Tumor resistance to anti-mesothelin CAR-T cells caused by binding to shed mesothelin is overcome by targeting a juxtamembrane epitope

Despite many clinical trials, CAR-T cells are not yet approved for human solid tumor therapy. One popular target is mesothelin (MSLN) which is highly expressed on the surface of about 30% of cancers including mesothelioma and cancers of the ovary, pancreas, and lung. MSLN is shed by proteases that cleave near the C terminus, leaving a short peptide attached to the cell. Most anti-MSLN antibodies bind to shed MSLN, which can prevent their binding to target cells. To overcome this limitation, we developed an antibody (15B6) that binds next to the membrane at the protease-sensitive region, does not bind to shed MSLN, and makes CAR-T cells that have much higher anti-tumor activity than a CAR-T that binds to shed MSLN. We have now humanized the Fv (h15B6), so the CAR-T can be used to treat patients and show that h15B6 CAR-T produces complete regressions in a hard-to-treat pancreatic cancer patient derived xenograft model, whereas CAR-T targeting a shed epitope (SS1) have no anti-tumor activity. In these pancreatic cancers, the h15B6 CAR-T replicates and replaces the cancer cells, whereas there are no CAR-T cells in the tumors receiving SS1 CAR-T. To determine the mechanism accounting for high activity, we used an OVCAR-8 intraperitoneal model to show that poorly active SS1-CAR-T cells are bound to shed MSLN, whereas highly active h15B6 CAR-T do not contain bound MSLN enabling them to bind to and kill cancer cells.

Nanobody-Based ImmunoPET for Hepatocellular Carcinoma

PURPOSE/OBJECTIVE(S)

HCC accounts for 75-90% of all primary liver cancers, the majority of which are treated with liver-directed therapy. Treatment response and recurrence are difficult to discern using conventional imaging with MR/CT. Tumor-selective PET imaging could help with clinical management in this setting. Here, we engineer HN3, a single-domain antibody (nanobody) specific to GPC3, a histopathologically-defining HCC marker, as an immunoPET agent. We compared both conventional and sortase-based site-specific modification methods for synthesizing HN3 immunoPET tracers.

MATERIALS/METHODS

Stochastic lysine conjugation with deferoxamine (DFO-NCS) was done to synthesize nHN3-DFO. ssHN3-DFO was engineered utilizing sortase-mediated conjugation of HN3 containing an LPETG C-terminal tag and a triglycine-DFO chelator. Biolayer interferometry (BLI) and radioligand saturation assays were done to determine binding affinity pre- and post-Zirconium-89 labeling. Following, PET/CT with a terminal 3-hour biodistribution was done in mice inoculated with isogenic A431 and A431-GPC3+ xenografts to determine conjugate specificity for GPC3. Finally, conjugates were evaluated in a HepG2 liver cancer model via ex vivo biodistribution studies and a comparative PET/CT study in mice bearing HepG2 tumors that were imaged with both [18F]FDG and 89Zr-ssHN3.

RESULTS

Both conjugates exhibited nanomolar binding affinity for GPC3 in vitro (11-30 nM for nHN3 and 10-15 nM for ssHN3). A431 and A431-GPC3+ PET/CT and biodistribution studies showed specificity to GPC3 by both probes, with more favorable tumor uptake by 89Zr-ssHN3 at 3 hours post-injection (14% IA/g vs. 7% IA/g for nHN3). Both tracers also displayed uptake in HepG2 (GPC3+) liver tumors, again with the site specifically conjugated probe having higher tumor accumulation and lower liver signal than the conventionally modified HN3 (7% IA/g vs. 5 % IA/g for tumor and 2% IA/g vs. 4% IA/g for liver at 1-hour post-injection). PET/CT studies in mice imaged with [18F]FDG and 89Zr-ssHN3 demonstrated more consistent tumor accumulation for the nanobody conjugate (4/4 mice had uptake by the tumor vs. 1/4 for FDG).

CONCLUSION

We successfully designed, synthesized, and characterized novel GPC3-selective nanobody PET probes that can image liver tumors in vivo. The site-specifically conjugated tracer showed more favorable biodistribution and pharmacokinetic properties, resulting in a much higher tumor: liver signal compared to 89Zr-nHN3. We also show the superiority of the 89Zr-ssHN3 imaging over conventional [18F]FDG, highlighting a clear advantage in using targeted tumor imaging for this cancer type. Successful translation of the site-specifically conjugated nanobody may ultimately aid in characterizing lesions following liver-directed therapy and allow for more comprehensive screening, early diagnosis, and post-treatment surveillance of HCC.

