Assessing Bladder Radiotherapy Response With Quantitative Diffusion-Weighted Magnetic Resonance Imaging Analysis

AIMS

Radiotherapy with radiosensitisation offers opportunity for cure with organ preservation in muscle-invasive bladder cancer (MIBC). Treatment response assessment and follow-up are reliant on regular endoscopic evaluation of the retained bladder. In this study we aim to determine the role of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) analysis to assess bladder radiotherapy response.

MATERIALS AND METHODS

Patients with T2-T4aN0-3M0 MIBC suitable for radical radiotherapy were recruited prospectively to an ethics approved protocol. Following transurethral resection of the bladder tumour and prior to any treatment, magnetic resonance imaging including DWI was performed on a 1.5T system using b values of 0, 100, 150, 250, 500, 750 s/mm2. DWI was repeated 3 months after completing radiotherapy. Cystoscopy and tumour site biopsy were undertaken following this. The response was dichotomised into response (

RESULTS

Thirty-four patients were evaluated. Response was associated with a significant increase in ΔADC mean compared with poor response at ΔADCall (0.57 × 10-3 mm2/s versus -0.01 × 10-3 mm2/s; P < 0.0001) and ΔADCb100 (0.58 × 10-3 mm2/s versus -0.10 x 10-3 mm2/s; P = 0.007). A 48.50% increase in %ΔADCall mean was seen in response compared with a 1.37% decrease in poor response (P < 0.0001). This corresponded to a %ΔADCb100 mean increase of 50.34% in response versus a 7.36% decrease for poor response (P < 0.0001). Significant area under the curve (AUC) values predictive of radiotherapy response were identified at ΔADC and %ΔADC for ADCall and ADCb100 mean, 10th, 25th, 50th, 75th and 90th percentiles (AUC >0.9, P < 0.01). ΔADCall mean of 0.16 × 10-3 mm2/s and ΔADCb100 mean 0.12 × 10-3 mm2/s predicted radiotherapy response with sensitivity/specificity/positive predictive value/negative predictive value of 92.9%/100.0%/100.0%/75.0% and 89.3%/100.0%/100.0%/66.7%, respectively.

CONCLUSIONS

Quantitative DWI analysis can successfully provide non-invasive assessment of bladder radiotherapy response. Multicentre validation is required before prospective testing to inform MIBC radiotherapy follow-up schedules and decision making.

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Key Words

• Bladder cancer
• Diffusion-weighted MRI
• MRI
• Radiotherapy

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MESH Headings

• Diffusion Magnetic Resonance Imaging/methods
• Humans
• Magnetic Resonance Imaging
• Prospective Studies
• ROC Curve
• Urinary Bladder/diagnostic imaging
• Urinary Bladder Neoplasms/diagnostic imaging
• Urinary Bladder Neoplasms/pathology
• Urinary Bladder Neoplasms/radiotherapy

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Grants

• 28724 Cancer Research UK
• C33589/A19727 Cancer Research UK
• Department of Health
• C33589/A28284 Cancer Research UK

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In vivo tumor immune microenvironment phenotypes correlate with inflammation and vasculature to predict immunotherapy response

Response to immunotherapies can be variable and unpredictable. Pathology-based phenotyping of tumors into ‘hot’ and ‘cold’ is static, relying solely on T-cell infiltration in single-time single-site biopsies, resulting in suboptimal treatment response prediction. Dynamic vascular events (tumor angiogenesis, leukocyte trafficking) within tumor immune microenvironment (TiME) also influence anti-tumor immunity and treatment response. Here, we report dynamic cellular-level TiME phenotyping in vivo that combines inflammation profiles with vascular features through non-invasive reflectance confocal microscopic imaging. In skin cancer patients, we demonstrate three main TiME phenotypes that correlate with gene and protein expression, and response to toll-like receptor agonist immune-therapy. Notably, phenotypes with high inflammation associate with immunostimulatory signatures and those with high vasculature with angiogenic and endothelial anergy signatures. Moreover, phenotypes with high inflammation and low vasculature demonstrate the best treatment response. This non-invasive in vivo phenotyping approach integrating dynamic vasculature with inflammation serves as a reliable predictor of response to topical immune-therapy in patients.

