Potential limits of AAV-based gene therapy with the use of new transgenes expressing factor IX fusion proteins

Introduction: The variety of treatment for haemophilia B (HB) has recently improved with the emergence of both AAV‐based gene therapy and bioengineered human factor IX (hFIX) molecules with prolonged half‐life due to fusion to either albumin (Alb) or immunoglobulin Fc fragment (Fc). / Aim: Adeno‐associated viral vectors (AAV) mediating expression of hFIX‐Alb and hFIX‐Fc fusion proteins was investigated for gene therapy of HB to explore if their extended half‐life translates to higher plasma levels of FIX. / Methods: Single‐stranded cross‐packaged AAV2/8 vectors expressing hFIX‐Alb, hFIX‐Fc and hFIX were evaluated in vitro, and in mice. / Results: Both hFIX‐Alb and hFIX‐Fc fusion proteins were synthesized and expressed as single chains of expected size following AAV‐mediated gene transfer in vitro and in vivo. The procoagulant properties of these hFIX‐fusion proteins were comparable to wild‐type hFIX. However, their expression levels were threefold lower than wild‐type hFIX in vivo most likely due to inefficient secretion. / Conclusion: This, the first, evaluation of hFIX‐fusion proteins in the context of AAV gene transfer suggests that the hFIX‐fusion proteins are secreted inefficiently from the liver, thus preventing their optimal use in gene therapy approaches

Patients With Normal Tension Glaucoma Have Relative Sparing of the Relative Afferent Pupillary Defect Compared to Those With Open Angle Glaucoma and Elevated Intraocular Pressure

PURPOSE: We determined whether there is relative sparing of pupil function in glaucoma patients with normal pressures compared to those with high pressures. METHODS: A cross-sectional study was done of 68 patients with primary open angle glaucoma (POAG): 38 had normal IOPs on all-day phasing before treatment (never >21 mm Hg), with confirmed progression of glaucomatous optic neuropathy (NTG) and 30 had glaucomatous optic neuropathy associated with elevated intraocular pressures (>25 mm Hg; HP-POAG). The relative afferent pupillary defect (RAPD) was quantified with the RAPDx device, and mean deviation of visual field loss was obtained from reliable Humphrey visual fields. Outcomes measures evaluated were difference in slope between NTG and HP-POAG when plotting: (1) RAPD score against difference in mean deviation (MD) between eyes, and (2) RAPD score against difference in RNFL thickness between eyes. RESULTS: The slopes for magnitude of RAPD versus difference in MD were -0.06 (95% confidence interval [CI], -0.076, -0.044) for patients with NTG and -0.08 (95% CI, -0.109, -0.067) for those with HP-POAG. Fitting the interaction term showed a statistically significant difference between the slopes (0.023; 95% CI [0.0017, 0.0541]; P value = 0.037; HP-POAG reference group). Thus, for difference in MD, the slope for patients with NTG was flatter than the slope for those with HP-POAG. CONCLUSIONS: Glaucoma patients with NTG have a lesser RAPD for a given level of intereye difference of HVF MD, compared to patients with high IOPs. This suggests that damage to intrinsically photosensitive retinal ganglion cells (ipRGCs) differs between the normal and high-pressure forms of open-angle glaucoma (OAG), and supports the theory that mitochondrial optic neuropathies may have a role in the group of diagnoses currently termed normal tension glaucoma

Polonium-210 poisoning: a first-hand account

Background: Polonium-210 (210Po) gained widespread notoriety after the poisoning and subsequent death of Mr Alexander Litvinenko in London, UK, in 2006. Exposure to 210Po resulted initially in a clinical course that was indistinguishable from infection or exposure to chemical toxins, such as thallium. Methods: A 43-year-old man presented to his local hospital with acute abdominal pain, diarrhoea, and vomiting, and was admitted to the hospital because of dehydration and persistent gastrointestinal symptoms. He was initially diagnosed with gastroenteritis and treated with antibiotics. Clostridium difficile toxin was subsequently detected in his stools, which is when he first raised the possibility of being poisoned and revealed his background and former identity, having been admitted under a new identity with which he had been provided on being granted asylum in the UK. Within 6 days, the patient had developed thrombocytopenia and neutropenia, which was initially thought to be drug induced. By 2 weeks, in addition to bone marrow failure, he had evidence of alopecia and mucositis. Thallium poisoning was suspected and investigated but ultimately dismissed because blood levels of thallium, although raised, were lower than toxic concentrations. The patient continued to deteriorate and within 3 weeks had developed multiple organ failure requiring ventilation, haemofiltration, and cardiac support, associated with a drop in consciousness. On the 23rd day after he first became ill, he suffered a pulseless electrical activity cardiorespiratory arrest from which he could not be resuscitated and was pronounced dead. Findings: Urine analysis using gamma-ray spectroscopy on day 22 showed a characteristic 803 keV photon emission, raising the possibility of 210Po poisoning. Results of confirmatory analysis that became available after the patient's death established the presence of 210Po at concentrations about 109-times higher than normal background levels. Post-mortem tissue analyses showed autolysis and retention of 210Po at lethal doses in several organs. On the basis of the measured amounts and tissue distribution of 210Po, it was estimated that the patient had ingested several 1000 million becquerels (a few GBq), probably as a soluble salt (eg, chloride), which delivered very high and fatal radiation doses over a period of a few days. Interpretation: Early symptoms of 210Po poisoning are indistinguishable from those of a wide range of chemical toxins. Hence, the diagnosis can be delayed and even missed without a high degree of suspicion. Although body surface scanning with a standard Geiger counter was unable to detect the radiation emitted by 210Po, an atypical clinical course prompted active consideration of poisoning with radioactive material, with the diagnosis ultimately being made with gamma-ray spectroscopy of a urine sample

