C-C chemokine receptor type 7 (CCR7) regulates hepatic CD8 + T cell homeostasis and response to acute liver injury

BACKGROUND AND AIMS

Acute liver failure (ALF) is a rare but life-threatening condition, and DILI, particularly acetaminophen toxicity, is the leading cause of ALF. Innate immune mechanisms further perpetuate liver injury, while the role of the adaptive immune system in DILI-related ALF is unclear.

APPROACH AND RESULTS

We analyzed liver tissue from 2 independent patient cohorts with ALF and identified hepatic T cell infiltration as a prominent feature in human ALF. CD8 + T cells were characterized by zonation toward necrotic regions and an activated gene expression signature. In murine acetaminophen-induced liver injury, intravital microscopy revealed zonation of CD8 + but not CD4 + T cells at necrotic areas. Gene expression analysis exposed upregulated C-C chemokine receptor 7 (CCR7) and its ligand CCL21 in the liver as well as a broadly activated phenotype of hepatic CD8 + T cells. In 2 mouse models of ALF, Ccr7-/- mice had significantly aggravated early-phase liver damage. Functionally, CCR7 was not involved in the recruitment of CD8 + T cells, but regulated their activation profile potentially through egress to lymphatics. Ccr7-/- CD8 + T cells were characterized by elevated expression of activation, effector, and exhaustion profiles. Adoptive transfer revealed preferential homing of CCR7-deficient CD8 + T cells to the liver, and depletion of CD8 + T cells attenuated liver damage in mice.

CONCLUSIONS

Our study demonstrates the involvement of the adaptive immune system in ALF in humans and mice. We identify the CCR7-CCL21 axis as an important regulatory pathway, providing downstream protection against T cell-mediated liver injury.

pH-dependent structural transitions in cationic ionizable lipid mesophases are critical for lipid nanoparticle function

Lipid nanoparticles (LNPs) are advanced core-shell particles for messenger RNA (mRNA) based therapies that are made of polyethylene glycol (PEG) lipid, distearoylphosphatidylcholine (DSPC), cationic ionizable lipid (CIL), cholesterol (chol), and mRNA. Yet the mechanism of pH-dependent response that is believed to cause endosomal release of LNPs is not well understood. Here, we show that eGFP (enhanced green fluorescent protein) protein expression in the mouse liver mediated by the ionizable lipids DLin-MC3-DMA (MC3), DLin-KC2-DMA (KC2), and DLinDMA (DD) ranks MC3 ≥ KC2 > DD despite similar delivery of mRNA per cell in all cell fractions isolated. We hypothesize that the three CIL-LNPs react differently to pH changes and hence study the structure of CIL/chol bulk phases in water. Using synchrotron X-ray scattering a sequence of ordered CIL/chol mesophases with lowering pH values are observed. These phases show isotropic inverse micellar, cubic Fd3m inverse micellar, inverse hexagonal [Formula: see text] and bicontinuous cubic Pn3m symmetry. If polyadenylic acid, as mRNA surrogate, is added to CIL/chol, excess lipid coexists with a condensed nucleic acid lipid [Formula: see text] phase. The next-neighbor distance in the excess phase shows a discontinuity at the Fd3m inverse micellar to inverse hexagonal [Formula: see text] transition occurring at pH 6 with distinctly larger spacing and hydration for DD vs. MC3 and KC2. In mRNA LNPs, DD showed larger internal spacing, as well as retarded onset and reduced level of DD-LNP-mediated eGFP expression in vitro compared to MC3 and KC2. Our data suggest that the pH-driven Fd3m-[Formula: see text] transition in bulk phases is a hallmark of CIL-specific differences in mRNA LNP efficacy.

2022 White Paper on Recent Issues in Bioanalysis: Enzyme Assay Validation, BAV for Primary End Points, Vaccine Functional Assays, Cytometry in Tissue, LBA in Rare Matrices, Complex NAb Assays, Spectral Cytometry, Endogenous Analytes, Extracellular Vesicles Part 2 - Recommendations on Biomarkers/CDx, Flow Cytometry, Ligand-Binding Assays Development & Validation; Emerging Technologies; Critical Reagents Deep Characterization

The 16th Workshop on Recent Issues in Bioanalysis (16th WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations on LBA, Biomarkers/CDx and Cytometry. Part 1 (Mass Spectrometry and ICH M10) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 15 of Bioanalysis, issues 16 and 14 (2023), respectively.