Comparison of United Kingdom and United States screening criteria for detecting retinopathy of prematurity in Hong Kong

INTRODUCTION

We examined whether the United Kingdom (UK) or the United States (US) screening criteria are more appropriate for retinopathy of prematurity (ROP) screening in Hong Kong, in terms of sensitivity for detecting type 1 ROP and the number of infants requiring screening.

METHODS

In this retrospective cohort study, we reviewed the medical records of all infants who underwent ROP screening from 2009 to 2018 at a tertiary hospital in Hong Kong. During this period, all infants born at gestational age (GA) ≤31 weeks and 6 days or birth weight (BW) <1501 g (ie, the UK screening criteria) underwent ROP screening. We determined the number of infants requiring screening and the number of type 1 ROP cases that would have been missed if the US screening criteria (GA ≤30 weeks & 0 days or BW ≤1500 g) had been used.

RESULTS

Overall, 796 infants were screened using the UK screening criteria. If the US screening criteria had been used, the number of infants requiring screening would have decreased by 21.1%; all type 1 ROP cases would have been detected (38/38, 100% sensitivity). Of the 168 infants who would not have been screened using the US screening criteria, only four of them (2.4%) had developed ROP (all maximum stage 1 only).

CONCLUSION

In our population, the use of the US screening criteria could reduce the number of infants screened without compromising sensitivity for the detection of type 1 ROP requiring treatment. We suggest narrowing the GA criterion for consistency with the US screening criteria during ROP screening in Hong Kong.

Improved responsiveness to change in joint space width over 24-month follow-up: comparison of 3D JSW on weight-bearing CT vs 2D JSW on radiographs in the MOST study

OBJECTIVE

Radiographic joint space width (JSW) has been a standard for measuring knee osteoarthritis (OA) structural change. Limitations in the responsiveness of this approach might be overcome by instead measuring 3D JSW on weight-bearing CT (WBCT). This study compared the responsiveness of 3D JSW measurements using WBCT with the responsiveness of radiographic 2D JSW.

DESIGN

Standing, fixed-flexion knee radiographs (XR) and WBCT were acquired ancillary to the 144- and 168-month Multicenter Osteoarthritis Study visits. Tibiofemoral JSW was measured on both XR and WBCT. Responsiveness to change was defined by the standardized response mean (SRM) for change in JSW (1) at predetermined mediolateral locations (JSWx) on both modalities and (2) in the following subregions measured on WBCT images: central medial and lateral femur (CMF/CLF) and tibia (CMT/CLT), and anterior and posterior tibia (AMT/ALT, PMT/MLT).

RESULTS

Baseline and 24-month follow-up JSWx measurements were completed for 265 participants (58.1% women). Responsiveness of 3D JSWx for medial tibiofemoral compartment on coronal WBCT (SRM range: -0.18, -0.24) exceeded that for 2D JSWx (-0.10, -0.16). Responsiveness of 3D JSW subregional mean (-0.06, -0.36) and maximal (-1.14, -1.75) CMF and CMT and maximal CLF/CLT 3D JSW changes were statistically significantly greater in comparison with respective medial and lateral 2D JSWx (P ≤ 0.002).

CONCLUSIONS

Subregional 3D JSW on WBCT is substantially more responsive to 24-month changes in tibiofemoral joint structure compared to radiographic measurements. Use of subregional 3D JSW on WBCT could enable improved detection of OA structural progression over a 24-month duration in comparison with measurements made on XR.

Food industry shaping of the principles of scientific integrity

Background

There is evidence that food industry actors try to shape science on nutrition and physical activity. But they are also involved in the influence of scientific integrity principles. Our research objective was to study the extent of that involvement, with a case study of ILSI as a key actor in that space.

Methods

We conducted a qualitative document analysis, triangulating data from an existing scoping review, publicly available information, internal industry documents, and existing freedom of information requests.

