Genetic risk of osteoarthritis operates during human skeletogenesis.

Osteoarthritis (OA) is a polygenic disease of older people resulting in the breakdown of cartilage within articular joints. Although it is a leading cause of disability, there are no disease-modifying therapies. Evidence is emerging to support the origins of OA in skeletogenesis. Whereas methylation quantitative trait loci (mQTLs) co-localizing with OA genome-wide association study signals have been identified in aged human cartilage and used to identify effector genes and variants, such analyses have never been conducted during human development. Here, for the first time, we have investigated the developmental origins of OA genetic risk at seven well-characterized OA risk loci, comprising 39 OA-mQTL CpGs, in human fetal limb (FL) and cartilage (FC) tissues using a range of molecular genetic techniques. We identified significant OA-mQTLs at 14 and 29 CpGs in FL and FC tissues, respectively, and compared our results with aged cartilage samples (AC). Differential methylation was observed at 26 sites between FC and AC, with the majority becoming actively hypermethylated in old age. Notably, 6/9 OA effector genes showed allelic expression imbalances during fetal development. Finally, we conducted ATAC-sequencing in cartilage from the developing and aged hip and knee to identify accessible chromatin regions and found enrichment for transcription factor binding motifs including SOX9 and FOS/JUN. For the first time, we have demonstrated the activity of OA-mQTLs and expression imbalance of OA effector genes during human skeletogenesis. We show striking differences in the spatiotemporal function of these loci, contributing to our understanding of OA aetiology, with implications for the timing and strategy of pharmacological interventions.

Imagery re-scripting for PTSD: session content and its relation to symptom improvement.

Imagery rescripting (ImRs) is a therapy technique that, unlike traditional re-living techniques, focuses less on exposure and verbal challenging of cognitions and instead encourages patients to directly transform the intrusive imagery to change the depicted course of events in a more desired direction. However, a comprehensive account of how and in what circumstances ImRs brings about therapeutic change is required if treatment is to be optimised, and this is yet to be developed. The present study reports on the development of a coding scheme of ImRs psychotherapy elements identified in the literature as potential ImRs mechanisms. The codes were assessed in relation to short-term outcomes of 27 individuals undergoing ImRs for post-traumatic stress disorder. The timing of the change in the image, degree of activation of the new image and associated cognitive, emotional and physiological processes, self-guided rescripting, rescript believability, narrative coherence and cognitive and emotional shift were identified as being related to symptom change and so are potentially important factors for the re-scripting process.

Self-efficacy and oral health outcomes in a regional Australian Aboriginal population.

BACKGROUND: Perceived self-efficacy has been associated with psychological well-being, health behaviours and health outcomes. Little is known about the influence of self-efficacy on oral health outcomes for Aboriginal adults in Australia, a population experiencing high levels of oral health conditions. This study examines associations between oral health-related self-efficacy and oral health outcomes in a regional Aboriginal Australian population and investigates whether the associations persist after adjusting for sociodemographic characteristics and other general and oral health-related psychosocial factors. METHODS: Cross-sectional data were obtained from the baseline questionnaire of the Indigenous Oral Heath Literacy Project, South Australia. Oral health-related self-efficacy was measured using a six item scale, with total sum scores dichotomised into high/low self-efficacy. Oral health outcomes included self-rated oral health and oral health impacts, measured using the Oral Health Impact Profile (OHIP-14). Generalized linear models with a log-Poisson link function were used to estimate Prevalence Ratios (PR) of poor self-rated oral health according to levels of oral health-related self-efficacy. Multivariable linear regressions were used to estimate the association between oral health-related self-efficacy and OHIP-14 scores. Blocks of confounders were subsequently added into the models, with the final model including all factors. RESULTS: Complete data were available for 252 participants (63%) aged 18 to 82 years (mean age of 37.6 years). Oral health-related self-efficacy was associated with poor self-rated oral health, with a 43% (PR = 1.43 (95% CI 1.09, 1.88)) greater prevalence of poor self-rated oral health among those with low self-efficacy. Oral health-related self-efficacy was associated with OHIP-14 severity scores, with a score over six points higher for those with low self-efficacy (B = 6.27 95% CI 2.71, 9.83). Although addition of perceived stress into the models attenuated the relationship, associations remained in the final models. CONCLUSION: Lower levels of oral health-related self-efficacy were associated with a higher prevalence of poor self-rated oral health and greater impacts of oral health among Aboriginal adults in regional South Australia. These associations persisted after controlling for sociodemographic and psychosocial confounders, suggesting that increasing self-efficacy may provide an opportunity for improving oral health outcomes for Aboriginal adults.

