Single cell analysis of Chinese hamster ovary cells during a bioprocess using a novel dynamic imaging system

Reliable monitoring of mammalian cells in bioreactors is essential to biopharmaceutical production. Trypan blue exclusion is a method of determining cell density and viability that has been used for over one hundred years to monitor cells in culture and is the current standard method in biomanufacturing. This method has many disadvantages however and there is a growing demand for more detailed and in-line measurements of cell growth in bioreactors. This article assesses a novel dynamic imaging system for single cell analysis. This data shows that comparable total cell density, viable cell density and percentage viability data shown here, generated by the imaging system, aligned well with conventional trypan blue counting methods for an industrially relevant Chinese Hamster Ovary (CHO) cell line. Furthermore, detailed statistical analysis shows that the classification system used by the PharmaFlow system can reveal trends of interest in monitoring the health of mammalian cells over a 6-day bioreactor culture. The system is also capable of sampling at-line, removing the necessity for taking samples off-line and enabling real time monitoring of cells in a bioreactor culture.

N-glycomic profiling of capsid proteins from Adeno-Associated Virus serotypes

Adeno-associated virus (AAV) vector has become the leading platform for gene delivery. Each serotype exhibits a different tissue tropism, immunogenicity, and in vivo transduction performance. Therefore, selecting the most suitable AAV serotype is critical for efficient gene delivery to target cells or tissues. Genome divergence among different serotypes is due mainly to the hypervariable regions of the AAV capsid proteins. However, the heterogeneity of capsid glycosylation is largely unexplored. In the present study, the N-glycosylation profiles of capsid proteins of AAV serotypes 1 to 9 have been systemically characterized and compared using a previously developed high-throughput and high-sensitivity N-glycan profiling platform. The results showed that all 9 investigated AAV serotypes were glycosylated, with comparable profiles. The most conspicuous feature was the high abundance mannosylated N-glycans, including FM3, M5, M6, M7, M8, and M9, that dominated the chromatograms within a range of 74 to 83%. Another feature was the relatively lower abundance of fucosylated and sialylated N-glycan structures, in the range of 23%-40% and 10%-17%, respectively. However, the exact N-glycan composition differed. These differences may be utilized to identify potential structural relationships between the 9 AAV serotypes. The current research lays the foundation for gaining better understanding of the importance of N-glycans on the AAV capsid surface that may play a significant role in tissue tropism, interaction with cell surface receptors, cellular uptake, and intracellular processing.

Measurement and control of foam generation in a mammalian cell culture

Foam is generated in mammalian cell cultures by excessive agitation or gas sparging. This occurs particularly in cultures that generate recombinant proteins at high cell concentrations. Three antifoam agents were tested for their compatibility with antibody-producing Chinese hamster ovary (CHO) cells. One agent (antifoam 204) was completely inhibitory to growth at a concentration of 10 ppm, one agent (antifoam C) showed partial inhibition and a third (antifoam SE-15) showed no inhibition at this concentration. A novel foam image analyzer (LabCam) was used to evaluate two antifoams (C and SE-15) for their ability to dissipate foam generated in cell culture media by enhanced agitation. The presence of antifoam in the media reduced significantly the foam layer that was generated and this was shown to be rapidly dissipated in the presence of 10 ppm SE-15. The antifoams were also tested for foam dissipation in cultures of CHO cells at >106 cells/mL. Supplementation of the cultures with SE-15 resulted in dissipation of foam generated by excessive gas sparging within 2 min. Under equivalent conditions 75% of foam dissipated in the presence of antifoam C, within 2 min but there was a residual foam layer up to 25 min. This study showed the value of an optical monitoring system (LabCam) for measuring foam generation and dissipation in a bioreactor to assess the efficiency of antifoam agents to reduce foam in a bioreactor. This has the potential for use as a control system that could be designed for continuous monitoring and foam control in a mammalian cell bioprocess.

Multi-attribute analysis of adeno-associated virus by size exclusion chromatography with fluorescence and triple-wavelength UV detection

Adeno-associated virus (AAV) is the leading platform for in vivo gene therapy to treat numerous genetic diseases. Comprehensive analysis of the AAV particles is essential to ensure desired safety and efficacy. An array of techniques is required to evaluate their critical quality attributes. However, many of these techniques are expensive, time-consuming, labour-intensive, and varying in accuracy. Size exclusion chromatography coupled with fluorescence and triple-wavelength ultraviolet detection (SEC-FLD-TWUV) and incorporating an aromatic amino acid of tryptophan as an internal standard offers a simple, rapid, and reliable approach for simultaneous multi-attribute analysis of AAVs. In the current study, we demonstrate its capability for AAV characterization and quantification, that includes capsid concentration, empty to full capsid ratio, vector genome concentration, and the presence of aggregates or fragments. All were performed in 20-min chromatographic runs with minimal sample handling. Data analysis involves the assessment of intrinsic fluorescence and UV absorbance of samples at three wavelengths that can be utilised to determine the content of the capsid protein and genome copy number. The separation efficiency using SEC columns with different pore sizes, and elution buffers of varying compositions, ionic strength, and pH values was also evaluated. This SEC-FLD-TWUV method may serve as a powerful yet cost-effective tool for responsive quality evaluation of AAVs. This may enhance performance, robustness, and safety of bioprocessing for AAV vectors to be used in gene therapy.

Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation

BACKGROUND

The prevalence of type 2 diabetes is increasing rapidly, particularly among younger age groups. Estimates suggest that people with diabetes die, on average, 6 years earlier than people without diabetes. We aimed to provide reliable estimates of the associations between age at diagnosis of diabetes and all-cause mortality, cause-specific mortality, and reductions in life expectancy.

METHODS

For this observational study, we conducted a combined analysis of individual-participant data from 19 high-income countries using two large-scale data sources: the Emerging Risk Factors Collaboration (96 cohorts, median baseline years 1961-2007, median latest follow-up years 1980-2013) and the UK Biobank (median baseline year 2006, median latest follow-up year 2020). We calculated age-adjusted and sex-adjusted hazard ratios (HRs) for all-cause mortality according to age at diagnosis of diabetes using data from 1 515 718 participants, in whom deaths were recorded during 23·1 million person-years of follow-up. We estimated cumulative survival by applying age-specific HRs to age-specific death rates from 2015 for the USA and the EU.

FINDINGS

For participants with diabetes, we observed a linear dose-response association between earlier age at diagnosis and higher risk of all-cause mortality compared with participants without diabetes. HRs were 2·69 (95% CI 2·43-2·97) when diagnosed at 30-39 years, 2·26 (2·08-2·45) at 40-49 years, 1·84 (1·72-1·97) at 50-59 years, 1·57 (1·47-1·67) at 60-69 years, and 1·39 (1·29-1·51) at 70 years and older. HRs per decade of earlier diagnosis were similar for men and women. Using death rates from the USA, a 50-year-old individual with diabetes died on average 14 years earlier when diagnosed aged 30 years, 10 years earlier when diagnosed aged 40 years, or 6 years earlier when diagnosed aged 50 years than an individual without diabetes. Using EU death rates, the corresponding estimates were 13, 9, or 5 years earlier.

INTERPRETATION

Every decade of earlier diagnosis of diabetes was associated with about 3-4 years of lower life expectancy, highlighting the need to develop and implement interventions that prevent or delay the onset of diabetes and to intensify the treatment of risk factors among young adults diagnosed with diabetes.