Standard assessment of immune infiltration of biopsies is not sufficient to accurately predict response to immunotherapy. Here, the authors show that reflectance confocal microscopy can be used to quantify dynamic vasculature and inflammatory features to better predict treatment response in skin cancers.

Time Series Simulation and Forecasting of Air Quality Using In-situ and Satellite-Based Observations Over an Urban Region

Air quality is directly associated with the health of society. So, it becomes essential to forecast air pollution, which assumes an imperative part in air pollution warnings and control. A time-series simulation approach was adapted for the forecasting of monthly mean ambient air pollutants (PM2.5, O3, NO2) concentration and Aerosol Optical Depth (AOD) at an urban traffic site (Mathura Road, CSIR-CRRI) in New Delhi, India. Satellite-based aerosol loading (AOD550) retrieved from the Terra MODIS (Collection 6) enhanced Deep Blue (DB) algorithm was used for further analysis. The analysis considered the average monthly mean concentration of air pollutants and AOD between 2012-2017 and, simulates the concentrations of PM2.5, O3, NO2, and AOD for the same period and then forecasts air quality for the years 2020-2023. The forecasted results were validated with 24 months of in-situ and satellite data from 2018-to and 2019. In the year 2020, observed and simulated results are in lower agreement due to the shutdown of anthropogenic activities to combat pandemic situations. Otherwise, modeled and forecasted results are in good harmony with the in-situ and satellite observations. The results also signify that the time series Autoregressive Integrated Moving Average (ARIMA) modeling approach can be an effective and simple tool for air pollution simulation and future forecast. The results are evocative concerning the forecast of near future aerosol loading information and will also be profound to address the problems.

Identifications of good and bad structural fragments of hydrazone/2,5-disubstituted-1,3,4-oxadiazole hybrids with correlation intensity index and consensus modelling using Monte Carlo based QSAR studies, their molecular docking and ADME analysis

The application of QSAR along with other in silico tools like molecular docking, and molecular dynamics provide a lot of promise for finding new treatments for life-threatening diseases like Type 2 diabetes mellitus (T2DM). The present study is an attempt to develop Monte Carlo algorithm-based QSAR models using freely available CORAL software. The experimental data on the α-amylase inhibition by a series of benzothiazole-linked hydrazone/2,5-disubstituted-1,3,4-oxadiazole hybrids were selected as endpoint for the model generation. Initially, a total of eight QSAR models were built using correlation intensity index (CII) as a criterion of predictive potential. The model developed from split 6 using CII was the most reliable because of the highest numerical value of the determination coefficient of the validation set (r²_VAL = 0.8739). The important structural fragments responsible for altering the endpoint were also extracted from the best-built model. With the goal of improved prediction quality and lower prediction errors, the validated models were used to build consensus models. Molecular docking was used to know the binding mode and pose of the selected derivatives. Further, to get insight into their metabolism by living beings, ADME studies were investigated using internet freeware, SwissADME.

