Quantifying Fluid and Function in Suboptimal Responders Switched From an Anti-vascular Endothelial Growth Factor (VEGF) to Faricimab

Background Anti-vascular endothelial growth factor (VEGF) injections have been successful in reducing vision loss from neovascular age-related macular degeneration, a leading cause of blindness. Due to the high treatment burden and suboptimal responses, switching to bi-specific faricimab treatment may lead to improved outcomes. Methods This retrospective chart review evaluated if suboptimal responders to anti-VEGF injections had better outcomes when switched to faricimab. Suboptimal responders were defined as patients with a history of >3 months of injections and the presence of fluid after ≥3 injections. The primary endpoints were best-corrected visual acuity, treatment interval, and fluid levels. Visual acuity measurements and optical coherence tomography were performed before each injection. The total fluid area (TFA) was measured using MATLAB 2023a (MathWorks, Natick, MA, USA). Results Nineteen eyes were included in the analysis. After three faricimab injections, average letters increased from 54.5 to 59.0 (SD: 15.3; p<0.05), and the injection interval was extended from 7.6 to 9.3 weeks (SD: 3.9; p<0.01) after four injections. Patients also experienced anatomical retinal changes, with a reduction in the TFA to 47.3% (p<0.005) after the second injection and a reduction in pigment epithelial detachment height to 82.3% (p<0.005) after one injection. The central subfield thickness was significantly reduced after the second injection (90.6% (SD: 17.6%) p<0.05). Conclusion Switching to faricimab after a suboptimal anti-VEGF response results in improvements in visual acuity, reduced treatment burden, and reduced fluid levels.

Enhancing emission control and analyzing the performance and combustion attributes of vehicular engines with spirulina microalgae diesel Ce2O3 nanoparticles blends

The current research investigates the utilization of spirulina microalgae biodiesel blends in a naturally aspirated constant speed compression ignition engine with Ce2O3 nanoparticles at the concentration of 50 ppm under diverse engine loading conditions. Blends of microalgae dispersed with neat diesel at the volume of 20% and 40%. A series of tests were conducted to evaluate the combined effects of microalgae and nanoparticles on engine performance, combustion efficiency, and emission characteristics. The study revealed that increasing the microalgae concentration in the diesel fuel resulted in reduced brake thermal efficiency due to less effective atomization and lower calorific value. Surprisingly, the 20% biodiesel blend with nanoparticles exhibited the highest brake thermal efficiency across various engine loads, while the 40% blend showed higher brake specific fuel consumption compared to both the 20% blend and neat diesel, primarily because of its lower heating value necessitating increased fuel consumption. Furthermore, the biodiesel blends led to lower in-cylinder pressure than pure diesel, mainly attributable to suboptimal atomization. In terms of emissions, the utilization of microalgae-based fuel led to a significant reduction in NOx, CO, and smoke emissions, attributed to the lower cylinder temperatures associated with these blends. In conclusion, this study underscores the potential of spirulina microalgae, particularly when combined with nanoparticles at an optimal concentration, as a promising and environmentally friendly alternative for compression ignition engines.

Experience of irreproducibility as a risk factor for poor mental health in biomedical science doctoral students: A survey and interview-based study

High rates of irreproducibility and of poor mental health in graduate students have been reported in the biomedical sciences in the past ten years, but to date, little research has investigated whether these two trends interact. In this study, we ask whether the experience of failing to replicate an expected finding impacts graduate students' mental health. Using an online survey paired with semi-structured qualitative interviews, we examined how often biomedical science doctoral students at a large American public university experienced events that could be interpreted as failures to replicate and how they responded to these experiences. We found that almost all participants had experience with irreproducibility: 84% had failed to replicate their own results, 70% had failed to replicate a colleague's finding, and 58% had failed to replicate a result from the published literature. Participants reported feelings of self-doubt, frustration, and depression while experiencing irreproducibility, and in 24% of cases, these emotional responses were strong enough to interfere with participants' eating, sleeping, or ability to work. A majority (82%) of participants initially believed that the anomalous results could be attributed to their own error. However, after further experimentation, most participants concluded that the original result was wrong (38%), that there was a key difference between the original experiment and their own (17%), or that there was a problem with the protocol (17%). These results suggest that biomedical science graduate students may be biased towards initially interpreting failures to replicate as indicative of a lack of skill, which may trigger or perpetuate feelings of anxiety, depression, or impostorism.

Bioluminescence resonance energy transfer biosensor for measuring activity of a protease secreted by Pseudomonas fluorescens growing in milk

Bacterial proteases are sporadic contributors to milk spoilage, reducing the quality of ultra-heat treated (UHT) milk and other dairy products. Current methods for measuring bacterial protease activity in milk are insensitive and too slow to be used in routine testing in dairy processing plants. We have designed a novel bioluminescence resonance energy transfer (BRET)-based biosensor to measure the activity of proteases secreted by bacteria in milk. The BRET-based biosensor is highly selective for bacterial protease activity compared with other proteases tested, notably including plasmin, which is abundant in milk. It incorporates a novel peptide linker that is selectively cleaved by P. fluorescens AprX proteases. The peptide linker is flanked by green fluorescent protein (GFP²) at the N-terminus and a variant Renilla luciferase (RLuc2) at the C-terminus. Complete cleavage of the linker by bacterial proteases from Pseudomonas fluorescens strain 65, leads to a 95% decrease in the BRET ratio. We applied an azocasein-based calibration method to the AprX biosensor using standard international enzyme activity units. In a 10-min assay, the detection limit for AprX protease activity in buffer was equivalent to 40 pg/mL (≈0.8 pM, 22 μU/mL) and 100 pg/mL (≈2pM, 54 μU/mL) in 50% (v/v) full fat milk. The EC₅₀ values were 1.1 ± 0.3 ng/mL (87 μU/mL) and 6.8 ± 0.2 ng/mL (540 μU/mL), respectively. The biosensor was approximately 800x more sensitive than the established FITC-Casein method in a 2-h assay, the shortest feasible time for the latter method. The protease biosensor is sensitive and fast enough to be used in production settings. It is suitable for measuring bacterial protease activity in raw and processed milk, to inform efforts to mitigate the effects of heat-stable bacterial proteases and maximise the shelf-life of dairy products.

