Preservation of memory B cell homeostasis in an individual producing broadly neutralising antibodies against HIV-1.

Immunological determinants favouring emergence of broadly neutralising antibodies are crucial to the development of HIV-1 vaccination strategies. Here, we combined RNAseq and B cell cloning approaches to isolate a broadly neutralising antibody (bnAb) ELC07 from an individual living with untreated HIV-1. Using single particle cryogenic electron microscopy (cryo-EM), we show that the antibody recognises a conformational epitope at the gp120-gp41 interface. ELC07 binds the closed state of the viral glycoprotein causing considerable perturbations to the gp41 trimer core structure. Phenotypic analysis of memory B cell subsets from the ELC07 bnAb donor revealed a lack of expected HIV-1-associated dysfunction, specifically no increase in CD21-/CD27- cells was observed whilst the resting memory (CD21+/CD27+) population appeared preserved despite uncontrolled HIV-1 viraemia. Moreover, single cell transcriptomes of memory B cells from this bnAb donor showed a resting memory phenotype irrespective of the epitope they targeted or their ability to neutralise diverse strains of HIV-1. Strikingly, single memory B cells from the ELC07 bnAb donor were transcriptionally similar to memory B cells from HIV-negative individuals. Our results demonstrate that potent bnAbs can arise without the HIV-1-induced dysregulation of the memory B cell compartment and suggest that sufficient levels of antigenic stimulation with a strategically designed immunogen could be effective in HIV-negative vaccine recipients.

Clinical features and management of individuals admitted to hospital with monkeypox and associated complications across the UK: a retrospective cohort study.

BACKGROUND: The scale of the 2022 global mpox (formerly known as monkeypox) outbreak has been unprecedented. In less than 6 months, non-endemic countries have reported more than 67 000 cases of a disease that had previously been rare outside of Africa. Mortality has been reported as rare but hospital admission has been relatively common. We aimed to describe the clinical and laboratory characteristics and outcomes of individuals admitted to hospital with mpox and associated complications, including tecovirimat recipients. METHODS: In this cohort study, we undertook retrospective review of electronic clinical records and pathology data for all individuals admitted between May 6, and Aug 3, 2022, to 16 hospitals from the Specialist and High Consequence Infectious Diseases Network for Monkeypox. The hospitals were located in ten cities in England and Northern Ireland. Inclusion criteria were clinical signs consistent with mpox and MPXV DNA detected from at least one clinical sample by PCR testing. Patients admitted solely for isolation purposes were excluded from the study. Key outcomes included admission indication, complications (including pain, secondary infection, and mortality) and use of antibiotic and anti-viral treatments. Routine biochemistry, haematology, microbiology, and virology data were also collected. Outcomes were assessed in all patients with available data. FINDINGS: 156 individuals were admitted to hospital with complicated mpox during the study period. 153 (98%) were male and three (2%) were female, with a median age of 35 years (IQR 30-44). Gender data were collected from electronic patient records, which encompassed full formal review of clincian notes. The prespecified options for data collection for gender were male, female, trans, non-binary, or unknown. 105 (71%) of 148 participants with available ethnicity data were of White ethnicity and 47 (30%) of 155 were living with HIV with a median CD4 count of 510 cells per mm3 (IQR 349-828). Rectal or perianal pain (including proctitis) was the most common indication for hospital admission (44 [28%] of 156). Severe pain was reported in 89 (57%) of 156, and secondary bacterial infection in 82 (58%) of 142 individuals with available data. Median admission duration was 5 days (IQR 2-9). Ten individuals required surgery and two cases of encephalitis were reported. 38 (24%) of the 156 individuals received tecovirimat with early cessation in four cases (two owing to hepatic transaminitis, one to rapid treatment response, and one to patient choice). No deaths occurred during the study period. INTERPRETATION: Although life-threatening mpox appears rare in hospitalised populations during the current outbreak, severe mpox and associated complications can occur in immunocompetent individuals. Analgesia and management of superimposed bacterial infection are priorities for patients admitted to hospital. FUNDING: None.

SARS-COV-2 antibody responses to AZD1222 vaccination in West Africa.

Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies. Previous IgG anti-N positivity significantly increased post two-dose neutralizing antibody titres in both populations. Serological evidence of breakthrough infection was observed in 8/49 (16%). Neutralising antibodies were observed to wane in both populations, especially in anti-N negative participants with an observed waning rate of 20% highlighting the need for a combination of additional markers to characterise previous infection. We conclude that AZD1222 is immunogenic in two independent West African cohorts with high background seroprevalence and incidence of breakthrough infection in 2021. Waning titres post second dose indicates the need for booster dosing after AZD1222 in the African setting despite hybrid immunity from previous infection.

A multi-centre observational study of HIV, tuberculosis and risk of chronic lung disease in urban West Africa.