FUNDING

British Heart Foundation, Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

A242 DELAYED STEROID TAPER MAY REDUCE RISK OF RELAPSE IN PATIENTS WITH IMMUNE CHECKPOINT INHIBITOR ASSOCIATED HEPATOTOXICIT

Background

Immune checkpoint inhibitors (ICI) have become the cornerstone of treatment of certain malignancies. However, they can result in systemic toxicities including hepatitis. Societal guidelines recommend initial management with high dose steroids, then a slow taper as hepatitis resolves. However, there is significant variation in steroid response with some patients experiencing a relapse of hepatitis as steroid doses are tapered (“steroid relapse”).

Purpose

Identify clinical features that predict relapse, and to explore variations in steroid management, in patients with ICI hepatotoxicity.

Method

Patients receiving ICI in early phase clinical trials at Princess Margaret Cancer Centre, or treated at the Toronto Centre for Liver Disease for ICI hepatotoxicity, were included. Patients with CTCAE Grade (G)3 ICI hepatotoxicity (ALT >5 x ULN) were identified and clinical records reviewed for management and outcomes. Patients with an alternate cause for ALT elevation; who did not receive corticosteroids; or with HCC or viral hepatitis, were excluded.

Result(s)

Between August 2012 and December 2021, 36 patients with G3 ICI hepatotoxicity were identified. Most (23; 64%) had metastatic melanoma. Thirteen received anti-CTLA-4/PD-1; 18 anti-PD-1 or anti-PD-L1, and 5 anti-CTLA-4 monotherapy. All patients initially received corticosteroids (1-2mg/kg/day methylprednisone equivalent). Thirteen patients (36%) were steroid relapsers. Consistent steroid response was seen in 18 (50%). Age, sex, liver metastases, prior ICI exposure, peak ALT or starting dose of steroids (≤1.5 vs >1.5mg/kg/day methylprednisolone equivalents) did not predict relapse, although relapsers were more likely to have been treated with combination anti-CTLA-4/PD-1 (7 (54%) relapsers, vs 3 (16%) responders, p = 0.02). Relapse occurred after a median of 14.5 days (range 8-111), and after taper to median 54% (5-100) of initial steroid dose. In responders, ALT normalisation occurred after median 14 days (range 3-56). In 27 patients where sufficient data were available, societal guidelines on ALT thresholds to initiate steroid taper were followed in 13 (48%; 6 relapsers and 7 responders). However, initiation of steroid taper was delayed in responders compared to relapsers (after median 7 days (2-15) in responders vs 4 days (range 2-9) in relapsers, p = 0.04). Overall, 5 relapsers responded to re-escalation of steroids. Eight required additional treatment with MMF, and 4 required 3^rd line therapy with Tacrolimus. Ultimately, hepatitis resolved in all patients.

Conclusion(s)

In patients with ICI hepatotoxicity, combination ICI therapy confers a higher risk of steroid relapse than monotherapy. There is significant heterogeneity in management of steroid dosing in patients with ICI hepatotoxicity. Delayed initiation of steroid taper may be associated with a reduced risk of relapse and warrants prospective evaluation as part of a standardised management algorithm.

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Disclosure of Interest

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Abstract TP110: Incident ICU Transfer Characteristics Among Ischemic Stroke Patients: A 4-year Retrospective Analysis

Background: Neurologic patients transferred to an intensive care unit (ICU) have increased length of stays, mortality, and healthcare cost. There is limited data regarding incident transfers in stroke-specific cohorts. We sought to identify clinical features, transfer timing, and outcomes of patients admitted with ischemic stroke who required ICU escalation.

Methods: We identified all patients age >18 admitted to our institution with a principle diagnosis of ischemic stroke between 2016 and 2019. We included patients requiring transfer to an ICU at any point in their hospitalization. We identified indications for transfer (IFT), time to ICU transfer (TTI), and outcomes at discharge and at 90-days post-discharge. We subdivided the IFT into neurologic and non-neurologic etiologies, and used chi-square testing and Kaplan-Meier curves with log-rank modeling to identify differences between patients with neurologic and non-neurologic transfer indications.

Results: 3176 patients were admitted with a principle diagnosis of ischemic stroke across the four-year study period. 118 stroke patients (3.7%) underwent incident ICU transfer, 49 (41.5%) due to neurological causes and 69 (58.5%) due to non-neurological causes. The most common neurologic IFTs were cerebral edema (51.0%) and intracerebral hemorrhage (14.3%). The most common non-neurologic IFTs were respiratory decline (47.8%) and shock (21.7%). There were no differences in stroke characteristics (last known normal prior to arrival, baseline NIHSS, thrombolytic rates) between patients with neurologic vs. non-neurologic IFTs. Patients with neurologic IFTs had shorter mean TTI (2.45 vs. 4.80 days; p = 0.035) and were less likely to be discharged home compared to patients with non-neurologic IFTs (21.7% vs. 6.1%; p = 0.021). We corroborated differences in IFTs by adjusted log-rank comparisons on survival analysis. There were no significant difference in length of ICU stay (4.66 vs. 4.83 days) or total length of stay (12.37 vs 16.75 days).

Conclusions: Most ischemic stroke patients’ incident ICU transfers occur in the first 48 hours, highlighting the need for early vigilance. Neurologic and non-neurologic etiologies for IFT may contribute to the patients’ disposition outcome.

Quantitative profiling of N-glycosylation of SARS-CoV-2 spike protein variants

With the global spread of the corona virus disease-2019 pandemic, new spike variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continuously emerge due to increased possibility of virus adaptive amino acid mutations. However, the N-glycosylation profiles of different spike variants are yet to be explored extensively, although the spike protein is heavily glycosylated and surface glycans are well-established to play key roles in viral infection and immune response. Here, we investigated quantitatively the N-glycosylation profiles of seven major emerging spike variants including Original, Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Kappa (B.1.671.1), Delta (B.1.671.2), and Omicron (B.1.1.529). The aim was to understand the changing pattern of N-glycan profiles in SARS-CoV-2 evolution in addition to the widely studied amino acid mutations. Different spike variants exhibit substantial variations in the relative abundance of different glycan peaks and subclasses, although no specific glycan species are exclusively present in or absent from any specific variant. Cluster analysis shows that the N-glycosylation profiles may hold the potential for SARS-CoV-2 spike variants classification. Alpha and Beta variants exhibit the closest similarity to the Original, and the Delta variant displays substantial similarity to Gamma and Kappa variants, while the Omicron variant is significantly different from its counterparts. We demonstrated that there is a quantifiable difference in N-glycosylation profiles among different spike variants. The current study and observations herein provide a valuable framework for quantitative N-glycosylation profiling of new emerging viral variants and give us a more comprehensive picture of COVID-19 evolution.

Metamorphosis Imposes Variable Constraints on Genome Expansion through Effects on Development

Genome size varies ∼100,000-fold across eukaryotes and has long been hypothesized to be influenced by metamorphosis in animals. Transposable element accumulation has been identified as a major driver of increase, but the nature of constraints limiting the size of genomes has remained unclear, even as traits such as cell size and rate of development co-vary strongly with genome size. Salamanders, which possess diverse metamorphic and non-metamorphic life histories, join the lungfish in having the largest vertebrate genomes-3 to 40 times that of humans-as well as the largest range of variation in genome size. We tested 13 biologically-inspired hypotheses exploring how the form of metamorphosis imposes varying constraints on genome expansion in a broadly representative phylogeny containing 118 species of salamanders. We show that metamorphosis during which animals undergo the most extensive and synchronous remodeling imposes the most severe constraint against genome expansion, with the severity of constraint decreasing with reduced extent and synchronicity of remodeling. More generally, our work demonstrates the potential for broader interpretation of phylogenetic comparative analysis in exploring the balance of multiple evolutionary pressures shaping phenotypic evolution.