Utilization of the Nannochloropsis microalgae biochar prepared via microwave assisted pyrolysis on the mixed biomass fuel pellets

Nannochloropsis microalgae biochar has become increasingly attractive due to its potential as a component of microalgae-based biodiesel blends. This biochar is a by-product of the pyrolysis process, but its use in the energy sector has been limited. In this study, pellets were formed using microalgae residues and their physiochemical properties were analyzed to assess the feasibility of using microalgae biochar as a fuel source. Three types of biomasses, namely date seed dust, coconut shell waste, and microalgae biochar, were utilized to produce fuel pellets. These pellets were categorized into three types, B1, B2, and B3, based on the composition of the biomass. The inclusion of microalgae biochar in the pellets resulted in enhanced calorific value, as well as improved heating value and bulk density. Moreover, the mechanical strength of microalgae-based pellets was higher due to their high lignin content compared to another biomass. The moisture absorption test results showed that the use of mixed biomass reduced the moisture content over an extended period. Microalgae pellets exhibited higher young's modulus and greater impact resistance, indicating greater mechanical strength. Furthermore, due to their higher calorific value, the combustion time of microalgae pellets was greater than that of other biomass. In conclusion, the results of this study suggest that microalgae biochar can be a promising alternative fuel source for the energy sector.

Loss of Progranulin Results in Increased Pan-Cathepsin Activity and Reduced LAMP1 Lysosomal Protein

Mutations in the progranulin (PGRN) encoding gene, GRN, cause familial frontotemporal dementia (FTD) and neuronal ceroid lipofuscinosis (NCL) and PGRN is also implicated in Parkinson's disease (PD). These mutations result in decreased PGRN expression. PGRN is highly expressed in peripheral immune cells and microglia and regulates cell growth, survival, repair, and inflammation. When PGRN is lost, the lysosome becomes dysfunctional, but the exact mechanism by which PGRN plays a role in lysosome function and how this contributes to inflammation and degeneration is not entirely understood. To better understand the role of PGRN in regulating lysosome function, this study examined how loss of GRN impacts total LAMP1 protein expression and cathepsin activities. Using mouse embryonic fibroblasts (MEFs), immunocytochemistry and immunoblotting assays were performed to analyze fluorescent signal from LAMP1 (lysosomal marker) and BMV109 (marker for pan-cathepsin activity). GRN-/- MEFs exhibit increased expression of pan-cathepsin activity relative to GRN+/+ MEFs, and significantly impacts expression of LAMP1. The significant increase in pan-cathepsin activity in the GRN-/- MEFs confirms that PGRN loss does alter cathepsin expression, which may be a result of compensatory mechanisms happening within the cell. Using NTAP PGRN added to GRN-/- MEFs, specific cathepsin activity is rescued. Further investigations should include assessing LAMP1 and BMV109 expression in microglia from GRN-/- mice, in the hopes of understanding the role of PGRN in lysosomal function in immune cells of the central nervous system and the diseases in which it is implicated.

The Myth of Man the Hunter: Women's contribution to the hunt across ethnographic contexts

The sexual division of labor among human foraging populations has typically been recognized as involving males as hunters and females as gatherers. Recent archeological research has questioned this paradigm with evidence that females hunted (and went to war) throughout the Homo sapiens lineage, though many of these authors assert the pattern of women hunting may only have occurred in the past. The current project gleans data from across the ethnographic literature to investigate the prevalence of women hunting in foraging societies in more recent times. Evidence from the past one hundred years supports archaeological finds from the Holocene that women from a broad range of cultures intentionally hunt for subsistence. These results aim to shift the male-hunter female-gatherer paradigm to account for the significant role females have in hunting, thus dramatically shifting stereotypes of labor, as well as mobility.

Daytime Sleepiness Is Associated with Lower Cognitive Scores: The Look AHEAD Study

Background

Daytime sleepiness is common in older adults and may result from poor nighttime sleep due to sleep disordered breathing, fragmented sleep, or other sleep disorders. Daytime sleepiness may be associated with cognition in older adults.

Objectives

We investigated the association between self-reported daytime sleepiness and cognitive function in the Look AHEAD clinical trial.

Design

Observational follow-up of a randomized clinical trial of an intensive lifestyle intervention.

Setting

Clinic.

Participants

Participants (n=1,778) aged 45-76 years at baseline with type 2 diabetes and overweight or obesity.

Interventions

Participants were randomized to an intensive lifestyle intervention for weight loss or a control condition of diabetes support and education.

Measurements

Participants provided self-reported levels of daytime sleepiness at baseline and years 12-13. Cognitive function was assessed with a neurocognitive battery at years 12-13 and 18-20.

Results

Participants who reported having frequent daytime sleepiness (often or always) performed significantly worse than others on the cognitive composite (-0.35; p-value=0.014) after controlling for covariates. When stratified by intervention arm, participants assigned to the intensive lifestyle intervention who reported often/always having daytime sleepiness performed worse on Digit Symbol Coding (-0.63; p-value=0.05) and Trail Making Part-B (-0.56; p-value=0.02) after controlling for covariates. Statistical interactions revealed associations between daytime sleepiness and the following covariates: race and ethnicity, APOE ε4 carrier status, baseline history of cardiovascular disease, and depression.

Conclusions

Daytime sleepiness over ~13 years predicted poorer cognitive performance in older individuals who, by virtue of having diabetes and overweight/obesity, are at high risk for sleep disorders and cognitive impairment.