2022 White Paper on Recent Issues in Bioanalysis: FDA Draft Guidance on Immunogenicity Information in Prescription Drug Labeling, LNP & Viral Vectors Therapeutics/Vaccines Immunogenicity, Prolongation Effect, ADA Affinity, Risk-based Approaches, NGS, qPCR, ddPCR Assays (Part 3 - Recommendations on Gene Therapy, Cell Therapy, Vaccines Immunogenicity & Technologies; Immunogenicity & Risk Assessment of Biotherapeutics and Novel Modalities; NAb Assays Integrated Approach)

The 2022 16th Workshop on Recent Issues in Bioanalysis (WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations on Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity. Part 1 (Mass Spectrometry and ICH M10) and Part 2 (LBA, Biomarkers/CDx and Cytometry) are published in volume 15 of Bioanalysis, issues 16 and 15 (2023), respectively.

Pattern of pterygomaxillary disarticulation associated with Le Fort I maxillary osteotomy

Pterygomaxillary disarticulation (PMD) contributes to surgical complications of Le Fort 1 osteotomy and is associated with undesirable fractures of the pterygoid plates. The aim of this paper was to investigate the patterns of PMD in Le Fort I osteotomies using Rowe's disimpaction forceps, and to evaluate correlations with age and anatomical measurements. Cone-beam computed tomography (CBCT) scans of 70 consecutive orthognathic patients were retrospectively evaluated to study four patterns of PMD: Type 1 - PMD at, or anterior to, the pterygomaxillary junction (PMJ); Type 2 - PMD posterior to the PMJ; Type 3 - PMJ separation with comminuted fracture of the pterygoid plates; Type 4 - disarticulation of the maxilla involving the pterygoid plates above the level of the osteotomy line. The preoperative anteroposterior and mediolateral thicknesses of the PMJ and the length of the medial and lateral pterygoid plates were assessed. Satisfactory PMD was achieved in all cases and no severe complications were reported, including vascular, dental, mucosal, or neural damage. The most common PMD was Type 1 (54.3%), followed by Type 2 (40%). Comminuted fracture of the pterygoid plates was limited to 5.7% of cases, and no Type 4 was detected. A weak correlation was detected between PMJ thickness and PMD pattern (p = 0.04). No statistically significant correlation was detected between patients' age and type of PMD. PMD of Le Fort I maxillary osteotomy using a Smith spreader and Rowe's disimpaction forceps proved safe, with minimal damage to the pterygoid plates.

How are medical schools supporting student’s mental wellbeing during the COVID-19 pandemic?

Introduction

The COVID-19 pandemic has impacted medical students in many ways. They are not exempt from personal struggles caused by the health crisis, and many have faced similar challenges adapting to a new learning experience. The University of East Anglia (UEA) has initiatives in place to support medical students including the society Headucate UEA and the Wellbeing Champions scheme established by Norwich Medical School (NMS).

Objectives

Headucate aims to improve mental wellbeing by educational online webinars and social events aimed at university students. NMS Wellbeing Champions offer support and signpost students to resources and the wider student support system at the UEA.

Methods

Headucate was established in 2012 by NMS students that began running workshops at local secondary schools. Their work has expanded to include wellbeing workshops, social events for students and mental health first aid training, so members can provide peer support. Wellbeing Champions are medical student representatives responsible for completing mental health first aid training, communication between students and faculty, providing resources and signposting, creating mental health bulletin newsletters, and running socials exclusively for medical students.

Results

100% of Headucate workshop attendees who completed anonymous feedback agreed that they enjoyed it and that it was useful. No feedback has been collected regarding the success of the Wellbeing Champions. This should be carried out to assess and enhance the project further.

Conclusions

More data is needed to establish the success of the initiatives at NMS and their impact on medical student’s wellbeing.

