Enabling mRNA medicine for brain tumors

mRNA is a new class of drugs that has the potential to revolutionize the treatment of brain tumors. Thanks to the COVID-19 mRNA vaccines and numerous therapy-based clinical trials, it is now clear that lipid nanoparticles (LNPs) are a clinically viable means to deliver RNA therapeutics. However, LNP-mediated mRNA delivery to brain tumors remains elusive. Over the past decade, numerous studies have shown that tumor cells communicate with each other via small extracellular vesicles, which are around 100 nm in diameter and consist of lipid bilayer membrane similar to synthetic lipidbased nanocarriers. We hypothesized that rationally designed LNPs based on extracellular vesicle mimicry would enable efficient delivery of RNA therapeutics to brain tumors without undue toxicity. We synthesized LNPs using four components similar to the formulation used in the mRNA COVID19 vaccines (Moderna and Pfizer): ionizable lipid, cholesterol, helper lipid and polyethylene glycol (PEG)-lipid. For the in vitro screen, we tested ten classes of helper lipids based on their abundance in extracellular vesicle membranes, commercial availability, and large-scale production feasibility while keeping rest of the LNP components unchanged. The transfection kinetics of GFP mRNA encapsulated in LNPs and doped with 16 mol% of helper lipids was tested using GL261, U87 and SIM-A9 cell lines. Several LNP formations resulted in stable transfection (upto 5 days) of GFP mRNA in all the cell lines tested in vitro. The successful LNP candidates (enabling >80% transfection efficacy) were then tested in vivo to deliver luciferase mRNA to brain tumors via intrathecal administration in a syngeneic glioblastoma (GBM) mouse model, which confirmed luciferase expression in brain tumors in the cortex. LNPs were then tested to deliver Cre recombinase mRNA in syngeneic GBM mouse model genetically modified to express tdTomato under LoxP marker cassette that enabled identification of LNP targeted cells. mRNA was successfully delivered to tumor cells (70-80% transfected) and a range of different cells in the tumor microenvironment, including tumor-associated macrophages (80-90% transfected), neurons (31- 40% transfected), neural stem cells (39-62% transfected), oligodendrocytes (70-80% transfected) and astrocytes (44-76% transfected). Then, LNP formulations were assessed for delivering Cas9 mRNA and CD81 sgRNA (model protein) in murine syngeneic GBM model to enable gene editing in brain tumor cells. Sanger sequencing showed that CRISPR-Cas9 editing was successful in ~94% of brain tumor cells in vivo. In conclusion, we have developed a library of safe LNPs that can transfect GBM cells in vivo with high efficacy. This technology can potentially be used to develop novel mRNA therapies for GBM by delivering single or multiple mRNAs and holds great potential as a tool to study brain tumor biology.

Non-Hodgkin's lymphoma complicated with human coronavirus HKU1 pneumonia: A case report and literature review.

Objective: To analyze the clinical manifestations, diagnostic methods and treatment process of the patients with non-Hodgkin's lymphoma complicated with human coronavirus(HCoV)-HKU1 pneumonia and improve the clinical medical staff's awareness of the disease, and to reduce the occurrence of clinical adverse events. Method(s): The clinical data of a patient with non-Hodgkin's lymphoma complicated with HCoV-HKU1 pneumonia with hot flashes and night sweats, dry cough and dry throat as the main clinical features who were hospitalized in the hospital in January 2021 were analyzed, and the relevant literatures were reviewed and the clinical manifestations and diagnosis of HCoV-HKU1 were analyzed. Result(s): The female patient was admitted to the hospital due to diagnosed non-Hodgkin's lymphoma for more than 2 months. The physical examination results showed Karnofsky score was 90 points;there was no palpable enlargement of systemic superfical lymph nodes;mild tenderness in the right lower abdomen, no rebound tenderness, and slightly thicker breath sounds in both lungs were found, and a few moist rales were heard in both lower lungs. The chest CT results showed diffuse exudative foci in both lungs, and the number of white blood cells in the urine analysis was 158 muL-1;next generation sequencing technique(NGS) was used the detect the bronchoalveolar lavage fluid, and HCoV-HKU1 pneumonia was diagnosed. At admission, the patient had symptoms such as dull pain in the right lower abdomen, nighttime cough, and night sweats;antiviral treatment with oseltamivir was ineffective. After treatment with Compound Sulfamethoxazole Tablets and Lianhua Qingwen Granules, the respiratory symptoms of the patient disappeared. The re-examination chest CT results showed the exudation was absorbed. Conclusion(s): The clinical symptoms of the patients with non-Hodgkin's lymphoma complicated with HCoV-HKU1 pneumonia are non-specific. When the diffuse shadow changes in the lungs are found in clinic, and the new coronavirus nucleic acid test is negative, attention should still be paid to the possibility of other HCoV infections. The NGS can efficiently screen the infectious pathogens, which is beneficial to guide the diagnosis and treatment of pulmonary infectious diseases more accurately.Copyright © 2023 Jilin University Press. All rights reserved.