Total Ankle Replacement Versus Arthrodesis for End-Stage Ankle Osteoarthritis: A Randomized Controlled Trial

BACKGROUND

End-stage ankle osteoarthritis causes severe pain and disability. There are no randomized trials comparing the 2 main surgical treatments: total ankle replacement (TAR) and ankle fusion (AF).

OBJECTIVE

To determine which treatment is superior in terms of clinical scores and adverse events.

DESIGN

A multicenter, parallel-group, open-label randomized trial. (ISRCTN registry number: 60672307).

SETTING

17 National Health Service trusts across the United Kingdom.

PATIENTS

Patients with end-stage ankle osteoarthritis, aged 50 to 85 years, and suitable for either procedure.

INTERVENTION

Patients were randomly assigned to TAR or AF surgical treatment.

MEASUREMENTS

The primary outcome was change in Manchester-Oxford Foot Questionnaire walking/standing (MOXFQ-W/S) domain scores between baseline and 52 weeks after surgery. No blinding was possible.

RESULTS

Between 6 March 2015 and 10 January 2019, a total of 303 patients were randomly assigned; mean age was 68 years, and 71% were men. Twenty-one patients withdrew before surgery, and 281 clinical scores were analyzed. At 52 weeks, the mean MOXFQ-W/S scores improved for both groups. The adjusted difference in the change in MOXFQ-W/S scores from baseline was -5.6 (95% CI, -12.5 to 1.4), showing that TAR improved more than AF, but the difference was not considered clinically or statistically significant. The number of adverse events was similar between groups (109 vs. 104), but there were more wound healing issues in the TAR group and more thromboembolic events and nonunion in the AF group. The symptomatic nonunion rate for AF was 7%. A post hoc analysis suggested superiority of fixed-bearing TAR over AF (-11.1 [CI, -19.3 to -2.9]).

LIMITATION

Only 52-week data; pragmatic design creates heterogeneity of implants and surgical techniques.

CONCLUSION

Both TAR and AF improve MOXFQ-W/S and had similar clinical scores and number of harms. Total ankle replacement had greater wound healing complications and nerve injuries, whereas AF had greater thromboembolism and nonunion, with a symptomatic nonunion rate of 7%.

PRIMARY FUNDING SOURCE

National Institute for Health and Care Research Heath Technology Assessment Programme.

2022 Roger A. Mann Award Winner: Total Ankle Replacement vs Arthrodesis (TARVA) Randomized Controlled Trial: 2 Year Results

Category:

Ankle Arthritis; Ankle; Hindfoot; Other

Introduction/Purpose:

End-stage ankle osteoarthritis (EOA) causes severe pain and chronic disability. Once non operative measures have been exhausted the two main surgical treatments include total ankle replacement (TAR) and ankle fusion (AF). Systematic reviews have confirmed that both procedures are effective but there has never been a robust randomised multicentre level I study comparing the two treatments. Our objective was to investigate and compare the clinical and cost effectiveness of TAR against AF in the treatment of end-stage ankle osteoarthritis in patients aged 50-85 years.

Methods:

TARVA is a multi-centre, parallel-group, open label randomised trial. Patients with EOA, aged 50-85, suitable for either procedure were recruited at 17 UK hospitals. Randomisation was carried out using a secure on-line service and was stratified by surgeon and the presence or absence of adjacent joint OA (based on an independently reviewed preoperative MRI scan). Participants were randomised 1:1 to either TAR or ankle arthrodesis. The primary outcome was the change in the Manchester Oxford Foot & Ankle Questionnaire (MOXFQ) walking/standing domain scores between pre-operation and 52 weeks post- operation. Secondary outcomes measures included FAAM; FAAM (ADL); and Sport subscale scores. Quality of life was measured using the EQ-5D-5L. Total range of tibia to floor motion was measured using a validated method. Health economic analysis used mean incremental cost per quality-adjusted life years (QALY) gained. Analysis was by intention to treat. The trial registration is ISRCTN60672307.

Results:

Of 933 eligible patients 303 were randomised. 282 underwent surgery. Mean age 68 (71% male). Aetiology was post- trauma in 55.3%, and inflammatory in 7.1%. Groups were well balanced at baseline on all parameters. 54% TARs were fixed bearing. 61% of fusions were performed arthroscopically. At 2 years the adjusted mean difference in the change in MOXFQ W/S between TAR & AF was -4.4(95% CI -11.38 to 2.68, p=0∙23). Post hoc analysis of the commonest implant type (fixed bearing TAR) did show a statistically significant improvement over AF (p=0∙04, -8.9, 95% CI -17.2 to -0.6). Secondary outcomes, EQ5D-VAS and FAAM were significant. Complications included wound healing issues (13.8% vs 5.5%); nerve injuries (4.3% vs 0.7%). 11.8% of AF patients had plain radiographic evidence of non-union but only 6.9% had symptoms. Reoperation rate was 7.2% for TAR vs 5.2% for AF; and revision rate was 0.7% for TAR vs 2.8% for AF.

Conclusion:

Patients improved in all outcomes in both arms. We did not show a significant difference in our primary outcome measure between TAR and AF overall(p=0.23), but did show significance when fixed bearing TAR alone was compared against AF(p=0.04). Secondary outcomes did show significance. Adjacent joint arthritis increases the size of effect noted between arms. There were more wound healing issues and nerve injuries in TAR group. The symptomatic non-union rate for AF is 6.9%. TAR is likely to be cost-effective compared to AF at the NICE cost-effectiveness threshold of £20,000 per Quality Adjusted Life Year gained over the patients' lifetime.

Serum N-glycomic profiling may provide potential signatures for surveillance of COVID-19

Disease development and progression are often associated with aberrant glycosylation, indicating that changes in biological fluid glycome may potentially serve as disease signatures. The corona virus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a significant threat to global human health. However, the effect of SARS-CoV-2 infection on the overall serum N-glycomic profile has been largely unexplored. Here, we extended our 96-well-plate-based high-throughput, high-sensitivity N-glycan profiling platform further with the aim of elucidating potential COVID-19-associated serum N-glycomic alterations. Use of this platform revealed both similarities and differences between the serum N-glycomic fingerprints of COVID-19 positive and control cohorts. Although there were no specific glycan peaks exclusively present or absent in COVID-19 positive cohort, this cohort showed significantly higher levels of glycans and variability. On the contrary, the overall N-glycomic profiles for healthy controls were well-contained within a narrow range. From the serum glycomic analysis, we were able to deduce changes in different glycan subclasses sharing certain structural features. Of significance was the hyperbranched and hypersialylated glycans and their derived glycan subclass traits. T-distributed stochastic neighbour embedding (tSNE) and hierarchical heatmap clustering analysis were performed to identify 13 serum glycomic variables that potentially distinguished the COVID-19 positive from healthy controls. Such serum N-glycomic changes described herein may indicate or correlate to the changes in serum glycoproteins upon COVID-19 infection. Furthermore, mapping the serum N-glycome following SARS-CoV-2 infection may help us better understand the disease and enable "Long-COVID" surveillance to capture the full spectrum of persistent symptoms.

RetINal Toxicity And HydroxyChloroquine Therapy (INTACT): protocol for a prospective population-based cohort study

PURPOSE

Hydroxychloroquine (HCQ) is an important medication for patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and other rheumatic diseases. Although it is well-tolerated and cost-effective, the risk of HCQ retinal toxicity is of increasing concern. The aim of this study is to re-examine the HCQ retinal toxicity incidence rate, risk factors and clinical course after discontinuation.

