Aboriginal and Torres Strait Islander youth suicide mortality and previous mental health, suicidality and service use in Queensland, Australia, from 2001 to 2021

BACKGROUND

The current study aimed to compare current suicide rates, trends, previous treatment, suicidality and mental health diagnoses for First Nations and non-Indigenous young people who died by suicide.

METHODS

Age-specific suicide rates (ASSRs) were calculated per 100,000 persons/year using suicides aged 10-19 years in the Queensland Suicide Register. Rate Ratios (RRs) and 95 % CIs compared ASSRs for First Nations and non-Indigenous youth dying by suicide in Queensland, Australia, from 2001 to 2018. Risk ratios (RiskR) with 95 % CIs compared characteristics between First Nations and non-Indigenous youth suicides. Joinpoint regression was used to identify any changes in trends and annual percentage change (APC) in suicides with 95 % CIs.

RESULTS

The First Nations youth ASSR was 24.71 deaths per 100,000 persons/year, 4.5 times the non-Indigenous ASSR (95 % CI = 3.74-5.38, p < 0.001). Both non-Indigenous and First Nations suicide trends were stable with no joinpoints (APC: 0.3 %, 95 % CI: -1.6-2.2, p = 0.78; APC: 0.9 %, 95 % CI: -0.2-2.1, p = 0.11). Less than a quarter (23.9 %) of First Nations young people had ever received mental health treatment, significantly fewer than non-Indigenous youth (RiskR = 0.80, 95 % CI = 0.71-0.90, p < 0.001). Similarly, in the three months preceding their death, only 14.5 % of First Nations young people had received mental health treatment (RiskR = 0.89, 95 % CI = 0.83-97, p = 0.015).

LIMITATIONS

Reported mental illness, suicidality and help-seeking could be underreported due to concealment from family or police.

CONCLUSIONS

The current study finds no change in the gap between the First Nations and Non-Indigenous youth suicide rates nor evidence of decrease in the First Nations youth suicide rate. There is a need for alternative approaches to Indigenous youth suicide prevention, such as assertive outreach models outside of traditional triage and mental health systems to proactively build trusting relationships with young people in communities to identify young people needing support.

Health impacts of poor water quality on an endangered shorebird breeding programme in Aotearoa New Zealand

CASE HISTORY

Two clusters of mortality among endangered tūturuatu/tchūriwat'/shore plover (Thinornis novaeseelandiae) have occurred at captive breeding facilities around New Zealand in recent years. In the first, four chicks died at Pūkaha National Wildlife Centre (Mount Bruce, NZ) in February 2016, and in the second five adult birds at the Cape Sanctuary (Cape Kidnappers, NZ) died in 2022.

CLINICAL FINDINGS

In 2016, four chicks were noted to become weak, have increased vocalisations and closed eyes prior to death. The remaining chicks were treated for 5 days with amoxycillin/clavulanate orally twice daily. Water containers and brooders were cleaned and disinfected with chlorhexidine. No further mortality was seen.In the 2022 cluster, three adult breeding birds died acutely and five others showed inappetence, weight loss and diarrhoea approximately 10 days after heavy rains flooded the local river. The five birds were treated with amoxycillin/clavulanate orally twice daily and oral fluids for 5 days. Two birds died and three survived. No breeding occurred in the aviaries in the following season.

PATHOLOGICAL FINDINGS

In 2016, the chicks showed pulmonary changes ranging from congestion and oedema to heterophilic inflammation consistent with septicaemia.In 2022, the adult birds showed proliferation of bacteria in the distal small intestine associated with mucosal ulceration and heterophilic infiltration. Acid-fast staining of the caecal contents in one bird showed organisms consistent with Cryptosporidium spp.

LABORATORY FINDINGS

Aerobic bacterial cultures of the lung and liver of two affected chicks carried out in 2016 showed heavy growth of Plesiomonas shigelloides. The same organism was cultured from water trays and holding tanks containing water boatmen (Sigara arguta) on which the chicks were fed.In 2022, cultures from the livers of three dead birds each showed a mixed bacterial growth with differing dominant organisms (Aeromonas sobria, Hafnia alvei, Citrobacter freundii and an Enterococcus sp.). PCR and sequencing confirmed Cryptosporidium parvum in the caecum of one bird. Fresh faeces from 24 breeding birds from the captive breeding facilities were negative by PCR for Cryptosporidium spp.The captive breeding facilities obtain water for the aviaries and aquatic invertebrates to feed to the chicks from local freshwater sources. Water quality testing at the Cape Sanctuary revealed concentrations of faecal indicator bacteria in excess of safe drinking water guidelines, with peaks following heavy rainfall.

CLINICAL RELEVANCE

Fluctuations in water quality associated with mammalian faecal bacteria can adversely affect bird health and impact on captive rearing of endangered wildlife.

Predicting language outcomes in bilingual children with Down syndrome

Continuous approaches to measuring bilingualism have recently emerged as a means of understanding individual variation in language abilities. To date, limited information is available to assist in understanding the language abilities of bilingual children with Down syndrome (DS), who are specifically known to have a large variation in linguistic outcomes. Group studies in this population report that children exposed to two languages do not differ from their monolingual counterparts after considering age and non-verbal cognitive abilities, although no study to date has examined the relationship between the amount of exposure to one language and the linguistic abilities in the other language within this population. This study sought to identify whether exposure to an additional language, specifically Welsh, predicted linguistic abilities in the majority language, in this case, English. Sixty-five children between the ages of 5;5-16;9 who had varied linguistic experiences completed a range of cognitive and linguistic assessments. Results from hierarchical regression analyses show that the amount of exposure to Welsh had no impact on language abilities in English, after controlling for non-verbal cognitive abilities, short-term memory and socioeconomic status. This demonstrates that exposure to an additional language does not have a negative impact on language development, a finding that has important clinical and educational implications.

Other Novel PET Radiotracers for Breast Cancer

Many novel PET radiotracers have demonstrated potential use in breast cancer. Although not currently approved for clinical use in the breast cancer population, these innovative imaging agents may one day play a role in the diagnosis, staging, management, and even treatment of breast cancer.

Food Insecurity, Food Assistance, and Psychological Distress among University Students: Cross-Sectional Survey Western Australia, 2020

University students have been identified as a population sub-group vulnerable to food insecurity. This vulnerability increased in 2020 due to the COVID-19 pandemic. This study aimed to assess factors associated with food insecurity among university students and the differences between students with and without children. A cross-sectional survey of (n = 213) students attending one university in Western Australia measured food insecurity, psychological distress, and socio-demographic characteristics. Logistic regression analyses were conducted to identify factors associated with food insecurity. Forty-eight percent of students who responded to the survey had experienced food insecurity in 2020. International students who were studying in Australia were nine times more likely to experience food insecurity than domestic students (AOR = 9.13; 95% CI = 2.32-35.97). International students with children were more likely to experience food insecurity than international students without children (p < 0.001) and domestic students with (p < 0.001) or without children (p < 0.001). For each unit increase in depression level, the likelihood of experiencing food insecurity increased (AOR = 1.62; 95% CI = 1.12-2.33). Findings show a higher prevalence of food insecurity among international university students and students with children during the COVID-19 pandemic and that food insecurity was associated with higher levels of psychological distress. These findings highlight the need for targeted interventions to mitigate the risk of food insecurity among Australian university students, particularly among international students, students with children, and those experiencing psychological distress.

Alcohol-related brain damage: A mixed-method evaluation of an online awareness-raising programme for frontline care and support practitioners

INTRODUCTION

Alcohol-related brain damage (ARBD) is an umbrella term referring to the neurocognitive impairments caused by excessive and prolonged alcohol use and the associated nutritional deficiencies. This study evaluated the outcomes of an online research-informed training program for ARBD which aimed to improve client outcomes by promoting support staff's awareness and confidence in working with clients who may have (or who are at risk of developing) the condition.

