Establishing SARS-CoV-2 membrane protein-specific antibodies as a valuable serological target via high-content microscopy.

The prevalence and strength of serological responses mounted toward SARS-CoV-2 proteins other than nucleocapsid (N) and spike (S), which may be of use as additional serological markers, remains underexplored. Using high-content microscopy to assess antibody responses against full-length StrepTagged SARS-CoV-2 proteins, we found that 85% (166/196) of unvaccinated individuals with RT-PCR confirmed SARS-CoV-2 infections and 74% (31/42) of individuals infected after being vaccinated developed detectable IgG against the structural protein M, which is higher than previous estimates. Compared with N antibodies, M IgG displayed a shallower time-dependent decay and greater specificity. Sensitivity for SARS-CoV-2 seroprevalence was enhanced when N and M IgG detection was combined. These findings indicate that screening for M seroconversion may be a good approach for detecting additional vaccine breakthrough infections and highlight the potential to use HCM as a rapidly deployable method to identify the most immunogenic targets of newly emergent pathogens.

Longitudinal Lung Function Assessment of Patients Hospitalized With COVID-19 Using 1H and 129Xe Lung MRI.

BACKGROUND: Microvascular abnormalities and impaired gas transfer have been observed in patients with COVID-19. The progression of pulmonary changes in these patients remains unclear. RESEARCH QUESTION: Do patients hospitalized with COVID-19 without evidence of architectural distortion on structural imaging exhibit longitudinal improvements in lung function measured by using 1H and 129Xe MRI between 6 and 52 weeks following hospitalization? STUDY DESIGN AND METHODS: Patients who were hospitalized with COVID-19 pneumonia underwent a pulmonary 1H and 129Xe MRI protocol at 6, 12, 25, and 51 weeks following hospital admission in a prospective cohort study between November 2020 and February 2022. The imaging protocol was as follows: 1H ultra-short echo time, contrast-enhanced lung perfusion, 129Xe ventilation, 129Xe diffusion-weighted, and 129Xe spectroscopic imaging of gas exchange. RESULTS: Nine patients were recruited (age 57 ± 14 [median ± interquartile range] years; six of nine patients were male). Patients underwent MRI at 6 (n = 9), 12 (n = 9), 25 (n = 6), and 51 (n = 8) weeks following hospital admission. Patients with signs of interstitial lung damage were excluded. At 6 weeks, patients exhibited impaired 129Xe gas transfer (RBC to membrane fraction), but lung microstructure was not increased (apparent diffusion coefficient and mean acinar airway dimensions). Minor ventilation abnormalities present in four patients were largely resolved in the 6- to 25-week period. At 12 weeks, all patients with lung perfusion data (n = 6) showed an increase in both pulmonary blood volume and flow compared with 6 weeks, although this was not statistically significant. At 12 weeks, significant improvements in 129Xe gas transfer were observed compared with 6-week examinations; however, 129Xe gas transfer remained abnormally low at weeks 12, 25, and 51. INTERPRETATION: 129Xe gas transfer was impaired up to 1 year following hospitalization in patients who were hospitalized with COVID-19 pneumonia, without evidence of architectural distortion on structural imaging, whereas lung ventilation was normal at 52 weeks.

Risk factors for SARS-CoV-2 seroprevalence following the first pandemic wave in UK healthcare workers in a large NHS Foundation Trust.