Efficacy of Repeat Selective Laser Trabeculoplasty in Medication-Naïve Open Angle Glaucoma and Ocular Hypertension during the LiGHT Trial

PURPOSE: To determine the efficacy of repeat selective laser trabeculoplasty (SLT) in medication-naïve open angle glaucoma (OAG) and ocular hypertensive (OHT) patients requiring repeat treatment for early to medium-term failure during the Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. // DESIGN: Post-hoc analysis of SLT treatment arm of a multicentre prospective randomised-controlled-trial. // PARTICIPANTS: Treatment-naïve OAG or OHT requiring repeat 360-degree SLT within 18 months. Re-treatment was triggered by pre-defined IOP and disease-progression criteria (using objective individualised target IOPs) // METHODS: After SLT at baseline, patients were followed for a minimum of 18 months after second (‘repeat’) SLT. A mixed model analysis was performed with the eye as the unit of analysis, with crossed random-effects to adjust for correlation between fellow eyes and repeated measures within eyes. Kaplan-Meier curves plot the duration of effect. // OUTCOME MEASURES: Initial (‘early’) IOP lowering at 2-months and duration of effect following initial and Repeat SLT. // RESULTS: 115 eyes of 90 patients received Repeat SLT during first 18 months of the trial. Pre-treatment IOP prior to Initial SLT was significantly higher than that prior to pre-retreatment IOP of Repeat SLT (mean difference: 3.4, 95% confidence interval (CI) 2.6 to 4.3, mmHg; p<0.001). Absolute IOP reduction at 2-months was greater following Initial, compared to Repeat, SLT (mean difference: 1.0, 95% CI 0.2 to 1.8, mmHg; p=0.02). Adjusted absolute IOP reduction at 2-months (adjusting for IOP prior to initial or repeat laser) was greater following Repeat SLT (adjusted mean difference: -1.1, 95% CI -1.7 to -0.5, mmHg; p=0.001). 34 eyes were ‘early failures’ (retreated 2-months after Initial SLT) vs 81 ‘later failures’ (retreatment beyond 2-months following Initial SLT). No significant difference in early absolute IOP reduction at 2-months following Repeat SLT was noted between ‘early’ vs ‘later’ failures’ (mean difference: 0.3, 95% CI, -1.1 to 1.8,mmHg; p=0.655). Repeat SLT maintained drop-free IOP control in 67% of 115 eyes at 18 months, with no clinically-relevant adverse events. // CONCLUSION: These exploratory analyses demonstrate Repeat SLT can maintain IOP at or below Target IOP in medication-naive OAG and OHT eyes requiring retreatment with atleast an equivalent duration of effect to initial laser

In-hospital mortality is associated with inflammatory response in NAFLD patients admitted for COVID-19

Background & aims Although metabolic risk factors are associated with more severe COVID-19, there is little evidence on outcomes in patients with non-alcoholic fatty liver disease (NAFLD). We here describe the clinical characteristics and outcomes of NAFLD patients in a cohort hospitalised for COVID-19. Methods This study included all consecutive patients admitted for COVID-19 between February and April 2020 at Imperial College Healthcare NHS Trust, with either imaging of the liver available dated within one year from the admission or a known diagnosis of NAFLD. Clinical data and early weaning score (EWS) were recorded. NAFLD diagnosis was based on imaging or past medical history and patients were stratified for Fibrosis-4 (FIB-4) index. Clinical endpoints were admission to intensive care unit (ICU)and in-hospital mortality. Results 561 patients were admitted. Overall, 193 patients were included in the study. Fifty nine patients (30%) died, 9 (5%) were still in hospital, and 125 (65%) were discharged. The NAFLD cohort (n = 61) was significantly younger (60 vs 70.5 years, p = 0.046) at presentation compared to the non-NAFLD (n = 132). NAFLD diagnosis was not associated with adverse outcomes. However, the NAFLD group had higher C reactive protein (CRP) (107 vs 91.2 mg/L, p = 0.05) compared to non-NAFLD(n = 132). Among NAFLD patients, male gender (p = 0.01), ferritin (p = 0.003) and EWS (p = 0.047) were associated with in-hospital mortality, while the presence of intermediate/high risk FIB-4 or liver cirrhosis was not. Conclusion The presence of NAFLD per se was not associated with worse outcomes in patients hospitalised for COVID-19. Though NAFLD patients were younger on admission, disease stage was not associated with clinical outcomes. Yet, mortality was associated with gender and a pronounced inflammatory response in the NAFLD group