METHODS

Staff working within a large non-governmental non-profit housing organisation (n = 883) enrolled in the training program. Questionnaires were used pre- and post-training to collect self-reported awareness of ARBD and confidence in supporting individuals with the condition. Semi-structured interviews were conducted with 27 staff members approximately 10 weeks post-completion of the program. Interviews were audio-recorded, transcribed verbatim and analysed by employing qualitative content analysis.

RESULTS

Findings from the questionnaires indicated a significant increase in all measures after completing the training program. Three main themes were developed based on the interview data: changes to awareness and understanding; professional practice; and training-specific characteristics. Participants reported changes in their ability to identify potential service users with ARBD and confidence in doing so.

DISCUSSION AND CONCLUSION

Our findings demonstrate that online training programs can be effective in improving support staff's ability to identify ARBD, potentially leading an increase in signposting service users to relevant services. The research-informed nature of the training demonstrates that translating research findings directly to frontline workers can have a substantial impact and may improve outcomes for this client group.

A Rare Case of Bacillus cereus Septic Arthritis

Joint infections are rare in pediatrics, and those caused by Bacillus cereus are practically unheard of. In this case report, we examine a singular case of B. cereus septic arthritis in a child, with the purpose of educating clinicians on the presentation, inpatient and outpatient management, and clinical outcome. We report the case of a previously healthy pediatric patient who presented to the emergency department with symptoms of septic arthritis of the left knee. The orthopedics team performed arthroscopy and debridement, and the synovial fluid culture grew B. cereus. To our knowledge, this is the first case report on septic arthritis caused by B. cereus in the pediatric population. The treatment protocol consisted of intravenous vancomycin for one week, followed by three weeks of oral ciprofloxacin therapy. The patient had an excellent clinical outcome and returned to normal mobility without limitations. Despite being ubiquitous in the environment, extra-intestinal B. cereus infection is exceedingly rare in immunocompetent individuals. It is so rare, in fact, that it is often dismissed as a lab contaminant. In this case, we demonstrated that cooperation between multiple disciplines offers good clinical outcomes for rare infections, especially those in pediatrics.

Cloud-controlled microscopy enables remote project-based biology education in underserved Latinx communities

Project-based learning (PBL) has long been recognized as an effective way to teach complex biology concepts. However, not all institutions have the resources to facilitate effective project-based coursework for students. We have developed a framework for facilitating PBL using remote-controlled internet-connected microscopes. Through this approach, one lab facility can host an experiment for many students around the world simultaneously. Experiments on this platform can be run on long timescales and with materials that are typically unavailable to high school classrooms. This allows students to perform novel research projects rather than just repeating standard classroom experiments. To investigate the impact of this program, we designed and ran six user studies with students worldwide. All experiments were hosted in Santa Cruz and San Francisco, California, with observations and decisions made remotely by the students using their personal computers and cellphones. In surveys gathered after the experiments, students reported increased excitement for science and a greater desire to pursue a career in STEM. This framework represents a novel, scalable, and effective PBL approach that has the potential to democratize biology and STEM education around the world.

P52 Survey on the experience of children and families attending the Paediatric Rheumatology daycare unit during the COVID pandemic

Introduction/Background

Patients attend rheumatology daycare either for regular infusions or one episode depending on their treatment. A typical day for a child would involve observations, having a cannula put in and having the infusion before returning home. Due to the COVID-19 pandemic, there had been some changes to the day care pathway in our hospital including: only one parent being allowed to attend with their child; a strict timing schedule; COVID-19 testing prior to attending appointments. We felt it is vital to know the young person and the family’s perspectives of their experience at day care.

Description/Method

A special study module (SSM) medical student conducted a feedback survey over a 2 month period (December 2021 and January 2022). The aims and objectives were focused on the following: Whether the patients are receiving an appropriate level of care to optimise their experience at day-care.was their treatment given in a timely manner?Were there any delays, if so the reasons and actions taken to mitigate.

2 questionnaires were used, one for the patient and one for the parent/carers. The questionnaires were provided to the patient/carers during their admission by the admitting nursing staff. The medical student collected the questionnaires at the end of the day.

Discussion/Results

39 patients attended the daycare during this period. 9 completed questionnaires were received.

• Feedback from parents/carers:

- Carers (100%) said they were happy with how they had appointment dates and most appointments took their availability and preferences into consideration. Due to COVID, families were notified of their appointment time only one day prior; this was highlighted as an area for improvement to ensure enough notice for the appointment time.

- All parents (100%) agreed that they received enough information regarding their child’s appointment at daycare and this was delivered in an understandable manner.

- 77.8% (7 out of 9) of parents did not experience long waiting times at their appointment. 22.2% (2 out of 9) parents said there were long waiting times at their appointment, and they were made aware of the reasons regarding the wait. The main reasons highlighted was busy ward with lots of patients.

- 2 out of 7 parents indicate the care provided has remained the same pre- and post-pandemic. 3 out of 7 patients felt that their care has improved due to the following reason: treatment was completed more quickly; wards looked less busy as there were limited patients present at one time; there was a reduced length of stay compared to pre-COVID.

• Children’s questionnaires:

- 100% (9 out of 9) children were happy with the care received at daycare.

- 22.2% (2 out of 9) children reported being worried/anxious due to having bloods and cannula taken (1) and missing school (1).

- 5 out of 9 children had play therapist input and they all found it helpful.

Key learning points/Conclusion

Despite the COVID pandemic restrictions, all young people and families had a positive experience during their day care treatments. Effective communication and engaging the patients and families, and providing appropriate explanations to any delays in treatment is vital. The overall experience has provided an opportunity to reflect on the systems to manage the day care treatments, which we presume has been the case in many centres. Allied health professionals like play therapists and youth teams provide immense support to the young people who are attending day care for regular treatments. Provision of these services to all young people if appropriate will enable positive experiences to the patients. Limitation of this survey was a small sample size with the response rate of only 23%. Further survey over an extended period may provide more insight in this area.

P11 An unusual case of Systemic Sclerosis/JDM overlap in a child with PAX8-related congenital hypothyroidism

Introduction/Background

Juvenile dermatomyositis is a rare inflammatory disease with a reported incidence of 0.8–4.1 per million children per year. It presents with a constellation of symptoms and signs of inflammation of skin and muscle, and is associated with significant morbidity if untreated. Juvenile systemic sclerosis (JSSc) is an even rarer rheumatological condition of childhood with significant risk of internal organ involvement, especially cardiopulmonary disease. We herewith present the case of a 7-year-old boy with history of hypothyroidism associated with a PAX8 gene variant who presented with clinical features of an overlap of Systemic Sclerosis with JDM with supportive autoantibody profile.

Description/Method

A 7-year-old boy presented with a history of restricted range of movements in his hands – noted due to difficulties with pen grip – and calcinosis. He reported symptoms of fatigue, intolerance to cold with colour changes to hands and feet, stiffness of movements particularly in the morning, and infrequent episodes of choking. His past medical history was significant for hypothyroidism secondary to a paternally inherited PAX8 missense mutation, and there is a family history of Raynaud’s and hypothyroidism. A detailed examination identified diffusely swollen hands with sclerodactyly, calcinosis of his elbows and fingertips, and limited flexion of his fingers and wrists. He also had telangiectasia of his upper eyelids, Gottron’s papules over his knees and elbows, and sluggish circulation in his hands and feet. He had evidence of mild proximal muscle weakness.

His investigations revealed mild elevation of muscle enzymes with normal inflammatory markers. His autoantibody profile showed a moderately positive ANA titre of 1600 with a nucleolar pattern, and was positive for anti-NXP2 and anti-SCL-100 antibodies MRI scan of the pelvis showed no evidence of myositis, echocardiogram was normal and a high-resolution CT scan of chest was normal with no features of interstitial lung disease.