BACKGROUND: We aimed to measure SARS-CoV-2 seroprevalence in a cohort of healthcare workers (HCWs) during the first UK wave of the COVID-19 pandemic, explore risk factors associated with infection, and investigate the impact of antibody titres on assay sensitivity. METHODS: HCWs at Sheffield Teaching Hospitals NHS Foundation Trust (STH) were prospectively enrolled and sampled at two time points. SARS-CoV-2 antibodies were tested using an in-house assay for IgG and IgA reactivity against Spike and Nucleoprotein (sensitivity 99·47%, specificity 99·56%). Data were analysed using three statistical models: a seroprevalence model, an antibody kinetics model, and a heterogeneous sensitivity model. FINDINGS: As of 12th June 2020, 24·4% (n=311/1275) HCWs were seropositive. Of these, 39·2% (n=122/311) were asymptomatic. The highest adjusted seroprevalence was measured in HCWs on the Acute Medical Unit (41·1%, 95% CrI 30·0-52·9) and in Physiotherapists and Occupational Therapists (39·2%, 95% CrI 24·4-56·5). Older age groups showed overall higher median antibody titres. Further modelling suggests that, for a serological assay with an overall sensitivity of 80%, antibody titres may be markedly affected by differences in age, with sensitivity estimates of 89% in those over 60 years but 61% in those ≤30 years. INTERPRETATION: HCWs in acute medical units working closely with COVID-19 patients were at highest risk of infection, though whether these are infections acquired from patients or other staff is unknown. Current serological assays may underestimate seroprevalence in younger age groups if validated using sera from older and/or more symptomatic individuals. RESEARCH IN CONTEXT: Evidence before this study: We searched PubMed for studies published up to March 6th 2021, using the terms "COVID", "SARS-CoV-2", "seroprevalence", and "healthcare workers", and in addition for articles of antibody titres in different age groups against coronaviruses using "coronavirus", "SARS-CoV-2, "antibody", "antibody tires", "COVID" and "age". We included studies that used serology to estimate prevalence in healthcare workers. SARS-CoV-2 seroprevalence has been shown to be greater in healthcare workers working on acute medical units or within domestic services. Antibody levels against seasonal coronaviruses, SARS-CoV and SARS-CoV-2 were found to be higher in older adults, and patients who were hospitalised.Added value of this study: In this healthcare worker seroprevalence modelling study at a large NHS foundation trust, we confirm that those working on acute medical units, COVID-19 "Red Zones" and within domestic services are most likely to be seropositive. Furthermore, we show that physiotherapists and occupational therapists have an increased risk of COVID-19 infection. We also confirm that antibody titres are greater in older individuals, even in the context of non-hospitalised cases. Importantly, we demonstrate that this can result in age-specific sensitivity in serological assays, where lower antibody titres in younger individuals results in lower assay sensitivity.Implications of all the available evidence: There are distinct occupational roles and locations in hospitals where the risk of COVID-19 infection to healthcare workers is greatest, and this knowledge should be used to prioritise infection prevention control and other measures to protect healthcare workers. Serological assays may have different sensitivity profiles across different age groups, especially if assay validation was undertaken using samples from older and/or hospitalised patients, who tend to have higher antibody titres. Future seroprevalence studies should consider adjusting for age-specific assay sensitivities to estimate true seroprevalence rates.

Worldwide relative smoking prevalence among people living with and without HIV.

OBJECTIVE AND DESIGN: People living with HIV (PLH) suffer disproportionately from the chronic diseases exacerbated by smoking tobacco. We performed a systematic review and meta-analysis to establish the relative prevalence of smoking among PLH. METHODS: We included observational studies reporting current smoking rates among PLH and comparators without HIV. We searched Medline, EMBASE, LILACS and SciELO from inception to 31 August 2019. We excluded studies that recruited participants with smoking related illness. We used a random effects model to estimate the odds ratio for current smoking in PLH and people without HIV. We used the Newcastle--Ottawa scale to assess methodological bias. We performed subgroup analysis based on sex and WHO region. We quantified heterogeneity with meta-regression and predictive distributions. PROSPERO registration:CRD42016052608. RESULTS: We identified 6116 studies and included 37. Of 111 258 PLH compared with 10 961 217 HIV-negative participants pooled odds of smoking were 1.64 [(95% confidence interval, 95% CI: 1.45-1.85) (95% prediction interval: 0.66-4.10, I2 = 98.1%)]. Odds for men and women living with HIV were 1.68 [(95% CI: 1.44-1.95) (95% prediction interval: 0.71-3.98, I2 = 91.1%)] and 2.16 [(95% CI: 1.77-2.63) (95% prediction interval: 0.92-5.07, I2 = 81.7%)] respectively. CONCLUSION: PLH are more likely to be smokers than people without HIV. This finding was true in subgroup analyses of men, women and in four of five WHO regions from which data were available. Meta-regression did not explain heterogeneity, which we attribute to the diversity of PLH populations worldwide. Smoking is a barrier to PLH achieving parity in life expectancy and an important covariate in studies of HIV-associated multimorbidity.