The Association Between Antibody Response to Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Post-COVID-19 Syndrome in Healthcare Workers.

It is currently unknown how post-COVID-19 syndrome (PCS) may affect those infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This longitudinal study includes healthcare staff who tested positive for SARS-CoV-2 between March and April 2020, with follow-up of their antibody titers and symptoms. More than half (21 of 38) had PCS after 7-8 months. There was no statistically significant difference between initial reverse-transcription polymerase chain reaction titers or serial antibody levels between those who did and those who did not develop PCS. This study highlights the relative commonality of PCS in healthcare workers and this should be considered in vaccination scheduling and workforce planning to allow adequate frontline staffing numbers.

Longevity of SARS-CoV-2 immune responses in hemodialysis patients and protection against reinfection.

Patients with end stage kidney disease receiving in-center hemodialysis (ICHD) have had high rates of SARS-CoV-2 infection. Following infection, patients receiving ICHD frequently develop circulating antibodies to SARS-CoV-2, even with asymptomatic infection. Here, we investigated the durability and functionality of the immune responses to SARS-CoV-2 infection in patients receiving ICHD. Three hundred and fifty-six such patients were longitudinally screened for SARS-CoV-2 antibodies and underwent routine PCR-testing for symptomatic and asymptomatic infection. Patients were regularly screened for nucleocapsid protein (anti-NP) and receptor binding domain (anti-RBD) antibodies, and those who became seronegative at six months were screened for SARS-CoV-2 specific T-cell responses. One hundred and twenty-nine (36.2%) patients had detectable antibody to anti-NP at time zero, of whom 127 also had detectable anti-RBD. Significantly, at six months, 71/111 (64.0%) and 99/116 (85.3%) remained anti-NP and anti-RBD seropositive, respectively. For patients who retained antibody, both anti-NP and anti-RBD levels were reduced significantly after six months. Eleven patients who were anti-NP seropositive at time zero, had no detectable antibody at six months; of whom eight were found to have SARS-CoV-2 antigen specific T cell responses. Independent of antibody status at six months, patients with baseline positive SARS-CoV-2 serology were significantly less likely to have PCR confirmed infection over the following six months. Thus, patients receiving ICHD mount durable immune responses six months post SARS-CoV-2 infection, with fewer than 3% of patients showing no evidence of humoral or cellular immunity.

Self-efficacy and self-rated oral health among pregnant aboriginal Australian women.

BACKGROUND: Self-efficacy plays an important role in oral health-related behaviours. There is little known about associations between self-efficacy and subjective oral health among populations at heightened risk of dental disease. This study aimed to determine if low self-efficacy was associated with poor self-rated oral health after adjusting for confounding among a convenience sample of pregnant women. METHODS: We used self-reported data from 446 Australian women pregnant with an Aboriginal child (age range 14-43 years) to evaluate self-rated oral health, self-efficacy and socio-demographic, psychosocial, social cognitive and risk factors. Hierarchical entry of explanatory variables into logistic regression models estimated prevalence odds ratios (POR) and 95% confidence intervals (95% CI) for fair or poor self-rated oral health. RESULTS: In an unadjusted model, those with low self-efficacy had 2.40 times the odds of rating their oral health as 'fair' or 'poor' (95% CI 1.54-3.74). Addition of socio-demographic factors attenuated the effect of low self-efficacy on poor self-rated oral health by 10 percent (POR 2.19, 95% CI 1.37-3.51). Addition of the psychosocial factors attenuated the odds by 17 percent (POR 2.07, 95% CI 1.28-3.36), while addition of the social cognitive variable fatalism increased the odds by 1 percent (POR 2.42, 95% CI 1.55-3.78). Inclusion of the behavioural risk factor 'not brushing previous day' attenuated the odds by 15 percent (POR 2.11, 95%CI 1.32-3.36). In the final model, which included all covariates, the odds were attenuated by 32 percent (POR 1.80, 95% CI 1.05, 3.08). CONCLUSIONS: Low self-efficacy persisted as a risk indicator for poor self-rated oral health after adjusting for confounding among this vulnerable population.