The overall picture was one of Systemic Sclerosis/JDM overlap with CREST syndrome. He was commenced on induction therapy with IV Methylprednisolone and Cyclophosphamide in view of the calcinosis. After three cycles of Cyclophosphamide and weaning course of oral corticosteroids, his energy levels are significantly improved and he has better overall mobility with no significant proximal muscle weakness (Childhood Myositis Assessment Scale score 49/53). However, flexion of his fingers remains limited albeit better; he has ongoing fingertip calcinosis but fewer lesions over his elbows. He has been commenced on weekly subcutaneous Methotrexate as he completes Cyclophosphamide.

Discussion/Results

This patient had an unusual medical history of early onset thyroid dysfunction, the genetic testing for which revealed a missense PAX8 gene variant [c.49G>Ap.(Gly17Arg)] (also present in his father, who is euthyroid). This was classified as being of uncertain significance, although felt to clinically be the most likely cause for his hypothyroidism. There was no evidence to suggest that PAX8 gene mutations increased the risk of autoimmune conditions. There is evidence that PAX8 gene mutations, when expressed on malignant cells, may confer resistance to chemotherapy, which made us rethink the plan to commence him on Cyclophosphamide. However, we were reassured that in constitutional variants, there is no increased risk of cancer, and no known history of resistance to Cyclophosphamide.

This patient also demonstrated an interesting antibody pattern, as he was positive for anti-NXP2 antibodies (indicating high risk for calcinosis) and anti-SCL-100 antibodies, which are associated with a clinical subset of patients with overlap of Systemic Sclerosis and JDM and associated with extensive extra-muscular features. He had two distinct clinical phenotypes of calcinosis, which is probably explained by the presence of two autoantibodies that increase the risk of calcinosis.

Key learning points/Conclusion

Although JDM has bimodal age group for presentation in childhood, only 3% of systemic sclerosis are seen in childhood, which makes this an extremely unusual presentation, given the age, gender and the overlap features (clinical and immunological).

We explored whether this rare presentation could be linked to the underlying PAX8 gene mutations, but we could not find any association.

With the clinical diagnosis of systemic sclerosis, it was important to rule out cardiopulmonary complications.

The other consideration was regarding the choice of therapeutic agent - whether the germline PAX8 gene variants could increase the risk of malignancies or cause resistance to chemotherapeutic agents like Cyclophosphamide, for neither of which we could find any evidence.

Extensive calcinosis cutis in this patient could be explained by the presence of two risk factors (CREST syndrome and JDM with NXP2 antibodies).

Priorities for rheumatic and musculoskeletal disease research in Ireland

Background

Research priority setting is a useful approach to decide which unanswered questions are most worth trying to solve through research. The aim is to reduce bias in the research agenda. Traditionally, research was decided by funders, policymakers, and academics with limited influence from other stakeholders like people living with health conditions, caregivers, or the community. This can lead to research gaps that fail to address these important stakeholder needs. The objective of this study is to identify the top research priorities for Rheumatic and Musculoskeletal Disease (RMD) research in Ireland.

Methods

The process framework included a design workshop, two online surveys and a review of the literature.

Participants

545 people completed the first survey to identify RMD research topics relevant to Ireland, of which 72% identified as a person living with RMD. 460 people completed the second survey to prioritise these research topics.

Results

The first survey had 2185 research topics submitted. These were analysed and grouped into 38 topic areas which were ranked in the second survey. The top three research priorities for RMD research in Ireland focused on preventing RMD progression, RMD diagnosis and its impact, and pain management.

Conclusions

The prioritised research topics indicate important areas of RMD research for Ireland. Research funded in response to these co-created research priorities will have increased relevance and impact.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00285-9.

Large scale, single-cell FRET-based glucose uptake measurements within heterogeneous populations

Fluorescent biosensors are powerful tools allowing the concentration of metabolites and small molecules, and other properties such as pH and molecular crowding to be measured inside live single cells. The technology has been hampered by lack of simple software to identify cells and quantify biosensor signals in single cells. We have developed a new software package, FRETzel, to address this gap and demonstrate its use by measuring insulin-stimulated glucose uptake in individual fat cells of varying sizes for the first time. Our results support the long-standing hypothesis that larger fat cells are less sensitive to insulin than smaller ones, a finding that has important implications for the battle against type 2 diabetes. FRETzel has been optimized using the messy and crowded environment of cultured adipocytes, demonstrating its utility for quantification of FRET biosensors in a wide range of other cell types, including fibroblasts and yeast via a simple user-friendly quantitative interface.

•

FRETzel is a new software package for easy analysis of FRET signals in cells

•

FRETzel is used to quantify glucose uptake in adipocytes of different sizes

•

Reduced glucose uptake suggests that larger adipocytes have lower insulin sensitivity

•

FRETzel is demonstrated on a range of cell types: yeast, fibroblasts, and adipocytes

Spoken propositional idea density, a measure to help second language English speaking students: A multicentre cohort study

PURPOSE

Idea density has been shown to influence comprehension time for text in various populations. This study aims to explore the influence of spoken idea density on attainment in young, healthy subjects using demographic characteristics.

METHODS

Students watched two online lectures and answered 10 multiple choice questions on them. Students received one more idea dense (MID) and one less idea dense (LID) lecture on two different subjects.

RESULTS

Seventy-five students completed the study achieving a higher median score after a less idea-dense lecture (LID = 7(3), MID = 6(3), p = 0.04). Artificial neural network models revealed the first language as the main predictor of exam performance. The odds ratio (OR) of obtaining ≥70% after a more idea-dense lecture was six-time higher for the first language versus second language English speakers (OR = 5.963, 95% CI 1.080-32.911, p = 0.041). The odds ratio was not significant when receiving a less dense lecture (OR = 2.298, 95% CI 0.635-8.315, p = 0.205). Second-language speakers benefited from receiving a lower idea density, achieving a 10.8% score increase from high to low density, versus a 3.2% increase obtained by first language speakers.

CONCLUSIONS

The propositional idea density of lectures directly influences students' comprehension, and disproportionately for second language speakers; revealing the possibility of reduced spoken idea density in levelling the attainment differential between first and second language speakers.

Clinical utilisation of the Infant Monitor of vocal Production (IMP) for early identification of communication impairment in young infants at-risk of cerebral palsy: a prospective cohort study

AIM

To report prospective longitudinal data of early vocaliszations of infants identified "at-risk" of cerebral palsy (CP) for early identification of communication impairment.

METHOD

This case-control longitudinal prospective cohort study reports on the assessment of 36 infants, 18 identified as at-risk of CP at the time of enrolment and 18 typically developing (TD) children, at three time points: 6 months, 9 months and 12 months of age, Data were obtained through criterion and norm referenced assessments of vocaliszation behaviors.

RESULTS

Early vocal behaviors of infants identified as at-risk of CP did not differ from their age matched peers at 6 months of age, however, significant group differences emerged at 9 and 12 months when pre-canonical and canonical babble typically emerge. Generalized linear mixed models analysis showed that the rate of development of early language ability and more complex speech-related vocal behaviors was slower for infants at risk of CP when compared to TD infants, with over 75% of infants with CP showing below normal vocal production and impaired language by 12 months of age.

INTERPRETATION

Our data suggest characteristics of infant vocalizations associated with pre-canonical and canonical babbling provide a strong evidence base for predicting communication outcomes in infants at risk of CP.

A simple intervention to improve the use of postoperative antibiotics and intra-abdominal drains in appendicectomy patients

INTRODUCTION

Appendicitis remains the most common intra-abdominal surgical emergency, yet many patients receive postoperative antibiotics and intra-abdominal drains against recommended guidelines. This study assesses the impact of an educational poster on the appropriate use of postoperative antibiotics and intra-abdominal drains in appendicectomy patients.

