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ObjectivesTo assess antibody and T cell responses to SARS-CoV-2 vaccination in patients with rheumatoid arthritis (RA) on disease-modifying antirheumatic drugs (DMARDs).MethodsThis prospective study recruited 100 patients with RA on a variety of DMARDs for antibody and T cell analysis, pre-vaccination and 4 weeks post-vaccination. Positive antibody response was defined as sera IgG binding to ≥1 antigen. Those that remained seronegative after first vaccination were retested 4 weeks after second vaccination; and if still seronegative after vaccination three. A T cell response was defined an ELISpot count of ≥7 interferon (IFN)γ-positive cells when exposed to spike antigens. Type I IFN activity was determined using the luminex multiplex assay IFN score.ResultsAfter vaccine one, in patients without prior SARS-CoV-2 exposure, 37/83 (45%) developed vaccine-specific antibody responses, 44/83 (53%) vaccine-specific T cell responses and 64/83 (77%) developed either antibody or T cell responses. Reduced seroconversion was seen with abatacept, rituximab (RTX) and those on concomitant methotrexate (MTX) compared to 100% for healthy controls (pConclusionPatients with RA on DMARDs have reduced vaccine responses, particularly on certain DMARDs, with improvement on subsequent vaccinations but with approximately 10% still seronegative after three doses.

Objectives A retrospective population-based study to determine the incidence and prevalence of patients with the rare blood disease paroxysmal nocturnal haemoglobinuria (PNH). Methods All patients were identified by flow cytometric detection of blood cells deficient in glycosylphosphatidylinositol (GPI) linked proteins at a single diagnostic reference laboratory that serves the Yorkshire based, Haematological Malignancy Research Network (HMRN) with a population of 3.8 million. Results One hundred and ninety-seven patients with detectable PNH clones at a level of >0.01% in at least two lineages of cells (neutrophils, monocytes and/or red cells) were identified over a 15-year period (2004-2018). Of these, 88% had aplastic anaemia (AA), 8% classical PNH and 3% myelodysplastic syndrome. The overall incidence rate was estimated at 0.35 cases per 100 000 people per year. This equates to 220 cases newly diagnosed in the United Kingdom each year. The overall prevalence rate was 3.81 per 100 000, this equates to an estimated 2400 prevalent cases in the UK. The overall and relative 5-year survival rates were 72% and 82.7%, respectively. Conclusions This study showed that classical haemolytic PNH is a rare disease and represents only a small proportion overall of patients with detectable PNH cells, the majority of which have aplastic anaemia.

Many neuroscience experiments with animal subjects require free motion of the animal within a metal cage environment. In such cage environments, wireless communication with implanted devices, e.g., neural recording and stimulation is particularly challenging because the metal cage walls form a reverberant cavity with dense multipath. In the case of backscatter communication with the implanted device, the multipath challenge is particularly acute because of the round-trip nature of the backscatter channel. This paper demonstrates the reverberant cavity effect via measurement of the channel transfer function inside a metal cage used for nonhuman primate research in the 902–928 MHz ultrahigh-frequency industrial, scientific, and medical band. A reduced-size ceramic patch antenna developed for the Neurochip neural recording and stimulation device was affixed to a saline tissue proxy, while a commercial air-dielectric patch antenna was affixed to the ceiling of the cage. A measured 3 dB channel bandwidth greater than 6.5 MHz with a port-to-port insertion loss between 14 and 37 dB was achieved at 126 surveyed locations within the cage volume. A 6.25 Mb/s backscatter data uplink using a differential quadrature phase shift keying constellation was successfully validated inside the cage, with effectively 0% packet error rate for all but two of the surveyed locations. The simulation and experimental results show good agreement and reveal that wideband backscatter communication systems can perform well despite the significant multipath inside the reverberant cage environment.