SARS-COV-2 Infection in Children and Young People in Bulgaria - A Prospective, Single-Center, Cohort Study

Compared to other respiratory viruses, the proportion of hospitalizations due to SARS-CoV-2 among children is relatively low. While severe illness is not common among children and young individuals, a particular type of severe condition called multisystem inflammatory syndrome in children (MIS-C) has been reported. The aim of this prospective cohort study, which followed a group of individuals under the age of 19, was to examine the characteristics of patients who had contracted SARS-CoV-2, including their coexisting medical conditions, clinical symptoms, laboratory findings, and outcomes. The study also aimed to investigate the features of children who met the WHO case definition of MIS-C, as well as those who required intensive care. A total of 270 patients were included between March 2020 and December 2021. The eligible criteria were individuals between 0-18 with a confirmed SARS-CoV-2 infection at the Infectious Disease Hospital "Prof. Ivan Kirov"in Sofia, Bulgaria. Nearly 76% of the patients were <= 12 years old. In our study, at least one comorbidity was reported in 28.1% of the cases, with obesity being the most common one (8.9%). Less than 5% of children were transferred to an intensive care unit. We observed a statistically significant difference in the age groups, with children between 5 and 12 years old having a higher likelihood of requiring intensive care compared to other age groups. The median values of PaO2 and SatO2 were higher among patients admitted to the standard ward, while the values of granulocytes and C-reactive protein were higher among those transferred to the intensive care unit. Additionally, we identified 26 children who met the WHO case definition for MIS-C. Our study data supports the evidence of milder COVID-19 in children and young individuals as compared to adults. Older age groups were associated with higher incidence of both MIS-C and ICU admissions.Copyright © 2023 P. Velikov et al., published by Sciendo.

Programmable polymer materials empowered by DNA nanotechnology

Over the past century, synthetic polymers have had a transformative impact on human life, replacing nature-derived materials in many areas. Yet, despite their many advantages, the structure and function of synthetic polymers still appear rudimentary compared to biological matter: cells use dynamic self-assembly to construct complex materials and operate sophisticated macromolecular devices. The field of DNA nanotechnology has demonstrated that synthetic DNA molecules can be programmed to undergo predictable self-assembly, offering unparalleled control over the formation and dynamic properties of artificial nanostructures. Intriguingly, the principles of DNA nanotechnology can be applied to the engineering of soft programmable materials, bringing the abilities of synthetic polymers closer to their biological counterparts. In this perspective, we discuss the unique features of DNA-functionalized polymer materials. We describe design principles that allow researchers to build complex supramolecular architectures with predictable and dynamically adjustable material properties. Finally, we highlight two key application areas where this biologically inspired material class offers particularly promising opportunities: (1) as dynamic matrices for 3D cell and organoid culture and (2) as smart materials for nucleic acid sequencing and pathogen detection.

Persistent chemosensory dysfunction in COVID-19 patients: a deep dive into the psychophysical and genetic characterisation of an Italian cohort

Background/Objectives: Chemosensory dysfunction is a hallmark of SARS-CoV-2 infection;nevertheless, the genetic factors predisposing to long-term smell and taste loss are still unknown. This study aims to identify candidate genes possibly involved in persistent smell/taste loss through Whole Genome Sequencing (WGS) analysis of a large cohort of 130 fully characterised Italian individuals, previously diagnosed with COVID-19. Method(s): DNA of all analysed patients was used to perform WGS analysis, and a detailed personal anamnesis was collected. Moreover, orthonasal function was assessed through the extended Sniffin' Sticks test, retronasal function was tested with 20 powdered tasteless aromas, and taste was determined with validated Taste Strips. Self-reported smell and taste alterations were assessed via Visual Analog Scales plus questionnaires. Result(s): The clinical evaluation allowed to classify the patients in two groups: 88 cases affected by persistent smell dysfunction (median age, 49) and 42 controls (median age, 51). Among cases, 26.1% (n = 23) were functionally anosmic and 73.9% (n = 65) were hyposmic. Within cases, 77 underwent the taste strip test: 53.2% (n = 41) presented hypogeusia and 46.8% (n = 36) were normogeusic. Preliminary WGS results on a first subset of 76 samples confirmed the important role of UGT2A1 gene, previously described as involved in smell loss. Interestingly, we identified a nonsense variant (rs111696697, MAF 0.046) significantly associated with anosmia in males (p-value: 0.0183). Conclusion(s): Here, for the first time a large cohort of patients, fully characterised through a comprehensive psychophysical evaluation of smell and taste, have been analysed to better define the genetic bases of COVID-19-related persistent chemosensory dysfunction.