METHODS

Patients who underwent an appendicectomy between January and April 2019 ('Poster absent' group) as well as between November 2019 and February 2020 ('Poster present' group) were identified. Data were collected on patient demographics, the presence of complicating features (ie appendiceal abscesses, intraperitoneal pus, gangrene and/or perforation) as well as the use of postoperative antibiotics and intra-abdominal drains in accordance with World Society of Emergency Surgery guidelines.

RESULTS

One hundred and thirty patients were included in the 'Poster absent' (73 patients) and 'Poster present' (57 patients) groups. After introducing the educational poster there was a significant reduction in the use of postoperative antibiotics (60.5% to 13.8%; p<0.0001) and an insignificant reduction in intra-abdominal drain use (15.2% to 13.2% p>0.05) that were contraindicated in simple appendicitis. There was a significant improvement in the use of postoperative antibiotics (71.9% to 100%; p=0.0019) and an insignificant increase in intra-abdominal drain use (58.8% to 64.3%; p>0.05) that were indicated in complicated appendicitis. The rates of wound infection (4.10% to 0%; p=0.2556) and ileus/obstruction (5.48% to 1.75%; p=0.3846) also reduced.

CONCLUSION

This small study demonstrated that a simple and appropriately targeted intervention of an educational poster can significantly improve and reduce variation in the management of appendicectomy patients and may reduce postoperative complications.

Concordance between PCR-based extraction-free saliva and nasopharyngeal swabs for SARS-CoV-2 testing

Introduction: Saliva represents a less invasive alternative to nasopharyngeal swab (NPS) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. SalivaDirect is a nucleic acid extraction-free method for detecting SARS-CoV2 in saliva specimens. Studies evaluating the concordance of gold standard NPS and newly developed SalivaDirect protocols are limited. The aim of our study was to assess SalivaDirect as an alternative method for COVID-19 testing. Methods: Matching NPS and saliva samples were analysed from a cohort of symptomatic (n=127) and asymptomatic (n=181) participants recruited from hospital and university settings, respectively. RNA was extracted from NPS while saliva samples were subjected to the SalivaDirect protocol before RT-qPCR analysis. The presence of SARS-Cov-2 was assessed using RdRp and N1 gene targets in NPS and saliva, respectively. Results: Overall we observed 94.3% sensitivity (95% CI 87.2-97.5%), and 95.9% specificity (95% CI 92.4-97.8%) in saliva when compared to matching NPS samples. Analysis of concordance demonstrated 95.5% accuracy overall for the saliva test relative to NPS, and a very high level of agreement (κ coefficient = 0.889, 95% CI 0.833-0.946) between the two sets of specimens. Fourteen of 308 samples were discordant, all from symptomatic patients. Ct values were >30 in 13/14 and >35 in 6/14 samples. No significant difference was found in the Ct values of matching NPS and saliva sample ( p=0.860). A highly significant correlation (r = 0.475, p<0.0001) was also found between the Ct values of the concordant positive saliva and NPS specimens. Conclusions: Use of saliva processed according to the SalivaDirect protocol represents a valid method to detect SARS-CoV-2. Accurate and less invasive saliva screening is an attractive alternative to current testing methods based on NPS and would afford greater capacity to test asymptomatic populations especially in the context of frequent testing.

Language profiles of Welsh-English bilingual children with Down syndrome

PURPOSE

Given that children with Down syndrome (DS) have language learning difficulties, concerns have been raised about the capacity of these children to acquire two (or more) languages. This research examines the language profiles of bilingual children with DS and typically developing (TD) children in comparison to monolinguals, with a view towards identifying the factors associated with language abilities within these populations.

METHOD

Four groups of children were recruited: Welsh-English bilinguals with DS (n=10), English monolinguals with DS (n=10), TD Welsh-English bilinguals (n=10) and TD English monolinguals (n=10). Children were individually matched on nonverbal cognitive ability (NVCA) to each child in the bilingual DS group and the four groups were matched on socioeconomic status and gender. Bilinguals were matched on current and lifetime exposure to Welsh and age of first exposure to their L2. Within DS and TD groups, chronological age was statistically controlled for. Language abilities were assessed via standardised assessments and specially designed tasks. Bilinguals were assessed in both of their languages.

RESULTS

Results show no effect of language status on measures of expressive and receptive language abilities or phonological awareness. Language impairments were evident for both DS groups, particularly for expressive morphosyntax. Welsh receptive vocabulary scores of the bilinguals with DS were comparable to the TD bilinguals. Working memory, phonological awareness and chronological age were the strongest predictors of receptive language outcomes in both DS groups, explaining 90% of the variability.

CONCLUSIONS

In conclusion, we report no adverse outcomes on language development for bilinguals with DS. To our knowledge, this is the first group study of bilingualism in children with DS within the UK. Findings align with and add to the growing body of literature that reports that bilingualism does not negatively impact the language development of children with developmental disabilities. Clinical and educational implications are discussed.

Deferoxamine Treatment Prevents Post-Stroke Vasoregression and Neurovascular Unit Remodeling Leading to Improved Functional Outcomes in Type 2 Male Diabetic Rats: Role of Endothelial Ferroptosis

It is a clinically well-established fact that patients with diabetes have very poor stroke outcomes. Yet, the underlying mechanisms remain largely unknown. Our previous studies showed that male diabetic animals show greater hemorrhagic transformation (HT), profound loss of cerebral vasculature in the recovery period, and poor sensorimotor and cognitive outcomes after ischemic stroke. This study aimed to determine the impact of iron chelation with deferoxamine (DFX) on (1) cerebral vascularization patterns and (2) functional outcomes after stroke in control and diabetic rats. After 8 weeks of type 2 diabetes induced by a combination of high-fat diet and low-dose streptozotocin, male control and diabetic animals were subjected to thromboembolic middle cerebral artery occlusion (MCAO) and randomized to vehicle, DFX, or tPA/DFX and followed for 14 days with behavioral tests. Vascular indices (vascular volume and surface area), neurovascular remodeling (AQP4 polarity), and microglia activation were measured. Brain microvascular endothelial cells (BMVEC) from control and diabetic animals were evaluated for the impact of DFX on ferroptotic cell death. DFX treatment prevented vasoregression and microglia activation while improving AQP4 polarity as well as blood-brain barrier permeability by day 14 in diabetic rats. These pathological changes were associated with improvement of functional outcomes. In control rats, DFX did not have an effect. Iron increased markers of ferroptosis and lipid reactive oxygen species (ROS) to a greater extent in BMVECs from diabetic animals, and this was prevented by DFX. These results strongly suggest that (1) HT impacts post-stroke vascularization patterns and recovery responses in diabetes, (2) treatment of bleeding with iron chelation has differential effects on outcomes in comorbid disease conditions, and (3) iron chelation and possibly inhibition of ferroptosis may provide a novel disease-modifying therapeutic strategy in the prevention of post-stroke cognitive impairment in diabetes.

Concordance between PCR-based extraction-free saliva and nasopharyngeal swabs for SARS-CoV-2 testing

Introduction: Saliva represents a less invasive alternative to nasopharyngeal swab (NPS) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. SalivaDirect is a nucleic acid extraction-free method for detecting SARS-CoV2 in saliva specimens. Studies evaluating the concordance of gold standard NPS and newly developed SalivaDirect protocols are limited. The aim of our study was to to assess SalivaDirect as an alternative method for COVID-19 testing. Methods: Matching NPS and saliva samples were analysed from a cohort of symptomatic (n=127) and asymptomatic (n=181) participants recruited from hospital and university settings, respectively. RNA was extracted from NPS while saliva samples were subjected to the SalivaDirect protocol before RT-qPCR analysis. The presence of SARS-Cov-2 was assessed using RdRP and N1 gene targets in NPS and saliva, respectively. Results: Overall we observed 94.3% sensitivity (95% CI 87.2-97.5%), and 95.9% specificity (95% CI 92.4-97.8%) in saliva when compared to matching NPS samples. Analysis of concordance demonstrated 95.5% accuracy overall for the saliva test relative to NPS, and a very high level of agreement (κ coefficient = 0.889, 95% CI 0.833-0.946) between the two sets of specimens. Fourteen of 308 samples were discordant, all from symptomatic patients. Ct values were >30 in 13/14 and >35 in 6/14 samples. No significant difference was found in the Ct values of matching NPS and saliva sample ( p=0.860). A highly significant correlation (r = 0.475, p<0.0001) was also found between the Ct values of the concordant positive saliva and NPS specimens. Conclusions: Use of saliva processed according to the SalivaDirect protocol represents a valid method to detect SARS-CoV-2. Accurate and less invasive saliva screening is an attractive alternative to current testing methods based on NPS and would afford greater capacity to test asymptomatic populations especially in the context of frequent testing.