Disclosure

No significant relationships.

The Success of Headucate: The Student-Led Mental Health Society

Introduction

Headucate: University of East Anglia, a university student-led society, was founded almost 10 years ago by medical students to promote mental health education and raise awareness and funds for mental health causes.

Objectives

Headucate aims to spread mental health awareness and reduce stigma by working with schools, universities, other societies and charities internationally.

Methods

Headucate delivers workshops for children aged 4-18 in primary and secondary schools, community and youth groups and university students. These sessions were delivered in-person pre-COVID and online as interactive webinars since 2020, to spark discussion around mental health, and provide information about the variety of supports available for young people.

Results

In the past decade, Headucate UEA has grown to become one of UEA’s largest student-led groups boasting over 175 members in 2020-2021 from all courses. Within the online world, Headucate’s events have reached worldwide. The initiative has received national recognition, won national student awards and has expanded to set up three further Headucate branches nationwide. Outreach has accelerated and the school workshops reached over 1,000 students in the past year.

Conclusions

Headucate has grown from strength to strength and has plans to continue to develop, with passionate student drivers behind the project. Expansion of the project could include a national mental health university directory, bringing together like-minded mental health advocate students around the country and creating new Headucate branches across the country. To further develop, Headucate could expand outreach to the elderly community as discussed by previous committee.

Disclosure

No significant relationships.

Is TikTok increasing the number of self-diagnoses of ADHD in young people?

Introduction

TikTok is a free mobile application, that enables users to create short videos. TikTok has an estimated one billion monthly active users, comprised of a mostly younger audience. There has been a noticed rise in content discussing ADHD – hashtag ADHD on TikTok has 6.3 billion views. The discussions continue on Twitter, where users are reporting watching TikTok content explaining ADHD symptomatology, subsequently relating to the condition and requesting referrals to specialist psychiatry services. This study aims to identify key themes in discussions around TikTok and ADHD, and its ramifications.

Objectives

This study’s objective is to discuss the relationship between viewing ADHD content of TikTok and self-diagnoses of ADHD in young people.

Methods

In our study, Twitter posts were identified with the words ‘ADHD’ and ‘TikTok’ and established key themes relating to self-diagnosis of ADHD.

Results

Numerous tweets were found discussing individual’s experiences of self-diagnosis of ADHD after watching TikTok videos and relating with the symptomology. Furthermore, many users discussed their efforts to seek diagnosis from psychiatrists. These posts highlighted positive discussion of mental health, and the improvement in quality of life since diagnosis.

Conclusions

Many young people are self-diagnosing ADHD after viewing TikTok videos. This may improve mental health stigma, however the expertise of the video creators should be scrutinised. Furthermore, the impact on already stretched waiting lists should be considered, with individuals who’s perceived ADHD traits are not impacting on their quality of life.

Disclosure

No significant relationships.

The impact of COVID-19 on mental health charity fundraising: An account from the perspective of fundraisers

Introduction

The dawn of COVID-19 brought new rules, restrictions, and lockdowns but this led to the unlikely fall of many sectors, including the charitable sector. There has been a significant decline in funding received by mental health charities, especially during the pandemic. This study looks at the subsequent impact on fundraisers and mental health promotion during COVID-19.

Objectives

The main aim was to uncover how the COVID-19 pandemic has affected the way that mental health charities fundraise, raise awareness, and promote mental health. This aimed to look at the impact of the COVID-19 pandemic on fundraisers supporting mental health charities and their opinion on whether fundraising has either helped or hindered mental health promotion.

Methods

Accounts from fundraisers and local representatives for mental health charities during the COVID-19 pandemic were analysed. Common themes looked at the impact, adaptation, and reasons why fundraisers decided to help during a tough period for the charitable sector.

Results

Mental health charities expressed difficulty in sourcing funds to support their users, especially in a vulnerable time. Fundraisers tried innovative ways to promote mental health and raise money for charities.

Conclusions

Altruism and understanding how precious services such as mental health charities are for the population was the main driver for fundraisers. Mental health charities adapted by turning to online communication and reached out to fundraisers to continually highlight the importance of mental health to their users and fundraisers.

