Adeno-associated virus as a delivery vector for gene therapy of human diseases.

Adeno-associated virus (AAV) has emerged as a pivotal delivery tool in clinical gene therapy owing to its minimal pathogenicity and ability to establish long-term gene expression in different tissues. Recombinant AAV (rAAV) has been engineered for enhanced specificity and developed as a tool for treating various diseases. However, as rAAV is being more widely used as a therapy, the increased demand has created challenges for the existing manufacturing methods. Seven rAAV-based gene therapy products have received regulatory approval, but there continue to be concerns about safely using high-dose viral therapies in humans, including immune responses and adverse effects such as genotoxicity, hepatotoxicity, thrombotic microangiopathy, and neurotoxicity. In this review, we explore AAV biology with an emphasis on current vector engineering strategies and manufacturing technologies. We discuss how rAAVs are being employed in ongoing clinical trials for ocular, neurological, metabolic, hematological, neuromuscular, and cardiovascular diseases as well as cancers. We outline immune responses triggered by rAAV, address associated side effects, and discuss strategies to mitigate these reactions. We hope that discussing recent advancements and current challenges in the field will be a helpful guide for researchers and clinicians navigating the ever-evolving landscape of rAAV-based gene therapy.

Experiences and Perceptions of Healthcare Stakeholders in Disclosing Errors and Adverse Events to Historically Marginalized Patients.

OBJECTIVES: We sought to assess the experiences and perceptions of healthcare stakeholders involved in the response to historically marginalized patients who have been harmed in healthcare. We investigated the challenges in disclosing errors and adverse events and the types of tools and resources that would better address the needs of historically marginalized patient populations. METHODS: We conducted separate focus groups with two healthcare stakeholder groups: (1) frontline clinicians directly involved in the clinical care of historically marginalized patients and (2) risk and patient safety professionals involved in the hospital response to care breakdowns. We conducted an inductive analysis of the qualitative data to identify thematic clusters. RESULTS: We interviewed 7 clinicians and 5 risk safety professionals, with a total sample size of 12 participants. Participants shared multilevel challenges in responding to historically marginalized patients after harm (system-, organizational-, and patient-level), such as fragmentation of care, lack of standardized protocols, and patient mistrust. Participants also identified their desired tools and resources for disclosure to meet the needs of historically marginalized patients, which included culturally appropriate toolkits, disclosure training, and the inclusion of multidisciplinary healthcare team members in the disclosure process. CONCLUSIONS: Our results suggest that multiple interventions will be needed to achieve the goal of prompt disclosure of errors and adverse events across all populations engaged in health care. Future studies should investigate the perspectives of historically marginalized patients and their family members on how error and adverse event disclosure conversations should unfold.

Death after High-Dose rAAV9 Gene Therapy in a Patient with Duchenne's Muscular Dystrophy.

We treated a 27-year-old patient with Duchenne's muscular dystrophy (DMD) with recombinant adeno-associated virus (rAAV) serotype 9 containing dSaCas9 (i.e., "dead" Staphylococcus aureus Cas9, in which the Cas9 nuclease activity has been inactivated) fused to VP64; this transgene was designed to up-regulate cortical dystrophin as a custom CRISPR-transactivator therapy. The dose of rAAV used was 1×1014 vector genomes per kilogram of body weight. Mild cardiac dysfunction and pericardial effusion developed, followed by acute respiratory distress syndrome (ARDS) and cardiac arrest 6 days after transgene treatment; the patient died 2 days later. A postmortem examination showed severe diffuse alveolar damage. Expression of transgene in the liver was minimal, and there was no evidence of AAV serotype 9 antibodies or effector T-cell reactivity in the organs. These findings indicate that an innate immune reaction caused ARDS in a patient with advanced DMD treated with high-dose rAAV gene therapy. (Funded by Cure Rare Disease.).