Radiation Dosimetry of Theragnostic Pairs for Isotopes of Iodine in IAZA

Theragnostic pairs of isotopes are used to infer radiation dosimetry for a therapeutic radiopharmaceutical from a diagnostic imaging study with the same tracer molecule labelled with an isotope better suited for the imaging task. We describe the transfer of radiation dosimetry from the diagnostic radioiodine isotope ¹²³I, labelled for the hypoxia tracer molecule iodoazomycin arabinoside ([¹²³I]IAZA), to isotopes ¹³¹I (therapeutic) and ¹²⁴I (PET imaging). Uncertainties introduced by the dissimilar isotope half-lives are discussed in detail. Radioisotope dosimetries for [¹²³I]IAZA were obtained previously. These data are used here to calculate residence times for ¹³¹I and ¹²⁴I and their uncertainties. We distinguish two cases when extrapolating to infinity: purely physical decay (case A) and physical decay plus biological washout (case B). Organ doses were calculated using the MIRD schema with the OLIDNA/EXM code. Significant increases in some organ doses (in mSv per injected activity) were found for ¹³¹I and ¹²⁴I. The most affected organs were the intestinal walls, thyroid, and urinary bladder wall. Uncertainty remained similar to ¹²³I for case A but considerably greater for case B, especially for long biological half-lives (GI tract). Normal tissue dosimetries for IAZA must be considered carefully when substituting isotope species. A long biological half-life can significantly increase dosimetric uncertainties. These findings are relevant when considering PET imaging studies with [¹²⁴I]IAZA or therapeutic administration of [¹³¹I]IAZA.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Temporal Trends, Predictors, and Outcomes of Disseminated Intravascular Coagulation in Hospitalizations With Sepsis

Background

This retrospective study was conducted to analyze the temporal trends, predictors, and impact of disseminated intravascular coagulation (DIC) on outcomes among septicemic patients using a nationally representative database.

Methods

We derived data from the National Inpatient Sample (NIS) for the years 2008-2017 for adult hospitalizations due to sepsis. The primary outcomes were in-hospital mortality and discharge to facility. The Cochran-Armitage test and multivariable survey logistic regression models were used to analyze the data.

Results

Out of 12,820,000 hospitalizations due to sepsis, 153,181 (1.18%) were complicated by DIC. The incidence of DIC decreased from 2008 to 2017. In multivariable regression analysis, demographics and comorbidities were associated with higher odds of DIC. During the study period, in-hospital mortality among patients with sepsis decreased, but the attributable risk percent of in-hospital mortality due to DIC increased. We observed similar trends for discharge to facility; however, the adjusted odds of discharge to facility due to DIC remained stable over the study period.

Conclusion

Although the incidence of sepsis complicated by DIC decreased, the attributable in-hospital mortality rate due to DIC increased during the study period. We identified several predictors associated with the development of DIC in sepsis, some of which are potentially modifiable.

Chemical Composition and Biological Activities of Hedychium coccineum Buch.-Ham. ex Sm. Essential Oils from Kumaun Hills of Uttarakhand

Hedychium coccineum Buch. Ham. ex Sm. is a perennial rhizomatous herb belonging to the family Zingiberaceae. The aim of the present study was to compare the chemical composition and biological activities of H. coccineum rhizome essential oil (HCCRO) and H. coccineum aerial part essential oil (HCCAO). The plant material was subjected to hydro-distillation using Clevenger’s apparatus in order to obtain volatile oil and analyzed for its chemical constituents using GC-MS. The comparative study of the rhizome and aerial part essential oils of H. coccineum displayed that (E)-nerolidol (15.9%), bornyl acetate (13.95%), davanone B (10.9%), spathulenol (8.9%), and 1, 8-cineol (8.5%) contributed majorly to the HCCRO, while 7-hydroxyfarnesen (15.5%), α-farnesene (11.1%), α-pinene (10.9%), spathulenol (7.7%), and β-pinene (6.8%) were present as major constituents in the HCCAO. Both the essential oils were studied for their biological activities, such as nematicidal, insecticidal, herbicidal, antifungal, and antibacterial activities. The essential oils exhibited significant nematicidal activity against Meloidogyne incognita, insecticidal activity against Spodoptera litura, and moderate herbicidal activity against R. raphanistrum sub sp. sativus, and good antifungal activity against Fusarium oxysporum and Curvularialunata. Essential oils were also tested for antibacterial activity against Staphylococcus aureus and Salmonella enterica serotype Typhi. Both oils showed good to moderate activity against the tested pathogens. The significant nematicidal, insecticidal, herbicidal, antifungal, and antibacterial activities of both the essential oils might be helpful for the development of environmentally friendly pesticides that could be an alternative to synthetic pesticides in the future.