Computational psychiatry studies have investigated how reinforcement learning may be different in individuals with mood and anxiety disorders compared with control individuals, but results are inconsistent.To assess whether there are consistent differences in reinforcement-learning parameters between patients with depression or anxiety and control individuals.Web of Knowledge, PubMed, Embase, and Google Scholar searches were performed between November 15, 2019, and December 6, 2019, and repeated on December 3, 2020, and February 23, 2021, with keywords (reinforcement learning) AND (computational OR model) AND (depression OR anxiety OR mood).Studies were included if they fit reinforcement-learning models to human choice data from a cognitive task with rewards or punishments, had a case-control design including participants with mood and/or anxiety disorders and healthy control individuals, and included sufficient information about all parameters in the models.Articles were assessed for inclusion according to MOOSE guidelines. Participant-level parameters were extracted from included articles, and a conventional meta-analysis was performed using a random-effects model. Subsequently, these parameters were used to simulate choice performance for each participant on benchmarking tasks in a simulation meta-analysis. Models were fitted, parameters were extracted using bayesian model averaging, and differences between patients and control individuals were examined. Overall effect sizes across analytic strategies were inspected.The primary outcomes were estimated reinforcement-learning parameters (learning rate, inverse temperature, reward learning rate, and punishment learning rate).A total of 27 articles were included (3085 participants, 1242 of whom had depression and/or anxiety). In the conventional meta-analysis, patients showed lower inverse temperature than control individuals (standardized mean difference [SMD], -0.215; 95% CI, -0.354 to -0.077), although no parameters were common across all studies, limiting the ability to infer differences. In the simulation meta-analysis, patients showed greater punishment learning rates (SMD, 0.107; 95% CI, 0.107 to 0.108) and slightly lower reward learning rates (SMD, -0.021; 95% CI, -0.022 to -0.020) relative to control individuals. The simulation meta-analysis showed no meaningful difference in inverse temperature between patients and control individuals (SMD, 0.003; 95% CI, 0.002 to 0.004).The simulation meta-analytic approach introduced in this article for inferring meta-group differences from heterogeneous computational psychiatry studies indicated elevated punishment learning rates in patients compared with control individuals. This difference may promote and uphold negative affective bias symptoms and hence constitute a potential mechanistic treatment target for mood and anxiety disorders.

Eculizumab, the monoclonal antibody targeting C5, is the only licensed treatment for Paroxysmal Nocturnal Hemoglobinuria (PNH) in the UK. Inherent to the mechanism of action, C5 inhibitors increase patient susceptibility to encapsulated microorganisms, particularly Neisseria meningitidis. The PNH National service (UK), has 18 years of experience treating patients with PNH using complement inhibition. The risk of N. meningitidis is mitigated by vaccination, ciprofloxacin (500 mg bd) on days 1-13 since we moved to vaccination on day one of complement inhibitor therapy, followed by daily prophylaxis with penicillin (or erythromycin). Since a case of sepsis with penicillin-resistant meningococci was observed, patients also have a rescue course ciprofloxacin. Patient education, safety cards, prompt action in case of fever and a 24 hour on-call service for patients are equally important. Until 2010 patients were revaccinated with MenACWY every 3 years. Bexsero (MenB vaccine) vaccination (2 vaccines within first 6 months) with boosters every 5 years was added in 2015. In collaboration with the Public Health England Meningococcal Reference Unit in 2010 a program was developed to monitor antibody titers after vaccination and to revaccinate against MenACWY if titers declined to below protective levels. It is technically not possible to assay for meningoccal serogroup B antibody titers when on Eculizumab therapy. We present the outcome of this project. Methods: Antibody titers to serogroups ACWY were assayed following vaccination and then once per annum. Patients with unprotective antibody titers were revaccinated. We evaluate our practice and review the 9 meningococcal infections in 8 