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Chronic rhinosinusitis (CRS) refers to inflammation of the nasal sinuses and mucosa, with persistence of sinus inflammation and clinical manifestations beyond 12 weeks.1 CRS affects between 6 and 12% of adults and is a cause of reduced quality of life (QoL) and high healthcare costs.2 Management consisted of topical and systemic glucocorticoids, antibiotics and often repeated sinus surgery. Over the past 20 years, biologic therapies under investigation for asthma, with overlapping nasal polyposis, have shown significant improvement in sinonasal CRS symptoms and reduced nasal polyp swelling.3 This Cochrane Corner aims to summarize the effectiveness, safety and role of biological therapy in CRS to aid clinicians in the decision-making process.

Background The antibacterial, anti-inflammatory, and antiviral properties of azithromycin suggest therapeutic potential against COVID-19. Randomised data in mild-to-moderate disease are not available. We assessed whether azithromycin is effective in reducing hospital admission in patients with mild-to-moderate COVID-19. Methods This prospective, open-label, randomised superiority trial was done at 19 hospitals in the UK. We enrolled adults aged at least 18 years presenting to hospitals with clinically diagnosed, highly probable or confirmed COVID-19 infection, with fewer than 14 days of symptoms, who were considered suitable for initial ambulatory management. Patients were randomly assigned (1:1) to azithromycin (500 mg once daily orally for 14 days) plus standard care or to standard care alone. The primary outcome was death or hospital admission from any cause over the 28 days from randomisation. The primary and safety outcomes were assessed according to the intention-to-treat principle. This trial is registered at ClinicalTrials.gov (NCT04381962) and recruitment is closed. Findings 298 participants were enrolled from June 3, 2020, to Jan 29, 2021. Three participants withdrew consent and requested removal of all data, and three further participants withdrew consent after randomisation, thus, the primary outcome was assessed in 292 participants (145 in the azithromycin group and 147 in the standard care group). The mean age of the participants was 45·9 years (SD 14·9). 15 (10%) participants in the azithromycin group and 17 (12%) in the standard care group were admitted to hospital or died during the study (adjusted OR 0·91 [95% CI 0·43–1·92], p=0·80). No serious adverse events were reported. Interpretation In patients with mild-to-moderate COVID-19 managed without hospital admission, adding azithromycin to standard care treatment did not reduce the risk of subsequent hospital admission or death. Our findings do not support the use of azithromycin in patients with mild-to-moderate COVID-19. Funding National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford and Pfizer.

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To evaluate the effects of subcutaneous omalizumab versus placebo for asthma in adults and children.

Background: Non-suppression of fractional exhaled nitric oxide (FeNO) during remotely monitored inhaled corticosteroid (ICS) therapy is associated with persistent symptoms and blood eosinophilia. To provide mechanistic insight, we assessed sputum type 2 cytokines and chemokines before and after a FeNO suppression test. Methods: FeNO suppression was performed in 44 patients with severe asthma and FeNO > 40 ppb. FeNO was monitored for 7 days of 1000μg of fluticasone propionate delivered via an INCATM device, with clinical and sputum sampling on days 0 and 7. FeNO suppression was defined as a 42% reduction in FeNO. Sputum supernatant was analyzed in 15 paired samples by ELISA (Prostaglandin D2, Leukotriene E4) and MSD assays (IL-4,-5,-13,-25,-33, CCL26, TSLP). Results: Suppressors (n=21) vs non-suppressors had a greater drop in ACQ-5 (mean∆: -1.2 vs -0.3, p Conclusion: Failure to suppress FeNO during ICS treatment was associated with steroid-unresponsive sputum PGD2 and LTE4 levels.

Reduction of the risk of asthma attacks is a major goal of current asthma management. We propose to derive a risk scale predicting asthma attacks based on the blood eosinophil count and exhaled nitric oxide (FeNO). Biomarker-stratified trial-level attack rates were extracted and pooled from the control arms of the Novel START, CAPTAIN, QUEST, Benralizumab Phase 2b, PATHWAY, STRATOS 1–2 and DREAM trials (n=3051). These were used to derive rate ratios and the predicted asthma attack rate for different patient groups. The resultant prototype risk scale shows potential to predict asthma attacks, which may be prevented by anti-inflammatory treatment.