METHODS

We designed a prospective population-based cohort study in adult patients with SLE or RA, currently receiving HCQ for five or more years, who are residents of British Columbia (BC), Canada. Based on administrative data, we identified 5508 eligible participants (1346 SLE and 4162 RA). They will participate in annual or biannual retinal screening over 5 years in alignment with the recently revised American Academy of Ophthalmology guidelines. To standardise procedures for retinal screening, imaging, diagnostic criteria, severity staging and data transfer, a consensus meeting was convened in December 2019 with participation of BC retinal specialists and the research team. Agreement was attained on: use of spectral domain-optical coherence tomography as the primary objective screening modality; classification of images into categories of normal, equivocal or abnormal; and transferring the equivocal and abnormal images plus corresponding subjective test results via cloud-based server from each clinic to a reading centre. Confirmation of HCQ retinal toxicity diagnoses and severity staging will be performed by three independent and masked reviewers. The incidence of HCQ retinal toxicity will be calculated, accounting for the competing risk of death. Hazard ratios for each risk factor will be calculated for the risk of HCQ retinopathy, after adjusting for confounders. We will also estimate the risk of HCQ retinal toxicity progression over 5 years.

ETHICS AND DISSEMINATION

This study has received approval from the University of British Columbia Clinical Research Ethics Board (H20-00736) and the Vancouver Coastal Health Research Institute.

Cell Free Remodeling of Glycosylation of Antibodies

The N-glycosylation profile of a monoclonal antibody (mAb) is a critical quality attribute in relation to its therapeutic application. The control of this profile during biomanufacture is difficult because of the multiple parameters that affect the glycosylation metabolism within the cell and the environment in which the cell is grown. One of the approaches that can be used to produce a preferred glycan profile or a single glycoform is through chemoenzymatic remodeling during the isolation of a mAb. Here we describe protocols that can be utilized to produce preferred glycoforms that include galactosylated, agalactosylated, or sialylated glycoforms following isolation of a mAb. Methods for analysis and assignment of structures of the samples following glycoengineering are also described. Chemoenzymatic modeling of mAb glycans has the potential for scale-up and to be introduced into biomanufacturing of mAbs with higher specific therapeutic activities.

Construction of InstantPC derivatized glycan GU database: A foundation work for high-throughput and high-sensitivity glycomic analysis

Glycosylation is well-recognized as a critical quality attribute of biotherapeutics being routinely monitored to ensure desired product quality, safety, and efficacy. Additionally, as one of the most prominent and complex post-translational modifications, glycosylation plays a key role in disease manifestation. Changes in glycosylation may serve as a specific and sensitive biomarker for disease diagnostics and prognostics. However, the conventional 2-aminobenzamide based N-glycosylation analysis procedure is time-consuming and insensitive, with poor reproducibility. We have evaluated an innovative streamlined 96-well-plate-based platform utilizing InstantPC label for high-throughput, high-sensitivity glycan profiling, which is user-friendly, robust, and ready for automation. However, the limited availability of InstantPC labelled glycan standards has significantly hampered the applicability and transferability of this platform for expedited glycan structural profiling. To address this challenge, we have constructed a detailed InstantPC labelled glycan glucose unit database through analysis of human serum and a variety of other glycoproteins from various sources. Following preliminary hydrophilic interaction liquid chromatography with fluorescence detection separation and analysis, glycoproteins with complex glycan profiles were subjected to further fractionation by weak anion exchange hydrophilic interaction liquid chromatography and exoglycosidase sequential digestion for cross-validation of the glycan assignment. Hydrophilic interaction ultra-performance liquid chromatography coupled with electrospray ionization mass spectrometry was subsequently utilised for glycan fragmentation and accurate glycan mass confirmation. The constructed InstantPC glycan GU database is accurate and robust. It is believed that this database will enhance the application of the developed platform for high-throughput, high-sensitivity glycan profiling, and eventually advance glycan-based biopharmaceutical production and disease biomarker discovery.

HDX-MS and MD Simulations Provide Evidence for Stabilization of the IgG1-FcγRIa (CD64a) Immune Complex Through Intermolecular Glycoprotein Bonds

Previous reports present different models for the stabilization of the Fc-FcγRI immune complex. Although accord exists on the importance of L235 in IgG1 and some hydrophobic contacts for complex stabilization, discord exists regarding the existence of stabilizing glycoprotein contacts between glycans of IgG1 and a conserved FG-loop (¹⁷¹MGKHRY¹⁷⁶) of FcγRIa. Complexes formed from the FcγRIa receptor and IgG1s containing biantennary glycans with N-acetylglucosamine, galactose, and α2,6-N-acetylneuraminic terminations were measured by hydrogen-deuterium exchange mass spectrometry (HDX-MS), classified for dissimilarity with Welch's ANOVA and Games-Howell post hoc procedures, and modeled with molecular dynamics (MD) simulations. For each glycoform of the IgG1-FcγRIa complex peptic peptides of Fab, Fc and FcγRIa report distinct H/D exchange rates. MD simulations corroborate the differences in the peptide deuterium content through calculation of the percent of time that transient glycan-peptide bonds exist. These results indicate that stability of IgG1-FcγRIa complexes correlate with the presence of intermolecular glycoprotein interactions between the IgG1 glycans and the ¹⁷³KHR¹⁷⁵ motif within the FG-loop of FcγRIa. The results also indicate that intramolecular glycan-protein bonds stabilize the Fc region in isolated and complexed IgG1. Moreover, HDX-MS data evince that the Fab domain has glycan-protein binding contacts within the IgG1-FcγRI complex.

Aligning tumor mutational burden (TMB) quantification across diagnostic platforms: phase II of the Friends of Cancer Research TMB Harmonization Project

BACKGROUND

Tumor mutational burden (TMB) measurements aid in identifying patients who are likely to benefit from immunotherapy; however, there is empirical variability across panel assays and factors contributing to this variability have not been comprehensively investigated. Identifying sources of variability can help facilitate comparability across different panel assays, which may aid in broader adoption of panel assays and development of clinical applications.

MATERIALS AND METHODS

Twenty-nine tumor samples and 10 human-derived cell lines were processed and distributed to 16 laboratories; each used their own bioinformatics pipelines to calculate TMB and compare to whole exome results. Additionally, theoretical positive percent agreement (PPA) and negative percent agreement (NPA) of TMB were estimated. The impact of filtering pathogenic and germline variants on TMB estimates was assessed. Calibration curves specific to each panel assay were developed to facilitate translation of panel TMB values to whole exome sequencing (WES) TMB values.

RESULTS

Panel sizes >667 Kb are necessary to maintain adequate PPA and NPA for calling TMB high versus TMB low across the range of cut-offs used in practice. Failure to filter out pathogenic variants when estimating panel TMB resulted in overestimating TMB relative to WES for all assays. Filtering out potential germline variants at >0% population minor allele frequency resulted in the strongest correlation to WES TMB. Application of a calibration approach derived from The Cancer Genome Atlas data, tailored to each panel assay, reduced the spread of panel TMB values around the WES TMB as reflected in lower root mean squared error (RMSE) for 26/29 (90%) of the clinical samples.

CONCLUSIONS

Estimation of TMB varies across different panels, with panel size, gene content, and bioinformatics pipelines contributing to empirical variability. Statistical calibration can achieve more consistent results across panels and allows for comparison of TMB values across various panel assays. To promote reproducibility and comparability across assays, a software tool was developed and made publicly available.