IL-13 induced inflammation increases DPP4 abundance but does not enhance MERS-CoV replication in airway epithelia.

BACKGROUND: Chronic pulmonary conditions such as asthma and COPD increase the risk of morbidity and mortality during infection with the Middle East respiratory syndrome coronavirus (MERS-CoV). We hypothesized that individuals with such comorbidities are more susceptible to MERS-CoV infection due to increased expression of its receptor, dipeptidyl peptidase 4 (DPP4). METHODS: We modeled chronic airway disease by treating primary human airway epithelia with the Th2 cytokine IL-13, examining how this impacted DPP4 protein levels along with MERS-CoV entry and replication. RESULTS: IL-13 exposure for 3 days led to increased DPP4 protein abundance, while a 21-day treatment increased DPP4 levels and caused goblet cell metaplasia. Surprisingly, despite this increase in receptor availability, MERS-CoV entry and replication were not significantly impacted by IL-13 treatment. CONCLUSIONS: Our results suggest that increased DPP4 abundance is likely not the primary mechanism leading to increased MERS severity in the setting of Th2 inflammation. Transcriptional profiling analysis highlighted the complexity of IL-13 induced changes in airway epithelia, including altered expression of genes involved in innate immunity, antiviral responses, and maintenance of the extracellular mucus barrier. These data suggest that additional factors likely interact with DPP4 abundance to determine MERS-CoV infection outcomes.

Keeping development on time: Insights into post-transcriptional mechanisms driving oscillatory gene expression during vertebrate segmentation.

Biological time keeping, or the duration and tempo at which biological processes occur, is a phenomenon that drives dynamic molecular and morphological changes that manifest throughout many facets of life. In some cases, the molecular mechanisms regulating the timing of biological transitions are driven by genetic oscillations, or periodic increases and decreases in expression of genes described collectively as a "molecular clock." In vertebrate animals, molecular clocks play a crucial role in fundamental patterning and cell differentiation processes throughout development. For example, during early vertebrate embryogenesis, the segmentation clock regulates the patterning of the embryonic mesoderm into segmented blocks of tissue called somites, which later give rise to axial skeletal muscle and vertebrae. Segmentation clock oscillations are characterized by rapid cycles of mRNA and protein expression. For segmentation clock oscillations to persist, the transcript and protein molecules of clock genes must be short-lived. Faithful, rhythmic, genetic oscillations are sustained by precise regulation at many levels, including post-transcriptional regulation, and such mechanisms are essential for proper vertebrate development. This article is categorized under: RNA Export and Localization > RNA Localization RNA Turnover and Surveillance > Regulation of RNA Stability Translation > Regulation.

Effects of Practicing With and Obtaining Crowdsourced Feedback From the Video-Based Communication Assessment App on Resident Physicians' Adverse Event Communication Skills: Pre-post Trial.