Phytochemical profiling, anti-hyperglycemic, antifungal, and radicals scavenging potential of crude extracts of Athyrium asplenioides- an in-vitro approach

This research was aimed to evaluate the phytochemical profile, antifungal, anti-hyperglycemic, as well as antioxidant activity competence of different extracts of Athyrium asplenioides through in-vitro approach. The A. asplenioides crude methanol extract contained considerable quantity of pharmaceutically precious phytochemicals (saponins, tannins, quinones, flavonoid, phenols, steroid, and terpenoids) than others (acetone, ethyl acetate, and chloroform). Interestingly, the crude methanol extract showed remarkable antifungal activity against Candida species (C. krusei: 19.3 ± 2 mm > C. tropicalis: 18.4 ± 1 mm > C. albicans: 16.5 ± 1 mm > C. parapsilosis: 15.5 ± 2 mm  >  C. glabrate: 13.5 ± 2 mm > C. auris: 7.6 ± 1 mm) at a concentration of 20 mg mL-1. The crude methanol extract also showed remarkable anti-hyperglycemic activity on concentration basis. Surprisingly, remarkable free radicals scavenging potential against DPPH (76.38%) and ABTS (76.28%) free radicals at a concentration of 20 mg mL-1. According to the findings, the A. asplenioides crude methanol extract contains pharmaceutically valuable phytochemicals and may be useful for drug discovery.

Optimizing engine performance and reducing emissions of greenhouse gases through spirulina microalgae and nano-additive blends

The shift in focus towards biofuels has led to the attention towards fourth-generation fuels, particularly microalgae, due to its high oil productivity and simple cultivation processes. The current study aimed to examine the effects of spirulina microalgae blends in a naturally aspirated diesel engine by testing two blend percentages (15% and 30%) and incorporating Fe₂O₃ nanoparticles (75 ppm). A series of test conducted in a single-cylinder engine with an optimum compression ratio of 17.5. The fuels tested include 100% diesel (D0), diesel with Fe₂O₃ nanoparticles (DF), diesel with 15% microalgae blends (B15), diesel with 15% microalgae blends and Fe₂O₃ nanoparticles (B15F), diesel with 30% microalgae blends (B30), and diesel with 30% microalgae blends and Fe₂O₃ nanoparticles (B30F). The results showed that the addition of microalgae blends led to a marginal increase in engine performance, while the addition of Fe₂O₃ nanoparticles led to a significant increase in brake thermal efficiency and decreased fuel consumption. The emissions rate was also lower compared to diesel, but the addition of Fe₂O₃ nanoparticles increased the oxygen content in the fuel, thereby improving the combustion rates. By ensuring the complete combustion the formation of CO₂, HC and smoke intensity was also found to be significantly lower compared to diesel fuel. On the contrary, NOx increased due to the cylinder temperatures. This research highlights the potential of using microalgae as a sustainable source of biofuel, and the positive effects of adding Fe₂O₃ nanoparticles to enhance the fuel's efficiency.

Human macrophage-engineered vesicles for utilization in ovarian cancer treatment

Background

Ovarian cancer is a deadly female malignancy with a high rate of recurrent and chemotherapy-resistant disease. Tumor-associated macrophages (TAMs) are a significant component of the tumor microenvironment and include high levels of M2-protumor macrophages that promote chemoresistance and metastatic spread. M2 macrophages can be converted to M1 anti-tumor macrophages, representing a novel therapeutic approach. Vesicles engineered from M1 macrophages (MEVs) are a novel method for converting M2 macrophages to M1 phenotype-like macrophages.

Methods

Macrophages were isolated and cultured from human peripheral blood mononuclear cells. Macrophages were stimulated to M1 or M2 phenotypes utilizing LPS/IFN-γ and IL-4/IL-13, respectively. M1 MEVs were generated with nitrogen cavitation and ultracentrifugation. Co-culture of ovarian cancer cells with macrophages and M1 MEVs was followed by cytokine, PCR, and cell viability analysis. Murine macrophage cell line, RAW264.7 cells were cultured and used to generate M1 MEVs for use in ovarian cancer xenograft models.

Results

M1 MEVs can effectively convert M2 macrophages to an M1-like state both in isolation and when co-cultured with ovarian cancer cells in vitro, resulting in a reduced ovarian cancer cell viability. Additionally, RAW264.7 M1 MEVs can localize to ovarian cancer tumor xenografts in mice.

Conclusion

Human M1 MEVs can repolarize M2 macrophages to a M1 state and have anti-cancer activity against ovarian cancer cell lines. RAW264.7 M1 MEVs localize to tumor xenografts in vivo murine models.

Molecular Tumor Board-Assisted Care in an Advanced Cancer Population: Results of a Phase II Clinical Trial

PURPOSE

Multidisciplinary molecular tumor boards (MTBs) interpret next-generation sequencing reports and help oncologists determine best therapeutic options; however, there is a paucity of data regarding their clinical utility. The purpose of this study was to determine if MTB-directed therapy improves progression-free survival (PFS) over immediately prior therapy in patients with advanced cancer.

METHODS

This single-arm, prospective phase II clinical trial enrolled patients with advanced cancer with an actionable mutation who received MTB-recommended targeted therapy between January 1, 2017, and October 31, 2020. MTB-recommended both on-label (level 1 evidence) and off-label (evidence levels 2 and 3) therapies. Of the 93 enrolled patients, 43 were treated frontline and 50 received second-line or greater-line therapy. The primary outcome was the probability of patients treated with second-line or greater-line MTB-directed therapy who achieved a PFS ratio ≥ 1.3 (PFS on MTB-directed therapy divided by PFS on the patient's immediately prior therapy). Secondary outcomes included PFS for patients treated frontline and overall survival and adverse effects for the entire study population.

RESULTS

The most common disease sites were lung (35 of 93, 38%), gynecologic (17 of 93, 18%), GI (16 of 93, 17%), and head and neck (7 of 93, 8%). The Kaplan-Meier estimate of the probability of PFS ratio ≥ 1.3 was 0.59 (95% CI, 0.47 to 0.75) for patients treated with second-line or greater-line MTB-directed therapy. The median PFS was 449 (range 42-1,125) days for patients treated frontline. The median overall survival was 768 (range 22-1,240) days. There were four nontreatment-related deaths.