BackgroundIn people with mild asthma poor adherence to regular therapy is common and increases the risk of exacerbations, morbidity and mortality. The use of fixed-dose combination inhalers containing an inhaled corticosteroid (ICS) and a fast-acting β2-agonist (FABA) is established in moderate asthma, but they may also have potential utility in mild asthma.ObjectivesTo evaluate the efficacy and safety of single combined FABA/ICS inhaler only used as needed in people with mild asthma.Design and settingCochrane meta-analysis of available trial data.ParticipantsChildren aged 12+ and adults with mild asthma.Search methodsWe searched the Cochrane Airways Trials Register, Cochrane Central Register of Controlled Trials, MEDLINE and Embase, ClinicalTrials.gov and the WHO trials portal on 19 March 2021.InterventionsA single fixed-dose FABA/ICS inhaler used as required compared with no treatment, placebo, short-acting beta agonist (SABA) as required, regular ICS with SABA as required, regular fixed-dose combination ICS/long-acting beta agonist (LABA), or regular fixed-dose combination ICS/FABA with as required ICS/FABA.We included randomised controlled trials (RCTs) and cross-over trial. We excluded trials shorter than 12 weeks. We included full texts, abstracts and unpublished data.Data collection and analysisWe used Cochrane’s standard methodological procedures and applied the GRADE approach to assess the evidence.Main outcome measuresWe included six studies from which 9657 participants contributed to the meta-analyses. All used dry powder budesonide and formoterol as the combination inhaler. Two studies included children aged 12+ years and two studies were open-label.FABA/ICS as-required versus FABA as-requiredCompared with as-required FABA alone, as-required FABA/ICS reduced exacerbations requiring systemic steroids (OR 0.45, 95% CI 0.34 to 0.60, 2 RCTs, 2997 participants, high-certainty evidence), equivalent to 109 people out of 1000 in the FABA alone group experiencing an exacerbation requiring systemic steroids, compared with 52 (95% CI 40 to 68) out of 1000 in the FABA/ICS as-required group. FABA/ICS as required may also reduce the odds of an asthma-related hospital admission or emergency department or urgent care visit (OR 0.35, 95% CI 0.20 to 0.60, 2 RCTs, 2997 participants, low-certainty evidence). Changes in asthma control were small and less than the minimal clinically important difference (MCID). FABA/ICS as required was associated with reductions in fractional exhaled nitric oxide, probably reducing the odds of an adverse event (OR 0.82, 95% CI 0.71 to 0.95) and may reduce total systemic steroid dose (mean difference (MD) −9.90, 95% CI −19.38 to −0.42).FABA/ICS as required versus regular ICS plus FABA as requiredThere may be little or no difference in the number of people with asthma exacerbations requiring systemic steroids with FABA/ICS as required compared with regular ICS (OR 0.79, 95% CI 0.59 to 1.07, 4 RCTs, 8065 participants, low-certainty evidence), equivalent to 81 people out of 1000 in the regular ICS plus FABA group experiencing an exacerbation requiring systemic steroids, compared with 65 (95% CI 49 to 86) out of 1000 in the FABA/ICS as-required group. The odds of an asthma-related hospital admission or emergency department or urgent care visit may be reduced in those taking FABA/ICS as required (OR 0.63, 95% CI 0.44 to 0.91, 4 RCTs, 8065 participants, low-certainty evidence). Changes in asthma control were small and less than MCID. Adverse events and total systemic corticosteroid doses were similar between groups. FABA/ICS as required was likely associated with less average daily exposure to ICS than those on regular ICS (MD −154.51 mcg/day, 95% CI −207.94 to −101.09).ConclusionsFABA/ICS as required is clinically effective in adults and adolescents with mild asthma and reduced exacerbations, hospital admissions or unscheduled healthcare visits and exposure to systemic corticosteroids and probably reduces adverse events compared with FABA as required alone. FABA/ICS as required is as effective as regular ICS and reduced asthma-related hospital admissions or unscheduled healthcare visits, and average exposure to ICS, and is unlikely associated with increased adverse events.