BACKGROUND: US residents require practice and feedback to meet Accreditation Council for Graduate Medical Education mandates and patient expectations for effective communication after harmful errors. Current instructional approaches rely heavily on lectures, rarely provide individualized feedback to residents about communication skills, and may not assure that residents acquire the skills desired by patients. The Video-based Communication Assessment (VCA) app is a novel tool for simulating communication scenarios for practice and obtaining crowdsourced assessments and feedback on physicians' communication skills. We previously established that crowdsourced laypeople can reliably assess residents' error disclosure skills with the VCA app. However, its efficacy for error disclosure training has not been tested. OBJECTIVE: We aimed to evaluate the efficacy of using VCA practice and feedback as a stand-alone intervention for the development of residents' error disclosure skills. METHODS: We conducted a pre-post study in 2020 with pathology, obstetrics and gynecology, and internal medicine residents at an academic medical center in the United States. At baseline, residents each completed 2 specialty-specific VCA cases depicting medical errors. Audio responses were rated by at least 8 crowdsourced laypeople using 6 items on a 5-point scale. At 4 weeks, residents received numerical and written feedback derived from layperson ratings and then completed 2 additional cases. Residents were randomly assigned cases at baseline and after feedback assessments to avoid ordinal effects. Ratings were aggregated to create overall assessment scores for each resident at baseline and after feedback. Residents completed a survey of demographic characteristics. We used a 2×3 split-plot ANOVA to test the effects of time (pre-post) and specialty on communication ratings. RESULTS: In total, 48 residents completed 2 cases at time 1, received a feedback report at 4 weeks, and completed 2 more cases. The mean ratings of residents' communication were higher at time 2 versus time 1 (3.75 vs 3.53; P<.001). Residents with prior error disclosure experience performed better at time 1 compared to those without such experience (ratings: mean 3.63 vs mean 3.46; P=.02). No differences in communication ratings based on specialty or years in training were detected. Residents' communication was rated higher for angry cases versus sad cases (mean 3.69 vs mean 3.58; P=.01). Less than half of all residents (27/62, 44%) reported prior experience with disclosing medical harm to patients; experience differed significantly among specialties (P<.001) and was lowest for pathology (1/17, 6%). CONCLUSIONS: Residents at all training levels can potentially improve error disclosure skills with VCA practice and feedback. Error disclosure curricula should prepare residents for responding to various patient affects. Simulated error disclosure may particularly benefit trainees in diagnostic specialties, such as pathology, with infrequent real-life error disclosure practice opportunities. Future research should examine the effectiveness, feasibility, and acceptability of VCA within a longitudinal error disclosure curriculum.

Video-Based Communication Assessment of Physician Error Disclosure Skills by Crowdsourced Laypeople and Patient Advocates Who Experienced Medical Harm: Reliability Assessment With Generalizability Theory.

BACKGROUND: Residents may benefit from simulated practice with personalized feedback to prepare for high-stakes disclosure conversations with patients after harmful errors and to meet American Council on Graduate Medical Education mandates. Ideally, feedback would come from patients who have experienced communication after medical harm, but medical researchers and leaders have found it difficult to reach this community, which has made this approach impractical at scale. The Video-Based Communication Assessment app is designed to engage crowdsourced laypeople to rate physician communication skills but has not been evaluated for use with medical harm scenarios. OBJECTIVE: We aimed to compare the reliability of 2 assessment groups (crowdsourced laypeople and patient advocates) in rating physician error disclosure communication skills using the Video-Based Communication Assessment app. METHODS: Internal medicine residents used the Video-Based Communication Assessment app; the case, which consisted of 3 sequential vignettes, depicted a delayed diagnosis of breast cancer. Panels of patient advocates who have experienced harmful medical error, either personally or through a family member, and crowdsourced laypeople used a 5-point scale to rate the residents' error disclosure communication skills (6 items) based on audiorecorded responses. Ratings were aggregated across items and vignettes to create a numerical communication score for each physician. We used analysis of variance, to compare stringency, and Pearson correlation between patient advocates and laypeople, to identify whether rank order would be preserved between groups. We used generalizability theory to examine the difference in assessment reliability between patient advocates and laypeople. RESULTS: Internal medicine residents (n=20) used the Video-Based Communication Assessment app. All patient advocates (n=8) and 42 of 59 crowdsourced laypeople who had been recruited provided complete, high-quality ratings. Patient advocates rated communication more stringently than crowdsourced laypeople (patient advocates: mean 3.19, SD 0.55; laypeople: mean 3.55, SD 0.40; P<.001), but patient advocates' and crowdsourced laypeople's ratings of physicians were highly correlated (r=0.82, P<.001). Reliability for 8 raters and 6 vignettes was acceptable (patient advocates: G coefficient 0.82; crowdsourced laypeople: G coefficient 0.65). Decision studies estimated that 12 crowdsourced layperson raters and 9 vignettes would yield an acceptable G coefficient of 0.75. CONCLUSIONS: Crowdsourced laypeople may represent a sustainable source of reliable assessments of physician error disclosure skills. For a simulated case involving delayed diagnosis of breast cancer, laypeople correctly identified high and low performers. However, at least 12 raters and 9 vignettes are required to ensure adequate reliability and future studies are warranted. Crowdsourced laypeople rate less stringently than raters who have experienced harm. Future research should examine the value of the Video-Based Communication Assessment app for formative assessment, summative assessment, and just-in-time coaching of error disclosure communication skills.

