endpoint. Part 2 is an adaptive, open labelled trial based on Simon's two-stage design, with 21 patients receiving Good Manufacturing Practice (GMP)-grade polyclonally expanded Tregs to a dose of 5-10 × 106 cells/kg body weight. The primary EP is suppression of in vitro memory responses for 2 months post-infusion. 12 patients will receive treatment in stage 1 of Part 2, and 9 patients will receive treatment in stage 2 of Part 2 if ≥ 50% patients pass the primary EP in stage 1.

DISCUSSION

This is a prospective study aiming to identify patients with unregulated cellular memory responses to Pure HLA Proteins and determine baseline variation in these patterns of response. Part 2 will be an adaptive phase IIa clinical trial with 21 patients receiving a single infusion of GMP-grade polyclonally expanded Tregs in two stages. It remains to be demonstrated that modulating memory alloresponses clinically using Treg therapy is achievable.

TRIAL REGISTRATION

EudraCT Number: 2021-001,664-23. REC Number: 21/SC/0253. Trial registration number ISRCTN14582152.

POS0285 SUB-STANDARD CARE FOR PATIENTS WITH GOUT, DESPITE UPDATED GUIDELINES: A UK-WIDE, POPULATION-BASED COHORT STUDY

Background

Treat-to-target urate-lowering therapy (ULT) is highly effective at preventing flares and improving quality of life for patients with gout.1 However, in 2012, only 27% of patients with gout in UK primary care received prescriptions for ULT within 12 months of diagnosis.2 Since then, EULAR and BSR gout management guidelines have been updated, to recommend that all patients with gout should have ULT discussed and offered to them, with uptitration of dosing until target urate levels are achieved. We investigated whether gout management has improved in recent years.

Objectives

To assess temporal trends in the initiation of ULT and attainment of serum urate targets following new gout diagnoses in UK primary care from 2004 to 2020.

Methods

The Clinical Practice Research Datalink (CPRD) Gold database was used to assess the management of patients with index diagnostic codes for gout in UK primary care between January 2004 and October 2020. We analysed the proportion of patients with the following outcomes within 12 months of diagnosis: i) initiation of ULT (allopurinol, febuxostat, benzbromarone, probenecid or sulfinpyrazone); ii) serum urate ≤360 µmol/L; iii) serum urate ≤300 µmol/L; iv) treat-to-target urate monitoring (defined as two or more serum urate levels performed within 12 months of diagnosis and/or one or more urate ≤300 µmol/L). Interrupted time-series analyses (ITSA) were used to estimate the impact of updated EULAR and BSR gout management guidelines on these outcomes. Multivariate logistic regression was used to analyse predictors of ULT prescription and target attainment following new gout diagnoses.

Results

129,972 patients had index gout diagnoses between January 2004 and October 2020, of whom only 37,529 (28.9%) had ULT initiated within 12 months of diagnosis. ULT initiation improved modestly over the study period, from 26.8% for those diagnosed in 2004 to 36.6% in 2019, decreasing to 34.7% in 2020 (Figure 1). Of patients diagnosed in 2020 who had a serum urate performed within 12 months of diagnosis, 36.0% attained a urate ≤360 µmol/L, while 17.1% attained a urate ≤300 µmol/L. Of all participants, 18.9% received treat-to-target urate monitoring. In ITSA models, no statistically significant improvements in ULT prescription or urate target attainment were observed after publication of updated EULAR (2016) or BSR (2017) gout management guidelines, relative to before publication of these guidelines. In multivariate logistic regression models, comorbidities including chronic kidney disease, heart failure and obesity, and diuretic use were associated with increased odds of ULT initiation but decreased odds of attaining target urate levels by 12 months.

Figure 1.

Proportion of patients newly diagnosed with gout who: i) were initiated on urate-lowering therapy (ULT) within 12 months of diagnosis (black line); ii) had a serum urate performed and attained a level ≤360 µmol/L (light blue) or ≤300 µmol/L (dark blue) within 12 months of diagnosis.

Conclusion

In this UK-wide study, we demonstrate that the initiation of ULT and attainment of serum urate targets following new gout diagnoses remain poor, despite the introduction of updated management guidelines. If the evidence-practice gap in gout management is to be bridged successfully, strategies to implement best practice gout care are urgently needed.