Background Asthma affects 350 million people worldwide including 45% to 70% with mild disease. Treatment is mainly with inhalers containing beta₂‐agonists, typically taken as required to relieve bronchospasm, and inhaled corticosteroids (ICS) as regular preventive therapy. Poor adherence to regular therapy is common and increases the risk of exacerbations, morbidity and mortality. Fixed‐dose combination inhalers containing both a steroid and a fast‐acting beta₂‐agonist (FABA) in the same device simplify inhalers regimens and ensure symptomatic relief is accompanied by preventative therapy. Their use is established in moderate asthma, but they may also have potential utility in mild asthma. Objectives To evaluate the efficacy and safety of single combined (fast‐onset beta₂‐agonist plus an inhaled corticosteroid (ICS)) inhaler only used as needed in people with mild asthma. Search methods We searched the Cochrane Airways Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase, ClinicalTrials.gov and the World Health Organization (WHO) trials portal. We contacted trial authors for further information and requested details regarding the possibility of unpublished trials. The most recent search was conducted on 19 March 2021. Selection criteria We included randomised controlled trials (RCTs) and cross‐over trials with at least one week washout period. We included studies of a single fixed‐dose FABA/ICS inhaler used as required compared with no treatment, placebo, short‐acting beta agonist (SABA) as required, regular ICS with SABA as required, regular fixed‐dose combination ICS/long‐acting beta agonist (LABA), or regular fixed‐dose combination ICS/FABA with as required ICS/FABA. We planned to include cluster‐randomised trials if the data had been or could be adjusted for clustering. We excluded trials shorter than 12 weeks. We included full texts, abstracts and unpublished data. Data collection and analysis Two review authors independently extracted data. We analysed dichotomous data as odds ratios (OR) or rate ratios (RR) and continuous data as mean difference (MD). We reported 95% confidence intervals (CIs). We used Cochrane's standard methodological procedures of meta‐analysis. We applied the GRADE approach to summarise results and to assess the overall certainty of evidence. Primary outcomes were exacerbations requiring systemic steroids, hospital admissions/emergency department or urgent care visits for asthma, and measures of asthma control. Main results We included six studies of which five contributed results to the meta‐analyses. All five used budesonide 200 μg and formoterol 6 μg in a dry powder formulation as the combination inhaler. Comparator fast‐acting bronchodilators included terbutaline and formoterol. Two studies included children aged 12+ and adults; two studies were open‐label. A total of 9657 participants were included, with a mean age of 36 to 43 years. 2.3% to 11% were current smokers. FABA / ICS as required versus FABA as required Compared with as‐required FABA alone, as‐required FABA/ICS reduced exacerbations requiring systemic steroids (OR 0.45, 95% CI 0.34 to 0.60, 2 RCTs, 2997 participants, high‐certainty evidence), equivalent to 109 people out of 1000 in the FABA alone group experiencing an exacerbation requiring systemic steroids, compared to 52 (95% CI 40 to 68) out of 1000 in the FABA/ICS as‐required group. FABA/ICS as required may also reduce the odds of an asthma‐related hospital admission or emergency department or urgent care visit (OR 0.35, 95% CI 0.20 to 0.60, 2 RCTs, 2997 participants, low‐certainty evidence). Compared with as‐required FABA alone, any changes in asthma control or spirometry, though favouring as‐required FABA/ICS, were small and less than the minimal clinically‐important differences. We did not find evidence of differences in asthma‐associated quality of life or mortality. For other secondary outcomes FABA/ICS as required was associated with reductions in fractional exhaled nitric oxide, probably reduces the odds of an adverse event (OR 0.82, 95% CI 0.71 to 0.95, 2 RCTs, 3002 participants, moderate‐certainty evidence) and may reduce total systemic steroid dose (MD ‐9.90, 95% CI ‐19.38 to ‐0.42, 1 RCT, 443 participants, low‐certainty evidence), and with an increase in the daily inhaled steroid dose (MD 77 μg beclomethasone equiv./day, 95% CI 69 to 84, 2 RCTs, 2554 participants, moderate‐certainty evidence). FABA/ICS as required versus regular ICS plus FABA as required There may be little or no difference in the number of people with asthma exacerbations requiring systemic steroid with FABA/ICS as required compared with regular ICS (OR 0.79, 95% CI 0.59 to 1.07, 4 RCTs, 8065 participants, low‐certainty evidence), equivalent to 81 people out of 1000 in the regular ICS plus FABA group experiencing an exacerbation requiring systemic steroids, compared to 65 (95% CI 49 to 86) out of 1000 FABA/ICS as required group. The odds of an asthma‐related hospital admission or emergency department or urgent care visit may be reduced in those taking FABA/ICS as required (OR 0.63, 95% CI 0.44 to 0.91, 4 RCTs, 8065 participants, low‐certainty evidence). Compared with regular ICS, any changes in asthma control, spirometry, peak flow rates (PFR), or asthma‐associated quality of life, though favouring regular ICS, were small and less than the minimal clinically important differences (MCID). Adverse events, serious adverse events, total systemic corticosteroid dose and mortality were similar between groups, although deaths were rare, so confidence intervals for this analysis were wide. We found moderate‐certainty evidence from four trials involving 7180 participants that FABA/ICS as required was likely associated with less average daily exposure to inhaled corticosteroids than those on regular ICS (MD ‐154.51 μg/day, 95% CI ‐207.94 to ‐101.09). Authors' conclusions We found FABA/ICS as required is clinically effective in adults and adolescents with mild asthma. Their use instead of FABA as required alone reduced exacerbations, hospital admissions or unscheduled healthcare visits and exposure to systemic corticosteroids and probably reduces adverse events. FABA/ICS as required is as effective as regular ICS and reduced asthma‐related hospital admissions or unscheduled healthcare visits, and average exposure to ICS, and is unlikely to be associated with an increase in adverse events. Further research is needed to explore use of FABA/ICS as required in children under 12 years of age, use of other FABA/ICS preparations, and long‐term outcomes beyond 52 weeks.