Development of Gum-Acacia-Stabilized Silver Nanoparticles Gel of Rutin against Candida albicans

Candida spp. is one of the most causative pathogens responsible for fungal infections. It is often a hospital-acquired form of sepsis with a very high number of deaths. Currently, the most effective anti-fungal agents are based on polyenes or echinocandins. However, long-term treatments or repeated use of these anti-fungals lead to therapy limitations. Current research is urgently needed to overcome existing challenges for antimicrobials from natural sources. This study aims to determine the anti-fungal activity of rutin, which has the advantage of increasing the therapeutic value. Because of its low solubility in water and oils, rutin is limited in use. To address these constraints, we encapsulated rutin in a nanocarrier system. Silver nanoparticles (SNPs) and gum acacia (GAs) are emerging as attractive components and are widely studied as biologically safe nanomaterials/carrier systems for various drugs. Still, they are barely investigated as nano-sized vectors for the targeted delivery of rutin. In the present work, GA stabilised SNPs of rutin were successfully formulated and evaluated. It was later incorporated into carbapol 940 gels and formed SNP gels. Rutin-SNPs were developed with a consistent size in the nano range of 59.67 ± 44.24 nm in size, 0.295 ± 0.014 polydispersity index (PDI), and −11.2 ± 6.66 mV zeta potential. The drug released was found to be 81. 26 ± 4.06% in 600 min by following zero-order kinetics. The rutin-SNP gel showed considerable activity against C. albicans skin candidiasis at MIC 1.56 g/mL. The developed formulation was biocompatible. This first-ever interdisciplinary study suggests that the rutin-SNPs gel could play a vital role in drug resistance in this fungal pathogen.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Comparison of Dosimetric Parameters in Dysphagia Aspiration-Related Structures and Clinical Correlation in Head and Neck Cancer Patients Treated With Radiotherapy

Introduction

Chemoradiotherapy plays a major role in the treatment of head and neck cancer (HNC). Persistent dysphagia following primary chemoradiotherapy for head and neck cancers can have a devastating effect on a patient’s quality of life. Many studies have shown that the dosimetric sparing of critical structures which were included in swallowing such as the pharyngeal constrictor muscle and larynx can provide improved functional outcomes and better quality of life. However, there are no current randomized studies confirming the benefits of such swallowing-sparing strategies. The aim is to evaluate late dysphagia after chemoradiotherapy for head and neck cancer and to examine its correlation with clinical and dosimetric parameters.

Materials and methods

The period of this prospective study was from November 2018 to March 2020. Patients were divided randomly in 1:1 ratio into two groups, group 1 and group 2, each with 25 patients. Group 1 was planned by three-dimensional conformal radiotherapy (3D-CRT) technique and group 2 was planned by intensity-modulated radiotherapy technique (IMRT) technique. Treatment was delivered after approval of radiotherapy plan. To evaluate the dose to dysphagia aspiration-related structures (DARS), these structures were contoured and dose-volume histograms were generated. Various dosimetric parameters of DARS were evaluated. Swallowing status was clinically evaluated based on the Radiation Therapy Oncology Group and the Common Terminology Criteria for Adverse Events, version 5.

Results

A significant advantage was seen with intensity-modulated radiotherapy technique (IMRT) in comparison to three-dimensional conformal radiotherapy (3D-CRT) in terms of mean dose delivered to the pharyngeal constrictor muscles (66.03 Gy vs 68.77 Gy, p=0.003). The mean dose delivered to the combined dysphagia/aspiration-related structures (DARS) was statistically significantly lower in IMRT compared to 3D-CRT (66.15 Gy vs. 70.09 Gy, p<0.001). Other dose-volumes were also reduced in IMRT group (V30: {98.64% vs. 99.88%, p=0.05}; V50: {90.49% vs. 99.02%, p=0.0002}; V60: {83.92% vs. 95.04, p=0.0002}; D50: {70 Gy vs. 71.16 Gy, p=0.001); and D80: {61.18 Gy vs. 67.39 Gy, p=0.01}. Futhermore, the clinical worsening of dysphagia was less common in IMRT group (48% vs. 80%, p=0.039).