References

[1]Doherty M, et al. Efficacy and cost-effectiveness of nurse-led care involving education and engagement of patients and a treat-to-target urate-lowering strategy versus usual care for gout: a randomised controlled trial. Lancet 2018;392(10156):1403-12

[2]Kuo CF, et al. Rising burden of gout in the UK but continuing suboptimal management: a nationwide population study. Ann Rheum Dis 2015;74(4):661-7

Acknowledgements

This work is independent research supported by the National Institute for Health Research (NIHR) Doctoral Fellowship, Dr Mark Russell, NIHR300967. This study is based in part on data from the Clinical Practice Research Datalink obtained under licence from the UK Medicines and Healthcare products Regulatory Agency.

Disclosure of Interests

Mark Russell Speakers bureau: Lilly; Menarini, Andrew Rutherford: None declared, Benjamin Ellis: None declared, Sam Norton: None declared, Abdel Douiri: None declared, Martin Gulliford: None declared, Andrew Cope: None declared, James Galloway Speakers bureau: Abbvie, Biovitrum, BMS, Celgene, Chugai, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, Sobi and UCB

OPTIMUM: a protocol for a multicentre randomised controlled trial comparing Out Patient Talc slurry via Indwelling pleural catheter for Malignant pleural effusion vs Usual inpatient Management

INTRODUCTION

The development of malignant pleural effusion (MPE) results in disabling breathlessness, pain and reduced physical capability with treatment a palliative strategy. Ambulatory management of MPE has the potential to improve quality of life (QoL). The OPTIMUM trial is designed to determine whether full outpatient management of MPE with an indwelling pleural catheter (IPC) and pleurodesis improves QoL compared with traditional inpatient care with a chest drain and talc pleurodesis. OPTIMUM is currently open for any centres interested in collaborating in this study.

METHODS AND ANALYSIS

OPTIMUM is a multicentre non-blinded randomised controlled trial. Patients with a diagnosis of MPE will be identified and screened for eligibility. Consenting participants will be randomised 1:1 either to an outpatient ambulatory pathway using IPCs and talc pleurodesis or standard inpatient treatment with chest drain and talc pleurodesis as per British Thoracic Society guidelines. The primary outcome measure is global health-related QoL at 30 days measured using the EORTC QLQ-C30 questionnaire. Secondary outcome measures include breathlessness and pain measured using a 100 mm Visual Analogue Scale and health-related QoL at 60 and 90 days. A sample size of 142 patients is needed to demonstrate a clinically significant difference of 8 points in global health status at 30 days, for an 80% power and a 5% significance level.

ETHICS AND DISSEMINATION

The study has been approved by the NRES Committee South East Coast-Brighton and Sussex (reference 15/LO/1018). The trial results will be published in peer-reviewed journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBERS

UKCRN19615 and ISRCTN15503522; Pre-results.

Medium-term cost-effectiveness of an automated non-invasive ventilation outpatient set-up versus a standard fixed level non-invasive ventilation inpatient set-up in obese patients with chronic respiratory failure: a protocol description

INTRODUCTION

Obesity is an escalating issue, with an accompanying increase in referrals of patients with obesity-related respiratory failure. Currently, these patients are electively admitted to hospital for initiation of non-invasive ventilation (NIV), but it is unknown whether outpatient initiation is as effective as inpatient set-up. We hypothesise that outpatient set-up using an autotitrating NIV device will be more cost-effective than a nurse-led inpatient titration and set-up.

METHODS AND ANALYSIS

We will undertake a multinational, multicentre randomised controlled trial. Participants will be randomised to receive the usual inpatient set-up, which will include nurse-led initiation of NIV or outpatient set-up with an automated NIV device. They will be stratified according to the trial site, gender and previous use of NIV or continuous positive airway pressure. Assuming a 10% dropout rate, a total sample of 82 patients will be required. Cost-effectiveness will be evaluated using standard treatment costs and health service utilisation as well as health-related quality of life measures (severe respiratory insufficiency (SRI) and EuroQol-5 dimensions (EQ-5D)). A change in the SRI questionnaire will be based on the analysis of covariance adjusting for the baseline measurements between the two arms of patients.

ETHICS AND DISSEMINATION

This study has been approved by the Westminster National Research Ethics Committee (11/LO/0414) and is the trial registered on the UKCRN portfolio. The trial is planned to start in January 2015 with publication of the trial results in 2017.

TRIAL REGISTRATION NUMBER

ISRCTN 51420481.

A UK survey of rehabilitation following critical illness: implementation of NICE Clinical Guidance 83 (CG83) following hospital discharge

OBJECTIVE

To determine the implementation of National Institute for Health and Care Excellence guidance (NICE CG83) for posthospital discharge critical illness follow-up and rehabilitation programmes.