RNPS1 inhibits excessive tumor necrosis factor/tumor necrosis factor receptor signaling to support hematopoiesis in mice.

Null mutations of spliceosome components or cofactors are homozygous lethal in eukaryotes, but viable hypomorphic mutations provide an opportunity to understand the physiological impact of individual splicing proteins. We describe a viable missense allele (F181I) of Rnps1 encoding an essential regulator of splicing and nonsense-mediated decay (NMD), identified in a mouse genetic screen for altered immune cell development. Homozygous mice displayed a stem cell­intrinsic defect in hematopoiesis of all lineages due to excessive apoptosis induced by tumor necrosis factor (TNF)­dependent death signaling. Numerous transcript splice variants containing retained introns and skipped exons were detected at elevated frequencies in Rnps1F181I/F181I splenic CD8+ T cells and hematopoietic stem cells (HSCs), but NMD appeared normal. Strikingly, Tnf knockout rescued all hematopoietic cells to normal or near-normal levels in Rnps1F181I/F181I mice and dramatically reduced intron retention in Rnps1F181I/F181I CD8+ T cells and HSCs. Thus, RNPS1 is necessary for accurate splicing, without which disinhibited TNF signaling triggers hematopoietic cell death.

TRPV4 mutations causing mixed neuropathy and skeletal phenotypes result in severe gain of function.

OBJECTIVE: Distinct dominant mutations in the calcium-permeable ion channel TRPV4 (transient receptor potential vanilloid 4) typically cause nonoverlapping diseases of either the neuromuscular or skeletal systems. However, accumulating evidence suggests that some patients develop mixed phenotypes that include elements of both neuromuscular and skeletal disease. We sought to define the genetic and clinical features of these patients. METHODS: We report a 2-year-old with a novel R616G mutation in TRPV4 with a severe neuropathy phenotype and bilateral vocal cord paralysis. Interestingly, a different substitution at the same residue, R616Q, has been reported in families with isolated skeletal dysplasia. To gain insight into clinical features and potential genetic determinants of mixed phenotypes, we perform in-depth analysis of previously reported patients along with functional and structural assessment of selected mutations. RESULTS: We describe a wide range of neuromuscular and skeletal manifestations and highlight specific mutations that are more frequently associated with overlap syndromes. We find that mutations causing severe, mixed phenotypes have an earlier age of onset and result in more marked elevations of intracellular calcium, increased cytotoxicity, and reduced sensitivity to TRPV4 antagonism. Structural analysis of the two mutations with the most dramatic gain of ion channel function suggests that these mutants likely cause constitutive channel opening through disruption of the TRPV4 S5 transmembrane domain. INTERPRETATION: These findings demonstrate that the degree of baseline calcium elevation correlates with development of mixed phenotypes and sensitivity to pharmacologic channel inhibition, observations that will be critical for the design of future clinical trials for TRPV4 channelopathies.

Effects of Reduced Nicotine Content Cigarettes on Fractional Exhaled Nitric Oxide and Self-Reported Respiratory Health Outcomes Among Smokers With Psychiatric Conditions or Socioeconomic Disadvantage.