Disclosure

No significant relationships.

The impact of Gender Identity Clinic waiting times on the mental health of transitioning individuals

Introduction

Waiting times for gender identity services, even before the Covid-19 pandemic, have been a cause of concern. Despite the waiting time standard for planned elective care in the NHS being a maximum of 18 weeks, the average waiting time for a first appointment with a gender identity clinic is 18 months. This study aims to analyse the effect that these timings have on the transgender community, and whether they impact the risk of developing mental health conditions such as depression or anxiety.

Objectives

This study’s main aim is to analyse the correlation between waiting times and mental health burden in the transgender community.

Methods

A literature review and analysis on a transgender individual’s mental health and waiting times for Gender Identity Clinics; looking at any key themes and conclusions. Research papers were taken from MEDLINE, The International Journal of Transgender Health, Oxford Academic, SpringerLink and Emerald Insight, with studies publishing date ranging from 2014 – 2021.

Results

The transgender population were found to have higher rates of suicidal ideation, depression and self harm compared to the general population. Longer waiting times were found to contribute to feelings of low mood and suicidal ideation, as well as decreasing overall quality of life.

Conclusions

Longer waiting times can decrease a transgender individual’s quality of life and impact their overall mental wellbeing: especially with the impact of COVID-19 and the rise in referrals.

Disclosure

No significant relationships.

Taking Mental Health into Schools: The work of Headucate Student Society

Headucate: University of East Anglia (UEA) is a student-led organisation aiming to raise awareness around Mental Health through their workshops and events. Events in the last year have included a 24-hour live stream TV fundraiser, UEA’s first Psychiatry and Mental Health conference, a mental health themed stand-up show, mental health assistance workshops, a suicide prevention evening and a variety of panels. Headucate has also collaborated with Beat, the UK’s leading eating disorder charity, to run training aimed at Norwich Medical School students, other healthcare students and Professionals. Headucate provides opportunities for their members, including research, education within the medical community, organising group projects, hosting poster competitions and by collaborating with likeminded initiatives. Workshops were designed to include common mental health conditions; wellbeing; advice regarding looking after yourself and others; ways to get for support and the impact of COVID-19 on our mental health. They are arranged and delivered by our members to school children and university students; they have been adapted to an online platform, which allowed us to reach a wider audience. Outcome measures demonstrating the impact of Headucate’s work were analysed via verbal, written and rated feedback, obtained from participants of workshops and events. Headucate workshops can help to improve mental health awareness and education in schools; however, it is only a local initiative. To educate schools outside of Norfolk, Headucate’s repeatable model can be used to create new branches of organisations that can spread nationwide; so mental health education in schools can be promoted across the UK.

Comparative Studies of Renin-Null Zebrafish and Mice Provide New Functional Insights

BACKGROUND

The renin-angiotensin system is highly conserved across vertebrates, including zebrafish, which possess orthologous genes coding for renin-angiotensin system proteins, and specialized mural cells of the kidney arterioles, capable of synthesising and secreting renin.

METHODS

We generated zebrafish with CRISPR-Cas9-targeted knockout of renin (ren^-/-) to investigate renin function in a low blood pressure environment. We used single-cell (10×) RNA sequencing analysis to compare the transcriptome profiles of renin lineage cells from mesonephric kidneys of ren^-/- with ren^+/+ zebrafish and with the metanephric kidneys of Ren1^c-/- and Ren1^c+/+ mice.

RESULTS

The ren^-/- larvae exhibited delays in larval growth, glomerular fusion and appearance of a swim bladder, but were viable and withstood low salinity during early larval stages. Optogenetic ablation of renin-expressing cells, located at the anterior mesenteric artery of 3-day-old larvae, caused a loss of tone, due to diminished contractility. The ren^-/- mesonephric kidney exhibited vacuolated cells in the proximal tubule, which were also observed in Ren1^c-/- mouse kidney. Fluorescent reporters for renin and smooth muscle actin (tg(ren:LifeAct-RFP; acta2:EGFP)), revealed a dramatic recruitment of renin lineage cells along the renal vasculature of adult ren^-/- fish, suggesting a continued requirement for renin, in the absence of detectable angiotensin metabolites, as seen in the Ren1YFP Ren1^c-/- mouse. Both phenotypes were rescued by alleles lacking the potential for glycosylation at exon 2, suggesting that glycosylation is not essential for normal physiological function.