A pro-inflammatory gut mucosal cytokine response is associated with mild COVID-19 disease and superior induction of serum antibodies.

The relationship between gastrointestinal tract infection, the host immune response, and the clinical outcome of disease is not well understood in COVID-19. We sought to understand the effect of intestinal immune responses to SARS-CoV-2 on patient outcomes including the magnitude of systemic antibody induction. Combining two prospective cohort studies, International Severe Acute Respiratory and emerging Infections Consortium Comprehensive Clinical Characterisations Collaboration (ISARIC4C) and Integrated Network for Surveillance, Trials and Investigations into COVID-19 Transmission (INSTINCT), we acquired samples from 88 COVID-19 cases representing the full spectrum of disease severity and analysed viral RNA and host gut cytokine responses in the context of clinical and virological outcome measures. There was no correlation between the upper respiratory tract and faecal viral loads. Using hierarchical clustering, we identified a group of fecal cytokines including Interleukin-17A, Granulocyte macrophage colony-stimulating factor, Tumor necrosis factorα, Interleukin-23, and S100A8, that were transiently elevated in mild cases and also correlated with the magnitude of systemic anti-Spike-receptor-binding domain antibody induction. Receiver operating characteristic curve analysis showed that expression of these gut cytokines at study enrolment in hospitalised COVID-19 cases was associated negatively with overall clinical severity implicating a protective role in COVID-19. This suggests that a productive intestinal immune response may be beneficial in the response to a respiratory pathogen and a biomarker of a successful barrier response.

Electrochemical and Structural Investigation of ReO3.

The structural evolution with alkali ion insertion, and the subsequent thermal evolution of the alkali-ion inserted ReO3 electrodes are shown by employing in situ and ex situ synchrotron X-ray diffraction (XRD). During Na and K insertion, there is a combination of intercalation into ReO3 and a two-phase reaction. Interestingly in the case of Li insertion, a more complex evolution is noted, which suggests a conversion reaction takes place at deep discharge (insertion). Following these ion insertion studies, extracted electrodes at various states of discharge (kinetically determined) were examined with variable temperature XRD. The thermal evolution of the Ax ReO3 phases, where A=Li, Na, or K, are significantly modified from the parent ReO3 thermal evolution. This shows the impact of alkali-ion insertion on the thermal properties of ReO3 .

Hybrid immunity in older adults is associated with reduced SARS-CoV-2 infections following BNT162b2 COVID-19 immunisation.

BACKGROUND: Older adults, particularly in long-term care facilities (LTCF), remain at considerable risk from SARS-CoV-2. Data on the protective effect and mechanisms of hybrid immunity are skewed towards young adults precluding targeted vaccination strategies. METHODS: A single-centre longitudinal seroprevalence vaccine response study was conducted with 280 LCTF participants (median 82 yrs, IQR 76-88 yrs; 95.4% male). Screening by SARS-CoV-2 polymerase chain reaction with weekly asymptomatic/symptomatic testing (March 2020-October 2021) and serology pre-/post-two-dose Pfizer-BioNTech BNT162b2 vaccination for (i) anti-nucleocapsid, (ii) quantified anti-receptor binding domain (RBD) antibodies at three time-intervals, (iii) pseudovirus neutralisation, and (iv) inhibition by anti-RBD competitive ELISA were conducted. Neutralisation activity: antibody titre relationship was assessed via beta linear-log regression and RBD antibody-binding inhibition: post-vaccine infection relationship by Wilcoxon rank sum test. RESULTS: Here we show neutralising antibody titres are 9.2-fold (95% CI 5.8-14.5) higher associated with hybrid immunity (p < 0.00001); +7.5-fold (95% CI 4.6-12.1) with asymptomatic infection; +20.3-fold, 95% (CI 9.7-42.5) with symptomatic infection. A strong association is observed between antibody titre: neutralising activity (p < 0.00001) and rising anti-RBD antibody titre: RBD antibody-binding inhibition (p < 0.001), although 18/169 (10.7%) participants with high anti-RBD titre (>100BAU/ml), show inhibition <75%. Higher RBD antibody-binding inhibition values are associated with hybrid immunity and reduced likelihood of infection (p = 0.003). CONCLUSIONS: Hybrid immunity in older adults was associated with considerably higher antibody titres, neutralisation and inhibition capacity. Instances of high anti-RBD titre with lower inhibition suggests antibody quantity and quality as independent potential correlates of protection, highlighting added value of measuring inhibition over antibody titre alone to inform vaccine strategy.