BackgroundThe antibacterial, anti-inflammatory and antiviral properties of azithromycin suggest therapeutic potential against COVID-19. Randomised data in mild-moderate disease are lacking. We assessed whether azithromycin is effective in reducing hospitalisation in patients with mild-moderate COVID-19.MethodsThis open-label, randomised superiority clinical trial at 19 centres in the United Kingdom enrolled adults, ≥18 years, presenting to hospitals with clinically-diagnosed highly-probable or confirmed COVID-19 infection, with NCT04381962, Study closed.Findings298 participants were enrolled from 3rd June 2020 to 29th January 2021. The primary outcome was assessed in 292 participants. The primary endpoint was not significantly different between the azithromycin and control groups (Adjusted OR 0·91 [95% CI 0·43-1·92], p=0·80). Rates of respiratory failure, progression to pneumonia, all-cause mortality, and adverse events, including serious cardiovascular events, were not significantly different between groups.InterpretationIn patients with mild-moderate COVID-19 managed without hospital admission, adding azithromycin to standard care treatment did not reduce the risk of subsequent hospitalisation or death. Our findings do not support the use of azithromycin in patients with mild-moderate COVID-19.FundingNIHR Oxford BRC, University of Oxford and Pfizer Inc.Research in contextEvidence before this studyWe searched MEDLINE and the Cochrane Central register of Controlled Trials (CENTRAL) with the terms (“azithromycin”) AND (“COVID” OR “COVID-19”) AND (“clinical trials”), until March 25, 2021, with no language restrictions. We identified 42 studies, among which there were four completed randomised trials of azithromycin (with or without hydroxychloroquine) in hospitalised patients with severe disease, and three completed randomised trials of azithromycin in mild COVID-19 in primary care. The four trials in hospitalised patients randomised 8,988 participants to azithromycin or standard care or hydroxychloroquine and found no evidence of a difference in mortality, duration of hospital stay or peak disease severity. Of the three trials in primary care, these randomised participants with early disease to 3 or 5 days of therapy, of which only one assessed azithromycin as standalone therapy. This large, adaptive platform trial in the UK randomised 540 participants in primary care to 3 days treatment with azithromycin versus 875 to standard care alone and found no meaningful difference in time to first reported recovery, or of rates of hospitalisation (3% versus 3%) and there were no deaths. We did not identify any randomised trials in patients with COVID-19 managed in ambulatory care.Added value of this studyThe ATOMIC2 trial was uniquely-designed to assess azithromycin as a standalone therapy in those with mild-moderately COVID-19 presenting to emergency care, but assessed as appropriate for initial ambulatory management without hospital admission. ATOMIC2 also uniquely assessed high-dose, long-duration treatment to investigate the efficacy of putative anti-inflammatory effects. We found that azithromycin 500 mg daily for 14 days did not reduce the proportion of participants who died or required hospital admission from any cause over the 28 days from randomisation.Implications of all the available evidenceOur findings, taken together with existing data, suggest there is no evidence that azithromycin reduces hospitalisation, respiratory failure or death compared with standard care, either in early disease in the community, or those hospitalised with severe disease, or in those with moderate disease managed on an ambulatory pathway.

Background Whether the clinical or pathophysiologic significance of the “treatable trait” high blood eosinophil count in COPD is the same as for asthma remains controversial. We sought to determine the relationship between the blood eosinophil count, clinical characteristics and gene expression from bronchial brushings in COPD and asthma. Methods Subjects were recruited into a COPD (emphysema versus airway disease [EvA]) or asthma cohort (Unbiased BIOmarkers in PREDiction of respiratory disease outcomes, U‐BIOPRED). We determined gene expression using RNAseq in EvA (n = 283) and Affymetrix microarrays in U‐BIOPRED (n = 85). We ran linear regression analysis of the bronchial brushings transcriptional signal versus blood eosinophil counts as well as differential expression using a blood eosinophil > 200 cells/μL as a cut‐off. The false discovery rate was controlled at 1% (with continuous values) and 5% (with dichotomized values). Results There were no differences in age, gender, lung function, exercise capacity and quantitative computed tomography between eosinophilic versus noneosinophilic COPD cases. Total serum IgE was increased in eosinophilic asthma and COPD. In EvA, there were 12 genes with a statistically significant positive association with the linear blood eosinophil count, whereas in U‐BIOPRED, 1197 genes showed significant associations (266 positive and 931 negative). The transcriptome showed little overlap between genes and pathways associated with blood eosinophil counts in asthma versus COPD. Only CST1 was common to eosinophilic asthma and COPD and was replicated in independent cohorts. Conclusion Despite shared “treatable traits” between asthma and COPD, the molecular mechanisms underlying these clinical entities are predominately different., In a chronic obstructive pulmonary disease (COPD) cohort (EvA, n = 283), 12 genes, whereas in asthma cohort (UBIOPRED, n = 85), 1197 genes in bronchial epithelial brushes were correlated with a blood eosinophil count. The gene CST1 was common to eosinophilic asthma and COPD and was replicated in independent cohorts. Despite shared “treatable traits” between asthma and COPD, the molecular mechanisms underlying these clinical entities are predominately different.