A New Registry for Genetic Diagnosis of Inborn Errors of Immunity within the Military Health System

Genotypic definition of monogenic inborn errors of immunity (IEIs) continues to accelerate with broader access to next generation sequencing, underscoring this aggregated group of disorders as a major health burden impacting both civilian and military populations. At an estimated prevalence of 1 in 1200 individuals, IEIs affect ~8,000 patients within the Military Health System (MHS). Despite access to targeted gene/exome panels at military treatment facilities, most affected patients never receive a definitive genetic diagnosis that would significantly improve clinical care. To address this gap, we established the first registry of IEI patients within the MHS with the goal of identifying known and novel pathogenic genetic defects to increase diagnosis rates and enhance clinical care. Using the registry, a research protocol was opened in July 2022. Since July we have enrolled 75 IEI patients encompassing a breadth of phenotypes including severe and recurrent infections, bone marrow failure, autoimmunity/autoinflammation, atopic disease, and malignancy. Enrolled patients provide blood and bone marrow samples for whole genome, ultra-deep targeted panel and comprehensive transcriptome sequencing, plus cryopreservation of peripheral blood mononuclear cells for future functional studies. We are also implementing and developing analytical methods for identifying and interrogating non-coding and structural variants. Suspected pathogenic variants are adjudicated by a clinical molecular geneticist using state-of-the-art analysis pipelines. These analyses subsequently inform in vitro experiments to validate causative mutations using cell reporter systems and primary patient cells. Clinical variant validation and return of genetic results are planned with genetic counseling provided. As a proof of principle, this integrated genetic evaluation pipeline revealed a novel, candidate TLR7 nonsense variant in two adolescent brothers who both endured critical COVID-19 pneumonia, requiring mechanical ventilation and extracorporeal membrane oxygenation. Our protocol is therefore poised to greatly enrich clinical genetics resources available in the MHS for IEI patients, contributing to better diagnosis rates, informed family counseling, and targeted treatments that collectively improve the health and readiness of the military community. Moreover, our efforts should yield new mechanistic insights on immune pathogenesis for a broad variety of known and novel IEIs.Copyright © 2023 Elsevier Inc.

A Case of a Relapsing Remitting Macrophage Activating Syndrome After Covid-19 Vaccine In a Teenager with UNC13D Heterozygous Variant of Uncertain Significance

Introduction: Macrophage activation syndrome (MAS) is a severe hyper inflammatory condition caused by the over-activation and proliferation of T cells, NK cells and macrophages. It is often associated with complications of rheumatic/immune diseases. We present a case of a 15-year-old female who experiences recurrent episodes of MAS without any known definitive underlying etiology. Case Presentation: A 15-year-old previously healthy female developed fatigue, fevers, myalgia, chest pain, splenomegaly and lymphadenopathy 10 days after receiving her first Pfizer COVID-19 vaccine. Her symptoms recurred 10 days after receiving the second dose. Her myocarditis, MIS-C, and infectious work up was negative except for positive EBV IgG. Laboratory studies revealed anemia, hypertriglyceridemia, hypofibrinogenemia, and hyperferritinemia. She initially responded to decadron;however, her symptoms recurred with steroid taper. Bone marrow biopsy revealed hemophagocytosis. Whole exome sequencing (WES) revealed a heterozygous variant of uncertain significance in UNC13D c.962C>A (p.Thr321Asn). She had multiple re-admissions with significantly elevated inflammatory markers, including extremely high IL2-R, IL-18 and CXCL9. Each episode was complicated by an acute viral infection. She responds to high dose steroids, anti-IL-1, and JAK inhibitors. Nonetheless, it has been difficult to wean decadron without triggering a flare. She continues to require increasing doses of baricitinib. Discussion(s): MAS may be seen as a complication of rheumatic diseases, as well as inborn errors of immunity. However, none of these conditions have been diagnosed in this patient despite extensive testing, including WES. The degree of her immune dysregulation has been very severe making her disease process unpredictable and extremely difficult to control. She has frequent flares precipitated by viral infections or attempts at adjusting her immunomodulators. Weaning her medications has been challenging as she continues to require increasing doses of baricitinib and corticosteroids. The UNC13D gene is associated with autosomal recessive familial hemophagocytic lymphohistiocytosis type 3 (FHL3). Our patient is heterozygous for an UNC13D variant of uncertain significance. Additional genetic inquiries with whole genome sequencing to help elucidate the underlying etiology of her severe condition is being conducted. We hypothesize she developed MAS due to a combination of genetic predisposition, prior EBV infection, and immune stress associated with the COVID-19 vaccine. [Formula presented] [Formula presented] [Formula presented]Copyright © 2023 Elsevier Inc.