Older adults continue to be at risk of COVID-19, particularly in residential care home settings. We investigated the effect of infection and vaccination on antibody development and subsequent SARS-CoV-2 infection in older adults. Antibodies are proteins that the immune system produces on infection or vaccination that can help respond to subsequent infection with SARS-CoV-2. We found that older adults produce antibodies to SARS-CoV-2 after 2-doses of Pfizer BioNTech BNT162b2 vaccine. The strongest immune responses were seen among those older adults who also had prior history of infection. The results highlight the importance of both antibody quality and quantity when considering possible indicators of protection against COVID-19 and supports the need for a third, booster, vaccination in this age group..

Risk factors and vectors for SARS-CoV-2 household transmission: a prospective, longitudinal cohort study.

BACKGROUND: Despite circumstantial evidence for aerosol and fomite spread of SARS-CoV-2, empirical data linking either pathway with transmission are scarce. Here we aimed to assess whether the presence of SARS-CoV-2 on frequently-touched surfaces and residents' hands was a predictor of SARS-CoV-2 household transmission. METHODS: In this longitudinal cohort study, during the pre-alpha (September to December, 2020) and alpha (B.1.1.7; December, 2020, to April, 2021) SARS-CoV-2 variant waves, we prospectively recruited contacts from households exposed to newly diagnosed COVID-19 primary cases, in London, UK. To maximally capture transmission events, contacts were recruited regardless of symptom status and serially tested for SARS-CoV-2 infection by RT-PCR on upper respiratory tract (URT) samples and, in a subcohort, by serial serology. Contacts' hands, primary cases' hands, and frequently-touched surface-samples from communal areas were tested for SARS-CoV-2 RNA. SARS-CoV-2 URT isolates from 25 primary case-contact pairs underwent whole-genome sequencing (WGS). FINDINGS: From Aug 1, 2020, until March 31, 2021, 620 contacts of PCR-confirmed SARS-CoV-2-infected primary cases were recruited. 414 household contacts (from 279 households) with available serial URT PCR results were analysed in the full household contacts' cohort, and of those, 134 contacts with available longitudinal serology data and not vaccinated pre-enrolment were analysed in the serology subcohort. Household infection rate was 28·4% (95% CI 20·8-37·5) for pre-alpha-exposed contacts and 51·8% (42·5-61·0) for alpha-exposed contacts (p=0·0047). Primary cases' URT RNA viral load did not correlate with transmission, but was associated with detection of SARS-CoV-2 RNA on their hands (p=0·031). SARS-CoV-2 detected on primary cases' hands, in turn, predicted contacts' risk of infection (adjusted relative risk [aRR]=1·70 [95% CI 1·24-2·31]), as did SARS-CoV-2 RNA presence on household surfaces (aRR=1·66 [1·09-2·55]) and contacts' hands (aRR=2·06 [1·57-2·69]). In six contacts with an initial negative URT PCR result, hand-swab (n=3) and household surface-swab (n=3) PCR positivity preceded URT PCR positivity. WGS corroborated household transmission. INTERPRETATION: Presence of SARS-CoV-2 RNA on primary cases' and contacts' hands and on frequently-touched household surfaces associates with transmission, identifying these as potential vectors for spread in households. FUNDING: National Institute for Health Research Health Protection Research Unit in Respiratory Infections, Medical Research Council.

SARS-CoV-2 antibody responses associate with sex, age and disease severity in previously uninfected people admitted to hospital with COVID-19: An ISARIC4C prospective study.