Airborne protection for staff is associated with reduced hospital-acquired COVID-19 in English NHS Trusts

Introduction

The rate of hospital-acquired coronavirus disease 2019 has reduced from 14.3% to 4.2% over the last year, but substantial differences still exist between English National Health Service (NHS) hospital trusts.

Methods

This study assessed rates of hospital-acquired infection (HAI), comparing NHS hospital trusts using airborne respiratory protection (e.g. FFP3 masks) for all staff, as a marker of measures to reduce airborne spread, with NHS hospital trusts using mainly droplet precautions (e.g. surgical masks).

Results/discussion

The use of respiratory protective equipment was associated with a 33% reduction in the odds of HAI in the Delta wave, and a 21% reduction in the odds of HAI in the Alpha wave (P<0.00001). It is recommended that all hospitals should prioritize airborne mitigation.

Evaluation of the Modified Barium Swallow Study Conducted With and Without Radiologist Supervision: A Pre- and Post-Observational Study

PURPOSE

Assess quality metrics of modified barium swallow studies (MBSS) with and without a radiologist present during the procedure.

METHODS

Retrospective review of MBSS performed on adult inpatients at a tertiary care hospital 6-months pre- and post-institutional change from having to not having a radiologist present during the examination.

FACTORS ASSESSED INCLUDED

fluoroscopy time; study duration; number of cine loops; number of images; efficiency of collimation (using a 5-point scoring system); time to final report; radiologist-speech language pathologist report disagreement; and recalls for inadequate studies. Statistical analysis was via Welch's t-test and a test of proportions for continuous and count data under the normal approximation.

RESULTS

106 and 119 MBSS were analyzed from the radiologist present and radiologist absent periods, respectively. No statistically significant differences were found for: average fluoroscopy time (116.1 s vs. 126.9 s; P = 0.161); study duration (400.4 s vs. 417.3 s; P = 0.453); number of cine loops (9.3 vs. 10.2; P = 0.075); number of images (620.5 vs. 581.1; P = 0.350); or report disagreement. There was improved performance without the radiologist present for collimation (1.92 vs. 1.43; P = 0.003) and fewer non-diagnostic images (6.5 vs. 4.5; P = 0.001). Time to final report was longer with the radiologist absent due to more reports with significant delays. There were no repeated studies because of inadequate technique in either group.

CONCLUSION

MBSS performed by technologists without radiologist supervision is not inferior to those performed with radiologist supervision on multiple performance measures. This supports technologist operated MBSS without radiologist supervision, while acknowledging a need to further address radiologist report time delay.

Strategic feeding of NS0 and CHO cell cultures to control glycan profiles and immunogenic epitopes of monoclonal antibodies

The control of glycosylation profiles is essential to the consistent manufacture of therapeutic monoclonal antibodies that may be produced from a variety of cell lines including CHO and NS0. Of particular concern is the potential for generating non-human epitopes such as N-glycolylneuraminic acid (Neu5Gc) and Galα1-3 Gal that may be immunogenic. We have looked at the effects of a commonly used media supplements of manganese, galactose and uridine (MGU) on Mab production from CHO and NS0 cells in enhancing galactosylation and sialylation as well as the generation of these non-human glycan epitopes. In the absence of the MGU supplement, the humanized IgG1 antibody (Hu1D10) produced from NS0 cells showed a low level of mono- and di-sialylated structures (SI:0.09) of which 75 % of sialic acid was Neu5Gc. The chimeric human-llama Mab (EG2-hFc) produced from CHO cells showed an equally low level of sialylation (SI: 0.12) but the Neu5Gc content of sialic acid was negligible (<3%). Combinations of the MGU supplements added to the production cultures resulted in a substantial increase in the galactosylation of both Mabs (up to GI:0.78 in Hu1D10 and 0.81 in EG2-hFc). However, the effects on sialylation differed between the two Mabs. We observed a slight increase in sialylation of the EG2-hFc Mab by a combination of MG but it appeared that one of the components (uridine) was inhibitory to sialylation. On the other hand, MG or MGU increased sialylation of Hu1D10 substantially (SI:0.72) with an increase that could be attributed predominantly to the formation of Neu5Ac rather than Neu5Gc. The increased level of galactosylation observed with MG or MGU was attributed to an activation of the galactosyl transferase enzymes through enhanced intracellular levels of UDP-Gal and the availability of Mn²⁺ as an enzymic co-factor. However, this effect not only increased the desirable beta 1-4 Gal linkage to GlcNAc but unfortunately in NS0 cells increased the formation of Galα1-3 Gal which was shown to increase x3 in the presence of combinations of the MGU supplements. Supplementation of media with fetal bovine serum (FBS) increased the availability of free Neu5Ac which resulted in a significant increase in the sialylation of Hu1D10 from NS0 cells. This also resulted in a significant decrease in the proportion of Neu5Gc in the measured sialic acid from the Mab.

Reduced activity in a liaison psychiatry service during the peak of the COVID-19 pandemic: Comparison with 2019 data and characterisation of the SARS-COV-2 positive cohort

Introduction

The COVID-19 pandemic led to changes in how healthcare was accessed and delivered. It was suggested that COVID-19 will lead to an increased delirium burden in its acute phase, with variable effect on mental health in the longer term. Despite this, there are limited data on the direct effects of the pandemic on psychiatric care.

Objectives

1) describe the mental health presentations of a diverse acute inpatient population, 2) compare findings with the same period in 2019, 3) characterise the SARS-CoV-2 positive cohort of patients.

Methods

We present a descriptive summary of the referrals to a UK psychiatric liaison department during the exponential phase of the pandemic, and compare this to the same period in 2019.

Results

show a 40.3% reduction in the number of referrals in 2020, with an increase in the proportion of referrals for delirium and psychosis. One third (28%) of referred patients tested positive for COVID-19 during their admission, with 39.7% of these presenting with delirium as a consequence of their COVID-19 illness. Our data indicate decreased clinical activity for our service during the pandemic’s peak. There was a marked increase in delirium, though in no other psychiatric presentations.

Conclusions

In preparation for further exponential rises in COVID-19 cases, we would expect seamless integration of liaison psychiatry teams in general hospital wards to optimise delirium management in patients with COVID-19. Further consideration should be given to adequate staffing of community and crisis mental health teams to safely manage the potentially increasing number of people reluctant to visit the emergency department.

Management of acute disturbance: The intravenous route

Introduction

The intravenous (IV) is one of the main parenteral routes for drug administration. Rapid onset of action, precise titration, patient-specific dosing and bypass of liver metabolism are a few of its advantages, while hypersensitivity reactions, adverse effects, infection risk and a higher overall cost some of its most debated downsides. Unlike other areas of Medicine, IV has been significantly under-utilized in Psychiatry.

Objectives

This systematic review analyzed the evidence for effectiveness and safety behind the use of IV medication used for the management of acute disturbance.

Methods

APA PsycINFO, MEDLINE, and EMBASE databases were searched for eligible studies. Studies were included if they used IV medication to treat acute disturbance, in English language, had participants aged >18. The quality of the included studies was assessed using the National Institutes of Health quality checklist.

Results

17 studies were deemed eligible. Data analysis was limited to narrative synthesis since primary outcome measures varied significantly between each study. Findings showed strong evidence for efficacy and safety of dexmedetomidine, droperidol, midazolam, and olanzapine. These medications displayed a short time to sedation, reduction in agitation levels, or large percentage of patients adequately sedated with a low number of adverse events. Results did not provide enough evidence for the use of IV ketamine, haloperidol, diazepam, lorazepam, and promethazine.