CONCLUSIONS

Phenotypic similarities and transcriptional variations between mouse and zebrafish renin knockouts suggests evolution of renin cell function with terrestrial survival.

Evaluating compliance of dental radiography for paediatric patient assessment in specialised tertiary care units: a United Kingdom multi-centre survey

Aim The aim of this survey was to determine compliance towards dental radiography selection criteria for paediatric patients undergoing new patient examinations in specialised tertiary care centres in the United Kingdom.Methods Five university-associated dental hospitals were included in this study. Retrospective data was collected reviewing all paediatric patients on the new patient assessment clinics, where dental imaging was requested or the patient had relevant previous imaging. Data was collected from 28 June 2018, continuing retrospectively for a maximum of six months or until 150 patients were reached. Patients referred solely for orthodontic assessment were excluded.Results Seven hundred and fifty patients were included with an average age of eight years - 95.5% of patients had a radiographic justification provided. All patients were grouped into 56 disease categories and a total range of one cross-sectional and nine planar radiographs were prescribed in this cohort. Each radiograph was assessed for compliance to the Faculty of General Dental Practice, European Association of Paediatric Dentistry and national Italian guidelines for dental diagnostic imaging. Additionally, selection criteria for CBCT scans were taken from SEDENTEXCT guidelines. Full panoramic radiographs were the most commonly prescribed at 34.8% (n = 261). However, this demonstrated the lowest compliance rate as per selection criteria at 75.9%. This was due to referrers requesting radiographs primarily for assessing dental development (18.8%; n = 49) and caries assessment (2.7%; n = 7). Other radiograph formats demonstrated varying levels of guideline compliance ranging from 93.5-100%.Conclusion This study identifies common radiograph request errors and can inform paediatric clinicians to improve compliance to guidelines and reduce radiation exposure to young patients.

All Bad? Experiences of Aging Among LGBT Elders in South Africa

There is an almost complete dearth of research on the lives of lesbian, gay, bisexual, and transgender (LGBT) elders in South Africa. This study was a qualitative exploration through focus group discussions of the lived experiences of 22 LGBT people over 50 years of age in the Western Cape and Gauteng provinces of South Africa. Given high levels of poverty and inequality in South Africa, findings from a thematic analysis of participants’ narratives foregrounded surprisingly strong themes of inclusion and belonging despite the structural challenges faced by many in South Africa. While narratives of marginalization and exclusion were present, these were juxtaposed with reports of belonging and inclusion in families, communities, through friendship networks, and in health care. Findings indicate that, while experiences of homophobia and transphobia are real among LGBT elders in South Africa, participants experience agency, support, and relatively high reported levels of social belonging as they age.

Staphylococcus Aureus Endocarditis associated with Injecting New Psychoactive Substances

Background

Staphylococcus aureus infective endocarditis (IE) associated with injection of new psychoactive substances (NPS) in Edinburgh from 2014 to 2016 was observed. We compared these infections with a series of S. aureus IE cases in a non-injecting population within Edinburgh.

Methods

NPS-associated S. aureus IE diagnosed between 1 January 2014 and 31 May 2016 in persons who inject drugs (PWID) were compared with a series of S. aureus IE cases from non-PWID.

Results

There was a fourfold increase in the annual incidence of S. aureus IE, mainly due to NPS use in PWID. A larger vegetation diameter was seen on echocardiogram in PWID vs non-PWID (median 1.7 cm vs 0.65 cm; p = 0.009) with more embolic complications in PWID (15 PWID vs 1 non-PWID; p = 2.1 x 10-7) but no difference in 90-day mortality (2 PWID vs 4 non-PWID; p = 0.39).