patients. We present disease characteristics, serogroup and outcome, vaccination history and antibody status. Results: Between May 2002 and July 2020, 324 patients commenced complement inhibitor treatment for PNH. 801 vaccinations with MenACWY were administered; median 2 vaccinations per patient (range 1 - 10). A total of 1,671 antibody titer assessments were conducted in 294 patients, median of 4 tests per patient (range 1 - 15). Every test assessed antibodies against all four serogroups. Titers were not assessed in 9% of patients (30), due to vaccination prior to change in practice or recent commencement on treatment. A protective antibody response to all serogroups after first vaccination was observed in 170 / 294 patients (57.8%) and a partial response (antibodies to 3 serotypes) in 51 /294 (17.3%). Revaccination of 51 partial responders resulted in an additional 21 patients with a full response. Revaccination of 73 non-responders (antibodies to 0-2 serotypes) resulted in 32 more partial or full responses. 287 of 324 patients received MenB vaccinations; median 2 vaccinations per patient (range 1 - 4). Eight of 324 (2%) patients with median age 22.5 years developed meningococcal sepsis (see table); patient 5 had 2 episodes. 3 of 5 cases with serogroup B infection were before serogroup B vaccination was introduced. The other 4 episodes in 3 patients were due to Y, C, W meningococci, in one the serogroup is unknown. All except patient 1 were compliant with antibiotic prophylaxis. Patient 7 died from meningococcemia, a delay in seeking medical attention may have contributed, however this was also a penicillin resistant strain. Discussion: We report the largest experience of managing meningococcal risk in patients on complement inhibitor therapy for PNH. Despite our proactive management we had 9 cases of meningococcal sepsis, with one fatal infection. Our most recently introduced practice of prompt treatment with ciprofloxacin if pyrexic on antibiotic prophylaxis will prevent cases like patient 7 with a penicillin resistant strain. Three patients had a meningococci sepsis with serogroups C, W and Y; whilst 1 patient had no check of titers due to recent commencement on treatment, the titres of the other 2 had suggested protective immunity. We demonstrated that a full antibody response can be obtained on a second vaccination in most patients if the first one failed. If no response is achieved upfront or revaccination then further MenACWY vaccination is not likely to be successful. Current practice significantly mitigates the risk of meningococcal disease, however it is essential patients remain vigilant for fever, seeking immediate medical attention stating their diagnosis of PNH on complement inhibitor therapy. Disclosures Arnold: Alexion Pharmaceuticals: Honoraria. Borrow:Pfizer: Research Funding; GlaxoSmithKline: Research Funding; Alexion pharmacueticals: Research Funding; Sanofi: Research Funding. Riley:Alexion: Honoraria. Munir:Alexion: Honoraria; F. Hoffmann-La Roche: Consultancy, Other: Medical writing support, furnished by Scott Battle, PhD, of Health Interactions, was funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland. Kelly:Alexion: Honoraria. Pike:Apellis: Research Funding. Hillmen:Acerta: Other: Financial or material support; Roche: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; Pharmacyclics: Other: Financial or material support, Research Funding; Janssen: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Speakers Bureau; Gilead: Other: Financial or material support, Research Funding; Alexion: Consultancy, Research Funding, Speakers Bureau; Apellis: Consultancy, Research Funding, Speakers Bureau. Griffin:Alexion Pharmaceuticals: Honoraria, Other: Conference Support; Biocryst: Membership on an entity's Board of Directors or advisory committees.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hemolytic and thrombotic condition. Patients can experience severe anemia due to intravascular hemolysis, thrombotic events, renal impairment and pulmonary hypertension. Symptomatic patients are treated with complement inhibitors either in clinical trials or with eculizumab the only licensed treatment in the UK. Due to the mechanism of action of eculizumab, it increases susceptibility to Neisseria infection, including Neisseria meningitidis. To reduce this risk of infection, worldwide practice is for patients to be vaccinated at least 2 weeks prior to receiving eculizumab (serogroups A, C, Y, W 135 and B). It was noted within the PNH National Service at Leeds (UK) that a small number of patients