Covid-19: Is the placenta a safe space

Problem: Several large studies have demonstrated that COVID-19 pregnant individuals are at a significant risk for severe disease and adverse pregnancy outcomes. The mechanisms underlying these phenomena remain to be elucidated and are the focus of our project. Although fetal and placental infection is rare, placental abnormalities and adverse pregnancy outcomes associated with placental dysfunction in COVID-19 cases have been widely reported. In particular, placental thrombosis and lesions consistent with maternal vascular malperfusion (MVM) of the placenta are common in individuals with COVID-19. Since thrombotic complications have been associated with COVID-19, it is not surprising that pregnant individuals with COVID- 19 are at risk for placental thrombosis. Method of Study: Placentas were evaluated histologically. Extracellular vesicles were isolated by serial centrifugation. Result(s): Adverse pregnancy outcomes associated with these placental lesions, including hypertensive disorders of pregnancy (gestational hypertension and preeclampsia), small for gestational age (SGA, birthweight < 10th percentile for gestational age), and preterm birth (PTB, < 37 weeks) are significantly increased among pregnant individuals with COVID-19. Placental infection with SARSCoV- 2 is uncommon, but multiple inflammatory and metabolic factors are likely to affect the placenta, including circulating extracellular vesicles (EVs) derived from various organs that have been associated with COVID-19 pathology and disease severity.We have analyzed over 500 placentas from COVID-19 pregnancies and found marked changes in placental morphology, characterized by abnormal maternal and fetal vessels, intervillous thrombi, and fibrin deposition, even in the face of mild or asymptomatic disease. We detected increased levels of small EVs in maternal serum from COVID-19 cases compared to controls and increased levels of mitochondrial DNA in EVs from COVID-19 cases. In in vitro experiments, we found increased oxidative stress in uterine endothelial cells and primary trophoblasts. Syncytialization of trophoblast cells following exposure to EVs from pregnant COVID-19 patients was markedly reduced. RNAseq of trophoblast cells exposed to EVs from pregnant COVID-19 patients revealed disruption of multiple pathways related to mitochondria function, oxidative stress, coagulation defects, and inflammation. Timing of infection during pregnancy (first, second, and third trimester) altered EV size distribution, cargo content, and functional consequences of trophoblast EV exposure. Conclusion(s): Our studies show that COVID-19 infection during pregnancy has profound effects on placenta morphology and function. It remains to be determined what the long-term consequences are on the offspring.

Whole genome sequencing of a German cohort to understand host genetics in COVID-19

Background/Objectives: The disease course upon SARS-CoV-2 infection is highly variable and comprises a range from asymptomatic infection to severe (and even lethal) COVID-19. Genetic factors substantially contribute to this variability, as evidenced by epidemiological studies and recent results from genome-wide association studies (GWAS) as well as sequencing-based approaches. The host genetics group of the German COVID-19 OMICs Initiative (DeCOI) has been founded with the aim to identify additional genetic variants that influence COVID-19 severity through whole genome sequencing (WGS) analyses. Method(s): Until January 2022, WGS has been performed on approximately 1200 individuals affected by COVID-19. Result(s): The most recent data freeze comprised 952 individuals. In this dataset, no carrier of a deleterious protein-altering variant has been detected in TLR7, which is the only conclusive risk gene for severe COVID-19. Applying a gene-based association test of rare variants to the subcohort of European individuals (n = 752, mean age: 56 years, females: 44%), including 199 severely affected individuals, we did not observe any significant association after correction for multiple testing. Exome-wide association analysis of common variants in this subcohort replicated the GWAS-locus on chromosome 3. Conclusion(s): With this ongoing work, we are contributing to international efforts to elucidate the host genetics of COVID-19, also by sharing our summary statistics for meta-analyses. Currently, we are sequencing additional severely affected individuals and we are refining analytical strategies, which will also include the joint analysis of common and rare variants at genomewide scale.