CONCLUSION

When treated with MTB-directed therapy, most patients experienced improved PFS compared with immediately prior treatment. MTB-directed targeted therapy may be a strategy to improve outcomes for patients with advanced cancer.

Treatment of heavy metals containing wastewater using biodegradable adsorbents: A review of mechanism and future trends

The direct disposal of industrial effluents into the aquatic system is considered as a significant environmental hazard in many countries. Because of poisonous chemicals, substantial volumes of effluent release, as well as the lack of adequate of conventional treatment methodologies, industrial effluent treatment is extremely difficult. Numerous researchers have been interested in adsorption technology for its high efficiency of pollutant removal, low cost, and abundantly available adsorbent. Various adsorbent materials, both natural and modified form, have been widely used for the removal of toxic contaminants from industrial effluent. This paper highlights recent advancements in multiple modification types to functionalize the adsorbent material, resulting in higher adsorption capacity on various toxic pollutants. This review provides an overview of the adsorption mechanism and parameters (pH, adsorbent dosage, initial concentration, temperature and interaction time), which influencing the removal efficiency of adsorbents. Furthermore, this review compiles the desorption study to recover the adsorbent and improve the cycle's financial viability. This review provides a concise overview of the future directions and outlook in the framework of adsorbent application for industrial wastewater treatment.

Molecular Tumor Board Review and Improved Overall Survival in Non-Small-Cell Lung Cancer

With the introduction of precision medicine, treatment options for non-small-cell lung cancer have improved dramatically; however, underutilization, especially in disadvantaged patients, like those living in rural Appalachian regions, is associated with poorer survival. Molecular tumor boards (MTBs) represent a strategy to increase precision medicine use. UK HealthCare at the University of Kentucky (UK) implemented a statewide MTB in January 2017. We wanted to test the impact of UK MTB review on overall survival in Appalachian and other regions in Kentucky.

METHODS

We performed a case-control study of Kentucky patients newly diagnosed with non-small-cell lung cancer between 2017 and 2019. Cases were reviewed by the UK MTB and were compared with controls without UK MTB review. Controls were identified from the Kentucky Cancer Registry and propensity-matched to cases. The primary end point was the association between MTB review and overall patient survival.

RESULTS

Overall, 956 patients were included, with 343 (39%) residing in an Appalachian region. Seventy-seven (8.1%) were reviewed by the MTB and classified as cases. Cox regression analysis showed that poorer survival outcome was associated with lack of MTB review (hazard ratio [HR] = 8.61; 95% CI, 3.83 to 19.31; P < .0001) and living in an Appalachian region (hazard ratio = 1.43; 95% CI, 1.17 to 1.75; P = .004). Among individuals with MTB review, survival outcomes were similar regardless of whether they lived in Appalachia or other parts of Kentucky.

CONCLUSION

MTB review is an independent positive predictor of overall survival regardless of residence location. MTBs may help overcome some health disparities for disadvantaged populations.

A Framework for Developing Pharmacotherapy for Agitation in Alzheimer's Disease: Recommendations of the ISCTM* Working Group

Dementia is characterized by a significant decline in one of several cognitive domains such as memory, language and executive function, affecting independence and representing a significant deterioration from a previous level of functioning (1). Alzheimer’s Disease (AD) represents the most common form of dementia and contributes up to 70% of the almost 50 million dementia cases worldwide, a number that is projected to double in 20 years (2).

OP0033 REGULATORY T CELL CD39 EXPRESSION AS A PREDICTOR OF EARLY REMISSION-INDUCTION WITH METHOTREXATE IN NEW-ONSET RHEUMATOID ARTHRITIS

Background:

The long term outcomes for patients with rheumatoid arthritis (RA) depend on early and effective disease control. Methotrexate remains the key first line disease modifying therapy for the majority of patients, with 40% achieving an ACR50 on monotherapy(1). There are at present no effective biomarkers to predict treatment response, preventing effective personalisation of therapy. A putative mechanism of action of methotrexate, the potentiation of anti-inflammatory adenosine signalling, may inform biomarker discovery. By antagonism of the ATIC enzyme in the purine synthesis pathway, methotrexate has been proposed to increase the release of adenosine moieties from cells, which exert an anti-inflammatory effect through interaction with ADORA2 receptors(2). Lower expression of CD39 (a cell surface 5-’ectonucleotidase required for the first step in the conversion of ATP to adenosine) on circulating regulatory T-Lymphocytes (Tregs) was previously identified in patients already established on methotrexate who were not responding (DAS28 >4.0 vs <3.0)(3). We therefore hypothesised that pre-treatment CD39 expression on these cells may have clinical utility as a predictor of early methotrexate efficacy.

Objectives:

To characterise CD39 expression in peripheral blood mononuclear cells in RA patients naïve to disease modifying therapy commencing methotrexate, and relate this expression to 4 variable DAS28CRP remission (<2.6) at 6 months.

Methods:

68 treatment naïve early RA patients starting methotrexate were recruited from the Newcastle Early Arthritis Clinic and followed up for 6 months. Serial blood samples were taken before and during methotrexate therapy with peripheral blood mononuclear cells isolated by density centrifugation. Expression of CD39 by major immune subsets (CD4+ and CD8+ T-cells, B-lymphocytes, natural killer cells and monocytes) was determined by flow cytometry. The statistical analysis used was binomial logistic regression with baseline DAS28CRP used as a covariate due to the significant association of baseline disease activity with treatment response.