Conclusions

NPS-associated S. aureus IE correlated with complications, such as deep organ embolic abscesses, that were different from non-PWID S. aureus IE. The alarming increase in incidence resolved with targeted public health and legislative measures.

The colorectal surgeon's personality may influence the rectal anastomotic decision

AIM

Colorectal surgeons regularly make the decision to anastomose, defunction or form an end colostomy when performing rectal surgery. This study aimed to define personality traits of colorectal surgeons and explore any influence of such traits on the decision to perform a rectal anastomosis.

METHOD

Fifty attendees of The Association of Coloproctology of Great Britain and Ireland 2016 Conference participated. After written consent, all underwent personality testing: alexithymia (inability to understand emotions), type of thinking process (intuitive versus rational) and personality traits (extraversion, agreeableness, openness, emotional stability, conscientiousness). Questions were answered regarding anastomotic decisions in various clinical scenarios and results analysed to reveal any influence of the surgeon's personality on anastomotic decision.

RESULTS

Participants were: male (86%), consultants (84%) and based in England (68%). Alexithymia was low (4%) with 81% displaying intuitive thinking (reflex, fast). Participants scored higher in emotional stability (ability to remain calm) and conscientiousness (organized, methodical) compared with population norms. Personality traits influenced the next anastomotic decision if: surgeons had recently received criticism at a departmental audit meeting; were operating with an anaesthetist that was not their regular one; or there had been no anastomotic leaks in their patients for over 1 year.

CONCLUSION

Colorectal surgeons have speciality relevant personalities that potentially influence the important decision to anastomose and could explain the variation in surgical practice across the UK. Future work should explore these findings in other countries and any link of personality traits to patient-related outcomes.

Preclinical evaluation of point-of-care prothrombin time as a biomarker test to guide prothrombin replacement therapy in coagulopathic bleeding

BACKGROUND

Hemorrhage is still a common cause of death in trauma. Central lab measured prothrombin time (lab PT) is predictive of low prothrombin concentration and clinical outcome in trauma patients, however, treatment guidance is limited by slow turnaround times. Here, we have preclinically evaluated the potential of a point-of-care prothrombin time test (POC PT) as a faster alternative to identify patients with low prothrombin concentration.

METHODS

Human whole blood was serially diluted and prothrombin time measured by POC PT (CoaguChek XS Pro, Roche) and lab PT. Recombinant human prothrombin (MEDI8111) was added to human whole blood with or without depletion of prothrombin by pretreatment with prothrombin neutralizing antibodies.

RESULTS

There was no observable difference in the sensitivity of either test to dilution at blood volumes of 60-100%. At blood volumes of ≤55% (equivalent to 47 mg/L prothrombin), PT sharply increased, with greater dilutional sensitivity observed in the POC test. Both tests were insensitive to prothrombin up to 194 mg/L added MEDI8111 (equivalent to 328 mg/L prothrombin versus endogenous concentration of 129 mg/L). Depletion of endogenous prothrombin inversely correlated with an increase in PT which returned to baseline following addition of 97 mg/L MEDI8111 or above. Both assays correlated well above 48.5 mg/L added MEDI8111 (65.9 mg/L prothrombin).

CONCLUSIONS

Our data supports that POC PT tests, such as the CoaguChek XS Pro, are fit for purpose to confirm a coagulopathic threshold for prothrombin and provide a fast, simple, and mobile method to guide MEDI8111 therapy in bleeding trauma patients.

Determining myeloperoxidase activity and protein concentration in a single assay: Utility in biomarker and therapeutic studies

Myeloperoxidase (MPO) is predominantly expressed by neutrophils and is an important enzyme used by the immune system for the neutralisation of bacteria and other microorganisms. The strong oxidative activity of MPO has been linked to pro-inflammatory responses in surrounding cells and tissues with implication in the pathophysiology of cardiovascular, neuroscience and inflammatory diseases. This broad disease association has made MPO an attractive biomarker and therapeutic target. Here we describe the construction and validation of a single combined MPO activity and protein concentration assay using commercially available reagents. This method offers the investigative laboratory the ability to generate results from blood plasma samples in a single analytical run using the same sample aliquot.