Background: The antibacterial, anti-inflammatory and antiviral properties of azithromycin suggest therapeutic potential against COVID-19. Randomised data in mild-moderate disease are lacking. We assessed whether azithromycin is effective in reducing hospitalisation in patients with mild-moderate COVID-19. Methods: This open-label, randomised superiority clinical trial at 19 centres in the United Kingdom enrolled adults, ≥18 years, presenting to hospitals with clinically-diagnosed highly-probable or confirmed COVID-19 infection, with

Summary Azithromycin (AZM) is a synthetic macrolide antibiotic effective against a broad range of bacterial and mycobacterial infections. Due to an additional range of anti‐viral and anti‐inflammatory properties, it has been given to patients with the coronaviruses SARS‐CoV or MERS‐CoV. It is now being investigated as a potential candidate treatment for SARS‐CoV‐2 having been identified as a candidate therapeutic for this virus by both in vitro and in silico drug screens. To date there are no randomised trial data on its use in any novel coronavirus infection, although a large number of trials are currently in progress. In this review, we summarise data from in vitro, murine and human clinical studies on the anti‐viral and anti‐inflammatory properties of macrolides, particularly AZM. AZM reduces in vitro replication of several classes of viruses including rhinovirus, influenza A, Zika virus, Ebola, enteroviruses and coronaviruses, via several mechanisms. AZM enhances expression of anti‐viral pattern recognition receptors and induction of anti‐viral type I and III interferon responses. Of relevance to severe coronavirus‐19 disease (COVID‐19), which is characterised by an over‐exuberant innate inflammatory response, AZM also has anti‐inflammatory properties including suppression of IL‐1beta, IL‐2, TNF and GM‐CSF. AZM inhibits T cells by inhibiting calcineurin signalling, mammalian target of rapamycin activity and NFκB activation. AZM particularly targets granulocytes where it concentrates markedly in lysosomes, particularly affecting accumulation, adhesion, degranulation and apoptosis of neutrophils. Given its proven safety, affordability and global availability, tempered by significant concerns about antimicrobial stewardship, there is an urgent mandate to perform well‐designed and conducted randomised clinical trials.

Background: Prednisolone is widely used to treat acute exacerbations of airway disease. There is evidence that they act by depleting circulating eosinophils within hours of the first dose. Potentially the anti-IL-5 biologics may be a safer and longer-lasting alternative, although whether they deplete blood eosinophils as quickly as prednisolone is unclear. Methods: We assessed blood eosinophil counts at baseline and, 2, 4, 6, 8, 24 and 96 h, or until blood eosinophils Results: Groups did not differ significantly in demographics, inhaled corticosteroid dose, lung function and baseline blood eosinophil count. The mean(SD) time for blood eosinophil level to decrease 50% from baseline was 25.8(14.3), 1.7(0.7) and 2.5(0.4) hours on mepolizumab, benralizumab and prednisolone respectively (p≤0.001 for both benralizumab and prednisolone compared to mepolizumab) (Fig. 1). Conclusion: Benralizumab depletes blood eosinophils as rapidly as prednisolone and may therefore be an alternative treatment for acute eosinophilic asthma exacerbations. Larger studies comparing this approach to current treatment are awaited.

Background: Pleural infection (PI) is a common and complex disease which can be life threatening for immunocompromised and elderly populations. Prior antibiotic use and special bacterial nutritional requirements hamper the accuracy of bacterial identification using current clinical culture-based techniques. Consequently, PI microbiology remains unclear. Next generation sequencing (NGS) has the potential to improve identification of the total bacterial population of a complex sample. Aim: To discover and characterise the microbial patterns of PI using NGS and bioinformatics techniques. Methods: Pleural fluid samples from the “Pleural Infection Longitudinal Outcome Study” (PILOT, ISRCTN50236700, n=243) underwent bacterial DNA extraction followed by 16S rRNA NGS using Illumina MiSeq. Data were analysed with DADA2 and Phyloseq R packages. Results: Analysis showed diverse microbiological patterns for PI as 391 different pathogens were identified up to the genus level. 131 (54%) samples had one pathogen with relative abundance over 50% and 89 (36%) samples had at least three pathogens with relative abundance over 10%, suggesting a polymicrobial infection. Streptococcus pneumoniae was detected in 40 (16%) and Staphylococcus aureus in 20 (8%) samples. Discussion: We established a methodology to extract bacterial DNA from patients with PI and used it as a template to apply NGS. 16S rRNA gene NGS provides a robust method to investigate the bacteriological patterns in pleural fluid of patients with PI. Funding: National Institute for Health Research, Oxford Biomedical Research Centre