Risk factors for SARS-CoV-2 seroprevalence following the first pandemic wave in UK healthcare workers in a large NHS Foundation Trust.

Background: We aimed to measure SARS-CoV-2 seroprevalence in a cohort of healthcare workers (HCWs) during the first UK wave of the COVID-19 pandemic, explore risk factors associated with infection, and investigate the impact of antibody titres on assay sensitivity. Methods: HCWs at Sheffield Teaching Hospitals NHS Foundation Trust were prospectively enrolled and sampled at two time points. We developed an in-house ELISA for testing participant serum for SARS-CoV-2 IgG and IgA reactivity against Spike and Nucleoprotein. Data were analysed using three statistical models: a seroprevalence model, an antibody kinetics model, and a heterogeneous sensitivity model. Results: Our in-house assay had a sensitivity of 99·47% and specificity of 99·56%. We found that 24·4% (n=311/1275) of HCWs were seropositive as of 12th June 2020. Of these, 39·2% (n=122/311) were asymptomatic. The highest adjusted seroprevalence was measured in HCWs on the Acute Medical Unit (41·1%, 95% CrI 30·0-52·9) and in Physiotherapists and Occupational Therapists (39·2%, 95% CrI 24·4-56·5). Older age groups showed overall higher median antibody titres. Further modelling suggests that, for a serological assay with an overall sensitivity of 80%, antibody titres may be markedly affected by differences in age, with sensitivity estimates of 89% in those over 60 years but 61% in those ≤30 years. Conclusions:  HCWs in acute medical units and those working closely with COVID-19 patients were at highest risk of infection, though whether these are infections acquired from patients or other staff is unknown. Current serological assays may underestimate seroprevalence in younger age groups if validated using sera from older and/or more severe COVID-19 cases.

Chronic Lung Disease in Patients With Perinatally Acquired HIV in England: A Retrospective Case-Note Review.

Chronic lung disease (CLD) is common in individuals living with perinatally acquired HIV (PA-HIV) in southern/eastern Africa. Most of the UK PA-HIV population are African. We conducted a case-note review of CLD in 3 UK PA-HIV cohorts (n = 98). Bronchiectasis or obliterative bronchiolitis occurred in 8.1% of patients and ring/tramline opacities occurred in 19.2% of patients on chest radiograph. There may be unrecognized and underdiagnosed CLD among PA-HIV in the UK.

HIV gp120 in the Lungs of Antiretroviral Therapy-treated Individuals Impairs Alveolar Macrophage Responses to Pneumococci.