Upskilling haematological services for WGS and germline assessments through a regional skin biopsy training programme

NHS England Genomics introduced whole genome sequencing (WGS) with standard-of- care (SoC) genetic testing for haemato-oncology patients who meet eligibility criteria, including patients with acute leukaemia across all ages, and exhausted SoC testing. Alongside, the role of germline mutations in haematological cancers is becoming increasingly recognised. DNA samples are required from the malignant cells (somatic sample) via a bone marrow aspirate, and from non-malignant cells (germline sample) for comparator analysis. Skin biopsy is considered the gold-standard tissue to provide a source of fibroblast DNA for germline analysis. Performing skin punch biopsies is not within the traditional skillset for haematology teams and upskilling is necessary to deliver WGS/germline testing safely, independently and sustainably. A teaching programme was designed and piloted by the dermatology and haematology teams in Sheffield and delivered throughout the NHS trusts in North East & Yorkshire Genomic Laboratory Hub. The training programme consisted of a 90-min session, slides, video and practical biopsy on pork belly or synthetic skin, designed to teach up to six students at one time. To disseminate best practice, the standard operating procedure and patient information used routinely in Sheffield were shared, to be adapted for local service delivery. From January 2021 to December 2022, 136 haematology staff from 11 hospitals, including 34 consultants, 41 registrars, 34 nurses and 8 physician associates, across the NEY GLH region completed the skin biopsy training programme. Feedback from the course was outstanding, with consistently high scores in all categories. Practical components of the course were especially valued;98.6% (71/72) trainees scored the practical element of the programme a top score of 5 out of 5, highlighting that despite the challenges of delivering face-to- face teaching due to COVID-19, teaching of practical skills was highly valued;training in this way could not have been replicated virtually. Costs of the programme have been approximately 16 000, including consultant input and teaching/educational materials. Recent support has been provided by a separately funded Genomic Nurse Practitioner (GNP), with succession planning for the GNP to take over leadership from the consultant dermatologist. Plans are in place to use the remaining budget to disseminate the programme nationally. Our training programme has shown that skin biopsy can be formally embedded into training for haematology consultants, trainees, nursing team, and physician associates. Delivery of training can be effective and affordable across regional GLHs with appropriate leadership and inter-speciality coordination, and ultimately sustainable with specialist nursing staff, including GNPs.

Design of a cost-effective diagnosis tool for SARSCov-2 variant detection through a next generation sequencing (NGS) based strategy

Background/Objectives: Current pandemic situation, together with the continuous emergence of new SARS-CoV-2 variants reveal the need to develop a more versatile tool than PCR-based methods that allows both high throughput COVID-19 diagnostic and specific variant detection at reduced cost and fast turnaround times. Thus, with the aim of overcoming current test limitations and providing a strategy with these characteristics arises our novel next generation sequencing based approach. Method(s): The developed strategy works with RNA samples obtained from nasopharyngeal swabs. RNA samples are processed with our custom laboratory protocol and can be sequenced with any Illumina platform to generate results within a 24h timeframe. A tailored bioinformatic pipeline analyzes the data and generates a clinical-level report. Result(s): Clinical validation results have shown that the designed solution, sensitively and specifically identifies negative and positive samples that display a broad range in viral loads and readily identifies the following major SARS-CoV-2 variants of concern (VoC): Alpha, Beta, Gamma, Delta, Lambda and Omicron (BA.1 and BA.2). Conclusion(s): The versatility of our solution allows the capability of identifying the presence of other common respiratory viruses as well as identifying patients at risk through the identification of susceptibility human variants in the host. This, together with the possibility of easily adding new VoC as they emerge, will make VoC monitoring in entire populations feasible, providing a new perspective on the application of NGS methods in the field of clinical microbiology.