Conclusions

This review supports dexmedetomidine, droperidol, midazolam, and olanzapine as safe and efficacious options for managing acute disturbance via the intravenous route, particularly in special clinical settings where trained staff, optimal monitoring, resuscitation equipment and ventilators are all at hand.

The role of protein hydrolysates in prolonging viability and enhancing antibody production of CHO cells

Four independent mAb-producing CHO cell lines were grown in media supplemented with one of seven protein hydrolysates of animal and plant origin. This generated a 7x4 matrix of replicate cultures which was analysed for viable cell density and mAb productivity. In all cultures, a consistent growth rate was shown in batch culture up to 4 to 5 days. Differences between cultures appeared in the decline phase which was followed up to 7 days beyond the start of the cultures. There was a marginal but significant overall increase (x1.1) in the integral viable cell density (IVCD) in the presence of hydrolysate but a more substantial increase in the cell-specific mAb (qMab) productivity (x1.5). There were individual differences between hydrolysates in terms of enhancement of mAb productivity, the highest being a 166% increase of mAb titre (to 117 mg/L) in batch cultures of CHO-EG2 supplemented with UPcotton hydrolysate. The effect of one of the most active hydrolysates (HP7504) on antibody glycosylation was investigated. This showed no change in the predominant seven glycans produced but a significant increase in the galactosylation and sialylation of some but not all the antibodies. Overall, the animal hydrolysate, Primatone and two cotton-derived hydrolysates provided the most substantial benefit for enhanced productivity. The cotton-based hydrolysates can be viewed as valuable supplements for animal-derived component-free (ADCF) media and as a source for the investigation of chemically defined bioactive components. KEY POINTS: • Protein hydrolysates enhanced both IVCD & qMab; the effect on qMab being consistently greater. • Cotton-based hydrolysates showed high bioactivity and potential for use in serum-free media. • Enhanced galactosylation and sialylation was shown for some of the Mabs tested.

Adapting Mindfulness Training for Military Service Members With Chronic Pain

INTRODUCTION

Rates of chronic pain in military personnel are disproportionately high. Chronic pain is often associated with mental health and substance use disorders as comorbid conditions, making treatment of chronic pain complex. Mindfulness-based interventions (MBIs) are a promising behavioral approach to managing chronic pain and psychosocial sequelae. The unique nature of the military context may require adaptations to original MBIs for successful delivery in active-duty military populations. This study adapted the mindfulness-based stress reduction (MBSR) program to create a mindfulness training program that was relevant to active-duty Army personnel experiencing chronic pain. This article delineates the adaptation process employed to modify the MBSR program to the military context and discusses the resulting training program.

MATERIALS AND METHODS

The adaptation process consisted of three iterative stages: 1) Drafting the preliminary intervention protocol with recommendations from stakeholders, including military healthcare providers; 2) Refining the preliminary protocol after pretesting the sessions with research team members and a military Veteran advisory committee; and 3) Delivering the preliminary protocol to one cohort of active-duty Soldiers with chronic pain, collecting feedback, and further refining the intervention protocol.

RESULTS

Military-related adaptations to MBSR addressed three areas: military culture, language and terminology, and practical and logistical factors relevant to implementation in the military setting. This adaptation process resulted in a live, online program with six, weekly, sessions. Feedback from a military Veteran advisory committee resulted in modifications, including increasing military-relevant examples; preliminary testing with the target population resulted in additional modifications, including shortening the sessions to 75 min and structuring discussions more efficiently.

CONCLUSIONS

The adaptation process was successful in generating an engaging mindfulness training program that was highly relevant to the military context. Obtaining input from stakeholders, such as military healthcare providers and active-duty soldiers, and iterative feedback and modification, were key to the process. Moreover, the program was designed to maintain the integrity and core elements of MBIs while adapting to military culture. A future randomized controlled trial design will be used to evaluate the effectiveness of the intervention in improving chronic pain in military personnel. This program is responsive to the military's call for nonpharmacologic treatments for chronic pain that are easily accessible. If effective, the mindfulness program has the potential for widespread dissemination to complement standard care for Service Members experiencing chronic pain.

Dataset from HDX-MS Studies of IgG1 Glycoforms and Their Interactions with the FcγRIa (CD64) Receptor

This document presents hydrogen-deuterium exchange mass spectrometry (HDX-MS) data from measurements of three purified IgG1 glycoform samples, predominantly G0F, G2F, and SAF, in isolation and in complexation with the high-affinity receptor, FcγRIa (CD64). The IgG1 antibody used in this study, aIL8hFc, is a murine-human chimeric IgG1, which inhibits IL-8 binding to human neutrophils.

Estimated population prevalence of cardiac transthyretin amyloidosis in elderly men derived from incidental cardiac uptake from routine bone scans – “we're going to need a bigger boat”

Background/Introduction

Transthyretin amyloidosis (TTR) is a cause of restrictive cardiomyopathy and heart failure predominantly in elderly men. Two main factors have moved TTR amyloidosis from super-specialist centres into mainstream cardiology:

We aimed to determine the potential magnitude of referrals to our embryonic cardiac TTR service from patients having routine bone scans for non-cardiac reasons. We planned to estimate the prevalence of cardiac TTR in our local over 65 male population to plan service provision.

Methods

All HDP bone scans performed at a teaching and research hospital in the UK from the 2017/18 financial year were reviewed (n=1530). Our hospital is the only provider of these scans locally. Of these, 1399 were for oncological and musculoskeletal (oncology/MSK) indications and 37 were referred to specifically “exclude amyloidosis”. We excluded paediatric and duplicate follow-up imaging. There are approximately 140,000 people over aged 65 living within our catchment region. We have assumed approximately 50% are male.

Results

Myocardial uptake was present in 7/1399 of the oncology/MSK group and 3/7 (43%) of these already had features of heart failure. In these 7 patients bone scans were performed to investigate bony metastases in 6 (1 oesophageal cancer and 5 for prostate cancer) and 1 following an orthopaedic procedure. Cardiac uptake was present in 10/37 of the “exclude amyloid” group. In those with cardiac uptake across both groups (17) 94% were male with a mean age of 83 (sd ±6.59) and 41% were from the oncology/musculoskeletal group. Incidental cardiac uptake was seen in 1:200 routine HDP scans. When looking at males &gt;65 specifically the uptake rate increases to (6 out of 701 scans) i.e. 1:117. Assuming there is no increased risk of TTR in patients with prostate or oesophageal cancer, then an estimate of cardiac TTR in the 75,000 males over the age of 65 locally would be approximately 640 men.

Conclusions

Bone scans account for 41% of all HDP scans with incidental cardiac uptake and therefore represents a significant potential referral source for a cardiac amyloid service. Our data suggests a potential prevalence of cardiac amyloidosis in 1:117 men over 65 with 43% already having heart failure symptoms and signs. Our age and sex specific prevalence suggests cardiac TTR is neither a rare nor unusual diagnosis. We will use our prevalence estimate to ensure our cardiac TTR service is resourced appropriately. We suggest that cardiac amyloid and cardio-oncology services should include pathways incorporating rapid access routes for suitable patients with incidental cardiac uptake on bone scans performed by non-cardiologists.

Funding Acknowledgement

Type of funding source: None

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial

IMPORTANCE

Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited.

OBJECTIVE

To determine whether hydrocortisone improves outcome for patients with severe COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020.

INTERVENTIONS

The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108).

MAIN OUTCOMES AND MEASURES

The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%).

RESULTS

After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02735707.