The SARS-CoV-2 pandemic enables the analysis of immune responses induced against a novel coronavirus infecting immunologically naïve individuals. This provides an opportunity for analysis of immune responses and associations with age, sex and disease severity. Here we measured an array of solid-phase binding antibody and viral neutralising Ab (nAb) responses in participants (n=337) of the ISARIC4C cohort and characterised their correlation with peak disease severity during acute infection and early convalescence. Overall, the responses in a Double Antigen Binding Assay (DABA) for antibody to the receptor binding domain (anti-RBD) correlated well with IgM as well as IgG responses against viral spike, S1 and nucleocapsid protein (NP) antigens. DABA reactivity also correlated with nAb. As we and others reported previously, there is greater risk of severe disease and death in older men, whilst the sex ratio was found to be equal within each severity grouping in younger people. In older males with severe disease (mean age 68 years), peak antibody levels were found to be delayed by one to two weeks compared with women, and nAb responses were delayed further. Additionally, we demonstrated that solid-phase binding antibody responses reached higher levels in males as measured via DABA and IgM binding against Spike, NP and S1 antigens. In contrast, this was not observed for nAb responses. When measuring SARS-CoV-2 RNA transcripts (as a surrogate for viral shedding) in nasal swabs at recruitment, we saw no significant differences by sex or disease severity status. However, we have shown higher antibody levels associated with low nasal viral RNA indicating a role of antibody responses in controlling viral replication and shedding in the upper airway. In this study, we have shown discernible differences in the humoral immune responses between males and females and these differences associate with age as well as with resultant disease severity.

Reducing disease burden and health inequalities arising from chronic disease among Indigenous children: an early childhood caries intervention.

BACKGROUND: This study seeks to determine if implementing a culturally-appropriate early childhood caries (ECC) intervention reduces dental disease burden and oral health inequalities among Indigenous children living in South Australia, Australia. METHODS/DESIGN: This paper describes the study protocol for a randomised controlled trial conducted among Indigenous children living in South Australia with an anticipated sample of 400. The ECC intervention consists of four components: (1) provision of dental care; (2) fluoride varnish application to the teeth of children; (3) motivational interviewing and (4) anticipatory guidance. Participants are randomly assigned to two intervention groups, immediate (n = 200) or delayed (n = 200). Provision of dental care (1) occurs during pregnancy in the immediate intervention group or when children are 24-months in the delayed intervention group. Interventions (2), (3) and (4) occur when children are 6-, 12- and 18-months in the immediate intervention group or 24-, 30- and 36-months in the delayed intervention group. Hence, all participants receive the ECC intervention, though it is delayed 24 months for participants who are randomised to the control-delayed arm. In both groups, self-reported data will be collected at baseline (pregnancy) and when children are 24- and 36-months; and child clinical oral health status will be determined during standardised examinations conducted at 24- and 36-months by two calibrated dental professionals. DISCUSSION: Expected outcomes will address whether exposure to a culturally-appropriate ECC intervention is effective in reducing dental disease burden and oral health inequalities among Indigenous children living in South Australia.

An oral health literacy intervention for Indigenous adults in a rural setting in Australia.

BACKGROUND: Indigenous Australians suffer substantially poorer oral health than their non-Indigenous counterparts and new approaches are needed to address these disparities. Previous work in Port Augusta, South Australia, a regional town with a large Indigenous community, revealed associations between low oral health literacy scores and self-reported oral health outcomes. This study aims to determine if implementation of a functional, context-specific oral health literacy intervention improves oral health literacy-related outcomes measured by use of dental services, and assessment of oral health knowledge, oral health self-care and oral health- related self-efficacy. METHODS/DESIGN: This is a randomised controlled trial (RCT) that utilises a delayed intervention design. Participants are Indigenous adults, aged 18 years and older, who plan to reside in Port Augusta or a nearby community for the next two years. The intervention group will receive the intervention from the outset of the study while the control group will be offered the intervention 12 months following their enrollment in the study. The intervention consists of a series of five culturally sensitive, oral health education workshops delivered over a 12 month period by Indigenous project officers. Workshops consist of presentations, hands-on activities, interactive displays, group discussions and role plays. The themes addressed in the workshops are underpinned by oral health literacy concepts, and incorporate oral health-related self-efficacy, oral health-related fatalism, oral health knowledge, access to dental care and rights and entitlements as a patient. Data will be collected through a self-report questionnaire at baseline, at 12 months and at 24 months. The primary outcome measure is oral health literacy. Secondary outcome measures include oral health knowledge, oral health self-care, use of dental services, oral health-related self-efficacy and oral health-related fatalism. DISCUSSION: This study uses a functional, context-specific oral health literacy intervention to improve oral health literacy-related outcomes amongst rural-dwelling Indigenous adults. Outcomes of this study will have implications for policy and planning by providing evidence for the effectiveness of such interventions as well as provide a model for working with Indigenous communities.