OBJECTIVE: HIV and tuberculosis (TB) are risk factors for non-communicable chronic lung disease (CLD). Despite the high prevalence of these infections in West Africa, there are no studies that compare CLD between people with HIV and HIV-negative populations in this setting. This study sought to quantify the contribution of HIV and TB infection in addition to conventional CLD risk factors, such as tobacco and biofuel exposure, to CLD in urban West Africa. DESIGN: A multi-centre cross-sectional study was conducted in three community clinics in Lagos, Nigeria between 2018 and 2019. METHODS: Spirometry, questionnaires and clinical records were used to estimate prevalence of CLD and association with risk factors. RESULTS: In total, 148 HIV-negative individuals and 170 HIV-positive individuals completed the study. Current cigarette (11 of 318, 3.5%) and lifetime domestic biofuel (6 of 318, 1.8%) exposures were low. Airway obstruction (33 of 170, 19.4% vs. 12 of 148, 8.1%, P  = 0.004) and CLD (73 of 170, 42.9% vs. 34 of 148, 23%, P  < 0.0001) were more prevalent in people with HIV compared with the HIV-negative group. HIV infection [odds ratio 2.35 (1.33, 4.17), P  = 0.003] and history of TB [odds ratio 2.09 (1.04, 4.20), P  = 0.038] were independently associated with increased risk of CLD. CONCLUSION: HIV and TB far outweigh conventional risk factors, including tobacco and domestic biofuel exposure, as drivers of non-communicable CLD in urban West Africa. Current global policy for CLD may have limited impact on CLD in this setting. Enhanced prevention, diagnosis and management strategies for incident HIV and TB infections are likely to have a significant impact on long-term lung health in sub-Saharan Africa.

HIV-2/SIV Vpx antagonises NF-κB activation by targeting p65.

BACKGROUND: The NF-κB family of transcription factors and associated signalling pathways are abundant and ubiquitous in human immune responses. Activation of NF-κB transcription factors by viral pathogen-associated molecular patterns, such as viral RNA and DNA, is fundamental to anti-viral innate immune defences and pro-inflammatory cytokine production that steers adaptive immune responses. Diverse non-viral stimuli, such as lipopolysaccharide and cytokines, also activate NF-κB and the same anti-pathogen gene networks. Viruses adapted to human cells often encode multiple proteins targeting the NF-κB pathway to mitigate the anti-viral effects of NF-κB-dependent host immunity. RESULTS: In this study we have demonstrated using a variety of assays, in a number of different cell types including primary cells, that plasmid-encoded or virus-delivered simian immunodeficiency virus (SIV) accessory protein Vpx is a broad antagonist of NF-κB signalling active against diverse innate NF-κB agonists. Using targeted Vpx mutagenesis, we showed that this novel Vpx phenotype is independent of known Vpx cofactor DCAF1 and other cellular binding partners, including SAMHD1, STING and the HUSH complex. We found that Vpx co-immunoprecipitated with canonical NF-κB transcription factor p65, but not NF-κB family members p50 or p100, preventing nuclear translocation of p65. We found that broad antagonism of NF-κB activation by Vpx was conserved across distantly related lentiviruses as well as for Vpr from SIV Mona monkey (SIVmon), which has Vpx-like SAMHD1-degradation activity. CONCLUSIONS: We have discovered a novel mechanism by which lentiviruses antagonise NF-κB activation by targeting p65. These findings extend our knowledge of how lentiviruses manipulate universal regulators of immunity to avoid the anti-viral sequelae of pro-inflammatory gene expression stimulated by both viral and extra-viral agonists. Importantly our findings are also relevant to the gene therapy field where virus-like particle associated Vpx is routinely used to enhance vector transduction through antagonism of SAMHD1, and perhaps also through manipulation of NF-κB.

HIV-1 Vpr antagonizes innate immune activation by targeting karyopherin-mediated NF-κB/IRF3 nuclear transport.

HIV-1 must replicate in cells that are equipped to defend themselves from infection through intracellular innate immune systems. HIV-1 evades innate immune sensing through encapsidated DNA synthesis and encodes accessory genes that antagonize specific antiviral effectors. Here, we show that both particle associated, and expressed HIV-1 Vpr, antagonize the stimulatory effect of a variety of pathogen associated molecular patterns by inhibiting IRF3 and NF-κB nuclear transport. Phosphorylation of IRF3 at S396, but not S386, was also inhibited. We propose that, rather than promoting HIV-1 nuclear import, Vpr interacts with karyopherins to disturb their import of IRF3 and NF-κB to promote replication in macrophages. Concordantly, we demonstrate Vpr-dependent rescue of HIV-1 replication in human macrophages from inhibition by cGAMP, the product of activated cGAS. We propose a model that unifies Vpr manipulation of nuclear import and inhibition of innate immune activation to promote HIV-1 replication and transmission.

High prevalence of COVID-19-associated diabetic ketoacidosis in UK secondary care.

We aim to describe the prevalence of diabetic ketoacidosis (DKA) in individuals admitted to a single centre with COVID-19. We identified 218 individuals hospitalised with COVID-19, of these four fulfilled criteria for DKA (4/218, 1.8%). We conclude DKA is common and severe in individuals hospitalised with COVID-19.