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial

IMPORTANCE

Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited.

OBJECTIVE

To determine whether hydrocortisone improves outcome for patients with severe COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020.

INTERVENTIONS

The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108).

MAIN OUTCOMES AND MEASURES

The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%).

RESULTS

After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02735707.

Sara Alert: An enduring national resource to support public health monitoring & disease containment

Background

Public health agencies had to respond swiftly to the novel coronavirus that emerged in 2019 (COVID-19) to try to contain the virus, which requires early identification of new cases. Monitoring exposed individuals is labor intensive and available tools are often limited. MITRE, a company that operates federally funded research and development centers for the U.S. government, rapidly developed a configurable monitoring tool that allows public health authorities to monitor potentially exposed individuals in their jurisdictions.

Methods

A team, including public health leaders, field epidemiologists, software engineers, and health communication specialists, was quickly assembled to design and develop an open source, disease-independent monitoring tool called Sara Alert. Outreach to key public health stakeholders, including partner organizations and local and state health departments, was conducted early for requirements gathering and to validate assumptions. Public health law experts were consulted regarding data privacy and security.

Results

By four weeks, a minimally viable monitoring tool was available for testing by public health partners. Exposed individuals can be enrolled and reminded daily to enter a temperature and any symptoms by web or mobile interface, SMS messaging or phone. Public health officials monitor and can quickly take action if symptoms consistent with COVID-19 are reported of if there is failure to report within a configurable time frame. Dashboards provide insight into aggregated data appropriate to level of view.

Conclusions

Sara Alert serves as a force multiplier that supports disease containment and allows resources to be directed where they are most needed. Successful development was possible because key stakeholders across public health practice were consulted early. Sara Alert is available, free, to state and local public health departments and serves as an enduring resource easily configured for the next public health emergency.

Key messages

Sara Alert serves as a force multiplier that supports disease containment and allows resources to be directed where they are most needed.

Sara Alert serves as an enduring resource easily configured for the next public health emergency.

Purification of rabies virus glycoprotein produced in Drosophila melanogaster S2 cells: An efficient immunoaffinity method

Most rabies vaccines are based on inactivated virus, which production process demands a high level of biosafety structures. In the past decades, recombinant rabies virus glycoprotein (RVGP) produced in several expression systems has been extensively studied to be used as an alternative vaccine. The immunogenic characteristics of this protein depend on its correct conformation, which is present only after the correct post-translational modifications, typically performed by animal cells. The main challenge of using this protein as a vaccine candidate is to keep its trimeric conformation after the purification process. We describe here a new immunoaffinity chromatography method using a monoclonal antibody for RVGP Site II for purification of recombinant rabies virus glycoprotein expressed on the membrane of Drosophila melanogaster S2 cells. RVGP recovery achieved at least 93%, and characterization analysis showed that the main antigenic proprieties were preserved after purification.

Analysis of Radiation Exposure during Endovascular Aneurysm Repair

Endovascular aneurysm repair (EVAR) is now the preferred procedure for abdominal aortic aneurysm repair. As a result of the need for fluoroscopy during EVAR, radiation exposure is a potential hazard. We studied the quantity of radiation delivered during EVAR to identify risks for excessive exposure. Fluoroscopy time, contrast volume used, and procedural details were recorded prospectively during EVARs. Using data collected from similar EVARs, an equation was derived to calculate approximate dose-area product (DAP) from fluoroscopy time. DAP values were then compared between procedures in which a relevant postdeployment procedure (PDP) was necessary intraoperatively with those without. Clinical data on 17 patients were collected. The mean age of patients was 68 (±9) years. Fluoroscopy times and approximate DAP values were found to be significantly higher in the seven patients with a PDP compared with the 10 patients without an intraoperative PDP (31.2 [±9.6] vs 22.7 [±6.0] minutes, P = 0.033 and 537 [±165] vs 390 [±103] Gy-cm2, P = 0.033, respectively). The average amount of contrast volume used was not significantly different between groups. Radiation emitted during EVARs with PDPs was significantly greater relative to those without PDPs. Device design and operators should thus aim to decrease PDPs and to minimize fluoroscopy time.

Mass spectrometric analysis of core fucosylation and sequence variation in a human-camelid monoclonal antibody

Electrospray mass spectrometry (ESI-MS) was used to measure the masses of an intact dimeric monoclonal antibody (Mab) and assess the fucosylation level. The Mab under study was EG2-hFc, a chimeric human-camelid antibody of about 80 kDa (A. Bell et al., Cancer Lett., 2010, 289(1), 81-90). It was obtained from cell culture with and without a fucosylation inhibitor, and treated with EndoS which cleaves between the two core N-acetyl glucosamine (GlcNAc) residues. It is the first time that this combined approach with a unique mass spectrometer was used to measure 146 Da differences as part of a large intact dimeric antibody. Results showed that in the dimer, both heavy chains were fucosylated on the core GlcNAc of the Fc Asn site equivalent to Asn297. In the presence of the fucosylation inhibitor, fucosylation was lost on both subunits. Following reduction, monomers were analyzed and the masses obtained corroborated the dimer results. Dimeric EG2-hFc Mab treated with PNGase F, to deglycosylate the protein, was also measured by MS for mass comparison. In spite of the success of fucosylation level measurements, the experimental masses of deglycosylated dimers and GlcNAc-Fuc bearing dimers did not correspond to masses of our sequence of reference (A. Bell et al., Cancer Lett., 2010, 289(1), 81-90; ; ), which prompted experiments to determine the protein backbone sequence. Digest mixtures from trypsin, GluC, as well as trypsin + GluC proteolysis were analyzed by matrix-assisted laser desorption/ionization (MALDI) MS and MS/MS. A few variations were found relative to the reference sequence, which are discussed in detail herein. These measurements allowed us to build a new "experimental" sequence for the EG2-hFc samples investigated in this work, although there are still ambiguities to be resolved in this new sequence. MALDI-MS/MS also confirmed the fucosylation pattern in the Fc tryptic peptide EEQYNSTYR.

0377 A Strengths-Based Approach to Examine Obstructive Sleep Apnea in Black and White Patients

Introduction

The majority of studies on race/ethnic disparities in OSA are derived from a deficit-based perspective (i.e. &gt;BMI, non-adherence to PAP). It would prove useful to identify which aspects are protective to inform potential treatment approaches. We focused on two potential factors: resilience and social support, in patients newly diagnosed with OSA. Given the high prevalence of insomnia complaints in patients with OSA, insomnia was our outcome of interest.

Methods

91 patients newly diagnosed with OSA provided demographic and socioeconomic status, sleep measures (Epworth, DBAS), resilience (Connor Davidson Resiliency Scale), social support (MOS Social Support Scale) and completed the Insomnia Severity Index. The cross-sectional associations between ISI, race/ethnicity, resilience, social support and their interaction effects were examined using linear regression models with covariate adjustment for participant age, sex and BMI. We ascertained total ISI score and individual items.

Results

The sample was 34.1% black (n=31), mean age of 57.6 years, SD=13.6, 64.8% male (n=59), and mean BMI of 32.4, SD=7.04. Mean sleep duration (as reported by sleep diary) was 6.64, SD=1.35. Black, white differences were not observed for sleepiness (M=8.60; 10.43, p=0.11) or DBAS (M=4.61; M=5.04, p=0.30). Blacks, reported clinically significant insomnia (M=15.00, SD=7.17) compared to whites (M=12.02, SD=6.83, p=0.05). On the individual ISI items, blacks were significantly more likely to endorse difficulty falling asleep (M=1.58, SD=1.54; M=0.75, SD=0.93,p=0.002) and waking up too early (M=2.09, SD=1.26; M=1.45, SD=0.93,p=0.021) compared to whites. Resilience (M=30.04, SD=6.42) and social support scores (M=74.13, SD=21.36) did not differ by race/ethnicity. In adjusted linear analysis, resilience had significant effect on ISI score (b=-0.36, SE=0.12, p=0.003) but not social support (b=-0.06, SE=0.08, p=0.31).

