Australian experience with total pancreatectomy with islet autotransplantation to treat chronic pancreatitis

BACKGROUND

This study aimed to describe the clinical outcomes of total pancreatectomy with islet autotransplantation (TP-IAT) in Australia.

METHODS

Individuals selected for TP-IAT surgery according to the Minnesota Criteria (Appendix) without evidence of diabetes were evaluated including time to transplantation from pancreatectomy, islet numbers infused and post-transplantation HbA1c, C-peptide, total daily insulin and analgesic requirement.

RESULTS

Sixteen individuals underwent TP-IAT from Australia and New Zealand between 2010 and 2020. Two recipients are deceased. The median islet equivalents/kg infused was 4244 (interquartile range (IQR) 2290-7300). The median C-peptide 1 month post-TP-IAT was 384 (IQR 210-579) pmol/L and at median 29.5 (IQR 14.5-46.5) months from transplant was 395 (IQR 139-862) pmol/L. Insulin independence was achieved in eight of 15 (53.3%) surviving recipients. A higher islet equivalents transplanted was most strongly associated with the likelihood of insulin independence (P < 0.05). Of the 15 surviving recipients, 14 demonstrated substantial reduction in analgesic requirement.

CONCLUSION

The TP-IAT programme in Australia has been a successful new therapy for the management of individuals with chronic pancreatitis including hereditary forms refractory to medical treatment to improve pain management with 50% insulin independence rates.

816 The Effect Of COVID-19 And Service Delivery Changes On 30-Day Mortality in Fractured Neck of Femur Patients: A Case-Control Study

Introduction

The majority of neck of femur (NOF) fractures occur within the home, therefore admissions were not expected to change during the COVID-19 pandemic₍₁₎ . This study investigates the effect of coronavirus and our department’s response on 30-day mortality for patients admitted with NOF fractures.

Method

Data from 65 fractured NOF admissions (22^nd March - 24^th May 2020) was compared with 62 patients from the same period in 2019. Binary logistic regression was used to explore 30-day mortality; accounting for differences in ASA, anaesthetic type, anticoagulation status, surgery type, age, time to surgery and year of admission.

Results

The odds of 30-day mortality was statistically significantly higher in patients who were suspected/confirmed COVID-19 positive (n = 10),(OR 2.39, 95%CI (1.60-74.13)). In COVID-19 negative patients (n = 55), the odds of 30-day mortality was lower in 2020, and approached statistical significance (0.232, 95%CI (0.053-1.02)), compared to the same period in 2019. Median length of stay (LOS) in patients who survived was 11 days in 2020 and 15.5 days in 2019 (p = 0.003).

Conclusions

The results suggest that a COVID-19 diagnosis significantly increases the 30-day mortality in patients with a fractured NOF. The changes implemented in service delivery have shortened LOS and appeared to improve 30-day mortality for those without COVID-19.

Dichloroacetate as a possible treatment for endometriosis-associated pain: a single-arm open-label exploratory clinical trial (EPiC)

Background

Endometriosis (where endometrial-like tissue is found outside the uterus) affects ~ 176 million women worldwide and can lead to debilitating pelvic pain. There is an unmet need for new medical treatment options for endometriosis. Pelvic peritoneal mesothelial cells of women with endometriosis exhibit detrimental metabolic reprogramming that creates an environment favouring the formation and survival of endometriosis lesions. We have generated powerful preclinical proof-of-concept data to show that it is possible to correct this metabolic phenotype using dichloroacetate (DCA), a non-hormonal compound previously used to treat rare metabolic disorders in children. We plan a single-arm, open-label, single site exploratory clinical trial to inform the design of a future randomised controlled trial (RCT) to determine the efficacy of DCA for the treatment of endometriosis-associated pain.

Methods

We will recruit 30 women with endometriosis-associated pain over a 6-month period. All participants will receive approximately 6.25 mg/kg oral DCA capsules twice daily for 6 weeks, with a dose increase to approximately 12.5 mg/kg twice daily for a further 6 weeks if their pain has not been adequately controlled on this dose regime and side-effects are acceptable. If pain is adequately controlled with minimal side-effects, the lower dose will be continued for a further 6 weeks. The primary objective is to determine whether it is possible to achieve acceptable recruitment and retention rates within the defined exclusion and inclusion criteria. Secondary objectives are to determine the acceptability of the trial to participants, including the proposed methods of recruitment, treatment, follow-up frequency and number of questionnaires. The recruitment rate will be determined by the proportion of patients recruited from the pool of eligible women. The retention rate will be determined by the proportion of participants who attended the final trial visit.