PPP1R13L-Related Cardiomyopathy Stability Following IL1 Inhibition

Introduction: Variants in PPP1R13L are associated with severe childhood-onset cardiomyopathy resulting in rapid progression to death or cardiac transplantation. PPP1R13L is proposed to encode a protein that limits the transcriptional activity of the NFkappaB pathway leading to elevated IL-1, IL-6, and TNF-alpha production in murine models. Optimal medical management for PPP1R13L-related cardiomyopathy is unknown. Here we report usage of a targeted anti-IL-1 immuno-modulatory therapy resulting in cardiac stabilization in a pediatric patient with congenital cardiomyopathy secondary to PPP1R13L variants. Case Report: A 4-year-old boy presented acutely with fever in the setting of persistent abdominal pain, vomiting, fatigue, and decreased appetite for two months following a mild COVID-19 related illness. Echocardiogram revealed severely depressed biventricular systolic function with an ejection fraction of 30%. Due to acute decompensated heart failure symptoms with hemodynamic instability, he was intubated and placed on continuous inotropic infusions with aggressive diuresis. Cardiac MRI demonstrated extensive subepicardial to near transmural fibrosis by late gadolinium enhancement in right and left ventricles. An implantable cardioverter-defibrillator (ICD) was placed due to frequent runs of polymorphic non-sustained ventricular tachycardia. Testing for viral pathogens was positive for rhino/enterovirus. Initial genetic testing was non-diagnostic (82-gene cardiomyopathy panel) but given the patient's significant presentation whole genome sequencing was pursued that showed two separate PPP1R13L variants in trans (c.2167A>C,p.T723P and c.2179_2183del,p. G727Hfs*25, NM_006663.4). Patient serum cytokine testing revealed elevations in IL-10 (4.7 pg/mL) and IL-1beta (20.9 pg/mL). Given the patient's tenuous circumstances and concern for continued progression of his cardiac disease, a trial of IL-1 inhibition via anakinra dosed at 3 mg/kg or 45 mg daily was initiated following hospital discharge. With approximately 6 months of therapy, the patient's cardiac function is stable with normalization of IL-10 and IL-1beta serum levels. Notably, the ventricular arrhythmia decreased after initiation of anakinra with no ICD shocks given. Therapy overall has been well tolerated without infectious concerns. Conclusion(s): In patients with PPP1R13L-related cardiomyopathy, immuno-modulatory therapies should be considered in an attempt to slow cardiac disease progression.Copyright © 2023 Elsevier Inc.

Genotype-phenotype correlations in five patients harboring SERPINA1 mutations and previously showing a severe COVID-19 infection

Background/Objectives: During COVID-19 pandemic, it is essential to detect patients potentially at risk of life-threatening complications, due to possible specific genetic mutations. The aim of our work is to show a practical application of genetic testing, allowing a diagnosis of alpha 1 antitrypsin deficiency in cases with a severe clinical course during COVID-19 infection. Method(s): During hospitalization for COVID-19, we identified 5 patients (3 female, 2 males from two different families, age range 18-47 years) with a severe course of COVID-19 infection, requiring high pressure ventilation with high volume oxygen supply. Two months after discharge, those patients were reevaluated with respiratory function tests, biochemical tests, genetic counselling and genetic testing. A peripheral blood sampling for SERPINA1 genetic testing has been performed, using Sanger sequencing. Result(s): Two months after discharge, in all 5 patients respiratory function tests were consistent with a dysventilatory obstructive syndrome, in contrast with usual findings related to COVID-19 infection. Blood test still showed increase plasmatic transaminase concentration in 3 out of 5 patients, one having increased serum bilirubin as well. We performed SERPINA1 genetic testing showing homozygosity for SERPINA1 pathogenic mutations (c.193del and c.875C>T, respectively) in all 5 patients. Conclusion(s): These cases showed the importance of genetic testing for patients with unexplained severe COVID-19 infection. Genetic testing allowed the diagnosis of cases affected by alpha 1 antitrypsin deficiency, associated with dysventilatory obstructive syndrome, that may worsen the short and long term prognosis of COVID-19.