Conclusion

In this study we did not observe race/ethnic differences for sleepiness and dysfunctional beliefs about sleep. With respect to the protective factors, race/ethnic differences were not observed. Resilience, not social support, was related to insomnia complaints. Future studies should examine a variety of factors that may serve black and other racial/ethnic groups with OSA, and help elucidate protective processes.

Support

K23HL125939

A systematic review and meta-analysis of patient data from the West Africa (2013-16) Ebola virus disease epidemic

BACKGROUND

Over 28 000 individuals were infected with Ebola virus during the West Africa (2013-2016) epidemic, yet there has been criticism of the lack of robust clinical descriptions of Ebola virus disease (EVD) illness from that outbreak.

OBJECTIVES

To perform a meta-analysis of published data from the epidemic to describe the clinical presentation, evolution of disease, and predictors of mortality in individuals with EVD. To assess the quality and utility of published data for clinical and public health decision-making.

DATA SOURCES

Primary articles available in PubMed and published between January 2014 and May 2017.

ELIGIBILITY

Studies that sequentially enrolled individuals hospitalized for EVD and that reported acute clinical outcomes.

METHODS

We performed meta-analyses using random-effect models and assessed heterogeneity using the I2 method. We assessed data representativeness by comparing meta-analysis estimates with WHO aggregate data. We examined data utility by examining the availability and compatibility of data sets.

RESULTS

In all, 3653 articles were screened and 34 articles were included, representing 16 independent cohorts of patients (18 overlapping cohorts) and at least 6168 individuals. The pooled estimate for case fatality rate was 51% (95% CI 46%-56%). However, pooling of estimates for clinical presentation, progression, and predictors of mortality in individuals with EVD were hampered by significant heterogeneity, and inadequate data on clinical progression. Our assessment of data quality found that heterogeneity was largely unexplained, and data availability and compatibility were poor.

CONCLUSIONS

We have quantified a missed opportunity to generate reliable estimates of the clinical manifestations of EVD during the West Africa epidemic. Clinical data standards and data capture platforms are urgently needed.

NaCl Nanoparticles as a Cancer Therapeutic

Many inorganic nanoparticles are prepared and their behaviors in living systems are investigated. Yet, common electrolytes such as NaCl are left out of this campaign. The underlying assumption is that electrolyte nanoparticles will quickly dissolve in water and behave similarly as their constituent salts. Herein, this preconception is challenged. The study shows that NaCl nanoparticles (SCNPs) but not salts are highly toxic to cancer cells. This is because SCNPs enter cells through endocytosis, bypassing cell regulations on ion transport. When dissolved inside cancer cells, SCNPs cause a surge of osmolarity and rapid cell lysis. Interestingly, normal cells are much more resistant to the treatment due to their relatively low sodium levels. Unlike conventional chemotherapeutics, SCNPs cause immunogenic cell death or ICD. In vivo studies show that SCNPs not only kill cancer cells, but also boost an anticancer immunity. The discovery opens up a new perspective on nanoparticle-based therapeutics.

Evaluating steady-state resting energy expenditure using indirect calorimetry in adults with overweight and obesity

BACKGROUND

Determining a period of steady state (SS) is recommended when estimating resting energy expenditure (REE) using a metabolic cart. However, this practice may be unnecessarily burdensome and time-consuming in the research setting.

AIM

The aim of the study was to evaluate the use of SS criteria, and compare it to alternative approaches in adults with overweight and obesity.

METHODS

In this cross-sectional, ancillary analysis, participants enrolled in a bariatric (study 1; n = 13) and lifestyle (study 2; n = 51) weight loss intervention were included. Indirect calorimetry was performed during baseline measurements using a metabolic cart for 25 min, including a 5-min stabilization period at the start. SS was defined as the first 5-min period with a coefficient of variation (CV) ≤10% for both VO₂ and VCO₂ (hereafter REE_5-SS). Body composition was measured using bioelectrical impedance analysis in study 2 participants only. REE_5-SS was compared against the lowest CV (REE_CV-lowest), 5-min time intervals (REE_6-10, REE_11-15, REE_16-20, REE_21-25), 4-min and 3-min SS intervals (REE_4-SS and REE_3-SS), and time intervals of 6-15, 6-20 and 6-25 min (REE_6-15, REE_6-20, and REE_6-25) using repeated measures ANOVA and Bland-Altman analysis to test for bias, limits of agreement and accuracy (±6% measured REE).

RESULTS

Participants were 54 ± 13 years old, mostly women (75%) and had a BMI of 35 ± 5 kg/m². Overall, 54/63 (84%) of participants reached REE_5-SS, often (47/54, 87%) within the first 10-min (6-15 min). Alternative approaches to estimating REE had a relatively low bias (-16 to 13 kcals), narrow limits of agreement and high accuracy (83-98%) when compared to REE_5-SS, in particular, outperforming standard prediction equations (e.g., Mifflin St. Joer).

CONCLUSION

Indirect calorimetry measurements that utilize the 5-min SS approach to estimate REE are considered the gold-standard. Under circumstances of non-SS, it appears 4-min and 3-min SS periods, or fixed time intervals of atleast 5 min are accurate and practical alternatives for estimating REE in adults with overweight and obesity. However, future trials should validate alternative methods in similar populations to confirm these findings.

An allied health rehabilitation program for patients following surgery for abdomino-pelvic cancer: a feasibility and pilot clinical study

PURPOSE

To investigate the feasibility of conducting a rehabilitation program for patients following surgery for abdomino-pelvic cancer.

METHODS

A non-randomised controlled before-and-after study. Patients who had undergone surgery for stage I-III abdomino-pelvic cancer (colorectal, gynaecological or prostate cancer) were recruited. The rehabilitation group (n = 84) received an 8-week, bi-weekly education and exercise program conducted by a physiotherapist, exercise physiologist, health psychologist and dietician, supplemented by exercise diaries and telephone coaching sessions. The comparator group (n = 104) completed postal questionnaires only. Feasibility measures, functional exercise capacity, muscle strength, physical activity levels, pelvic floor symptoms, anxiety and depression, health-related quality of life (HRQoL) and self-efficacy were measured at baseline (time 1), immediately post-intervention (time 2) and at 6 months post-baseline (time 3) and compared within- and between-groups.

RESULTS

The consent rate to the rehabilitation program was 24%. Eighty-one percent of the rehabilitation group attended 85-100% of 16 scheduled sessions. Overall satisfaction with the program was 96%. Functional exercise capacity, handgrip strength in males, bowel symptoms, physical activity levels, depression and HRQoL were significantly improved in the rehabilitation group (p < 0.05) at time 2. The improvements in all these outcomes were sustained at time 3. The rehabilitation group had significantly improved physical activity levels, depression and HRQoL compared with the comparator group at times 2 and 3 (p < 0.05).

CONCLUSION

Recruitment to this oncology rehabilitation program was more difficult than expected; however, attendance and patient satisfaction were high. This program had positive effects on several important clinical outcomes in patients following abdomino-pelvic cancer treatment.

TRIAL REGISTRATION

ANZCTR 12614000580673.