Discussion

This is a feasibility study to explore effectiveness and acceptability of the proposed field methodology (recruitment, retention, study processes and compliance with treatment). The results will be used to inform the design of a future RCT.

Trial registration

ClinicalTrials.gov, NCT04046081 Registered 6 August 2019

Synthesis of Biologically Active Heterospirocycles through Iterative 1,3-Dipolar Cycloaddition Pathways

We demonstrate the novel spiroannulation of exo-imines with 1,3-dipoles, for the first time, leading to 3D spirocycles with a secondary amine (NH) in the spiro-ring. The synthetic method described herein allows access to these previously unexplored heterospirocyclic cores that have application in the discovery of functional molecules for medicinal and materials science. This was demonstrated by discovering an unprecedented class of heterospirocycles with antimalarial activity against the human protozoan P. falciparum.

Ultrafiltration pretreatment enhances membrane distillation flux, resilience and permeate quality during water recovery from concentrated blackwater (urine/faeces)

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UF is used as a pre-treatment to reduce membrane distillation fouling.

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UF removes particles and colloids from blackwater but low MW fraction increases.

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Whilst UF treated blackwater high in organics, flux and water quality is stable.

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Without UF pre-treatment, severe fouling reduces flux, which reduces quickly.

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With UF pre-treatment, permeate quality consistently meets treatment quality.

In this study, the pretreatment of concentrated blackwater using ultrafiltration (UF) was shown to improve the permeability, selectivity and robustness of membrane distillation (MD) for application to wastewater treatment. Concentrated blackwater comprises urine and faeces, with minimal flushwater added. The faecal contribution increased the soluble organic fraction and introduced coarse and colloidal particles into the urine, which increased resistance to filtration during dead-end UF. Ultrafiltration removed the particulate and colloidal fractions (MW > 500 kDa) from the blackwater, which permitted similar permeability and robustness for MD to that observed with urine (29.9 vs 25.9 kg m⁻² h⁻¹), which comprises a lower colloidal organic concentration. Without UF pretreatment, a higher density organic layer formed on the MD surface (197 vs 70 gCOD m⁻²) which reduced mass transfer, and transformed the contact angle from hydrophobic to hydrophilic (144.9° to 49.8°), leading to pore wetting and a dissipation in product water quality due to breakthrough. In comparison, with UF pretreatment, MD delivered permeate water quality to standards satisfactory for discharge or reuse. This is particularly timely as the ISO standard for non-sewered sanitation has been adopted by several countries at a national level, and to date there are relatively few technologies to achieve the treatment standard. Membrane distillation provides a robust means for concentrated blackwater treatment, and since the energy required for separation is primarily heat, this advanced treatment can be delivered into areas with more fragile power networks.

Managing power dissipation in closed-loop reverse electrodialysis to maximise energy recovery during thermal-to-electric conversion

Whilst the efficiency of reverse electrodialysis (RED) for thermal-to-electrical conversion has been theoretically demonstrated for low-grade waste heat, the specific configuration and salinity required to manage power generation has been less well described. This study demonstrates that operating RED by recycling feed solutions provides the most suitable configuration for energy recovery from a fixed solution volume, providing a minimum unitary cost for energy production. For a fixed membrane area, recycling feeds achieves energy efficiency seven times higher than single pass (conventional operation), and with an improved power density. However, ionic transport, water flux and concentration polarisation introduce complex temporal effects when concentrated brines are recirculated, that are not ordinarily encountered in single pass systems. Regeneration of the concentration gradient at around 80% energy dissipation was deemed most economically pragmatic, due to the increased resistance to mass transport beyond this threshold. However, this leads to significant exergy destruction that could be improved by interventions to better control ionic build up in the dilute feed. Further improvements to energy efficiency were fostered through optimising current density for each brine concentration independently. Whilst energy efficiency was greatest at lower brine concentrations, the work produced from a fixed volume of feed solution was greatest at higher saline concentrations. Since the thermal-to-electrical conversion proposed is governed by volumetric heat utilisation (distillation to reset the concentration gradient), higher brine concentrations are therefore recommended to improve total system efficiency. Importantly, this study provides new evidence for the configuration and boundary conditions required to realise RED as a practical solution for application to sources of low-grade waste heat in industry.