Intro: Prior metagenomic studies in asthma are limited by inconsistent clinical phenotyping and inadequate sequencing depth for species-level bacterial identification. We hypothesise chronic bacterial infection is i) a ‘treatable trait’ whose prevalence, clinical phenotype and reliable biomarkers need definition and ii) is best characterised using Nanopore sequencing. Aims/Methods: To compare performance of Illumina MiSeq, Nanopore sequencing, and RT-qPCR on total DNA extracts against culture/MALDI-TOF for analysis of induced sputum samples from well-phenotyped severe asthma. Results: In 23 patients with with severe asthma Haemophilus influenzae was commonly cultured (n=8/23), and identified as the dominant bacterial species by metagenomic sequencing using MiSeq and Nanopore. Nanopore provided superior operational characterisitics and longer read lengths allowing whole bacterial genome reconstruction and greater resolution between species. Clinically significant infection was confirmed with validated H.inf plasmid-based RT-qPCR assay. H.inf culture positive patients had sputum neutrophilia and lower FeNO. Conclusions:H.inf is a clinically-relevant pathogen in severe ashma and is identified reliably using molecular microbiological methods. Application of these optimised protocols in ongoing analysis of 3 large patient cohorts is allowing full characterisation of this clinical phenotype.

Background Azithromycin is an orally active synthetic macrolide antibiotic with a wide range of anti-bacterial, anti-inflammatory and antiviral properties. It is a safe, inexpensive, generic licenced drug available worldwide and manufactured to scale and is a potential candidate therapy for pandemic coronavirus disease 2019 (COVID-19). Azithromycin was widely used to treat severe SARS-CoV and MERS-CoV, but to date, no randomised data are available in any coronavirus infections. Other ongoing trials are exploring short courses of azithromycin either in early disease, within the first 7 days of symptoms, when azithromycin’s antiviral properties may be important, or late in disease when anti-bacterial properties may reduce the risk of secondary bacterial infection. However, the molecule’s anti-inflammatory properties, including suppression of pulmonary macrophage-derived pro-inflammatory cytokines such as interleukins-1β, -6, -8, and -18 and cytokines G-CSF and GM-CSF may provide a distinct therapeutic benefit if given in as a prolonged course during the period of progression from moderate to severe disease. Methods ATOMIC2 is a phase II/III, multi-centre, prospective, open-label, two-arm randomised superiority clinical trial of azithromycin versus standard care for adults presenting to hospital with COVID-19 symptoms who are not admitted at initial presentation. We will enrol adults, ≥ 18 years of age assessed in acute hospitals in the UK with clinical diagnosis of COVID-19 infection where management on an ambulatory care pathway is deemed appropriate. Participants will be randomised in a 1:1 ratio to usual care or to azithromycin 500 mg orally daily for 14 days with telephone follow-up at days 14 and 28. The primary objective is to compare the proportion with either death or respiratory failure requiring invasive or non-invasive mechanical ventilation over 28 days from randomisation. Secondary objectives include mortality/respiratory failure in those with a PCR-confirmed diagnosis; all-cause mortality; progression to pneumonia; progression to severe pneumonia; peak severity of illness and mechanistic analysis of blood and nasal biomarkers. Discussion This trial will determine the clinical utility of azithromycin in patients with moderately severe, clinically diagnosed COVID-19 and could be rapidly applicable worldwide. Trial registration ClinicalTrials.gov NCT04381962. Registered on 11 May 2020. EudraCT identifier 2020-001740-26. Opened for accrual on 29 May 2020.

