Peripheral administration of a humanized anti-PrP antibody blocks Alzheimer's disease Aß synaptotoxicity.

Alzheimer's disease (AD) is associated with pathological assembly states of amyloid-ß protein (Aß). Aß-related synaptotoxicity can be blocked by anti-prion protein (PrP) antibodies, potentially allowing therapeutic targeting of this aspect of AD neuropathogenesis. Here, we show that intravascular administration of a high-affinity humanized anti-PrP antibody to rats can prevent the plasticity-disrupting effects induced by exposure to soluble AD brain extract. These results provide an in vivo proof of principle for such a therapeutic strategy.

Prion protein monoclonal antibody (PRN100) therapy for Creutzfeldt-Jakob disease: evaluation of a first-in-human treatment programme.

BACKGROUND: Human prion diseases, including Creutzfeldt-Jakob disease (CJD), are rapidly progressive, invariably fatal neurodegenerative conditions with no effective therapies. Their pathogenesis involves the obligate recruitment of cellular prion protein (PrPC) into self-propagating multimeric assemblies or prions. Preclinical studies have firmly validated the targeting of PrPC as a therapeutic strategy. We aimed to evaluate a first-in-human treatment programme using an anti-PrPC monoclonal antibody under a Specials Licence. METHODS: We generated a fully humanised anti-PrPC monoclonal antibody (an IgG4κ isotype; PRN100) for human use. We offered treatment with PRN100 to six patients with a clinical diagnosis of probable CJD who were not in the terminal disease stages at the point of first assessment and who were able to readily travel to the University College London Hospital (UCLH) Clinical Research Facility, London, UK, for treatment. After titration (1 mg/kg and 10 mg/kg at 48-h intervals), patients were treated with 80-120 mg/kg of intravenous PRN100 every 2 weeks until death or withdrawal from the programme, or until the supply of PRN100 was exhausted, and closely monitored for evidence of adverse effects. Disease progression was assessed by use of the Medical Research Council (MRC) Prion Disease Rating Scale, Motor Scale, and Cognitive Scale, and compared with that of untreated natural history controls (matched for disease severity, subtype, and PRNP codon 129 genotype) recruited between Oct 1, 2008, and July 31, 2018, from the National Prion Monitoring Cohort study. Autopsies were done in two patients and findings were compared with those from untreated natural history controls. FINDINGS: We treated six patients (two men; four women) with CJD for 7-260 days at UCLH between Oct 9, 2018, and July 31, 2019. Repeated intravenous dosing of PRN100 was well tolerated and reached the target CSF drug concentration (50 nM) in four patients after 22-70 days; no clinically significant adverse reactions were seen. All patients showed progressive neurological decline on serial assessments with the MRC Scales. Neuropathological examination was done in two patients (patients 2 and 3) and showed no evidence of cytotoxicity. Patient 2, who was treated for 140 days, had the longest clinical duration we have yet documented for iatrogenic CJD and showed patterns of disease-associated PrP that differed from untreated patients with CJD, consistent with drug effects. Patient 3, who had sporadic CJD and only received one therapeutic dose of 80 mg/kg, had weak PrP synaptic labelling in the periventricular regions, which was not a feature of untreated patients with sporadic CJD. Brain tissue-bound drug concentrations across multiple regions in patient 2 ranged from 9·9 µg per g of tissue (SD 0·3) in the thalamus to 27·4 µg per g of tissue (1·5) in the basal ganglia (equivalent to 66-182 nM). INTERPRETATION: Our academic-led programme delivered what is, to our knowledge, the first rationally designed experimental treatment for human prion disease to a small number of patients with CJD. The treatment appeared to be safe and reached encouraging CSF and brain tissue concentrations. These findings justify the need for formal efficacy trials in patients with CJD at the earliest possible clinical stages and as prophylaxis in those at risk of prion disease due to PRNP mutations or prion exposure. FUNDING: The Cure CJD Campaign, the National Institute for Health Research UCLH Biomedical Research Centre, the Jon Moulton Charitable Trust, and the UK MRC.

Flow Cytometric Detection of G0 in Live Cells by Hoechst 33342 and Pyronin Y Staining.

Hoechst 33342 and Pyronin Y double staining can be used to measure DNA and RNA content in live cells by flow cytometry. Quiescent cells at G0 phase have the same amount of DNA as cells at G1 phase but lower RNA levels compared to proliferating cells. Therefore, resting cells in G0 phase can be distinguished from proliferating cells in G1, S, and G2 M phases. This chapter describes a protocol for double staining of live cells with Hoechst 33342 and Pyronin Y. Combined with immunophenotyping of intact and live cells Hoechst 33342 and Pyronin Y staining is a powerful noninvasive method for the analysis and isolation of quiescent cells from any defined cell population.

Improving Access to Gastroenterologist Using eConsultation: A Way to Potentially Shorten Wait Times.

BACKGROUND: Wait times for gastroenterologists in Canada continue to exceed recommended targets. Electronic consultation (eConsult) may reduce the need for face-to-face gastroenterologist visits. OBJECTIVE: The goal of this study was to identify the cases submitted to gastroenterologists though the Champlain BASE™ (Building Access to Specialists through eConsultation) eConsult service and explore their impact on primary care physicians' (PCPs) courses of action. METHODS: Gastroenterology cases submitted between June 2013 and January 2015 were categorized using a modification of the International Classification for Primary Care (ICPC-2) taxonomy. Question type (e.g., diagnosis or management) was classified using a validated taxonomy. RESULTS: Of the 121 gastroenterology consults reviewed, 33% were related to hepatology, 23% to GI symptoms, and 13% to specific luminal diseases. Among hepatology eConsults (n=40), 47% pertained to abnormal liver function testing. Overall, 51% of eConsults were related to diagnosis, 30% to management, 9% to drug treatments and 7% to procedures. PCPs received a reply within a median of 2.9 days. Only 25% of cases resulted in a face-to-face referral. CONCLUSIONS: The eConsult service provided timely, highly regarded advice from gastroenterologists directly to PCPs and often eliminated the need for a face-to-face consultation. An evaluation of the most commonly-posed questions could inform future continuing medical education activities for PCPs.