Donation after circulatory death hearts recipients compared to donation after brain death heart recipients have comparable systolic left ventricular function and better myocardial strain at 1 year

Purpose

Cardiac transplantation from donation after circulatory death (DCD) has been implemented at our hospital since February 2015. Despite encouraging results some concerns may be raised about the impact of the warm ischemia and reperfusion injury on the myocardium status at longer follow-up. Therefore, we aimed to analyse systolic performance of the left ventricle at 1 year follow in DCD and donation after brain death (DBD) cardiac recipients, as assessed by echocardiography with myocardial deformation imaging.

Methods

We identified 46 consecutive DCD cardiac recipients who were transplanted from February 2015 to August 2018 and we matched them with 46 DBD cardiac recipients. Six and 7 patients from DCD and DBD group, respectively, died in the first-year post transplant. In the remaining patients we have compared the classical echocardiographic measurements as well as global longitudinal strain (GLS) and global circumferential strain (GCS) at 1-year follow-up.

Results

DCD and DBD patients did not present with differences in terms of classical echocardiographic parameters of left ventricular (LV) structure and systolic function at one-year follow-up. LVEDV was similar in DCD and DBD patients (101±24 vs. 95±32 ml, p=0.4 respectively), as well as LVESV (42±13 vs. 42±16 ml, p=0.9, respectively), LV ejection fraction (58±6 vs. 56±8%, p=0.22) and LV mass (156±39 vs. 163±38 gr, p=0.2, respectively). In contrast, myocardial deformation parameters, such as GLS and GCS, were better in DCD than in DBD (16.1 vs. −14.5%, p&lt;0.01; and −25.2 vs. 22.3%, p&lt;0.05, respectively). The diastolic LV function parameters were similar in DCD and DBD group, as evidenced by E wave velocity, A wave velocity and deceleration time of mitral inflow, however E over E prime was lower in DCD than in DBD recipients (7.7±8.7, p&lt;0.05). Fractional area change of the right ventricle was higher in DCD in comparison with DBD (46±7 vs. 40±7%, p&lt;0.01) while right atrial volume index was lower in DCD than in DBD (25±8 vs. 29±9 ml/m2, p&lt;0.01). Other parameters of RV function (systolic excursion of the tricuspid annulus, TAPSE) were similar in both groups.

Conclusion

DCD and DBD heart recipients present with similar systolic LV function at 1-year follow, as assessed by classical echocardiographic parameters. DCD cardiac recipients have better myocardial deformation parameters as assessed by the speckle tracking, better systolic right ventricular function and lower filling pressures of the left ventricle.

Funding Acknowledgement

Type of funding source: None

A fall in the previous 12 months predicts fracture in the subsequent 5 years in postmenopausal women

PURPOSE

The purpose of this study was to evaluate if a history of falls predicts future postmenopausal fractures and if this prediction variesaccording to frequency, mechanism, and severity of falls and site of fractures.

METHODS

This study used data from OSTPRE prospective cohort. Total study population consisted of 8744 postmenopausal women (mean age 62.2 years) who responded to postal enquiry in 1999 (baseline) and in 2004 (follow-up).

RESULTS

Women were classified by frequency (non/occasional/frequent fallers), mechanism (slip/nonslip), and severity (injurious/ non-injurious) of falls and fractures by site (major osteoporotic/other). A total of 1693 (19.4%) women reported a fall during the preceding 12 months in 1999; 812 a slip fall, 654 a nonslip, 379 an injurious fall, and 1308 a non-injurious fall. A total of 811 women (9.3%) sustained a fracture during the 5-year follow-up period (1999-2004); 431 major osteoporotic fractures and 380 other fractures. Compared with non-fallers, earlier falls predicted subsequent fractures with an OR of 1.41 (95% CI 1.19-1.67, p ≤ 0.001), 1.43 (95% CI 1.14-1.80, p = 0.002) for earlier slip falls, and 1.35 (95% CI 1.04-1.74, p = 0.02) for earlier nonslip falls. Earlier injurious falls predicted future fractures (OR = 1.64, 95% CI 1.21-2.23, p ≤ 0.01), especially other fractures (OR = 1.86, 95% CI 1.24-2.80, p ≤ 0.01), but not major osteoporotic fractures (OR = 1.37, 95% CI 0.89-2.10, p = 0.151). Fracture risk predictions for earlier non-injurious falls was OR = 1.36, 95% CI 1.12-1.64, p = 0.002. These risk patterns remain same after adjustments.