Smart microfluidics: Synergy of machine learning and microfluidics in the development of medical diagnostics for chronic and emerging infectious diseases

The COVID-19 pandemic, emerging/re-emerging infections as well as other non-communicable chronic diseases, highlight the necessity of smart microfluidic point-of-care diagnostic (POC) devices and systems in developing nations as risk factors for infections, severe disease manifestations and poor clinical outcomes are highly represented in these countries. These POC devices are also becoming vital as analytical procedures executable outside of conventional laboratory settings are seen as the future of healthcare delivery. Microfluidics have grown into a revolutionary system to miniaturize chemical and biological experimentation, including disease detection and diagnosis utilizing muPads/paper-based microfluidic devices, polymer-based microfluidic devices and 3-dimensional printed microfluidic devices. Through the development of droplet digital PCR, single-cell RNA sequencing, and next-generation sequencing, microfluidics in their analogous forms have been the leading contributor to the technical advancements in medicine. Microfluidics and machine-learning-based algorithms complement each other with the possibility of scientific exploration, induced by the framework's robustness, as preliminary studies have documented significant achievements in biomedicine, such as sorting, microencapsulation, and automated detection. Despite these milestones and potential applications, the complexity of microfluidic system design, fabrication, and operation has prevented widespread adoption. As previous studies focused on microfluidic devices that can handle molecular diagnostic procedures, researchers must integrate these components with other microsystem processes like data acquisition, data processing, power supply, fluid control, and sample pretreatment to overcome the barriers to smart microfluidic commercialization.Copyright © 2023 by Begell House, Inc.

Presence of rare potential pathogenic variants in subjects under 60 years old with very severe or fatal COVID-19

Background/Objectives: Genetic variants affecting host defense against pathogens may help explain COVID-19 fatal outcomes. Our aim was to identify rare genetic variants related to COVID-19 severity in a selected group of patients under 60 years who required intubation or resulting in death. Method(s): Forty-four very severe COVID-19 patients were selected from the Spanish STOP-Coronavirus cohort, which comprises more than 3,500 COVID-19 patients. Genotype was performed by whole exome sequencing and variants were selected by using a gene panel of 867 candidate genes (immune response, primary immunodeficiencies or coagulation, among other). Variants were filtered, priorized and their potential pathogenicity was assessed following ACGM criteria. Result(s): We detected 44 different variants of interest, in 29 different patients (66%). Some of these variants were previously described as pathogenic (26%). Mostly, the candidate variants were located in genes related to immune response (38%), congenital disorders of glycosylation (14%) or damaged DNA binding genes (9%). A network analysis, showed three main components, consisting of 25 highly interconnected genes related to immune response and two additional networks enriched in carbohydrate metabolism and in DNA metabolism and repair processes. Conclusion(s): The variants identified affect different, but interrelated, functional pathways such as immune response and glycosylation. Further studies are needed for confirming the ultimate role of the new candidate genes described in the present study on COVID-19 severity.

COVID-19 pre-exposure prophylaxis with tixagevimab/cilgavimab in patients with haematological malignancy: A single-centre experience

Background: COVID-19 pandemic still pose a substantial threat worldwide despite increasing vaccine availability. Patients with haematological malignancies have been shown to have increased risk of contracting COVID-19 and are more susceptible to develop severe illness from SARS-CoV- 2 infection. The immune response to vaccines is impaired in patients with haematological malignancy due to underlying disease or antineoplastic therapies. The monoclonal-antibody combination, Evusheld is composed of tixagevimab and cilgavimab, two neutralising antibodies against SARS-CoV- 2. It has been shown to be safe and have efficacy for the prevention of COVID-19. Our aim of study is to describe the incidence and outcome of breakthrough COVID-19 infection among patients who received Evusheld in our centre and analyse the factors that possibly increase the risk of breakthrough infection. Material(s) and Method(s): A retrospective review of all adult patients with haematological malignancy who received tixagevimab/ cilgavimab 150/150 mg injection in Hospital Pulau Pinang from 1 July 2022 to 31 August 2022 with a follow-up period to 30 November 2022 was conducted. Demographic data, clinical characteristics and outcome will be retrieved from patient's medical records. Data were analysed using Statistical Package for Social Sciences software (version 21.0). Result(s): A total of 96 patients (50 males and 46 females) received tixagevimab/cilgavimab injection during the study period with a median age of 61 years (range 19-82). Majority of them were diagnosed with multiple myeloma (42.7%), followed by lymphoma (33.3%) and leukaemia (24%). One third of them had history of therapy with monoclonal antibody and 20% had haematopoietic stem cell transplantation. No major adverse effects of tixagevimab/cilgavimab injection were noted among the study population. Of the 12 patients (12.5%) who had COVID-19 infection, all of them had mild infection;three were asymptomatic and six patients received Paxlovid antiviral therapy. The median time from tixagevimab/cilgavimab to the onset of COVID-19 infection was 35 days (range 5-97 days). The mean age of patients with breakthrough COVID-19 infection were older compared to those without breakthrough infection but was not statistically significant. The incidence of breakthrough COVID-19 infection was not affected by type of haematological malignancy, history of monoclonal antibody therapy or COVID-19 vaccination. Discussion and Conclusion(s): Our findings showed that tixagevimab/cilgavimab was safe and effective in preventing COVID-19- related morbidity and mortality among patients with haematological malignancy during the study period. However, the limitation is the lack of access to whole genome sequencing for detection of resistant variants for breakthrough infections.