Bilingualism in children with a dual diagnosis of Down syndrome and Autism Spectrum Disorder

Research shows that a substantial proportion of children with Down syndrome (DS) also meet the clinical criteria for Autism Spectrum Disorder (ASD). Children with this dual diagnosis display a linguistic profile that includes significant language delays and language impairments which often differ from the impairments observed in each developmental disability (DD) separately. Given the challenges observed with language acquisition for children with DS-ASD, concerns might be raised regarding the outcomes and suitability of a bilingual environment for children with this dual diagnosis specifically. The aim of this research was to explore the language profiles of four children with DS-ASD. A multiple case-study approach was employed. Four children with a confirmed DS-ASD diagnosis who had received exposure to two languages (English and Welsh) were assessed on a range of cognitive and linguistic measures. Performance was compared to three control groups; bilinguals with DS, English monolinguals with DS and mental age-matched typically developing bilinguals. Assessments comprised of expressive and receptive language, phonological awareness, working memory and non-verbal cognitive abilities. Considerable variability was found in the cognitive and linguistic profiles of the case-study participants. Children with DS-ASD displayed similar language profiles to that of the bilingual and monolingual children with DS in the areas tested, although performance was generally lower than that of the TD bilingual children. Although substantial variability was found, participants were developing bilingual abilities in a similar trajectory to children with DS in line with the degree of exposure to each language. This research highlights the need to assess bilingual children with complex dual diagnoses with an individualistic approach and carefully consider how to appropriately assess and treat bilingual children within speech and language therapy provisions.

AIP variant causing familial prolactinoma

Pathogenic variants in the aryl hydrocarbon receptor-interacting protein (AIP) gene are increasingly recognised as a cause of familial isolated pituitary adenoma. AIP-associated tumours are most commonly growth hormone (GH) producing. In our cohort of 175 AIP mutation positive patients representing 93 kindreds, 139 (79%) have GH excess, 19 have prolactinoma (17 familial and 2 sporadic cases) and out of the 17 clinically non-functioning tumours 4 were subsequently operated and found to be GH or GH & prolactin immunopositive adenoma. Here we report a family with an AIP variant, in which multiple family members are affected by prolactinoma, but none with GH excess. To our knowledge this is the first reported family with an AIP pathogenic variant to be affected solely by prolactinoma. These data suggest that prolactinoma families represent a small subset of AIP mutation positive kindreds, and similar to young-onset sporadic prolactinomas, AIP screening would be indicated.

Catheter-related complications and mortality of atrial fibrillation ablation following introduction of contact force-sensing technology

OBJECTIVES

Contact force-sensing catheters allow real-time catheter-tissue contact force monitoring during atrial fibrillation. These catheters were rapidly adopted into clinical practice following market introduction in 2014, but concerns have been raised regarding collateral damage such as esophageal injury. We sought to examine whether the introduction of force-sensing catheters was associated with a change in short-term and intermediate-term acute care use, complications and mortality following atrial fibrillation ablation.

DESIGN

Retrospective cohort analysis. We used inverse probability treatment weight matching to account for the differences in baseline characteristics between groups.

SETTING

We examined patients included in the OptumLabs Data Warehouse who underwent ablation for atrial fibrillation before (2011-2013) and after (2015-2017) the market introduction of contact force-sensing catheters.

MAIN OUTCOME MEASURES

We examined 30-day and 90-day rates of all-cause acute care use, including hospitalizations and emergency department visits, as well as death and hospitalization for catheter-related complications, including atrioesophageal fistula, pericarditis, cardiac tamponade/perforation and stroke/transient ischemic attack.

RESULTS

Our sample included 3470 and 5772 patients who underwent atrial fibrillation (AF) ablation before and after market introduction of contact force-sensing catheters, respectively. Complication rates were low and did not differ between the two periods (p>0.10 for each outcome). The 30-day and 90-day mortality was 0.1% and 0.3%, respectively after market introduction and unchanged from prior to 2014. The 90-day rates of all-cause acute care use decreased, from 27.0% in 2011-2013 to 23.9% in 2015-2017 (p<0.001).

CONCLUSIONS

AF ablation-related catheter complications and mortality are low and there has been no significant change following the introduction of force-sensing catheters.

Development of Anti-CD32b Antibodies with Enhanced Fc Function for the Treatment of B and Plasma Cell Malignancies

The sole inhibitory Fcγ receptor CD32b (FcγRIIb) is expressed throughout B and plasma cell development and on their malignant counterparts. CD32b expression on malignant B cells is known to provide a mechanism of resistance to rituximab that can be ameliorated with a CD32b-blocking antibody. CD32b, therefore, represents an attractive tumor antigen for targeting with a monoclonal antibody (mAb). To this end, two anti-CD32b mAbs, NVS32b1 and NVS32b2, were developed. Their complementarity-determining regions (CDR) bind the CD32b Fc binding domain with high specificity and affinity while the Fc region is afucosylated to enhance activation of FcγRIIIa on immune effector cells. The NVS32b mAbs selectively target CD32b⁺ malignant cells and healthy B cells but not myeloid cells. They mediate potent killing of opsonized CD32b⁺ cells via antibody-dependent cellular cytotoxicity and phagocytosis (ADCC and ADCP) as well as complement-dependent cytotoxicity (CDC). In addition, NVS32b CDRs block the CD32b Fc-binding domain, thereby minimizing CD32b-mediated resistance to therapeutic mAbs including rituximab, obinutuzumab, and daratumumab. NVS32b mAbs demonstrate robust antitumor activity against CD32b⁺ xenografts in vivo and immunomodulatory activity including recruitment of macrophages to the tumor and enhancement of dendritic cell maturation in response to immune complexes. Finally, the activity of NVS32b mAbs on CD32b⁺ primary malignant B and plasma cells was confirmed using samples from patients with B-cell chronic lymphocytic leukemia (CLL) and multiple myeloma. The findings indicate the promising potential of NVS32b mAbs as a single agent or in combination with other mAb therapeutics for patients with CD32b⁺ malignant cells.

Application of a likelihood ratio test based method for safety signal detection to left ventricular assist devices

Effective post-market safety surveillance of medical devices is critical for public health. However, many current statistical methods for safety signal detection do not control for type I error when assessing multiple device and adverse event (AE) combinations. This can result in increased false signals, underscoring the need for more robust statistical methods. Moreover, the duration of medical device use can be an important factor to consider in safety surveillance. In this study, we adapted a likelihood ratio test (LRT) based method, which was initially developed and applied to drugs, to identify safety signals for left ventricular assist devices (LVAD). Among patients with chronic, advanced left ventricular failure, we analyzed AE data for HeartWare and HeartMate II patients during a two-year period and further incorporated person-years (henceforth exposure-time). The novel modified LRT and conventional Z-test with p-values adjusted by the Benjamini-Hochberg (BH) procedure were used to explore safety signals by comparing HeartWare and HeartMate II patients in the presence of multiple adverse events. Both methods identified greater incidence of stroke among HeartWare as compared to HeartMate II patients without exposure-time (p = .025 for LRT and p = .027 for Z-test with BH) and with exposure-time (p = .002 for LRT and p = .005 for Z-test with BH). By using improved statistical methods for safety signal detection, potential safety issues can be identified and addressed in a more timely manner to enhance public safety.