To-date, there has not been a clear signal suggesting that asthma or treatment with inhaled steroids are a risk factor for severe COVID-19 disease. We have therefore explored ACE2 receptor mRNA expression, and co-factors for Sars-CoV-2 infectivity (TMPRSS2 and furin) in bronchial brushes and biopsies from people with asthma and healthy controls, and looked for relationships between asthma severity, Th2- and IL-17 dependent gene signatures, and clinical demographics (age, sex). We have looked at a cohort of 356 research participants from previously described studies. The only significant association was a positive correlation between ACE2 and IL-17-dependent gene expression, and an inverse correlation between ACE2 and Th2-cytokine-dependent gene expression. These data suggest that differences in ACE2, TMPRSS2 and furin epithelial and airway gene expression are unlikely to confer enhanced COVID-19 pneumonia risk in patients with asthma across all treatment intensities and severity., Expression of mRNA for ACE2, the Sars-CoV-2 receptor, is similar in the lower airways of healthy controls and people with mild-severe asthma. Altered ACE2 expression is unlikely to confer enhanced COVID-19 pneumonia risk in asthma.

Monoclonal antibodies targeting IgE or the type-2 cytokines interleukin (IL)-4, IL-5 and IL-13 are proving highly effective in reducing exacerbations and symptoms in people with severe allergic and eosinophilic asthma, respectively. However, these therapies are not appropriate for 30–50% of patients in severe asthma clinics who present with non-allergic, non-eosinophilic, “type-2 low” asthma. These patients constitute an important and common clinical asthma phenotype, driven by distinct, yet poorly understood pathobiological mechanisms. In this review we describe the heterogeneity and clinical characteristics of type-2 low asthma and summarise current knowledge on the underlying pathobiological mechanisms, which includes neutrophilic airway inflammation often associated with smoking, obesity and occupational exposures and may be driven by persistent bacterial infections and by activation of a recently described IL-6 pathway. We review the evidence base underlying existing treatment options for specific treatable traits that can be identified and addressed. We focus particularly on severe asthma as opposed to difficult-to-treat asthma, on emerging data on the identification of airway bacterial infection, on the increasing evidence base for the use of long-term low-dose macrolides, a critical appraisal of bronchial thermoplasty, and evidence for the use of biologics in type-2 low disease. Finally, we review ongoing research into other pathways including tumour necrosis factor, IL-17, resolvins, apolipoproteins, type I interferons, IL-6 and mast cells. We suggest that type-2 low disease frequently presents opportunities for identification and treatment of tractable clinical problems; it is currently a rapidly evolving field with potential for the development of novel targeted therapeutics.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a new rapidly spreading infectious disease. Current guidance from the World Health Organization (WHO) highlights asthmatics as a high-risk group for severe illness from COVID-19. Viruses are common triggers of asthma exacerbations and the current SARS-CoV-2 pandemic raises several questions regarding the optimum management strategies. Here, we discuss the contentious issue of whether the mainstay therapy systemic corticosteroids should be used in the routine management of COVID-19-associated asthma exacerbations. Recent guidance from the WHO has advised against the use of corticosteroids if COVID-19 is suspected due to concerns that these agents may impair protective innate antiviral immune responses. This may not be appropriate in the unique case of asthma exacerbation, a syndrome associated with augmented type 2 inflammation, a disease feature that is known to directly inhibit antiviral immunity. Corticosteroids, through their suppressive effects on type 2 inflammation, are thus likely to restore impaired antiviral immunity in asthma and, in contrast to non-asthmatic subjects, have beneficial clinical effects in the context of SARS-CoV-2 infection.

While there now exist effective treatments for type 2 high, eosinophilic asthma, there are no specific therapies for 40–50% of people with asthma with other phenotypes, which result from poorly understood underlying pathological mechanisms. One such pathology is neutrophilic inflammation, which has been associated with interleukin (IL)-17 family cytokines. Human genetic studies identified IL-17 polymorphisms associated with asthma; in murine models of allergic airways disease, IL-17A contributes to airway hyperresponsiveness, and in humans, elevated airway IL-17A levels are repeatedly observed in severe asthma. However, the directionality of this association is unknown, and the assumption that IL-17 cytokines drive disease pathology remains speculative. Here, we explore the evidence underlying the relationship between IL-17 and asthma, we review lessons learned from investigating IL-17 in other inflammatory diseases, and discuss the possibility that IL-17 may even be protective in asthma rather than pathogenic. We also critically examine the newly proposed paradigm of a reciprocal relationship between type 2 and type 17 airways inflammation. In summary, we suggest an association between IL-17 and asthma, but research is needed examining the diverse functions of these cytokines, their longitudinal stability, their response to clinical interventions, and for mechanistic studies determining whether they are protective or pathogenic., IL-17 cytokines have been implicated in neutrophilic asthma by genetic, murine and human data. Here, previous studies are critiqued and the assumption their dominant role is pathogenic rather than protective of airway epithelial barrier integrity is challenged. http://bit.ly/3axB4Zs