Results:

Higher pre-treatment CD39 expression was observed in circulating CD4+ T-cells of patients who subsequently achieved clinical remission at 6 months versus those who did not (median fluorescence 4854.0 vs 3324.2; p = 0.0108; Figure 1-A). This CD39 expression pattern was primarily accounted for by the CD4+CD25 high sub-population (median fluorescence 9804.7 vs 6455.5; p = 0.0065; Figure 1-B). These CD25 high cells were observed to have higher FoxP3 and lower CD127 expression than their CD39 negative counterparts, indicating a Treg phenotype. No significant associations were observed with any other circulating subset. A ROC curve demonstrates the discriminative utility of differential CD39 expression in the CD4+CD25 high population for the prediction of DAS28CRP remission in this cohort, showing greater specificity than sensitivity for remission prediction(AUC: 0.725; 95% CI: 0.53 - 0.92; Figure 1-C). Longitudinally, no significant induction or suppression of the CD39 marker was observed amongst patients who did or did not achieve remission over the 6 months follow-up period.

Figure 1.

Six month DAS28CRP remission versus pre-treatment median fluorescence of CD39 expression on CD4+ T-cells (A); CD25 High expressing CD4+ T-cells (B); and ROC curve of predictive utility of pre-treatment CD39 expression on CD25 High CD4+ T-cells (C).

Conclusion:

These findings support the potential role of CD39 in the mechanism of methotrexate response. Expression of CD39 on circulating Tregs in treatment-naïve RA patients may have particular value in identifying early RA patients likely to respond to methotrexate, and hence add value to evolving multi-parameter discriminatory algorithms.

References:

[1]Hazlewood GS, et al. BMJ. 2016 21;353:i1777

[2]Brown PM, et al. Nat Rev Rheumatol. 2016;12(12):731-742

[3]Peres RS, et al. Proc Natl Acad Sci U S A. 2015;112(8):2509-2514

Disclosure of Interests:

None declared

AB0025 CITRULLINATED-PEPTIDE SPECIFIC CD4+ T CELL RESPONSES IN RHEUMATOID ARHRITIS

Background:

CD4+ T cells reacting to post-translationally modified, citrullinated self-antigens are thought to play a central role in the pathogenesis of rheumatoid arthritis (RA)1. This is evidenced by a strong HLA class II association, the success of therapeutic co-stimulation blockade and the detection of autoantigen specific T-cells using HLA class II multimers2. These cells may represent a target for antigen-specific, tolerogenic therapies and their in-depth phenotyping may provide the means by which to monitor such treatment.

Objectives:

To identify the citrullinated-peptide (cit-peptide) induced cytokine repertoire of antigen-specific memory CD4+ T cells in both healthy controls (HCs) and ACPA positive RA patients using intracellular cytokine staining and flow cytometry. Of note, the HLA-types of both HCs and RA patients were not known.

Methods:

Cryopreserved peripheral blood mononuclear cells (PBMC) from both HCs (n = 8) and RA patients (n = 13) with both early (untreated) and established disease were thawed and labelled with a proliferation tracking dye (PTD). Labelled PBMC were then either incubated alone or with a pool of cit-peptides for 9-days, followed by a 5-hour restimulation with PMA and ionomycin, where cytokine secretion was blocked for the final 4-hours using brefeldin-A. Cells were then harvested, permeabilised and stained for T cell surface markers and intracellular cytokines including IFN-γ, IL-4, IL-21 and IL-17. Stained cells were immediately acquired using a BD Fortessa X20, where antigen-specific CD4+ T cells were identified as the viable CD45RO+ (memory) CD4+ T cell population that had proliferated (PTDlow) in response to the cit-peptides. Stimulation indices (SI) were calculated as the percentage of proliferated memory CD4+ T cells in the stimulated wells divided by the percentage in the unstimulated conditions, and cit-peptide responders were defined as those with an SI > 2.0. Net cytokine production was measured by subtracting the percentage cytokine production from unstimulated CD4+ CD45RO+ PTDlow cells, from those stimulated with the cit-peptides.

Results:

Comparable proliferative responses were observed in both donor groups in response to stimulation with the cit-peptide pool, where 37 % of HCs and 31 % of RA patients responded with an SI > 2.0 (Fig. 1A). While little cytokine production was observed in the cit-peptide responding HC T cells, for responding RA donors, cit-peptide responsive CD4+ memory T cells were predominantly IFN-γ and IL-21 producing (Fig. 1B and 1C). In contrast, these donors did not produce significant levels of either IL-17 or IL-4 (Fig. 1D and 1E).

Conclusion:

Cit-peptides were able to induce proliferation in both HCs and RA memory CD4+ T cells which, amongst the RA donors only, were of a Th1/Tfh subtype. In contrast, and while based only on a small sample, cit-peptides did not induce either IL-17 or IL-4 production in either donor group, suggesting a lack of Th17/Th2 responses. Not all donors responded to the peptide pool, possibly reflecting the limited number of pooled cit-peptides or to a lack of confirmed HLA-DRB1*04:01 positive donors, as peptides were selected for their specificity on this basis. Future work will therefore include HLA-typing, as well as the inclusion of additional citrullinated-epitopes to demonstrate autoreactivity in a wider cross-section of patients. Further phenotyping of the cit-peptide specific T cells will be performed, and future plans will be to study the assay data alongside clinical outcomes to assess its value for immune monitoring.

References:

[1]Malmström, V et al Nat Rev Immunol. 2017; 17(1):60-75.

[2]Gerstner, C et al BMC Immunol. 2020; 21(27):1-14.

Disclosure of Interests:

Jessica Swift: None declared, James Stanway: None declared, Ioana Nicorescu: None declared, Catharien Hilkens: None declared, Frederik Stevenaert Employee of: Janssen, Amy Anderson Grant/research support from: Pfizer, GSK and Janssen, Arthur Pratt Grant/research support from: Pfizer, GSK and Janssen, John D Isaacs Speakers bureau: Abbvie, Gilead, Roche, UC, Consultant of: Abbvie, Gilead, Roche, UC, Grant/research support from: Pfizer, GSK and Janssen

Figure 1.