CONCLUSION

History of falls (especially injurious falls) predicts subsequent fractures (mainly other fractures compared with major osteoporotic fractures) inpostmenopausal women. We aimed to investigate if history of falls (frequency, mechanism, and severity) is a predictor of future fractures in postmenopausal women. Our results indicate that history of falls (especially injurious falls) appeared to be an indicator for subsequent fracture overall. Earlier injurious falls were stronger predictors for future other fractures than for typical major osteoporotic fractures.

Uniportal subxiphoid bilateral removal of self-introduced thoracic foreign bodies

This is a report of a 31-year-old male refugee, who was admitted to Intensive Therapy Unit after being found in severe chest pain after escaping extreme torture from his home country. He was found to have four nails in his thorax. These were removed using a subxiphoid video-assisted thorascopic surgery (VATS) technique. This technique allowed excellent visualization of the right, left and anterior mediastinal part of the chest and therefore preventing damage or injury to surrounding structures. This was particularly useful in a complex case such as this. By avoiding an intercoastal incision and intercostal manipulation, our patient had limited pain post-procedure facilitating an earlier aggressive mobilization program with potential benefit in terms of improved lung expansion, reduction of atelectasis and lung infections. With the right training, the technical challenges of using the technique should be overcome and thus the benefits of subxiphoid VATS will be offered to a larger portion of thoracic surgical patients.

Abstract B44: ImmTAC molecules: Beyond HLA-A*02:01—the identification and isolation of dual-HLA-specific T cell receptors

ImmTAC (Immune mobilizing monoclonal TCRs against cancer) molecules are a new class of bi-specific biologic that combine a T-cell receptor (TCR)-targeting system with an anti-CD3 effector function to activate highly potent and specific T-cell responses to cancer cells. ImmTAC molecules have the potential to overcome many of the limitations of other immuno-oncology agents; using TCRs to target intracellularly processed peptides presented by HLA allows access to a vast landscape of cancer-specific antigens that antibody-based therapies cannot currently target. Soluble agents also have a number of benefits over cellular therapies in terms of ease of manufacture and supply. At Immunocore we are constantly striving for innovation and looking for new opportunities to advance the ImmTAC platform. One limitation of TCR-targeting is HLA-restriction, which means that a single ImmTAC molecule is highly specific towards a single HLA-subtype. Lead ImmTAC molecules target HLA-A2, which has the highest coverage in the Caucasian population of approximately 55%. Our desire is to cover all patients in need; therefore, we are developing ImmTAC molecules that target peptides on other HLA alleles with an aim to increase patient access across a range of ethnic groups. In addition, the ability to target peptides presented in multiple HLA alleles would significantly increase the number of patients eligible for this treatment. HLA-A3 and HLA-A11 are part of the same superfamily and share largely overlapping peptide repertoires. We have identified peptides from gp100, a melanoma associated-antigen, which are presented by both HLA-A3 and HLA-A11. Identifying a TCR that is able to recognize a peptide in both these HLA alleles is the first step in generating our first dual-HLA-specific ImmTAC. Here we describe the generation of new TCRs suitable for ImmTAC generation, using our integrated in-house TCR discovery process. TCRs were isolated using multiple methods from HLA-A3 or HLA-A11 donors. We were able to identify antigen-specific T cells from multiple donors that recognized the gp100-peptide-HLA complex. The majority of these T cells were specific to the HLA-allele of the donor and failed to recognize the same peptide in the alternative HLA allele. However, we were able to identify TCRs that had a measurable binding affinity to the gp100 peptide presented in both HLA-A3 and HLA-A11. These data illustrate the successful isolation of wild-type TCRs suitable for affinity maturation and the first step in generating our first dual-HLA-restricted ImmTAC molecule.

Citation Format: Vanessa L. Clark, Linda Hibbert, Debbie Wright, Sarah Bailey, Alice Barkell, Kathy Hale, Elizabeth Evans, Alasdair Gunn, Maria Busz, Karolina Lech, Michelle Teng, Luke Williams, Joseph Dukes, Annelise Vuidepot, Bent Jakobsen. ImmTAC molecules: Beyond HLA-A*02:01—the identification and isolation of dual-HLA-specific T cell receptors [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr B44.