The effects of REV5901 on intracellular calcium signalling in freshly isolated bovine articular chondrocytes.

REV5901 is an inhibitor of regulatory volume decrease (RVD) a mechanotransduction pathway regulating cell volume in response to hypotonicity, with protective properties upon chondrocyte trauma impact in situ. As the mechanism of action of REV5901 is unknown and changes in intracellular calcium ([Ca2+]i) have been linked to REV5901-loading, we investigated the effects of REV5901 on a known calcium signalling pathway. Upon REV5901 loading, there was significant increase in [Ca2+]i reaching 37.97 ± 5.67%, above basal levels which was reduced to 27.86 ± 3.15% in the presence of 2 mmol/l EGTA. In the presence of U73122 or neomycin there was a decrease in calcium with inhibition factors (I.F.) of 0.39 ± 0.09 and 0.37 ± 0.08, respectively, whereas rottlerin abolished the REV5901-induced [Ca2+]i rise. The role of calcium channels in contributing to the REV5901-induced calcium rise was investigated whereby the calcium rise was inhibited in the absence of extracellular sodium and by the addition of Gd3+ and Ruthenium red. These data show a phospholipase Cß3-dependent release of calcium from intracellular stores as well as a sodium calcium exchanger-mediated influx in response to REV5901 loading, suggesting a potential role for calcium signalling in mediating the action of REV5901 in chondrocytes.

Organic versus mixed specialist older adult inpatient mental health units for people with dementia.

Dementia presents a major public health challenge to healthcare providers globally. When older people with dementia need inpatient mental healthcare, they can be cared for in one of two different types of older adult ward. These patients can either be admitted to an organic inpatient ward for people with dementia or the subtypes of dementia, or they can be admitted to a mixed inpatient ward for older people who have either functional or organic conditions. Using a quality assurance pilot study, the authors aimed to investigate whether the quality of care for patients with dementia differed between mixed and organic inpatient wards in units exclusively serving older people. The quality of care on both types of ward was compared by analysing observed interactions between patients and staff, patient well-being and patient environment and mealtimes. The quality of care was measured with a specially developed instrument and against evidence-based standards of care. The ratings of both types of ward showed high levels of quality interactions between patients and staff. There were minimal differences in the quality of patient and staff interactions, patient well-being, and patient environment and mealtimes between the two types of ward. Further work on outcomes and carer experiences needs to be undertaken to establish the optimal care environment for people with dementia.

Highly sensitive and specific detection of the SARS-CoV-2 Delta variant by double-mismatch allele-specific real time reverse transcription PCR.

BACKGROUND: The highly transmissible Delta variant of SARS-CoV-2 (B.1.617.2), first identified in India, is currently replacing pre-existing variants in many parts of the world. To help guide public health policies it is important to monitor efficiently its spread. Genome sequencing is the gold standard for identification of Delta, but is time-consuming, expensive, and unavailable in many regions. OBJECTIVE: To develop and evaluate a rapid, simple and inexpensive alternative to sequencing for Delta identification. METHODS: A double-mismatch allele-specific RT-PCR (DMAS-RT-PCR) was developed. The technique exploits allele-specific primers, targeting two spike gene mutations, L452R and T478K, within the same amplicon. The discriminatory power of each primer was enhanced by an additional mismatch located at the fourth nucleotide from the 3' end. Specificity was assessed by testing well characterised cell culture-derived viral isolates and clinical samples, most of which had previously been fully sequenced. RESULTS: In all cases the results of viral genotyping by DMAS-RT-PCR were entirely concordant with the results of sequencing, and the assay was shown to discriminate reliably between the Delta variant and other variants (Alpha and Beta), and 'wild-type' SARS-CoV-2. Influenza A and RSV were non-reactive in the assay. The sensitivity of DMAS-RT-PCR matched that of the diagnostic SARS-CoV-2 RT-qPCR screening assay. Several samples that could not be sequenced due to insufficient virus were successfully genotyped by DMAS-RT-PCR. CONCLUSION: The method we describe would be simple to establish in any laboratory that can conduct PCR assays and should greatly facilitate monitoring of the spread of the Delta variant globally.

Identification of TMEM129, encoding a ubiquitin-protein ligase, as an effector gene of osteoarthritis genetic risk.