Citrullinated-peptide specific memory CD4+ T cell proliferation (A) and net % cytokine production of IFN-γ (B), IL-21 (C), IL-17 (D) and IL-4 (E) positive cells.

Young Adults' Perspectives of Childhood Food Allergies: Implications for School Nurses

The primary goal of this study was to examine young adults' perspectives about the effects of their food allergies (FAs) on their social lives from school-age to young adulthood. Young adults aged 18-21 (n = 10) at the University of South Carolina were interviewed. A qualitative descriptive method to find themes and commonalities from transcribed interviews was used for data analysis. Identified themes were (1) feeling different and being isolated, (2) strategies for managing feeling different and being isolated, (3) strategies for managing safety, and (4) acceptance of myself and by others. School-age children attributed the school lunch allergy table as contributing to social isolation. Additionally, participants described feeling different and concerns about safety. Strategies to mitigate those experiences were identified by participants. Implications for children with FAs, their parents, school nurses, and other education and health professionals who work with children are presented.

High somatostatin receptor expression and efficacy of somatostatin analogues in patients with metastatic Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive, high-grade, cutaneous neuroendocrine tumour (NET). Agents blocking programmed death 1/programmed death ligand 1 have efficacy in metastatic MCC (mMCC), but half of patients do not derive durable benefit. Somatostatin analogues (SSAs) are commonly used to treat low- and moderate-grade NETs that express somatostatin receptors (SSTRs).

OBJECTIVES

To assess SSTR expression and the efficacy of SSAs in mMCC, a high-grade NET. Methods In this retrospective study of 40 patients with mMCC, SSTR expression was assessed radiologically by somatostatin receptor scintigraphy (SRS; n = 39) and/or immunohistochemically when feasible (n = 9). Nineteen patients (18 had SRS uptake in MCC tumours) were treated with SSA. Disease control was defined as progression-free survival (PFS) of ≥ 120 days after initiation of SSA.

RESULTS

Thirty-three of 39 patients (85%) had some degree (low 52%, moderate 23%, high 10%) of SRS uptake. Of 19 patients treated with SSA, seven had a response-evaluable target lesion; three of these seven patients (43%) experienced disease control, with a median PFS of 237 days (range 152-358). Twelve of 19 patients did not have a response-evaluable lesion due to antecedent radiation; five of these 12 (42%) experienced disease control (median PFS of 429 days, range 143-1757). The degree of SSTR expression (determined by SRS and/or immunohistochemistry) did not correlate significantly with the efficacy endpoints.

CONCLUSIONS

In contrast to other high-grade NETs, mMCC tumours appear frequently to express SSTRs. SSAs can lead to clinically meaningful disease control with minimal side-effects. Targeting of SSTRs using SSA or other novel approaches should be explored further for mMCC.

THU0026 CLONAL HAEMATOPOIESIS ASSOCIATED SOMATIC MUTATIONS IN RHEUMATOID ARTHRITIS

Background:

Clonal haematopoiesis of indeterminate potential (CHIP) occurs when somatic mutations arise in myeloid neoplasia driver genes of haematopoietic progenitor cells, in the absence of overt cytopenia or dysplasia. The prevalence of CHIP increases with age. The most common genes affected by CHIP mutations in unselected populations are DNMT3A, ASXL1, and TET2. The presence of CHIP is linked to increased basal level of inflammation and a high risk of cardiovascular disease and all-cause mortality. Rheumatoid arthritis (RA) is one of the most common and debilitating multi-system autoimmune disorders, affecting up to 1% of adults in developed countries. The role of somatic mutations in the pathogenesis of autoimmune diseases is an unexplored area; therefore, we aimed to test the hypothesis that clonal haematopoiesis (CH) is associated with the incidence and severity of RA.

Objectives:

To evaluate the association of CH somatic mutation with severity of RA.

Methods:

163 RA patients were recruited from the following cohorts: (i)Early RA/treatment naive (n=31), (ii)Refractory RA - non-responders to Disease-Modifying Anti-Rheumatic Drugs (DMARDs) and biologics (n=48), (ii)Flare (n=41) vsRemission patients (n=43) –patients treated with DMARDs and withdrawn from treatment on achieving remission. Six months later, 50% relapse and 50% sustain remission. Single molecule molecular inversion probes (smMIPs) were used to screen for somatic mutations in 40 loci known to carry clonal haematopoiesis driver mutations (CHDMs). Whole exome sequencing was also performed on Flare/Remission patients (n = 84) to screen for CHDMs and other somatic mutations. In-house bioinformatics pipelines were used to call mutations from both the datasets.

Results:

We identified CH in RA with an overall prevalence of 14%. Twenty-four unique variants with a variant allele frequency (VAF) of 2-35% were found in ten genes including ASXL1, CBL, DNMT3A, GNAS, GNB1, PTPN11, PTPN12, SF3B1, TET2, and TP53. The number of unique patients carrying mutations in these genes are follows:refractory: n=12/48, flare: n=6/41,remission: n=4/43 andearly RA: n=2/31. The majority of the mutations occurred in DNMT3A (n=6) followed by TP53 (N=4) and TET2 (n=3). Two variants with VAF of 15% were identified in two patients under the age of 30, both with clinically severe disease. In patients between the ages of 50-59 yrs., 60-69 yrs., and 70-79 yrs., CH was observed at 11% (4/35), 23% (11/46) and 17%(7/41), respectively.

Conclusion:

We here report the prevalence of CH in RA, affecting more patients with clinically advanced/refractory disease compared to those with early/less severe disease.

Further study will be conducted to confirm the results.