Neurovascular protection in voltage-gated proton channel Hv1 knock-out rats after ischemic stroke: interaction with Na+ /H+ exchanger-1 antagonism

Experimental studies have demonstrated protective effects of NHE‐1 inhibition on cardiac function; however, clinical trials utilizing NHE‐1 antagonists found an increase in overall mortality attributed to thromboembolic strokes. NADPH oxidase‐derived reactive oxygen species (ROS) from microglial cells have been shown to contribute to injury following stroke. We have recently demonstrated that NHE‐1 inhibition enhances ROS in macrophages in a Hv1‐dependent manner. As Hv1 protein is highly expressed in microglia, we hypothesized that “NHE‐1 inhibition may augment neurovascular injury by activating Hv1,” providing a potential mechanism for the deleterious effects of NHE‐1. The goal of this study was to determine whether neurovascular injury and functional outcomes after experimental stroke differed in wild‐type and Hv1 mutant Dahl salt‐sensitive rats treated with an NHE‐1 inhibitor. Stroke was induced using both transient and permanent of middle cerebral artery occlusion (MCAO). Animals received vehicle or NHE‐1 inhibitor KR32568 (2 mg/kg, iv) either 30 min after the start of MCAO or were pretreated (2 mg/kg, iv, day) for 3 days and then subjected to MCAO. Our data indicate that Hv1 deletion confers both neuronal and vascular protection after ischemia. In contrast to our hypothesis, inhibition of NHE‐1 provided further protection from ischemic stroke, and the beneficial effects of both pre‐ and post‐treatment with KR32568 were similar in wild‐type and Hv1^−/− rats. These data indicate that Hv1 activation is unlikely to be responsible for the increased incidence of cerebrovascular events observed in the heart disease patients after NHE‐1 inhibition treatment.

Non-photopic and photopic visual cycles differentially regulate immediate, early, and late phases of cone photoreceptor-mediated vision

Cone photoreceptors in the retina enable vision over a wide range of light intensities. However, the processes enabling cone vision in bright light (i.e. photopic vision) are not adequately understood. Chromophore regeneration of cone photopigments may require the retinal pigment epithelium (RPE) and/or retinal Müller glia. In the RPE, isomerization of all-trans-retinyl esters to 11-cis-retinol is mediated by the retinoid isomerohydrolase Rpe65. A putative alternative retinoid isomerase, dihydroceramide desaturase-1 (DES1), is expressed in RPE and Müller cells. The retinol-isomerase activities of Rpe65 and Des1 are inhibited by emixustat and fenretinide, respectively. Here, we tested the effects of these visual cycle inhibitors on immediate, early, and late phases of cone photopic vision. In zebrafish larvae raised under cyclic light conditions, fenretinide impaired late cone photopic vision, while the emixustat-treated zebrafish unexpectedly had normal vision. In contrast, emixustat-treated larvae raised under extensive dark-adaptation displayed significantly attenuated immediate photopic vision concomitant with significantly reduced 11-cis-retinaldehyde (11cRAL). Following 30 min of light, early photopic vision was recovered, despite 11cRAL levels remaining significantly reduced. Defects in immediate cone photopic vision were rescued in emixustat- or fenretinide-treated larvae following exogenous 9-cis-retinaldehyde supplementation. Genetic knockout of Des1 (degs1) or retinaldehyde-binding protein 1b (rlbp1b) did not eliminate photopic vision in zebrafish. Our findings define molecular and temporal requirements of the nonphotopic or photopic visual cycles for mediating vision in bright light.

Abstract WP492: Differential Effects of Iron Chelation With Deferoxamine on Post-Stroke Neurovascular Inflammation: Disease and Sex Interactions

We have shown that 1) poor recovery in diabetes is associated with greater hemorrhagic transformation and significant loss of the cerebrovasculature, and 2) iron chelation therapy with deferoxamine (DFX) improves sensorimotor and cognitive outcomes while preventing vasoregression in male diabetic animals after stroke. This study tested the hypotheses that 1) diabetes mediates pathological post-stroke neovascularization in females and 2) DFX attenuates microglial activation and pathological neurovascular remodeling in both sexes. Control and diabetic animals were subjected to embolic middle cerebral artery occlusion (MCAO). DFX (100 mg/kg) or vehicle was given 1hour after MCAO and repeated every 12h for 7 days after stroke. Functional outcomes were assessed over time. Vascular indices, microglial morphology (activation), and neurovascular integrity (IgG and unpolarized Aquaporin-4) were measured at Day 14. Male and female microvascular endothelial cells (BMVECs) treated with iron and/or DFX were tested for viability and endothelial mesenchymal transition (EndMT) markers. DFX preserved vascular volume post-stroke in diabetic males. Stroke did not cause vasoregression in diabetic female animals; however, DFX reduced vascular indices while improving sensorimotor but not cognitive outcomes in both control and diabetic females. Ischemic injury amplified microglial activation and neurovascular remodeling in diabetes while DFX treatment restored these changes to control levels in male diabetic animals but not in females (Table). Female BMVECs grown under diabetic conditions expressed α-SMA and N-cadherin while VE-cadherin was decreased, indicative of EndMT (p<0.05 vs normal glucose). Data suggest that DFX treatment has sex- and disease-dependent effects on post-stroke neovascularization. Additional studies will aim to address the mechanisms by which DFX exerts these differential effects on functional outcomes and neurovascular remodeling.

Liquid Chromatographic Method for Determination of Diquat and Paraquat Herbicides in Potatoes: Collaborative Study

A liquid chromatographic (LC) method for the determination of diquat and paraquat herbicides/desiccants in potatoes was collaboratively studied in 6 laboratories. Analytes are extracted from 5 g sample with dilute acid by using a microreflux procedure; the hydrolysate is adjusted to pH 9–10 and passed through a disposable silica cartridge for rapid cleanup and preconcentration. Analytes are separated on a reversed-phase LC column and are measured as their heptanesulfonate ion pairs by UV detection. Each collaborator determined diquat and paraquat at 4 levels (0.05,0.1,0.5, and 1.0 ppm) in blind duplicate samples plus 2 blind negative control samples. Potatoes, obtained from each participant’s region, were spiked by the collaborators with unknown aqueous solutions containing no analyte or a mixture of diquat and paraquat standards. Repeatability and reproducibility relative standard deviations (RSDr and RSDR) averaged 17.1 and 29.0%, respectively, for determination of diquat and 10.8 and 29.5%, respectively, for paraquat. For analysis of standard solutions, RSDr and RSDR values were 6.3 and 12.0%, respectively, for diquat and 7.3 and 13.9%, respectively, for paraquat. Accuracy, measured by comparison with true spiking values (absolute recovery) averaged 77.6 and 76.2% for diquat and paraquat, respectively, and ranged from 71.8 to 88.0% for both compounds. The method was adopted first action by AOAC International.