DESIGN

Closed-question postal survey.

SETTING

Adult intensive care units (ICUs) across the UK, identified from national databases of organisations. Specialist-only and private ICUs were not included.

PARTICIPANTS

Senior respiratory critical care physiotherapy clinicians.

RESULTS

A representative sample of 182 surveys was returned from the 240 distributed (75.8% (95% CI 70.4 to 81.2)). Only 48 organisations (27.3% (95% CI 20.7 to 33.9)) offered a follow-up service 2-3 months following hospital discharge, the majority (n=39, 84.8%) in clinic format. 12 organisations reported posthospital discharge rehabilitation programmes (6.8% (95% CI 3.1 to 10.5)), albeit only 10 of these operated on a regular basis. Lack of funding was reported as the most frequent (n=149/164, 90%) and main barrier (n=99/156, 63.5%) to providing services. Insufficient resources (n=71/164, 43.3%) and lack of priority by the clinical management team (n=66/164, 40.2%) were also highly cited barriers to service delivery.

CONCLUSIONS

NICE CG83 has been successful in profiling the importance of rehabilitation for survivors of critical illness. However, 4 years following publication of CG83 there has been limited development of this clinical service across the UK. Strategies to support delivery of such quality improvement programmes are urgently required to enhance patient care.

A cohort study to identify simple clinical tests for chronic respiratory failure in obese patients with sleep-disordered breathing

BACKGROUND

Chronic respiratory failure complicating sleep-disordered breathing in obese patients has important adverse clinical implications in terms of morbidity, mortality and healthcare utilisation. Screening strategies are essential to identify obese patients with chronic respiratory failure.

METHOD

Prospective data were collected from patients with obesity-related sleep-disordered breathing admitted for respiratory assessment at a UK national sleep and ventilation centre. Hypercapnia was defined as an arterial partial pressure of carbon dioxide of >6kPa.

RESULTS

245 obese patients (56±13 years) with a body mass index of 48±12 kg/m(2), forced vital capacity (FVC) of 2.1±1.1 L, daytime oximetry (SpO2) of 91±6% and abnormal overnight oximetry were included in the analysis. Receiver operator curve analysis for the whole group showed that an FVC ≤3 L had a sensitivity of 90% and a specificity of 41% in predicting hypercapnia, and an SpO2 ≤95% had a sensitivity of 83% and a specificity of 63% in predicting hypercapnia. Gender differences were observed and receiver operator curve analysis demonstrated 'cut-offs' for (1) SpO2 of ≤95% for men and ≤93% for women and (2) FVC of ≤3.5 L for men and ≤2.3 L for women, in predicting hypercapnia.

CONCLUSIONS

The measurement of FVC and clinic SpO2 in obese patients with abnormal overnight limited respiratory studies predicted hypercapnia. This may have clinical utility in stratifying patients attending sleep clinics.

A comparison of the accuracy of film-screen mammography, full-field digital mammography, and digital breast tomosynthesis

AIM

To measure the change in diagnostic accuracy of conventional film-screen mammography and full-field digital mammography (FFDM) with the addition of digital breast tomosynthesis (DBT) in women recalled for assessment following routine screening.

MATERIALS AND METHODS

Ethics approval for the study was granted. Women recalled for assessment following routine screening with screen-film mammography were invited to participate. Participants underwent bilateral, two-view FFDM and two-view DBT. Readers scored each lesion separately for probability of malignancy on screen-film mammography, FFDM, and then DBT. The scores were compared with the presence or absence of malignancy based on the final histopathology outcome.

RESULTS

Seven hundred and thirty-eight women participated (93.2% recruitment rate). Following assessment 204 (26.8%) were diagnosed as malignant (147 invasive and 57 in-situ tumours), 286 (37.68%) as benign, and 269 (35.4%) as normal. The diagnostic accuracy was evaluated by using receiving operating characteristic (ROC) and measurement of area under the curve (AUC). The AUC values demonstrated a significant (p = 0.0001) improvement in the diagnostic accuracy with the addition of DBT combined with FFDM and film-screen mammography (AUC = 0.9671) when compared to FFDM plus film-screen mammography (AUC = 0.8949) and film-screen mammography alone (AUC = 0.7882). The effect was significantly greater for soft-tissue lesions [AUC was 0.9905 with the addition of DBT and AUC was 0.9201 for FFDM with film-screen mammography combined (p = 0.0001)] compared to microcalcification [with the addition of DBT (AUC = 0.7920) and for FFDM with film-screen mammography combined (AUC = 0.7843; p = 0.3182)].