Conclusion

IMRT can reduce the high-dose volumes received by the DARS receiving high doses by sparing these structures through optimization. This may provide a significant additional benefit that could improve dysphagia and hence the quality of life of patients with head and neck cancer.

P-394 Peripheral and uterine natural killer cell cut-off levels and their correlation in fertile controls and women with unexplained recurrent implantation failure (RIF)

Study question

What is cut-off value for peripheral and uterine natural killer (pNK, uNK) cells and any correlation between them in fertile and RIF women?

Summary answer

Cut-off values were 7% for uNK and 11.6% for pNK in fertile controls. No significant correlation observed among fertile and infertile women with RIF.

What is known already

Association of uNK and pNK cells with infertility is debatable. It is not clear whether measuring NK cell levels in RIF has a role. pNk cell levels however has been used in various studies to guide the need of immunotherapy in RIF women. Definition of normal range of uNK cell numbers has also not been stated clearly because of lack of standardised protocol. Literature reveals the cut off values for pNk cells to be 12% or 18% and for uNK cells between 5-12.9%. Correlation between uNK and pNK cells in fertile or RIF women has not been studied earlier.

Study design, size, duration

A prospective study was conducted at ART Centre, Department of Obstetrics and Gynecology at tertiary care institute during a period from January 2019 to January 2021. Thirty women with RIF and fifty fertile controls with age &lt;35 years having regular menstrual cycles and no hormonal treatment in last 3 months were enrolled in the study for uNK and pNK cell testing. The permission was obtained from the Institute Ethics Committee.

Participants/materials, setting, methods

Subjects included women with RIF with age 20-35 years, tubal and unexplained factors, normal ovarian reserve, normal karyotype and normal uterine cavity. In both subjects and controls, midluteal endometrial biopsy sample was taken for Immunohistochemistry staining of CD 56+ cells to determine uNK cells. Peripheral venous blood was also obtained at the time of biopsy for flow cytometry in peripheral blood mononuclear cells to determine pNK cells. Cut off values were derived from fertile controls.

Main results and the role of chance

The mean age and BMI were comparable between fertile control and study group(29.45±3.3 vs 31.17±3.3 years, 22.97±1.89 vs 23.21±2.2 kg/m2; p-value &gt;0.05). The control group had median value of 7% for uNK cell levels and 11.6% for pNK cell levels. In RIF subjects, the median value for uNK cells was 13.5% and even though higher compared to controls it was not statistically significant(p-value &gt;0.05) . The median pNK values were comparable among controls and RIF group (11.6% vs. 12%). All RIF subjects did not have elevated NK cell levels. 18 (60%) subjects had elevated uNK cell levels (more than 7%) whereas 40% had below the reference value. pNK cells were also elevated in only 53.3% of subject population. There was positive correlation found between uNK and pNK cell levels in RIF subjects, however it was not statistically significant (r 0.312, p-value 0.09). In fertile controls, there was insignificant negative correlation between uNK and pNK cell levels (r -0.231, p-value 0.33).

Limitations, reasons for caution

The small sample size is the foremost limitation of study.

Wider implications of the findings

uNK cell testing may be worthwhile in women with unexplained RIF so as to guide immunotherapy to improve pregnancy outcomes. As no significant correlation has been found between pNK and uNK cells in fertile and RIF women, pNK cell testing in RIF women may be done with caution.

Trial registration number

Not Applicable

Dabigatran for intracardiac thrombus, yet another promising role of a direct oral anticoagulant: a case report and short review of literature

A left ventricular (LV) thrombus is a relatively common and well-known condition associated with significant LV systolic dysfunction. However, LV thrombosis is unusual in the absence of kinetic abnormalities. The elderly gentleman presented with subacute onset of bilateral lower limb discomfort and cold extremities, but no gangrene. With normal LV function, an echocardiogram revealed a massive movable LV apical clot. He was treated with dual antiplatelets and heparin at first. He switched to dabigatran 110 mg twice a day in combination with dual antiplatelets. The thrombus had entirely vanished and leg problems had improved after a 2-week follow-up. For the next six months, he was treated with aspirin and dabigatran and was asymptomatic at follow-up. There are no specific guidelines for treating an intracardiac thrombus. Experts agree that a hypermobile and pedunculated LV thrombus with a high embolic risk should be surgically removed as soon as possible. According to ESC/ACC guidelines, all patients with LV thrombus associated with myocardial infarction should be treated with anticoagulation. Warfarin requires regular International Normalized Ratio (INR) monitoring and has a small therapeutic window; hence a direct oral anticoagulant (DOAC) could be a viable therapeutic solution. However, there are no guideline recommendations to date to guide DOAC therapy for this indication.