Abstract C028: Discovery and characterization of next generation monoclonal antibodies targeting the inhibitory Fc gamma receptor CD32b for the treatment of B and plasma cell malignancies

CD32b (FcγR2b), the sole inhibitory Fcγ receptor, negatively regulates immune function and is expressed throughout B cell development and on their malignant counterparts with the highest expression found on multiple myeloma. Additionally, CD32b expression on tumor cells is known to sequester IgG Fc thereby providing a mechanism of resistance to therapeutic monoclonal antibodies (mAb) with Fc dependent activity. Taken together, CD32b represents an attractive tumor antigen for targeting with a mAb. To this end, two anti-CD32b mAbs, NVS32b1 and NVS32b2, were developed. The complementarity-determining regions (CDRs) of these antibodies bind the CD32b Fc binding domain with high specificity and affinity while the Fc region is afucosylated enabling enhanced activation of FcγR on immune effector cells. This specificity and optimized potency is highlighted in whole blood assays where NVS32b2 depletes CD32b positive B cells but spares immune subsets with low CD32b expression or expression of the homologous CD32a. The antibodies mediate potent killing of opsonized cells via antibody dependent cell-mediated cytotoxicity, antibody dependent cellular phagocytosis, and complement dependent cytotoxicity. Additionally, NVS32b mAbs’ CDR block the CD32b Fc binding domain, thereby minimizing CD32b mediated resistance to therapeutic mAbs with Fc dependent activity including rituximab, obinutuzumab, and daratumumab. In vivo, NVS32b mAbs demonstrate robust antitumor activity against CD32b positive xenografts and immunomodulatory activity including recruitment of intratumoral macrophages. The NVS32b mAbs’ activity against malignant B and plasma cells featuring a range of CD32b expression demonstrates their therapeutic potential, as a single agent or in combination with therapeutics including mAbs with Fc dependent activity.

Citation Format: Haihui Lu, Dongshu Chen, Sunyoung Jang, Babette Wolf, Stefan Ewert, Meghan Flaherty, Fangmin Xu, Sinan Isim, Yeonjiu Shim, Christina Dornelas, Nicole Balke, Xavier Charles Leber, Meike Scharenberg, Johanna Koelln, Eugene Choi, Rebecca Ward, Jennifer Johnson, Thomas Calzascia, Isabelle Isnardi, Juliet Williams, Heather Huet, Emma Lees, Matthew J Meyer. Discovery and characterization of next generation monoclonal antibodies targeting the inhibitory Fc gamma receptor CD32b for the treatment of B and plasma cell malignancies [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C028. doi:10.1158/1535-7163.TARG-19-C028

AGEN2373 is a conditionally-active agonist antibody targeting the costimulatory receptor CD137 for the treatment of human malignancies

e14005

Background: Agonist antibodies targeting CD137 are potent inducers of tumor-reactive T cell proliferation, cytokine production, and cytotoxicity, and have been explored clinically for their ability to enhance immune cell-mediated destruction of tumor cells. Despite early signs of clinical activity, the development of first-generation anti-CD137 antibodies has been hampered by on-target dose-limiting hepatotoxicity or poor clinical activity. Subsequent CD137 therapies have therefore sought to localize CD137 agonism to the tumor microenvironment (TME) to potentially improve tolerability in patients. However, these approaches may also limit the potential benefit of CD137 signaling outside the TME that contributes to anti-tumor immunity, such as T cell priming in tumor draining lymph nodes. Here we describe the pharmacologic and non-clinical safety profile of a next-generation anti-CD137 monospecific antibody, AGEN2373. Methods: Flow cytometry and surface plasmon resonance-based binding, superantigen-driven immune cell activation, and luminescent reporter cell line assays were developed to test the ability of AGEN2373 to induce CD137 signaling. A non-clinical, multi-dose safety study was conducted wherein cynomolgus monkeys were injected intravenously with 100 mg/kg doses of AGEN2373. Results: AGEN2373 engages cell-expressed human and cynomolgus monkey CD137, and provides potent CD137 co-stimulation only in the presence of CD137 ligand and/or Fc gamma receptor-expressing antigen presenting cells. No changes in clinical parameters, importantly no sign of liver toxicity, were observed after administration of AGEN2373 in cynomolgus monkeys. Conclusions: AGEN2373, a novel conditionally-active anti-CD137 agonist antibody that is well-tolerated in non-human primates, is expected to have clinical activity in patients with human malignancies by its ability to selectively enhance tumor immunity in the context of immune co-stimulation.

Preclinical functional characterization of AGEN1181, a clinical stage Fc-engineered anti-CTLA-4 antibody for the treatment of patients with early and advanced malignancies

e14126

Background: Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) is an inhibitory receptor that modulates T cell priming and CD28-dependent T cell activation. Modulation of this pathway by CTLA-4 antibodies has demonstrated clinical responses in patients with advance disease, however the mechanism of action of these antibodies remains controversial. It is currently understood that anti-CTLA-4 antibodies mediate antitumor effects through receptor-ligand blockade, and, in preclinical models, through depletion of intratumoral regulatory T (Treg) cells via an Fc-dependent mechanism. Recently, we reported a novel Fc-mediated contribution to T cell priming underscored the importance of Fc selection for optimal CTLA-4 antibody activity. AGEN1181 is a clinical stage Fc-engineered IgG1 antibody that leverages this novel mechanism for enhanced functionality. Methods: Fab-mediated biology of AGEN1181 was confirmed by assessing binding affinity, specificity, and blockade of CTLA-4:CD80/86 interactions. Fc-mediated functions of AGEN1181 were evaluated by FcγR binding, reporter-based FcγR signaling, and antibody-mediated Treg cell cytotoxicity assays. In vitro and in vivo pharmacology of AGEN1181 (alone or in combination with anti-PD-1) were evaluated in superantigen (staphylococcal enterotoxin)-mediated T cell stimulation assays and in a non-human primate (NHP) model. Safety and tolerability of AGEN1181 were assessed in cynomolgus monkeys administered 5 once-weekly intravenous bolus infusions at doses of 5, 30, or 100 mg/kg. Results: AGEN1181 bound to CTLA-4 with high affinity and specificity and demonstrated a range of enhanced functional activities relative to first-generation CTLA-4 antibodies. This included superior CD16 (FcγRIIIA) binding, Treg depletion and T cell priming (as measured by ZAP70 phosphorylation and interleukin-2 secretion). In NHP studies, a single dose of AGEN1181, alone or in combination with anti-PD-1 antibody upregulated Ki67 and ICOS expression on peripheral T cells. Finally, AGEN1181 exhibited an acceptable toxicologic profile in multi-dose NHP studies. Conclusions: AGEN1181, an Fc-engineered anti-CTLA-4 antibody exhibits a range of enhanced functional attributes relative to first-generation anti-CTLA-4 antibodies in preclinical studies. Phase 1 clinical studies for AGEN1181 will be initiated imminently.

Non-aqueous formulations for ram and screen extrusion-spheronisation

The use of non-aqueous cellulose-based formulations for extrusion-spheronisation (E-S) is investigated. A 10 wt% hydroxypropyl cellulose/isopropyl alcohol solution (HPC/IPA) was identified as a suitable sticky liquid binder for preparing non-aqueous pastes. Preliminary tests were performed on a series of pastes using a ram as well as a laboratory roller screen extruder, since the former is commonly used in batch testing and the latter replicates the shear range in a manufacturing screen extruder. Pellets with acceptable size and shape distributions were obtained with Avicel® HFE-102 NF/HPC/IPA for ram E-S, and with Avicel® RC-591/HPC/IPA for screen E-S. Further investigation was performed with calcium carbonate added as a model active pharmaceutical ingredient. Both formulations were able to generate pellets with acceptable size and shape characteristics at up to 50 wt% carbonate loading: further work is required to optimise yields.