Results

Food companies have joined forces through ILSI to shape the development of scientific integrity principles. These activities started in 2007, in direct response to the growing criticism of the food industry's funding of research. ILSI first built a niche literature on conflicts of interest (COI) in food science and nutrition at the individual and study levels. Because the literature was scarce on that topic, these publications were used and cited in ILSI's and others' further work on COI, scientific integrity, and PPP, beyond the fields of nutrition and food science. In the past few years, ILSI started to shape the very principles of scientific integrity then and to propose that government agencies, professional associations, non-for-profits, and others, adopt these principles. In the process, ILSI built a reputation in the scientific integrity space. ILSI's work on scientific integrity ignores the risks of accepting corporate funding and fails to provide guidelines to protect from these risks.

Conclusions

The activities developed by ILSI on scientific integrity principles are part of a broader set of political practices of corporations to influence public health policy, research, and practice. It is important to learn about and counter these practices as they risk shaping scientific standards to suit corporate interests rather than public health ones.

Key messages

ILSI, a group funded by corporations, shaped the very principles of scientific integrity. ILSI built a reputation in the scientific integrity space.

1512 A Service Evaluation of Transoral Laser Resection Procedures for Oral Cancer and Dysplasia

Aim

The use of the diode laser is a frequently employed treatment modality in primary surgical excision, especially for early oral cancer. This is due to advantages offered in precision of excision, and potential reduced post-operative pain compared to other excision methods. Additionally, haemostasis can often be obtained simultaneous to excision. Despite frequent use of laser excision for oral cancer/dysplasia, there is limited information on the incidence of postoperative complications.

Method

Data was collected retrospectively by review of electronic healthcare records for a 5-year period (Jan 2015-Jan 2020) for patients who underwent transoral laser excision of oral dysplasia in a major UK teaching hospital. The number of short (&lt;30 days) and longer-term complications was evaluated and categorised using the Clavien-Dindo classification.

Results

A total 260 patients received diode laser resection for oral cancer/dysplasia in this period. Approximately one third of patients had the diagnosis of SCC and 52% of patients were treated on a day case basis. Approximately one third of patients experienced postoperative complications.; including positive or close resection margins (16%), bleeding (8%), superficial infection (6%) and significant postoperative pain (2%). A total of 16% of patients required further treatment in theatre (Clavien-Dindo IIIb).

Conclusions

The use of lasers for excision of oral tumours and dysplastic lesions is a frequently employed modality, offering advantages to the operating surgeon (improved haemostasis, excellent manoeuvrability) and patients (reduced pain and scarring). Complications are largely predictable in nature, but the surgical team should be aware of potential issues to ensure safe, effective patient care.

Prevalence of lower limb venous disease in surgeons: a case study and results of a survey by the BAOMS Reconstruction Surgical Subspecialty Interest Group

We report a case of venous leg ulceration in a reconstructive oral and maxillofacial surgeon. An online survey was created by the British Association of Oral and Maxillofacial Surgeons (BAOMS) Reconstruction Surgical Subspecialty Interest Group (SSIG), primarily to target head and neck surgeons, to investigate the perceived risk and occurrence of venous leg disease. Two respondents had received treatment for lower limb venous disease thus compromising their ability to work, while 13 had symptoms of early venous disease. Our study shows an interesting area of concern for occupational health in surgeons, particularly in those carrying out long operations, as will be the case for members of the Reconstruction SSIG.

Investigating Risk Factors for Falls among Community-Dwelling Older Adults According to WHO's Risk Factor Model for Falls

OBJECTIVES

The World Health Organization developed the Risk Factor Model for Falls to describe fall risks in a comprehensive manner. However, there was a lack of study adopting such framework in quantifying falls risk from different factors in a single model. Therefore, this study examined the risk factors from four domains in the Risk Factor Model for Falls among older adults.

DESIGN

Secondary data analysis of 10-year assessment records of the Minimum Data Set-Home Care instrument.

SETTING

Hong Kong.

PARTICIPANTS

89,100 community-dwelling adults aged 65 and over who first applied for publicly funded long-term care services from 2005 to 2014.

MEASUREMENTS

The Minimum Data Set-Home Care instrument was used to ascertain older adults' care needs and match them with appropriate services. Additionally, meteorological records from the same period were extracted from the Hong Kong Observatory. The logistic regression model was used to examine risk factors and their associations with falls.