The health and economic burden of bloodstream infections caused by antimicrobial-susceptible and non-susceptible Enterobacteriaceae and <i>Staphylococcus aureus</i> in European hospitals, 2010 and 2011:a multicentre retrospective cohort study

We performed a multicentre retrospective cohort study including 606,649 acute inpatient episodes at 10 European hospitals in 2010 and 2011 to estimate the impact of antimicrobial resistance on hospital mortality, excess length of stay (LOS) and cost. Bloodstream infections (BSI) caused by third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE), meticillin-susceptible (MSSA) and -resistant Staphylococcus aureus (MRSA) increased the daily risk of hospital death (adjusted hazard ratio (HR) = 1.80; 95% confidence interval (CI): 1.34-2.42, HR = 1.81; 95% CI: 1.49-2.20 and HR = 2.42; 95% CI: 1.66-3.51, respectively) and prolonged LOS (9.3 days; 95% CI: 9.2-9.4, 11.5 days; 95% CI: 11.5-11.6 and 13.3 days; 95% CI: 13.2-13.4, respectively). BSI with third-generation cephalosporin-susceptible Enterobacteriaceae (3GCSE) significantly increased LOS (5.9 days; 95% CI: 5.8-5.9) but not hazard of death (1.16; 95% CI: 0.98-1.36). 3GCRE significantly increased the hazard of death (1.63; 95% CI: 1.13-2.35), excess LOS (4.9 days; 95% CI: 1.1-8.7) and cost compared with susceptible strains, whereas meticillin resistance did not. The annual cost of 3GCRE BSI was higher than of MRSA BSI. While BSI with S. aureus had greater impact on mortality, excess LOS and cost than Enterobacteriaceae per infection, the impact of antimicrobial resistance was greater for Enterobacteriaceae

Effects of type and level of training on variation in physician knowledge in the use and acquisition of blood cultures: a cross sectional survey

BACKGROUND: Blood culture (BCX) use is often sub-optimal, and is a user-dependent diagnostic test. Little is known about physician training and BCX-related knowledge. We sought to assess variations in caregiver BCX-related knowledge, and their relation to medical training. METHODS: We developed and piloted a self-administered BCX-related knowledge survey instrument. Expert opinion, literature review, focus groups, and mini-pilots reduced > 100 questions in multiple formats to a final questionnaire with 15 scored content items and 4 covariate identifiers. This questionnaire was used in a cross-sectional survey of physicians, fellows, residents and medical students at a large urban public teaching hospital. The responses were stratified by years/level of training, type of specialty training, self-reported practical and theoretical BCX-related instruction. Summary scores were derived from participant responses compared to a 95% consensus opinion of infectious diseases specialists that matched an evidence based reference standard. RESULTS: There were 291 respondents (Attendings = 72, Post-Graduate Year (PGY) = 3 = 84, PGY2 = 42, PGY1 = 41, medical students = 52). Mean scores differed by training level (Attending = 85.0, PGY3 = 81.1, PGY2 = 78.4, PGY1 = 75.4, students = 67.7) [p ≤ 0.001], and training type (Infectious Diseases = 96.1, Medicine = 81.7, Emergency Medicine = 79.6, Surgery = 78.5, Family Practice = 76.5, Obstetrics-Gynecology = 74.4, Pediatrics = 74.0) [p ≤ 0.001]. Higher summary scores were associated with self-reported theoretical [p ≤ 0.001] and practical [p = 0.001] BCX-related training. Linear regression showed level and type of training accounted for most of the score variation. CONCLUSION: Higher mean scores were associated with advancing level of training and greater subject-related training. Notably, house staff and medical students, who are most likely to order and/or obtain BCXs, lack key BCX-related knowledge. Targeted education may improve utilization of this important diagnostic tool

Antimicrobial Stewardship from Policy to Practice: Experiences from UK Antimicrobial Pharmacists

Antimicrobial stewardship in the UK has evolved dramatically in the last 15 years. Factors driving this include initial central funding for specialist pharmacists and mandatory reductions in healthcare-associated infections (particularly Clostridium difficile infection). More recently, the introduction of national stewardship guidelines, and an increased focus on stewardship as part of the UK five-year antimicrobial resistance strategy, have accelerated and embedded developments. Antimicrobial pharmacists have been instrumental in effecting changes at an organizational and national level. This article describes the evolution of the antimicrobial pharmacist role, its impact, the progress toward the actions listed in the five-year resistance strategy, and novel emerging areas in stewardship in the UK