Abstract A92: Assessing the T-cell exhaustion status of TCR discovery outputs

Identification of antigen-specific T cell receptors (TCRs) is an essential component of the ImmTAC (Immune mobilizing monoclonal TCRs Against Cancer) platform at Immunocore. ImmTAC molecules are formed of a soluble TCR fused to an anti-CD3 effector function that engages, redirects and activates T cells to kill cancerous cells. TCRs recognize peptide antigens presented on the surface of the cancer cell by human leukocyte antigen (HLA). Thus, a fundamental step in our pipeline is to isolate T-cell receptors specific for validated cancer antigens for downstream development. T cells are isolated from whole blood of healthy donors to identify antigen-specific T cell clones using an in vitro model that consists of several stimulation steps. Activated CD8+ T cells are sorted into single cells for subsequent analysis and characterization. Despite the relative success of this approach, often analysis of T-cell clones is limited by low or absent mRNA expression for either or both TCR alpha (TRAV) and beta (TRBV) chains. We predict that TCR downregulation may result from overstimulation of T cells, leading to exhaustion. Here, we aimed to establish an in vitro model of T-cell exhaustion that would enable us to better understand the molecular mechanisms behind this process and thus facilitate method development. We induced extreme conditions of stimulation using CD3/CD28 beads and recombinant human IL-2 (rhIL-2) for 2-3 weeks. Whole-transcriptome analysis of the resulting activated T cells was compared to rested cells using a 5′ single-cell RNA-seq method from 10X Genomics (California, USA). Our preliminary analysis indicates that the activated T cells express several checkpoint inhibitors at higher levels. Our findings will be further investigated by performing full-length RNA sequencing of previously isolated single T-cell clones with low TRAV and/or TRBV detection rates. By identifying a molecular signature that represents the phenotype of exhausted T cells, we can potentially assess the state of T cells in TCR discovery outputs. Most importantly, determination of the expression levels of inhibitory receptors that are responsible for the decrease or loss of TCR expression is expected to enhance our understanding of the potential impact of T-cell exhaustion.

Citation Format: Paraskevi Mallini, Filipa Bravo-Lopes, Karolina Lech, Sunir Malla, Maria Busz, Nathaniel Davies, Jacob Hurst, Luke Williams, Sterenn Davis, Michelle Teng. Assessing the T-cell exhaustion status of TCR discovery outputs [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A92.

A simple foot pedal device in a horizontal bore imaging facility replicates weightbearing outcomes for Hallux Valgus patients

BACKGROUND

Weightbearing images are important to the diagnosis of foot pathologies as are the three dimensional views available from CT and MRI. Standard three-dimensional imaging hardware, however, does not have a simple tool to obtain weightbearing images. The current research aimed to design, build and test a simple device to apply load in a horizontal bore imaging facility.

METHODS

With the immediate need in hallux valgus studies, hallux valgus subjects were imaged using the new loading device, which could be easily transported and had no additional electronics.

RESULTS

Testing showed that the usual angular measures of the foot (intermetatarsal and hallux valgus) replicated the results from the standard of care standing plain film results. With application of load, HV angle changed from 29.9° non-weightbearing to 32.2° weightbearing, while IM angle changed from nonweightbearing 15.8° to weightbearing 16.5°.

CONCLUSION

The pedal-like device can provide weightbearing images in a horizontal bore MRI facility.

An assessment of histological margins and recurrence of completely excised cutaneous SCC

There is a paucity of data relating to histological margins of cutaneous squamous cell carcinoma (cSCC) and local recurrence. Retrospective data were collected for 721 patients with cSCC treated at Queen Victoria Hospital, UK, and followed up for five years. The local recurrence rate was 6.1%, the mean time to recurrence was 12.61 months and 93% of recurrences occurred within two years. Sixty-six per cent of recurrences had a deep margin of 2.5 mm or less (p 0.041). The Pearson's correlation coefficient showed a strong correlation with tumour grade (r=0.82, p, 0.05), lymphovascular invasion (r=0.73. p<0.05), medium correlation with deep histological margin(r= -0.55, p<0.05), a weak correlation with male sex (r= 0.31, p<0.05) and the anatomical site of head and neck (r=0.31, p<0.05).The multiple regression analysis model using the 5 variables generated an r value of 0.71 and adjusted r square of 0.7. In conclusion, our findings are consistent with previously mentioned prognostic indicators and also demonstrate that deep histological margin is a significant predictor of local recurrence of cSCC. We recommend larger multi-institutional studies to confirm the above results to subsequently guide the specialist skin multidisciplinary teams' recommendations.