Assessing antibiotic stewardship using the surgical site infection prevention bundle.

BACKGROUND:: Antibiotic prophylaxis is crucial in head and neck surgery to prevent infection from clean contaminated wounds. Scottish Intercollegiate Guidelines Network (SIGN) guidance, the gold standard of practice, recommends that administration of broad spectrum antibiotics is discontinued after 24 hours post-operation. A three-audit cycle quality improvement project was conducted to assess clinical practice against SIGN guidance at a large London teaching hospital. METHODS:: Three change initiatives were implemented to improve antibiotic stewardship. First, an update of Trust guidelines with an associated poster campaign to educate staff and improve awareness. Second, introduction of a specific 'prophylactic antibiotics in head and neck surgery' bundle on the electronic hospital-wide prescribing system. Third, an update to an antibiotic prescribing guide (Microguide). RESULTS:: Over a 3-year study period the number of patients receiving antibiotics beyond 24 hours declined significantly (88% in 2015, 76% in 2016, 25% in 2018), demonstrating improved compliance with SIGN guidelines overall. Despite this, staff documentation of indications for extended antibiotic use remains suboptimal (58% in 2016 and 44% in 2018) as does the number of specimens sent for microbiological analysis (52% in 2016 and 0% in 2018). CONCLUSIONS:: Appropriate prophylactic antibiotic prescribing can improve morbidity and mortality rates in head and neck cancer patients. Three change initiatives have been demonstrated which can help to improve prescribing compliance in line with SIGN guidance. Ongoing auditing is required to maintain the longevity of improvements made and encourage staff documentation of indications for extended antibiotic use and microbiology specimen analysis.

Febrile illness in healthcare workers caring for Ebola virus disease patients in a high-resource setting.

Ebola virus disease (EVD) patients treated in high-resource facilities are cared for by large numbers of healthcare staff. Monitoring these healthcare workers (HCWs) for any illness that may represent transmission of Ebola virus is important both for the individuals and to minimise the community risk. International policies for monitoring HCWs vary considerably and their effectiveness is unknown. Here we describe the United Kingdom (UK) experience of illness in HCWs who cared for three patients who acquired EVD in West Africa. Five of these 93 high-level isolation unit (HLIU) HCWs presented with fever within 21 days of working on the unit; one of these five presented outside of the UK. This article discusses different approaches to monitoring of HCW symptom reporting. The potential impact of these approaches on HLIU staff recruitment, including travel restrictions, is also considered. An international surveillance system enhancing collaboration between national public health authorities may assist HLIU HCW monitoring in case they travel.

Lick of death: Capnocytophaga canimorsus is an important cause of sepsis in the elderly.

A 70-year-old Caucasian woman was treated for Capnocytophaga canimorsus septicaemia. The source of bacteraemia was very likely to be her household pet, an Italian greyhound. The patient presented with a presumed complex partial seizure but deteriorated rapidly with sepsis and multiorgan dysfunction. Neither scratch nor bite was established, although close petting including licks was reported. Blood cultures grew Gram-negative rods, identified by molecular techniques as C. canimorsus-a bacterium frequently isolated in the oral cavities of dogs and cats. A full recovery was made following 2 weeks of intensive care support and broad-spectrum antibiotics. No underlying immune dysfunction was found.

Liver transplantation for acute liver failure due to efavirenz hepatotoxicity: the importance of routine monitoring.

We present the first case report in the UK of acute liver failure caused by efavirenz therapy culminating in liver transplantation. A 26-year-old Zimbabwean woman commenced emtricitabine, tenofovir and efavirenz (Atripla) in December 2011. Her liver function tests at baseline and at 20 days after initiating antiretroviral therapy were normal. At three months of therapy her blood tests haemolysed and were not processed. She had previously missed follow-up appointments and on this occasion failed to return for repeat tests. She was not seen again until after six months of antiretroviral therapy when she presented to her general practitioner with acute liver failure. Her condition deteriorated and she required liver transplantation. She recovered well and re-started antiretroviral therapy to good effect. The case illustrates the value of routine monitoring after initiating antiretroviral therapy and the fundamental importance of engaging patients in long-term management to ensure safe treatment.

Postcardiotomy syndrome: recurrent cardiac tamponade and an exquisite steroid response.

A 26-year-old woman presented moribund with fever and pleuritic chest pain 3 times in 4 months following elective aortic root surgery. She was admitted 41 days after surgery with cardiac tamponade requiring surgical drainage twice within 1 week. Despite this, she was re-admitted for a second time 4 days after discharge with persistent pericardial effusion. High fevers and an incidental regurgitant murmur were extensively investigated for and treated as possible endocarditis or graft infection without conclusive results. The patient spent a total of 61 days in hospital during this period, receiving seven different antibiotic courses. Her third admission, with most severe clinical features, nearly led to further surgery and removal of her aortic graft but instead culminated in a multidisciplinary team decision to initiate steroid therapy for postcardiotomy syndrome. A short course of oral prednisolone saw her pericardial effusion and symptoms resolve completely.