deteriorated with enhanced intravascular hemolysis and thrombosis during the period between vaccination and eculizumab, leading to a review of practice. We report five of 121 patients with events in the intervening 2 weeks between vaccination and commencement of eculizumab from 2002-2012:A 44 year female presented with hemolysis and hemoglobinuria, with a granulocyte PNH clone of 99.4%. She was transfusion dependent and on anticoagulation. She consented to the PNH pilot eculizumab study, undergoing meningococcal vaccination as per protocol. Twenty two days later, she suffered an ischemic stroke with left hemiplegia and permanent weakness, resulting in exclusion from the study. Two years later she received eculizumab in the TRIUMPH study.A 37 year male presented with hemoglobinuria and fatigue with a granulocyte PNH clone of 99.58%. He had significant hemolysis, managed initially with warfarin and blood transfusions. He consented to start eculizumab and received meningococcal vaccination. 4 days later he presented with a symptomatic right hepatic vein thrombosis, promptly commenced eculizumab.A 29 year male, with abdominal pain and hemoglobinuria for 3 years developed a stroke and portal vein thrombosis leading to a diagnosis of PNH, with a granulocyte PNH clone of 84.99%. He commenced anticoagulation. Four months after the stroke he received meningococcal vaccination in preparation for scheduled commencement with eculizumab. He experienced a left central retinal vein thrombosis 15 days after its administration prior to starting eculizumab.A 47 year old male, was diagnosed with haemolytic PNH but only had mild symptoms and anaemia. Twenty four years later, he developed increasing hemolysis and symptoms; granulocyte PNH clone of 96.45%. Eculizumab was planned and he received meningococcal vaccination, but presented ten days later with acute renal failure secondary to massive intravascular haemolysis, necessitating emergency eculizumab therapy.A 35 year female, with a granulocyte PNH clone of 99.87%. Although she had active intravascular hemolysis, eculizumab was declined, and anticoagulation commenced. Four years later she consented to start eculizumab, receiving meningococcal vaccination. She was admitted 24 hours later with a stroke and commenced eculizumab the same day, but has persistent neurological impairment to date. See Table 1 Discussion: The close time proximity of these serious events to the patients' vaccinations raised concern that the complement system was being activated by administration of the vaccine, precipitating complications of PNH. It is also concerning that 4 of the 5 patients experienced thrombotic events despite therapeutic anticoagulation, confirming that anticoagulation only partially mitigates the risk of thrombosis in patients with PNH. The decision was taken to administer the vaccination immediately after the first dose of eculizumab, with therapeutic doses of antibiotic (ciprofloxacin 500mg bd) for the first 14 days post vaccination, followed by long term meningococcal prophylaxis (penicillin V or erythromycin 500mg bd) whilst receiving a complement inhibitor. Since this change in practice in 2012 we have commenced eculizumab therapy in 211 patients with no similar complications as described. Thus the change in practice appears to reduce the occurrence of these severe complications associated with vaccinations prior to initiating anti-complement therapy. Whilst it is possible these events could have been caused by the underlying condition of PNH, we would advise colleagues to also adopt a change in practice to reduce potentially significant complications. Disclosures Arnold: Alexion Pharmaceuticals: Honoraria. Kelly:Alexion: Honoraria. Munir:F. Hoffmann-La Roche: Consultancy, Other: Medical writing support, furnished by Scott Battle, PhD, of Health Interactions, was funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland; Alexion: Honoraria. Pike:Apellis: Research Funding. Riley:Alexion: Honoraria. Griffin:Alexion Pharmaceuticals: Honoraria, Other: Conference Support; Biocryst: Membership on an entity's Board of Directors or advisory committees. Hillmen:Acerta: Other: Financial or material support; Roche: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; Pharmacyclics: Other: Financial or material support, Research Funding; Janssen: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Speakers Bureau; Apellis: Consultancy, Research Funding, Speakers Bureau; Alexion: Consultancy, Research Funding, Speakers Bureau; Gilead: Other: Financial or material support, Research Funding.