INTRODUCTION: This study examined whether exposure to reduced-nicotine-content cigarettes (RNCCs) for 12 weeks alters respiratory health using Fractional Exhaled Nitric Oxide (FeNO), a validated biomarker of respiratory epithelial health, and the Respiratory Health Questionnaire (RHQ), a subject-rated questionnaire on respiratory symptoms. Participants were 747 adult daily smokers enrolled in three double-blind, randomized clinical trials evaluating effects of cigarette nicotine content (0.4, 2.4, 15.8 mg nicotine/g tobacco) in people with affective disorders, opioid use disorder (OUD), or socioeconomic disadvantage. AIMS AND METHODS: FeNO levels and RHQ ratings were collected at baseline and Weeks 6 and 12 following randomization. Multiple regression was used to assess associations of FeNO and RHQ with smoking characteristics. Mixed-model repeated-measures ANOVA was used to evaluate the effects of nicotine content on FeNO and RHQ outcomes over the 12-week study period. RESULTS: FeNO levels but not RHQ ratings varied inversely with smoking characteristics at baseline (Ps < 0.0001) in smokers with affective disorders and socioeconomic disadvantage but less so in those with OUD. Participants with affective disorders and socioeconomic disadvantage, but not those with OUD, who were assigned to RNCCs had higher FeNO levels at Week 12 than those assigned to the 15.8 mg/g dose [F(2,423) = 4.51, p = .01, Cohen's d = 0.21]. No significant dose-related changes in RHQ scores were identified. CONCLUSIONS: Use of RNCCs across a 12-week period attenuates smoking-related reductions in FeNO levels in smokers with affective disorders and socioeconomic disadvantage although not those with OUD. FeNO changes were not accompanied by changes in respiratory-health ratings. TRIAL REGISTRATION: Inclusion and exclusion criteria for the sample and experimental manipulation of the nicotine content of assigned cigarettes are registered: NCT02232737, NCT02250664, NCT02250534. The FeNO measure reported in this manuscript is an exploratory outcome that was not registered. IMPLICATIONS: Should a reduced nicotine content standard be implemented; these results suggest that reduced nicotine content in cigarettes will not exacerbate and instead may attenuate smoking-related decreases in FeNO. This is significant as NO is an important component in maintaining a healthy respiratory system and necessary to defend against infection. Furthermore, the results of the current study demonstrate that the adoption of the reduced nicotine content standard may result in beneficial impacts on respiratory epithelial health among vulnerable populations that are disproportionally affected by the adverse health outcomes precipitated by combustible tobacco use.

Addressing personal protective equipment (PPE) decontamination: Methylene blue and light inactivates severe acute respiratory coronavirus virus 2 (SARS-CoV-2) on N95 respirators and medical masks with maintenance of integrity and fit.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of personal protective equipment (PPE), underscoring the urgent need for simple, efficient, and inexpensive methods to decontaminate masks and respirators exposed to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). We hypothesized that methylene blue (MB) photochemical treatment, which has various clinical applications, could decontaminate PPE contaminated with coronavirus. DESIGN: The 2 arms of the study included (1) PPE inoculation with coronaviruses followed by MB with light (MBL) decontamination treatment and (2) PPE treatment with MBL for 5 cycles of decontamination to determine maintenance of PPE performance. METHODS: MBL treatment was used to inactivate coronaviruses on 3 N95 filtering facepiece respirator (FFR) and 2 medical mask models. We inoculated FFR and medical mask materials with 3 coronaviruses, including SARS-CoV-2, and we treated them with 10 µM MB and exposed them to 50,000 lux of white light or 12,500 lux of red light for 30 minutes. In parallel, integrity was assessed after 5 cycles of decontamination using multiple US and international test methods, and the process was compared with the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method. RESULTS: Overall, MBL robustly and consistently inactivated all 3 coronaviruses with 99.8% to >99.9% virus inactivation across all FFRs and medical masks tested. FFR and medical mask integrity was maintained after 5 cycles of MBL treatment, whereas 1 FFR model failed after 5 cycles of VHP+O3. CONCLUSIONS: MBL treatment decontaminated respirators and masks by inactivating 3 tested coronaviruses without compromising integrity through 5 cycles of decontamination. MBL decontamination is effective, is low cost, and does not require specialized equipment, making it applicable in low- to high-resource settings.