References:

[1]Acuna-Hidalgo, R., Sengul, H., Steehouwer, M., van de Vorst, M., Vermeulen, S., & Kiemeney, L. et al. (2017). Ultra-sensitive Sequencing Identifies High Prevalence of Clonal Hematopoiesis-Associated Mutations throughout Adult Life.The American Journal Of Human Genetics,101(1), 50-64. doi: 10.1016/j.ajhg.2017.05.013

[2]NRAS - National Rheumatoid Arthritis Society. (2020). Retrieved 30 January 2020, fromhttps://www.nras.org.uk/what-is-ra-article

[3]Steensma, D., Bejar, R., Jaiswal, S., Lindsley, R., Sekeres, M., Hasserjian, R., & Ebert, B. (2015). Clonal hematopoiesis of indeterminate potential and its distinction from myelodysplastic syndromes.Blood,126(1), 9-16. doi: 10.1182/blood-2015-03-631747

Acknowledgments:

National Institute for Health Research, United Kingdom

Disclosure of Interests:

Fareeha Tariq: None declared, Bilal Alobaidi: None declared, Miguel Xavier: None declared, Michael McCorkindale: None declared, Joris Veltman: None declared, John Isaacs Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche, Arthur Pratt Grant/research support from: Pfizer, GSK, Amy Anderson: None declared, Matthew Collin: None declared

SAT0013 PIM-1 KINASE IS A MEASURABLE MEDIATOR OF CD4+ T CELL DYSREGULATION AND THERAPEUTIC TARGET IN EARLY RHEUMATOID ARTHRITIS

Background:

As well as being an established oncoprotein and a therapeutic target in cancer,Proviral Integration site for murine Moloney leukemia virus-1(pim-1) has been implicated in human autoimmunity. We previously confirmed this serine-threonine protein kinase to be strikingly upregulated in circulating CD4+ T cells of untreated rheumatoid arthritis (RA) patients as a consequence of IL-6 signalling1-2. Evidence for the relevance of pim-1 signalling in the disruption of RA synovial fibroblast (RASF) homeostasis3further supports its candidacy as a therapeutic target.

Objectives:

To investigate PIM1 and its family members (PIM2 and PIM3) as potential candidates for drug repurposing in RA.

Methods:

A flow cytometric assay for PIM1 transcript measurement in circulating CD4+ T cells of early arthritis patients was validated against real-time PCR in paired cells isolated by bead selection. Synovial protein expression in tissue from the same cohort of untreated RA patients and disease controls was determined by quantitative multiplex immunofluorescence. The functional consequences of manipulating pim kinase family expression in freshly purified T cell receptor (TCR)-stimulated CD4+ T cells from early RA patients was explored. The impact of pim-1 specific and pim-1-3 (pan-pim) kinase inhibition on progression of the IL-6 dependent collagen-induced arthritis (CIA) model was assessed.

Results:

The percentage of circulating CD4+ T cells positive forPIM1transcript by flow cytometry proved a faithful surrogate for gene expression in early arthritis (Figure 1A), distinguishing RA from other pathologies (Figure 1B). Pim-1 protein expression was increased in the synovium of untreated RA compared with disease controls, including amongst infiltrating CD4+ T cells (Figure 1C-D).In vitro, exposure of TCR-stimulated early RA CD4+ T cells to pim kinase inhibitors restrained their activation and proliferative capacity; diminished pro-inflammatory cytokine production (IFN-g and IL-17) and an expanded CD25hiFoxP3+ regulatory T cell (Treg) fraction were also observed in treatedversusun-treated cells. Finally, administration of pim inhibitors robustly attenuated clinical scores of arthritis in the CIA model, with reduced cartilage loss observed in animals treated with a pan-PIM inhibitor compared with vehicle control (Figure 2).

Conclusion:

Our data highlight pim kinases as plausible therapeutic targets for a subgroup of early RA patients that may be identifiable using tractable in vitro assays. Pim kinase inhibitors could simultaneously target immune inflammation and RASF dysregulation; consideration should now be given to their repurposing for this condition.

References:

[1] Anderson AE et al Annals of the Rheumatic Diseases 2016; 75:466-73.

[2] Anderson AE et al Rheumatology 2019; 58:1250-1258

[3] Ha YJ et al Rheumatology 2019; 58:154-64

Disclosure of Interests:

Nicola Maney Consultant of: Current employee of Eli Lilly, Henrique De Paula-Lemos: None declared, Ben Barron-Millar: None declared, Andrew Mellor Shareholder of: NewLink Genetics PLC, and has received patent licensing income from this source., John D Isaacs Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche, Amy Anderson: None declared, Arthur Pratt Grant/research support from: Pfizer, GlaxoSmithKlein

OP0129 AUTOREACTIVE, CITRULLINATED PEPTIDE-SPECIFIC T CELLS IN RHEUMATOID ARTHRITIS

Background:

Self-reactive CD4+ T cells are thought to play a key role in the pathogenesis of rheumatoid arthritis (RA) and represent a target for antigen-specific, tolerogenic therapies1. Phenotyping such cells could provide the means with which to monitor these treatments. Here, we aimed to demonstrate antigen-induced T cell responses to RA relevant epitopes using peptide stimulation of peripheral blood mononuclear cells (PBMC). Several autoantigens have been described in RA, including various citrullinated peptide (cit-peptide) epitopes2; here we have used a combination of cit-peptides that will be used to load tolerogenic dendritic cells in a forthcoming experimental medicine study (AuToDeCRA II).

Objectives:

To detect peripheral blood T cell proliferation in response to candidate autoantigens in RA patients and healthy controls (HCs) using flow cytometry.

Methods:

PBMC from RA patients and HCs were obtained following informed consent and were cryopreserved. Prior to use, cells were thawed in medium supplemented with human serum and were labelled with a proliferation tracking dye (PTD). 2x105labelled cells were plated into 96 well plates with a minimum of 7 replicates per condition and were either cultured alone or stimulated with individual peptides at varying concentrations or a peptide pool. On day 9, cells from replicate wells were harvested, pooled and stained for surface markers and viability. Samples were acquired on a BD Fortessa X20 and analysis was performed in FlowJo version 10. A manual gating strategy was used to identify CD45RO+ (memory) CD4+ T cells and amongst this population, activated/proliferated cells were defined as CD25+ PTD low. Stimulation indices (SI) were calculated as the percentage of activated/proliferated cells from stimulated wells divided by the percentage from unstimulated wells.