Background Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare acquired disorder characterised by intravascular hemolysis and thrombosis. Patients with symptomatic PNH are commenced on the complement inhibitor eculizumab (600mg weekly for 5 weeks then 900mg 2 weekly). This monoclonal antibody targets C5 in the complement cascade, halting terminal complement activation thus inhibiting intravascular hemolysis. In some patients intravascular hemolysis is not adequately controlled on the standard regimen. Patient symptoms, transfusion requirements and raised Lactate dehydrogenase (LDH) levels are indicators for suboptimal control of PNH and review of eculizumab dosing. The 50% hemolytic complement (CH50) test is a functional assay assessing capability of serum complement components of the classical pathway to lyse sheep red blood cells pre-coated with rabbit anti-sheep red blood cell antibody. Patients with complement inhibited PNH should demonstrate absent lysis. As the test is expensive and difficult to organise, we tested if incomplete complete blockade as determined by CH50 activity would be better to confirm under-dosing than LDH value. Methods The Leeds (UK) PNH National Service reviewed patients who underwent CH50 assay between January 2015 and March 2020. All patients were on eculizumab with clinical concerns regarding suboptimal control of PNH. Patients receive eculizumab infusions intravenously every 14 days and routine follow up from the PNH Service. Serum samples were obtained 24 hours prior to infusions for CH50 assay; LDH values were routinely collected. Complete complement blockade was defined by 1.5x upper limit of normal (ULN). Confidence intervals were set at 95% and significance set at p Results In the study period, 327 tests (median 2, range 1 - 8) were carried out in 146 patients (median age 54 years, range 16 - 89; 74 female). 81% (265) were successful; 19% (62) were unsuccessful due to processing errors. Of the successful tests, 74% (197 in 127 patients) indicated complete complement blockade and 26% (68 in 38 patients) indicated incomplete blockade. Of the patients with incomplete blockade, 68% (26) demonstrated complete blockade on repeat testing and 32% (12) had their eculizumab dose increased. Clinical symptoms of under-dosing in the 12 patients requiring a dose increase included increased transfusion requirements and/or breakthrough hemolysis (7), pregnancy (2; both returned to 900mg post pregnancy) and significant lethargy (3). Of the patients requiring a dose increase, 3 were on 1200mg before 2015; their dose was increased to 1500mg. Repeat testing was carried out in 10/12 patients after dose increase; 8 indicated complete blockade; 2 patients were incompletely blocked at 1200mg and received a further dose increase to 1500mg. Further testing indicated complete blockade in 1 patient; 1 required a 3rd dose increase to 1800mg due to incomplete blockade and ongoing transfusion requirement. Corresponding LDH values were analysed; median LDH for the complete blockade group was 1.16xULN (range 0.54 - 2.16) and 1.28xULN (range 0.76 - 2.38) for the incomplete blockade group. LDH values were not significantly higher in the incomplete blockade group compared to the complete blockade group, p=0.08. There was no significant difference in LDH values pre- and post-dose increase, p=0.38 (Figure 1); median pre-dose increase LDH 1.14xULN; median post-dose increase LDH 1.13xULN. Correlation coefficient shows that CH50 activity was positively correlated with LDH value, r(123)=0.18, p=0.04. Conclusion We report the effective utilisation of CH50 analysis where there is clinical concern of suboptimal control of PNH. All patients demonstrating hemolytic activity on CH50 assays indicated subsequent complement blockade following increase of eculizumab dose. Increasing eculizumab is costly requiring robust evidence of suboptimal complement inhibition; a positive correlation between CH50 activity and LDH values was shown however this is not sufficient to guide clinical decisions. LDH values of the incomplete blockade group were not significantly higher than those with complete blockade, suggesting the use of LDH values as an assessment of complement inhibition in patients with ongoing symptoms or transfusion requirements is not sufficient to guide eculizumab dose increases. Disclosures Munir: Alexion: Honoraria; F. Hoffmann-La Roche: Consultancy, Other: Medical writing support, furnished by Scott Battle, PhD, of Health Interactions, was funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland. Pike:Apellis: Research Funding. Arnold:Alexion Pharmaceuticals: Honoraria. Hillmen:AstraZeneca: Consultancy, Speakers Bureau; Alexion: Consultancy, Research Funding, Speakers Bureau; Acerta: Other: Financial or material support; Roche: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; Pharmacyclics: Other: Financial or material support, Research Funding; Janssen: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; Apellis: Consultancy, Research Funding, Speakers Bureau; Gilead: Other: Financial or material support, Research Funding. Griffin:Alexion Pharmaceuticals: Honoraria, Other: Conference Support; Biocryst: Membership on an entity's Board of Directors or advisory committees.