RATIONALE: People living with HIV are at significantly increased risk of invasive pneumococcal disease, despite long-term antiretroviral therapy (ART). The mechanism explaining this observation remains undefined. OBJECTIVES: To determine if apoptosis-associated microbicidal mechanisms, required to clear intracellular pneumococci that survive initial phagolysosomal killing, are perturbed. METHODS: Alveolar macrophages (AM) were obtained by BAL from healthy donors or HIV-1-seropositive donors on long-term ART with undetectable plasma viral load. Monocyte-derived macrophages (MDM) were obtained from healthy donors and infected with HIV-1BaL or treated with gp120. Macrophages were challenged with opsonized serotype 2 Streptococcus pneumoniae and assessed for apoptosis, bactericidal activity, protein expression, and mitochondrial reactive oxygen species (mROS). AM phenotyping, ultrasensitive HIV-1 RNA quantification, and gp120 measurement were also performed in BAL. MEASUREMENTS AND MAIN RESULTS: HIV-1BaL infection impaired apoptosis, induction of mROS, and pneumococcal killing by MDM. Apoptosis-associated pneumococcal killing was also reduced in AM from ART-treated HIV-1-seropositive donors. BAL fluid from these individuals demonstrated persistent lung CD8+ T lymphocytosis, and gp120 or HIV-1 RNA was also detected. Despite this, transcriptional activity in AM freshly isolated from people living with HIV was broadly similar to healthy volunteers. Instead, gp120 phenocopied the defect in pneumococcal killing in healthy MDM through post-translational modification of Mcl-1, preventing apoptosis induction, caspase activation, and increased mROS generation. Moreover, gp120 also inhibited mROS-dependent pneumococcal killing in MDM. CONCLUSIONS: Despite ART, HIV-1, via gp120, drives persisting innate immune defects in AM microbicidal mechanisms, enhancing susceptibility to pneumococcal disease.

Clostridium difficile infection in patients with HIV/AIDS.

Clostridium difficile infection (CDI) affects significant numbers of hospitalized patients and is an increasing problem in the community. It is also among the most commonly isolated pathogens in HIV patients with diarrheal illness and is ≥2 fold more common in HIV-seropositive individuals. This association is stronger in those with low absolute CD4 T cell counts or meeting clinical criteria for an AIDS diagnosis, and was most pronounced before the wide availability of highly active antiretroviral therapy. The presentation and outcome of CDI in HIV appears similar to the general population. The increased risk can in part be attributed to increased hospitalization and antimicrobial use, but HIV related alterations in fecal microbiota, gut mucosal integrity, and humoral and cell mediated immunity are also likely to play a role. Here we review the evidence for these observations and the relevance of recent advances in the diagnosis and management of CDI for the HIV clinician.

Low concordance with HIV testing guidelines in a retrospective review of intensive care practice.

UNLABELLED: Records were reviewed (n=1052) for patients admitted to a large general intensive care unit (GICU) and examined for HIV testing criteria published in UK national testing guidelines (UKNG). All actual tests sent from GICU were also examined for comparison. Strict application of the UKNG revealed 30% of patients met criteria for HIV testing on admission to GICU. With pragmatic application, 18% of admissions met criteria for testing. Less than 5% of admissions were actually tested when no testing guideline was adopted. DISCUSSION: The UKNG can be adopted in a representative GICU to increase HIV testing rate by 4-6-fold.

Clostridium difficile infection in HIV-seropositive individuals and transplant recipients.

Immunocompromise is a commonly cited risk factor for Clostridium difficile infection (CDI). We reviewed the experimental and epidemiological literature on CDI in three immunocompromised groups, HIV-seropositive individuals, haematopoietic stem cell or bone marrow transplant recipients and solid organ transplant recipients. All three groups have varying degrees of impairment of humoral immunity, a major factor influencing the outcome of CDI. Soluble HIV proteins such as nef and immunosuppressive agents such as cyclosporin, azathioprine and mycophenalate mofetil modify signalling from the key cellular pathways triggered by C. difficile toxin A, although there is a paucity of data on how these factors may interact with pathways activated by toxin B. Despite this, there has been little direct investigation into the effect of immunosuppression on the pathogenesis of CDI. Epidemiological studies consistently show increased rates of CDI in these populations, which are higher in those with greater degrees of immunocompromise such as individuals with advanced AIDS not receiving combination antiretroviral therapy or allogeneic haematopoietic stem cell transplant recipients. Less consistently data suggests immunocompromise in each group also impacts rates of severe, recurrent or complicated CDI. However all these conditions are characterised by high levels of antibiotic use and prolonged hospital stay, both powerful drivers of CDI risk.