Spatiotemporal representativeness of air pollution monitoring in Dublin, Ireland

The importance of selecting appropriate air pollution monitoring sites in a city is vital for accurately reporting air quality, enhancing the quality of high-resolution modelling and informing policy to implement measures to deliver cleaner air in the urban environment. COVID-19 restrictions impacted air quality in urban centres worldwide as reduced mobility led to changes in traffic-related air pollution (TRAP). As such, it offered a unique dataset to examine the spatial and temporal variations in air quality between monitoring stations in Dublin, Ireland. Firstly, an analysis of mobility data showed reductions across almost all sectors after COVID-19 restrictions came into place, which was expected to lower TRAP. In addition, similar changes in air quality were evident to other cities around the world: reductions in fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) concentrations and an increase in ozone (O₃) concentrations. Average daily and diurnal concentrations for these three pollutants presented more statistically significant spatial and temporal changes during COVID-19 restrictions at monitoring sites with urban or traffic classifications than suburban background sites. Furthermore, substantial reductions in the range of average hourly pollutant concentrations were observed, 79% for PM_2.5 and 75% for NO₂, with a modest 24% reduction for O₃. Correlation analysis of air pollution between monitoring sites and years demonstrated an improvement in the R² for NO₂ concentrations only, suggesting that spatiotemporal homogeneity was most notable for this TRAP due to mobility restrictions during COVID-19. The spatiotemporal representativeness of monitoring stations across the city will change with greener transport, and air quality during COVID-19 can provide a benchmark to support the introduction of new policies for cleaner air.

Bioreducible polyethylenimine core-shell nanostructures as efficient and non-toxic gene and drug delivery vectors

Low molecular weight branched polyethylenimine (LMW bPEIs 1.8 kDa) have received considerable attention for the fabrication of nucleic acid carriers due to their biocompatible and non-toxic nature. However, due to the inadequate nucleic acid complexation ability and transportation across the cell membrane, these show poor transfection efficacy, limiting their clinical applications. Therefore, to overcome these challenges, in this study, we have grafted bPEI 1.8 kDa with a disulfide bond containing hydrophobic moiety, 3-(2-pyridyldithio) propionic acid (PDPA), via amide linkages through EDC/NHS-mediated coupling to obtain N-[3-(2-pyridyldithio)] propionoyl polyethylenimine (PDPP) conjugates. The best formulation for nucleic acid transfection was evaluated after preparing a series of PDPP conjugates by varying the amount of PDPA. In an aqueous environment, these PDPP conjugates self-assembled to form spherical shaped core-shell PDPP nanostructures with size ranging from ∼188-307 nm and zeta-potential from ∼ +3 to +19 mV. The positively charged surface of the core-shell nanocomposites helps in the binding of plasmid DNA (pDNA), its transportation inside the cell, and protection against enzymes. Evaluation of PDPP/pDNA complexes on mammalian cells revealed that all these complexes showed significantly improved transfection efficacy without hampering cytocompatibility. Amongst all, the pDNA complex of PDPP-2 exhibited the best transfection efficiency (i.e. >6-fold) in comparison to pDNA complex of the native bPEI. The nanocomposites exhibited the redox responsive behavior advantageous for therapeutic delivery to the tumor cells. The core of the nanostructures facilitate the encapsulation of a hydrophobic model drug, ornidazole. In vitro drug release analysis showed a faster release rate in response to a reductant mimicking the cellular environment. Altogether, these nanostructures have great potential to co-deliver both drug and gene simultaneously in response to tumor cell reductive microenvironment in vitro and could be used as the next-generation delivery system.