NLRP3 inflammasome inhibition with MCC950 improves diabetes-mediated cognitive impairment and vasoneuronal remodeling after ischemia

Diabetes increases the risk and worsens the progression of cognitive impairment via the greater occurrence of small vessel disease and stroke. Yet, the underlying mechanisms are not fully understood. It is now accepted that cardiovascular health is critical for brain health and any neurorestorative approaches to prevent/delay cognitive deficits should target the conceptual neurovascular unit (NVU) rather than neurons alone. We have recently shown that there is augmented hippocampal NVU remodeling after a remote ischemic injury in diabetes. NLRP3 inflammasome signaling has been implicated in the development of diabetes and neurodegenerative diseases, but little is known about the impact of NLRP3 activation on functional and structural interaction within the NVU of hippocampus, a critical part of the brain that is involved in forming, organizing, and storing memories. Endothelial cells are at the center of the NVU and produce trophic factors such as brain derived neurotrophic factor (BDNF) contributing to neuronal survival, known as vasotrophic coupling. Therefore, the aims of this study focused on two hypotheses: 1) diabetes negatively impacts hippocampal NVU remodeling and worsens cognitive outcome after stroke, and 2) NLRP3 inhibition with MCC950 will improve NVU remodeling and cognitive outcome following stroke via vasotrophic (un)coupling between endothelial cells and hippocampal neurons. Stroke was induced through a 90-min transient middle cerebral artery occlusion (MCAO) in control and high-fat diet/streptozotocin-induced (HFD/STZ) diabetic male Wistar rats. Saline or MCC950 (3 mg/kg), an inhibitor of NLRP3, was injected at 1 and 3 h after reperfusion. Cognition was assessed over time and neuronal density, blood-brain barrier (BBB) permeability as well as NVU remodeling (aquaporin-4 [AQP4] polarity) was measured on day 14 after stroke. BDNF was measured in endothelial and hippocampal neuronal cultures under hypoxic and diabetes-mimicking condition with and without NLRP3 inhibition. Diabetes increased neuronal degeneration and BBB permeability, disrupted AQP4 polarity, impaired cognitive function and amplified NLRP3 activation after ischemia. Inhibition with MCC950 improved cognitive function and vascular integrity after stroke in diabetic animals and prevented hypoxia-mediated decrease in BDNF secretion. These results are the first to provide essential data showing MCC950 has the potential to become a therapeutic to prevent neurovascular remodeling and worsened cognitive decline in diabetic patients following stroke.

Pharmacological restoration of visual function in a zebrafish model of von-Hippel Lindau disease

Von Hippel-Lindau (VHL) syndrome is a rare, autosomal dominant disorder, characterised by hypervascularised tumour formation in multiple organ systems. Vision loss associated with retinal capillary hemangioblastomas remains one of the earliest complications of VHL disease. The mortality of Vhl^-/- mice in utero restricted modelling of VHL disease in this mammalian model. Zebrafish harbouring a recessive germline mutation in the vhl gene represent a viable, alternative vertebrate model to investigate associated ocular loss-of-function phenotypes. Previous studies reported neovascularisation of the brain, eye and trunk together with oedema in the vhl^-/- zebrafish eye. In this study, we demonstrate vhl^-/- zebrafish almost entirely lack visual function. Furthermore, hyaloid vasculature networks in the vhl^-/- eye are improperly formed and this phenotype is concomitant with development of an ectopic intraretinal vasculature. Sunitinib malate, a multi tyrosine kinase inhibitor, market authorised for cancer, reversed the ocular behavioural and morphological phenotypes observed in vhl^-/- zebrafish. We conclude that the zebrafish vhl gene contributes to an endogenous molecular barrier that prevents development of intraretinal vasculature, and that pharmacological intervention with sunitinib can improve visual function and hyaloid vessel patterning while reducing abnormally formed ectopic intraretinal vessels in vhl^-/- zebrafish.

Association of Genetic Variants in NUDT15 With Thiopurine-Induced Myelosuppression in Patients With Inflammatory Bowel Disease

IMPORTANCE

Use of thiopurines may be limited by myelosuppression. TPMT pharmacogenetic testing identifies only 25% of at-risk patients of European ancestry. Among patients of East Asian ancestry, NUDT15 variants are associated with thiopurine-induced myelosuppression (TIM).

OBJECTIVE

To identify genetic variants associated with TIM among patients of European ancestry with inflammatory bowel disease (IBD).

DESIGN, SETTING, AND PARTICIPANTS

Case-control study of 491 patients affected by TIM and 679 thiopurine-tolerant unaffected patients who were recruited from 89 international sites between March 2012 and November 2015. Genome-wide association studies (GWAS) and exome-wide association studies (EWAS) were conducted in patients of European ancestry. The replication cohort comprised 73 patients affected by TIM and 840 thiopurine-tolerant unaffected patients.

EXPOSURES

Genetic variants associated with TIM.

MAIN OUTCOMES AND MEASURES

Thiopurine-induced myelosuppression, defined as a decline in absolute white blood cell count to 2.5 × 109/L or less or a decline in absolute neutrophil cell count to 1.0 × 109/L or less leading to a dose reduction or drug withdrawal.

RESULTS

Among 1077 patients (398 affected and 679 unaffected; median age at IBD diagnosis, 31.0 years [interquartile range, 21.2 to 44.1 years]; 540 [50%] women; 602 [56%] diagnosed as having Crohn disease), 919 (311 affected and 608 unaffected) were included in the GWAS analysis and 961 (328 affected and 633 unaffected) in the EWAS analysis. The GWAS analysis confirmed association of TPMT (chromosome 6, rs11969064) with TIM (30.5% [95/311] affected vs 16.4% [100/608] unaffected patients; odds ratio [OR], 2.3 [95% CI, 1.7 to 3.1], P = 5.2 × 10-9). The EWAS analysis demonstrated an association with an in-frame deletion in NUDT15 (chromosome 13, rs746071566) and TIM (5.8% [19/328] affected vs 0.2% [1/633] unaffected patients; OR, 38.2 [95% CI, 5.1 to 286.1], P = 1.3 × 10-8), which was replicated in a different cohort (2.7% [2/73] affected vs 0.2% [2/840] unaffected patients; OR, 11.8 [95% CI, 1.6 to 85.0], P = .03). Carriage of any of 3 coding NUDT15 variants was associated with an increased risk (OR, 27.3 [95% CI, 9.3 to 116.7], P = 1.1 × 10-7) of TIM, independent of TPMT genotype and thiopurine dose.

CONCLUSIONS AND RELEVANCE

Among patients of European ancestry with IBD, variants in NUDT15 were associated with increased risk of TIM. These findings suggest that NUDT15 genotyping may be considered prior to initiation of thiopurine therapy; however, further study including additional validation in independent cohorts is required.

Abstract 106: NLRP3 Inflammasome Inhibition With MCC950 Improves Diabetes-Mediated Cognitive Impairment and Vasoneuronal Remodeling After Ischemia

Diabetes increases the risk and worsens the progression of cognitive impairment via the greater occurrence of small vessel disease and stroke. While NLRP3 inflammasome signaling has been implicated in the development of neurodegenerative diseases, little is known about the impact of NLRP3 activation on functional and structural interaction within the neurovascular unit (NVU) in diabetes. Endothelial cells are at the center of NVU and produce trophic factors such as BDNF contributing to neuronal survival, known as vasotrophic coupling. Therefore, the goals of this study were to determine the role of NLRP3 activation: 1) on hippocampal NVU remodeling and cognitive outcome after stroke in diabetes, and 2) on vasotrophic uncoupling between endothelial cells and hippocampal neurons after hypoxic injury in diabetes-mimicking conditions. Control and high-fat diet/STZ induced diabetic male rats were treated with saline or MCC950 (3mg/kg), a small molecule inhibitor of NLRP3, after reperfusion following a 90-min MCAO. Cognition was assessed. Neuronal death, blood-brain barrier (BBB) permeability and glial remodeling was measured on Day 14 after stroke. BDNF was measured in endothelial and hippocampal cell cultures under hypoxic and diabetes-mimicking condition with and without NLRP3 inhibition. Diabetes increased neuronal degeneration, BBB permeability, disrupted AQP4 polarity, impaired cognitive function and increased NLRP3 activation after ischemia. Inhibition with MCC950 improved cognitive function and NVU indices after stroke in diabetic animals and prevented hypoxia-mediated decrease in BDNF secretion. These results are the first to provide essential data showing MCC950 has the potential to become a therapeutic to prevent neurovascular remodeling and worsened cognitive decline in diabetic patients following stroke.