Neuroscience research in non-human primates (NHPs) would benefit from multi-day neural recordings from freely moving animals in unconstrained home cage environments. However, wireless brain-computer interfaces (BCI) face two major challenges. First, a metal animal cage forms a reverberant cavity that leads to dense multipath, impairing the wireless communication channel. Second, the battery life of existing wireless neural recording devices is limited by the energy consumption of the neural data uplink.In this paper, we characterize the channel transfer function of a metal NHP home cage in the 2.4 GHz industrial, scientific, and medical (ISM) band, and demonstrate that there is adequate signal strength and bandwidth to support low-power Bluetooth Low Energy (BLE) compatible backscatter data uplinks. For a typical cage and antenna system, the measured maximum insertion loss of the cage-antenna system was 27.4 dB and the minimum −3 dB bandwidth was 5.0 MHz. We demonstrate a 1 Mbps BLE compatible backscatter communication link achieving a worst-case packet error rate of 1.05%, yielding an effective bit error rate of 5.6×10−5, exceeding the BLE requirement of ≤ 10−3. The backscatter link has a measured energy consumption of 158 pJ/bit, compared with ≈ 10nJ/bit for existing WiFi and Bluetooth chipsets.

Paroxysmal nocturnal haemoglobinuria (PNH) is an ultra-orphan disease, which until 15 years ago had limited treatment options. Eculizumab, a monoclonal antibody that inhibits C5 in the terminal complement cascade, has revolutionised treatment for this disease, near normalising life expectancy and improving quality of life for patients. The treatment landscape of PNH is now evolving, with ravulizumab a second longer acting intravenous C5 inhibitor now licenced by the FDA and EMA. With different therapeutic targets in the complement cascade and difference modalities of treatment, including subcutaneous, oral and intravenous therapies being developed, increasing independence for patients and reducing healthcare requirements. This review discusses the current and future therapies for PNH. Lay summary Review of current and future treatments for patients with Paroxysmal Nocturnal Haemoglobinuria What is Paroxysmal Nocturnal Haemoglobinuria? Paroxysmal nocturnal haemoglobinuria (PNH) is a very rare disease. It arises from PNH stem cells in the bone marrow. In a normal bone marrow these are inactive; however, if there has been a problem in the bone marrow, the PNH stem cells can expand and make PNH red blood cells, white blood cells and platelets. The problem with these cells is that they lack the cell surface markers that usually protect them. Red blood cells are broken down in the circulation rather than the spleen, which gives rise to PNH symptoms such as abdominal pain, difficulty swallowing, erectile dysfunction and red or black urine (known as haemoglobinuria). The white blood cells and platelets are ‘stickier’ increasing the risk of blood clots. Previously life expectancy was reduced as there were limited treatment options available. What was the aim of this review? To provide an overview of current and future treatment options for PNH Which treatments are available? • Eculizumab is an treatment given through a vein (intravenous) every week for 5 weeks then every 2 weeks after this, and has been available for 13 years, improving life expectancy to near normal. • Ravulizumab is a newer intravenous treatment similar to eculizumab but is given every 8 weeks instead of every 2 weeks. In clinical studies it was comparable with eculizumab. • Future Treatments - There is new research looking at different methods of treatment delivery, including injections under the skin (subcutaneous) that patients can give themselves, treatments taken by mouth (oral) or a combination of an intravenous and oral treatment for those patients who are not optimally controlled on eculizumab or ravulizumab. What does this mean? PNH is now treatable. For years, the only drug available was eculizumab, but now different targets and drug trials are available. Ravulizumab is currently the only second licenced product available, in USA and Europe, there are other medications active in clinical trials. Why is this important? The benefit for patients, from treatment every 2 weeks to every 8 weeks is likely to be improved further with the development of these new treatments, providing patients with improved disease control and independence. As we move into an era of more patient-friendly treatment options, the PNH community both physicians and patients look forward to new developments as discussed in this article.