POS1275 A RETROSPECTIVE STUDY ON UVEITIS FLARES FOLLOWING COVID19 VACCINATION: SHARING EXPERIENCE FROM A TEACHING HOSPITAL COMBINED RHEUMATOLOGY AND UVEITIS CLINIC

Background

Uveitis is a sight threatening disease caused by inflammation of the uveal tract of the eye. Uveitis is a manifestation of many autoimmune conditions and is associated with seronegative axial spondyloarthritis, reactive arthritis, Behçet’s disease, inflammatory bowel disease, and psoriatic arthritis. Acute anterior uveitis is the most common presentation and is most commonly idiopathic or associated with the HLA-B27 gene (around 20% of cases). Studies have shown that anterior uveitis frequently recurs in patients after it has previously remitted. (1) Patients suffering from autoimmune conditions are frequently prescribed immunosuppressant drugs to control their illness, thus leaving them more susceptible to bacterial and viral illnesses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Previous studies have shown that some patients suffer exacerbation of their autoimmune condition after coronavirus vaccination, including uveitis(2). We aim to evaluate our cohort of patients suffering from autoimmune conditions treated at Leicester Uveitis Service at Leicester Royal Infirmary and explore any proposed link.

Objectives

To assess if COVID19 vaccination is associated with uveitis flares in immunosuppressed patients.

Methods

A retrospective study, to determine if patients diagnosed with autoimmune conditions suffered from uveitis following COVID-19 vaccination. A data collection sheet was used to document demographic and clinical data: age, sex, ethnicity, autoimmune condition, dates of COVID-19 vaccination(s), type of vaccine, medication at the time of vaccine, symptoms of autoimmune recurrence, date of uveitis onset and number of days between uveitis onset and latest vaccine. We used an already existing uveitis database with an active register of 2346 patients, of which 246 were on immunomodulation.

Results

After reviewing the first 50 patients on immunosuppression for uveitis, we found a total of 4 patients had a uveitis flare despite tight control previously; 3 are female and 1 male, their median age was 39.5 years. They experienced a recurrence of uveitis in the last 6 months. Of these 4 patients 3 were on synthetic DMARDS (2 mycophenolate mofetil, 1 azathioprine), 1 was on steroids and 1 was on a biological DMARD (adalimumab). 2 of the patients suffered from posterior uveitis and 2 from anterior uveitis. All the 50 patients had been vaccinated against COVID19 however there was no clear record of booster dose.

Conclusion

Our study showed that of 50 immunosuppressed patients, 4 had a uveitis flare following vaccination. Clinicians need to be aware of uvetis flares in rheumatology patients following vaccination. This is a small retrospective analysis of our cohort however a large observational study on flare of uveitis following COVID-19 primary vaccination and booster vaccination would be useful to get meaningful data.

References

[1]Grunwald L, Newcomb CW, Daniel E, Kaçmaz RO, Jabs DA, Levy-Clarke GA, Nussenblatt RB, Rosenbaum JT, Suhler EB, Thorne JE, Foster CS, Kempen JH; Systemic Immunosuppressive Therapy for Eye Diseases Cohort Study. Risk of relapse in primary acute anterior uveitis. Ophthalmology. 2011 Oct;118(10):1911-5. doi: 10.1016/j.ophtha.2011.02.044. Epub 2011 Jun 16. PMID: 21680024; PMCID: PMC3179829.

[2]Bolletta E, Iannetta D, Mastrofilippo V, De Simone L, Gozzi F, Croci S, Bonacini M, Belloni L, Zerbini A, Adani C, Fontana L, Salvarani C, Cimino L. Uveitis and Other Ocular Complications Following COVID-19 Vaccination. J Clin Med. 2021 Dec 19;10(24):5960. doi: 10.3390/jcm10245960. PMID: 34945256; PMCID: PMC8704915.

Disclosure of Interests

None declared