CONCLUSION

The addition of DBT increases the accuracy of mammography compared to FFDM and film-screen mammography combined and film-screen mammography alone in the assessment of screen-detected soft-tissue mammographic abnormalities.

Acceleration of cortical thinning in familial Alzheimer's disease

BACKGROUND

MRI in presymptomatic autosomal dominant Alzheimer's disease mutation carriers (MC) provides an opportunity to detect changes that pre-date symptoms or clinical diagnosis. We used automated cortical thickness (CTh) measurement to compare the grey matter of such a group with cognitively normal controls.

METHODS

9 presymptomatic mutation carriers (4 PSEN1, 5 APP) and 25 healthy, age and sex-matched controls underwent longitudinal volumetric MRI brain imaging. CTh measurement was performed across the whole brain using a validated, automated technique. Four regions of interest (ROI) (entorhinal cortex (ERC), parahippocampal gyrus (PHG), posterior cingulate cortex and precuneus) and two control regions (paracentral and pericalcarine) were selected on the basis of imaging data in existing Alzheimer's disease (AD) literature. Linear mixed models were used to describe normal ageing in controls and the extent to which mean CTh in cases differed from controls according to time since clinical diagnosis, adjusting for normal ageing.

RESULTS

An accelerating decline in CTh was observed across all ROI in the MC group. No such decline was demonstrated in the control regions for the MC group. Relative to controls, and adjusting for normal ageing, there was evidence (p=0.05, one-sided test) of lower CTh in the posterior cingulate up to 1.8 years prior to diagnosis and in the precuneus up to 4.1 years prior to diagnosis in the MC group.

DISCUSSION

Automated CTh analysis is a relatively practical, rapid and effective technique for assessing subtle structural change in AD. There is evidence that cortical thickness is reduced in mutation carriers a number of years prior to clinical diagnosis.

Patterns of cortical thinning in the language variants of frontotemporal lobar degeneration

BACKGROUND

Frontotemporal lobar degeneration (FTLD) is a clinically, genetically, and pathologically heterogeneous neurodegenerative disorder. Two subtypes commonly present with a language disorder: semantic dementia (SemD) and progressive nonfluent aphasia (PNFA).

METHODS

Patients meeting consensus criteria for PNFA and SemD who had volumetric MRI of sufficient quality to allow cortical thickness analysis were recruited from a tertiary referral clinic: 44 (11 pathologically confirmed) patients with SemD and 32 (4 pathologically confirmed) patients with PNFA and 29 age-matched and gender-matched healthy controls were recruited. Cortical thickness analysis was performed using the Freesurfer software tools.

RESULTS

Patients with SemD had significant cortical thinning in the left temporal lobe, particularly temporal pole, entorhinal cortex, and parahippocampal, fusiform, and inferior temporal gyri. A similar but less extensive pattern of loss was seen in the right temporal lobe and (with increasing severity) also in left orbitofrontal, inferior frontal, insular, and cingulate cortices. Patients with PNFA had involvement particularly of the left superior temporal lobe, inferior frontal lobe, and insula, and (with increasing severity) other areas in the left frontal, lateral temporal, and anterior parietal lobes. Similar patterns were seen in the pathologically confirmed cases. Patterns of cortical thinning differed between groups: SemD had significantly more cortical thinning in the temporal lobes bilaterally while PNFA had significantly more thinning in the frontal and parietal lobes.

CONCLUSIONS

The language variants of frontotemporal lobar degeneration have distinctive and significantly different patterns of cortical thinning. Increasing disease severity is associated with spread of cortical thinning and the pattern of spread is consistent with progression of clinical deficits.

Improving energy resolution of EELS spectra: an alternative to the monochromator solution

In this paper, we propose a numerical method which can routinely improve the energy resolution down to 0.2-0.3eV of electron energy-loss spectra acquired in a transmission electron microscope. The method involves measurement of the point-spread function (PSF) corresponding to the spectrometer aberration and to the incident energy spread, and then an inversion of this PSF so as to restore the spectrum. The chosen algorithm is based on an iterative calculation of the maximum likelihood solution known to be very robust against small errors in the PSF used. Restorations have been performed on diamond and graphite C-K edges acquired with an initial energy resolution of around 1eV. After reconstruction, the sharp core exciton lines become clearly visible for both compounds and the final energy resolution is estimated to be about 200-300meV. In the case of graphite, restorations involving both energy resolution and angular resolution have been successfully conducted. Finally, restorations of Fe L(2,3) and O-K edges measured for various iron oxides will be shown.