BACKGROUND: Osteoarthritis is highly heritable and genome-wide studies have identified single nucleotide polymorphisms (SNPs) associated with the disease. One such locus is marked by SNP rs11732213 (T > C). Genotype at rs11732213 correlates with the methylation levels of nearby CpG dinucleotides (CpGs), forming a methylation quantitative trait locus (mQTL). This study investigated the regulatory activity of the CpGs to identify a target gene of the locus. METHODS: Nucleic acids were extracted from the articular cartilage of osteoarthritis patients. Samples were genotyped, and DNA methylation was quantified by pyrosequencing at 14 CpGs within a 259-bp interval. CpGs were tested for enhancer effects in immortalised chondrocytes using a reporter gene assay. DNA methylation at the locus was altered using targeted epigenome editing, with the impact on gene expression determined using quantitative polymerase chain reaction. RESULTS: rs11732213 genotype correlated with DNA methylation at nine CpGs, which formed a differentially methylated region (DMR), with the osteoarthritis risk allele T corresponding to reduced levels of methylation. The DMR acted as an enhancer and demethylation of the CpGs altered expression of TMEM129. Allelic imbalance in TMEM129 expression was identified in cartilage, with under-expression of the risk allele. CONCLUSIONS: TMEM129 is a target of osteoarthritis genetic risk at this locus. Genotype at rs11732213 impacts DNA methylation at the enhancer, which, in turn, modulates TMEM129 expression. TMEM129 encodes an enzyme involved in protein degradation within the endoplasmic reticulum, a process previously implicated in osteoarthritis. TMEM129 is a compelling osteoarthritis susceptibility target.

Tracking the incidence and risk factors for SARS-CoV-2 infection using historical maternal booking serum samples.

The early transmission dynamics of SARS-CoV-2 in the UK are unknown but their investigation is critical to aid future pandemic planning. We tested over 11,000 anonymised, stored historic antenatal serum samples, given at two north-west London NHS trusts in 2019 and 2020, for total antibody to SARS-CoV-2 receptor binding domain (anti-RBD). Estimated prevalence of seroreactivity increased from 1% prior to mid-February 2020 to 17% in September 2020. Our results show higher prevalence of seroreactivity to SARS-CoV-2 in younger, non-white ethnicity, and more deprived groups. We found no significant interaction between the effects of ethnicity and deprivation. Derived from prevalence, the estimated incidence of seroreactivity reflects the trends observed in daily hospitalisations and deaths in London that followed 10 and 13 days later, respectively. We quantified community transmission of SARS-CoV-2 in London, which peaked in late March / early April 2020 with no evidence of community transmission until after January 2020. Our study was not able to determine the date of introduction of the SARS-CoV-2 virus but demonstrates the value of stored antenatal serum samples as a resource for serosurveillance during future outbreaks.

Simple, sensitive, specific self-sampling assay secures SARS-CoV-2 antibody signals in sero-prevalence and post-vaccine studies.

At-home sampling is key to large scale seroprevalence studies. Dried blood spot (DBS) self-sampling removes the need for medical personnel for specimen collection but facilitates specimen referral to an appropriately accredited laboratory for accurate sample analysis. To establish a highly sensitive and specific antibody assay that would facilitate self-sampling for prevalence and vaccine-response studies. Paired sera and DBS eluates collected from 439 sero-positive, 382 sero-negative individuals and DBS from 34 vaccine recipients were assayed by capture ELISAs for IgG and IgM antibody to SARS-CoV-2. IgG and IgM combined on DBS eluates achieved a diagnostic sensitivity of 97.9% (95%CI 96.6 to 99.3) and a specificity of 99.2% (95% CI 98.4 to 100) compared to serum, displaying limits of detection equivalent to 23 and 10 WHO IU/ml, respectively. A strong correlation (r = 0.81) was observed between serum and DBS reactivities. Reactivity remained stable with samples deliberately rendered inadequate, (p = 0.234) and when samples were accidentally damaged or 'invalid'. All vaccine recipients were sero-positive. This assay provides a secure method for self-sampling by DBS with a sensitivity comparable to serum. The feasibility of DBS testing in sero-prevalence studies and in monitoring post-vaccine responses was confirmed, offering a robust and reliable tool for serological monitoring at a population level.