Risk Communication After Health Care Exposures: An Experimental Vignette Survey With Patients.

Purpose. We investigated how health care systems should communicate with patients about possible exposures to blood-borne pathogens that may have occurred during their care. Our goal was to determine how best to communicate uncertain risk information in a way that would minimize harm to patients, maintain their trust, and encourage patients to seek follow-up treatment. Methods. Participants (N = 1103) were randomized to receive one of six vignette surveys; 997 (98.4%) responded. All vignettes described the same event, but differed by risk level and recommendations (lower risk v. higher risk) and by communication mode (telephone, letter, social media). We measured participants' perceived risk of blood-borne infection, trust in the health care system, and shared decision making about next clinical steps. Open-ended questions were analyzed using grounded thematic analysis. Results. When the vignette requested patients to undergo testing and practice certain health behaviors (higher risk), participants' likelihood of seeking follow-up testing for blood-borne pathogens and their understanding of health issues increased. Perceived trust was unaffected by risk level or communication processes. Qualitative data indicated a desire for telephone communication from providers known to the patient. Limitations. It is not clear whether higher risk language or objective risk levels in vignettes motivated patients' behavioral intentions. Conclusion. Using higher risk language when disclosing large-scale adverse events increased participants' willingness to seek follow-up care. Implications. Health care organizations' disclosures should focus on the next steps to take after health care exposures. This communication should involve helping patients to understand their personal health issues better, make them feel that they know which steps to take following the receipt of this information, and encouraging them to seek follow-up infectious disease testing in order to better take care of themselves.

A low-cost educational intervention to reduce unplanned extubation in low-resourced pediatric intensive care units.

INTRODUCTION: Unplanned extubation (UE) is orders of magnitude worse in low-income Pediatric Intensive Care Units (PICUs) than their high-income counterparts. Furthermore, a significant percent (20 %) of UEs result in a destabilizing event or cardiac collapse that negatively contributes to morbidity and mortality. As the principles of safe airway management are universal, we hypothesize that a multi-disciplinary educational intervention bundle which included provision of low-cost cuffed endotracheal tubes (ETT) and ETT tape will decrease the rate of unplanned extubation (UE) in a low-resourced PICU. METHODS: This is a pre-post interventional study powered to evaluate UE of intubated pediatric patients in an El Salvadorian PICU after a multi-disciplinary educational effort and provision of low-cost disposable materials. A multidisciplinary (otolaryngologists, intensivists, anesthesiologists, respiratory therapists, and nurses) educational curriculum involving hands on training, online video modules readily available via bedside QR codes, and pre- and post-testing was administered. The cost of the intervention materials was $1.32 per child. PICU mortality was evaluated as an exploratory outcome. RESULTS: Nine-hundred and fifty-seven (859 pre-intervention and 98 post-intervention) patients met inclusion criteria. Patients with one or more UEs decreased significantly from 29.4 % to 17.3 % post-intervention (p = 0.01; CI: 0.28-0.88) with an odds ratio of 0.51. The use of a cuffed ETT increased from 12 % to 36 % (p < 0.001; CI: 0.17-0.44; OR:3.74) and cuffed ETT use was associated with a reduction in UE with an odds ratio of 0.40 (p < 0.001; CI: 0.24-0.66). Finally, there was a 4.3 % decrease in pediatric mortality from 26.7 % to 22.4 % that equates to a number needed to treat to prevent a single child mortality of 23. Therefore, the ICER per mortality prevented is $30.7 and the ICER per Disability Adjusted Life Year (DALY) is $0.44. CONCLUSION: This multi-faceted intervention bundle is an accessible, scalable, cost-effective means to reduce UE and has implications in reducing global pediatric mortality.