RESULTS

In total 70 factors were included in the analysis, of which 37 were significantly associated with falls. Behavioral risk factors generally had greater odds ratios of falling, as compared with biological, socioeconomic, and environmental factors. Out of all significant factors, functional status, alcohol drinking, and locomotion outdoors had the largest odds ratios of falling.

CONCLUSION

Behavioral risk factors for falls are of remarkable influence yet are modifiable among older adults. Hence, falls prevention programs may need to prioritize addressing these factors.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Noisy Preprocessing Facilitates a Photonic Realization of Device-Independent Quantum Key Distribution

Device-independent quantum key distribution provides security even when the equipment used to communicate over the quantum channel is largely uncharacterized. An experimental demonstration of device-independent quantum key distribution is however challenging. A central obstacle in photonic implementations is that the global detection efficiency, i.e., the probability that the signals sent over the quantum channel are successfully received, must be above a certain threshold. We here propose a method to significantly relax this threshold, while maintaining provable device-independent security. This is achieved with a protocol that adds artificial noise, which cannot be known or controlled by an adversary, to the initial measurement data (the raw key). Focusing on a realistic photonic setup using a source based on spontaneous parametric down conversion, we give explicit bounds on the minimal required global detection efficiency.

Referral indications and prevalence of sleep abnormalities in children with early onset scoliosis

This study describes the utility of overnight sleep studies in children with early onset scoliosis (EOS). Children with EOS have diminished respiratory reserve which is associated with abnormal breathing and sleep quality in children. Currently, there are no criteria for referral of these children to evaluate breathing during sleep or data on the use of sleep treatments as part of their supportive care. A review of the 159 patients with EOS who were followed at a single institution from 2003 to 2016 identified 68 who underwent overnight polysomnograms (PSGs). Sixty-five of 68 (96%) had elevated apnea-hypopnea index (AHI) and a majority (56%) were prescribed nighttime respiratory support. A majority of young children (< 5 years) with PSG were referred for a history of snoring, apnea, or restless sleep; all 30 had abnormal PSGs. Twenty-seven (90%) had nighttime hypoxemia (nadir oxygen saturation values < 92%). Eighteen (60%) were referred to otolaryngology, of whom 11 (37%) subsequently underwent tonsil and/or adenoid removal. In older children (≥ 5 years), those referred for PSGs had more severe restrictive chest wall disease [lower forced vital capacity (FVC) values] than those who were not sent for PSG. Correlation between FVC and apnea-hypopnea index, however, was not significant. Pre-operative coronal curve magnitude did not strongly correlate with nadir SaO₂ or AHI in either age group. These results suggest that sleep studies are underutilized in the management of children with EOS. Inadequate and poor-quality sleep adversely affects growth, behavior, and cognitive function in children. This study suggests that screening for sleep abnormalities should be incorporated into assessment and treatment of more patients with EOS.

ICES: Data, Discovery, Better Health

ICES was founded in 1992 to study the health care system and promote effective, efficient and equitable health care. Over 27 years later, the goal remains largely unchanged, though the institute has grown in size and impact. Created as an independent not-for-profit research institute and given what was, at the time, unprecedented access to administrative health data records for the population of Ontario, ICES’ initial focus was to better understand the delivery of hospital services and translate its findings into better health care and policy. From modest beginnings with a handful of researchers located in a few hospital offices, ICES has grown to encompass a community of almost 500 scientists and staff across a network of seven physical sites in Ontario. The original focus on hospital-based services has expanded significantly and now includes research and analysis of community-based health services, health policy, Indigenous health, social determinants of health, and data science.

Right Upper Lobe Collapse Secondary to an Anomalous Bronchus after Endotracheal Intubation for Routine Surgery

Perioperative hypoxaemia is a common but serious problem with well recognised causes. However, an anomalous bronchus causing lobar collapse as a cause is seldom mentioned. A healthy young male patient was anaesthetised for a knee operation. He required reintubation immediately postoperatively for hypoxia. He was found to have right upper lobe collapse. Fibreoptic examination of the trachea demonstrated an anomalous bronchus as the cause. Intra-operatively, the endotracheal tube had been inserted too deeply and the bronchial orifice had been obstructed by the tip. It took several hours for the lung to re-expand. Greater awareness of this potential complication is needed.