Results:

Ten RA patients (including early and established disease) were recruited alongside seven HCs. Cit-peptides were initially titrated on an individual basis to determine the optimum concentration for use (n = 2). We then compared stimulation with either single peptides or a pool (n = 2), and found that PBMC stimulated with the pooled cit-peptides had a higher proliferative response. Both single and pooled cit-peptide induced T cell proliferation was observed in both RA and HC samples (Figure 1); the largest responses were seen amongst RA patients, with a maximum stimulation index of 52.4 compared to a maximum of 6.75 in the HC group. Only 1 HC sample responded with an SI greater than 3.0, whereas 50 % of RA patients elicited responses above this. Two of the RA patients failed to respond to the peptide pool (SI < 1.0). Of note, RA patients were not selected on the basis of tissue type whereas selected peptides bind preferentially to class II HLA containing the shared epitope (SE).

Figure 1

Antigen-specific CD4+ CD45RO+ responses of citrullinated peptide stimulated PBMC from HCs and RA patients.

Conclusion:

In non-HLA typed individuals, cit-peptide induced proliferative T cell responses were detectable in both RA patients and HCs, and although SIs overall were higher amongst RA patients this did not reach statistical significance in this small sample. Not all RA patients responded to the peptide pool which may be due to the limited number of citrullinated epitopes used, or to RA patients with a non-SE HLA type. Additional work should establish the need for HLA typing in this assay; around half of seropositive RA patients would be expected to be SE positive3. Furthermore, a wider array of cit-peptides may be needed to demonstrate autoreactivity in a broader cross-section of RA patients. Our future plans are to further phenotype the cellular subsets responding to the peptide pool and to study assay data in the context of clinical outcomes, to assess its utility for immune monitoring.

References:

[1]McInnes, I. B. & Schett, G. N Engl J Med. 2011; 365(23):2205-2219

[2]James, E. Aet al. Arthritis Rheum. 2014; 66(7):1712-1722

[3]Thomson, Wet al. Arthritis Rheum. 1999; 42(4):757-762

Disclosure of Interests:

Jessica Swift: None declared, James Stanway: None declared, Catharien Hilkens: None declared, Amy Anderson: None declared, Arthur Pratt Grant/research support from: Pfizer, GlaxoSmithKlein, John Isaacs Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche

THU0005 VARIABILITY OF DNA METHYLATION IS A DRIVER OF LYMPHOCYTE DYSREGULATION IN EARLY RHEUMATOID ARTHRITIS

Background:

DNA methylation patterns differ between leukocyte subsets and mediate the impact of environmental exposures on the molecular and functional phenotype of immune cells. Besides differences in mean methylation of CpG positions amongst patients with immune mediated diseases, recent evidence indicates variability of site-specific DNA methylation also contributes to pathogenesis1,2.

Objectives:

To seek evidence of altered DNA methylation patterns in RA, controlling for systemic inflammation and immunotherapy use.

Methods:

Patients with confirmed clinical diagnoses were enrolled from the Northeast Early Arthritis Cohort (NEAC). CD4+and CD19+lymphocytes were isolated from fresh blood by positive selection prior to therapeutic immune modulation. Methylation was quantified in cell subset-specific DNA (Infinium MethylationEPIC BeadChip, Illumina)3. Differentially methylated positions and regions (DMPs, DMRs) between RA and non-RA patients were identified (linear modelling, filtering on 5% pairwise difference in mean DNA methylation, and DMRcate package). Next, to identify instances where methylation variance differed between comparator groups, Bartlett’s test was performed using the iEVORA package, which accounts for outlier values4. Findings were controlled for technical confounders and subject to multiple test correction (FDR). A validated hypergeometric test was used to annotate enriched pathways.

Results:

After sample- and probe-level quality control, CD4+ and B lymphocyte specific data were respectively available for 45 and 49 RA patients, and 64 and 81 disease controls matched for systemic inflammation (CRP, ESR). No DMPs were identified in either cell type at FDR < 0.05 and Δβ ≥0.05. Only following relaxation of multiple test correction was it possible to identify DMRs in either cell type, most notably encapsulating 10 CpGs relatively hypomethylated at the promoter of the endosome protein-encodingRUFY1gene in CD4+ lymphocytes of RA patients (Δβ = 0.076). By contrast, striking evidence for differential variation in DNA methylation was observed at 291 and 601 CpGs of CD4+ and B lymphocytes, respectively (exemplars depicted in Figure 1). Only 15 of these differentially variable positions (DVPs) were common to both cell types. Pathway analysis highlighted potential functional consequences of DVP associations; for example, RA-specific hypervariability implicates prostaglandinsignalling in CD4+ lymphocytes.

Conclusion:

We highlight a role for altered variability in DNA methylation during the molecular pathogenesis of RA, and emphasise the importance of its study in relevant cell subsets.

References:

[1]Paul DSet al. Nature Communications 7, 13555 doi: 10.1038/ncomms13555 (2016).

[2]Webster AP et al. Genome Medicine 10, 64 (2018)doi:10.1186/s13073-018-0575-9.

[3]Clark AD et al. Journal of Allergy and Clinical Immunology 2019; doi: 10.1016/j.jaci.2019.12.910

[4]Teschendorff AE et al. Nature Communications 2016; 7:12.

Disclosure of Interests:

Alexander Clark: None declared, Najib Naamane: None declared, Nisha Nair: None declared, Amy Anderson: None declared, Nishanthi Thalayasingam: None declared, Julie Diboll: None declared, Anne Barton Consultant of: AbbVie, Stephen Eyre: None declared, John D Isaacs Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche, Louise Reynard: None declared, Arthur Pratt Grant/research support from: Pfizer, GlaxoSmithKlein