GENETIC PATTERN OF THE COVID-19 COURSE AND REINFECTION

A new coronavirus infection (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out at the end of 2019 in Wuhan (China). The disease has become a global pandemic and claimed more than 6 million lives after spreading rapidly around the world. Issues related to the complicated course of COVID-19 mechanisms continue to be the subject of active study. It is known that morbidity and mortality increase dramatically with increasing age and concomitant diseases, including obesity, diabetes, cancer, and cardiovascular diseases. Although most infected people recover, even young and otherwise healthy patients can get sick with this disease. In this regard, an urgent task is to search for specific genetic factors that can explain the predisposition of people to infection and the development of a severe COVID-19 form. Human genetic determinants can provide the scientific basis for disease prediction and the development of personalized therapies to counteract the epidemic. In addition, cases of repeated infection with SARS-CoV-2 are increasingly being registered, which occurs 1–6 months after initial infection on average and depends on the virus genome structure. Studies conducted on sequencing viral genomes have shown that some patients were re-infected with the same strain of coronavirus, while others were different. This, in turn, causes researchers concerns about the effectiveness of immunity after infection and vaccine reliability. The genetic characteristics of a person and a virus commonly determine the tendency for reinfection. It is difficult to determine the true COVID-19 reinfection prevalence, which is explained by the low detectability of asymptomatic reinfection and the fact that many patients with a mild course of the disease were not tested at an early stage of the pandemic. Therefore, the true prevalence of reinfection with COVID-19 does not reflect the current reality. There are many more cases of reinfection than are described in the literature. In this regard, the true contribution of a virus' genetic features to reinfection of COVID-19 can be determined only after population studies, and when developing immunization programs against a COVID-19, it is necessary to take into account the prevalence of reinfection in the population. The article can be used under the CC BY-NC-ND 4.0 license © Authors, 2022.

Pericytes may facilitate SARS-CoV-2 entry into the nervous system

Objective: Although the neurological and olfactory symptoms of coronavirus disease 2019 have been identified, the neurotropic properties of the causative virus, severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2), remain unknown. We sought to identify the susceptible cell types and potential routes of SARS-CoV-2 entry into the central nervous system, olfactory system, and respiratory system. Method(s): We collected single-cell RNA data from normal brain and nasal epithelium specimens, along with bronchial, tracheal, and lung specimens in public datasets. The susceptible cell types that express SARS-CoV-2 entry genes were identified using single-cell RNA sequencing and the expression of the key genes at protein levels was verified by immunohistochemistry. We compared the coexpression patterns of the entry receptor angiotensin-converting enzyme 2 (ACE2) and the spike protein priming enzyme transmembrane serine protease (TMPRSS)/cathepsin L among the specimens. Result(s): The SARS-CoV-2 entry receptor ACE2 and the spike protein priming enzyme TMPRSS/cathepsin L were coexpressed by pericytes in brain tissue;this coexpression was confirmed by immunohistochemistry. In the nasal epithelium, ciliated cells and sustentacular cells exhibited strong coexpression of ACE2 and TMPRSS. Neurons and glia in the brain and nasal epithelium did not exhibit coexpression of ACE2 and TMPRSS. However, coexpression was present in ciliated cells, vascular smooth muscle cells, and fibroblasts in tracheal tissue;ciliated cells and goblet cells in bronchial tissue;and alveolar epithelium type 1 cells, AT2 cells, and ciliated cells in lung tissue. Conclusion(s): Neurological symptoms in patients with coronavirus disease 2019 could be associated with SARS-CoV-2 invasion across the blood-brain barrier via pericytes. Additionally, SARS-CoV-2-induced olfactory disorders could be the result of localized cell damage in the nasal epithelium.Copyright © Wolters Kluwer Health, Inc. All rights reserved.