Rationale: On November 21, 2016 in Australia, a major thunderstorm-asthma epidemic struck Melbourne with an unprecedented number of emergency presentations, hospital admissions and fatalities. Objectives: We identified affected patients who presented to The Royal Melbourne Hospital, an adult tertiary center in North-West Melbourne. We aimed to characterize individual patient factors associated with hospital admission and identify biomarkers in patient subgroups that are at risk of being severely affected by thunderstorm-asthma. Methods: Cross-sectional, retrospective analysis of demographics of 240 patients presenting to The Royal Melbourne Hospital on November 21 to 22, 2016 post thunderstorm-asthma event and clinical characteristics of 70 of those patients who subsequently attended an outpatient clinic review. Results: Patients were generally young adults (mean age 35 years), with seasonal rhinitis (96%) and universally (100%) sensitized to ryegrass pollen. Forty-four patients (63%) had a known diagnosis of asthma while 20% reported no previous diagnosis but had symptoms consistent with asthma. Patient characteristics associated with hospitalization were: uncontrolled asthma symptoms in the month before the thunderstorm-asthma event, symptomatic allergic rhinitis, high blood eosinophilia and lower lung function. Conclusion: Thunderstorm-asthma affects people with seasonal rhinitis, ryegrass sensitization and can occur without prior history of asthma, with dramatic potential to inundate a healthcare system. Our data suggests that hospitalization, and thus a more severe thunderstorm-asthma exacerbation, was associated with a known history of asthma, prior uncontrolled asthma symptoms, allergic rhinitis, high eosinophil count and lower lung function. These factors may inform strategies to identify those most at risk of thunderstorm-asthma.

COVID-19, caused by the novel coronavirus SARS-CoV-2, is a global health issue with more than 1 million fatalities to date. Understanding how host factors modify the viral life cycle could inform susceptibility to viral infection and the design of new therapies. Viral replication is shaped by the cellular microenvironment and one important factor is local oxygen tension, where hypoxia inducible factor (HIF) regulates transcriptional responses to hypoxia. SARS-CoV-2 primarily infects cells of the respiratory tract, entering via its Spike glycoprotein binding to angiotensin-converting enzyme (ACE2). We demonstrate that hypoxia and the HIF prolyl hydroxylase inhibitor Roxadustat (FG-4592) reduce ACE2 expression and inhibit SARS-CoV-2 entry and replication in lung epithelial cells via a HIF-1α dependent signalling pathway. Further, hypoxia and Roxadustat inhibit viral replication in SARS-CoV-2 infected cells, showing that post-entry steps in the viral life cycle are oxygen-sensitive. This study highlights the importance of hypoxia and HIF signalling in regulating multiple aspects of SARS-CoV-2 infection and raises the potential use of HIF prolyl hydroxylase inhibitors in the prevention and/or treatment of COVID-19. Funding: The McKeating laboratory is funded by a Wellcome Investigator Award (IA) 200838/Z/16/Z, UK Medical Research Council (MRC) project grant MR/R022011/1 and Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Science (CIFMS), China (grant number: 2018-I2M-2-002). The Ratcliffe laboratory is funded by the Oxford Branch of the Ludwig Institute for Cancer Research; Wellcome IA 106241/Z/14/Z; the Francis Crick Institute, which receives core funding from Cancer Research UK (FC001501), UK MRC (FC001501) and Wellcome (FC001501); the Paradifference Foundation. PJR, EJH and TB are additionally funded by the COVID-19 Research Response Fund, University of Oxford. SK is funded by the Clarendon Scholarships Fund and the Christopher Welch Trust. The Davis laboratory is funded by Wellcome IA 209412/Z/17/Z and Wellcome Strategic Awards 091911/B/10/Z and 107457/Z/15/Z. JYL is funded by the Medial Sciences Graduate Studentship, University of Oxford. The Hinks laboratory is funded by grants from the Wellcome (104553/z/14/z, 211050/Z/18/z) and the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre; the views expressed are those of the authors and not those of the NHS or NIHR. Conflict of Interest: EJH is employed under the Cambridge Experimental Medicine Initiative, which is partly funded by AstraZeneca although they have not been involved in this project. The other authors declare no financial interests. Ethical Approval: The study was reviewed by the Oxford Research Ethics Committee B (18/SC/0361).

The complexity of asthma is underscored by the number of cell types and mediators implicated in the pathogenesis of this heterogeneous syndrome. Type 2 CD4+ T-cells (Th2) and more recently, type 2 innate lymphoid cells dominate current descriptions of asthma pathogenesis. However, another important source of these type 2 cytokines, especially interleukin (IL)-5 and IL-13, are CD8+ T-cells, which are increasingly proposed to play an important role in asthma pathogenesis, because they are abundant and are comparatively insensitive to corticosteroids. Many common triggers of asthma exacerbations are mediated via corticosteroid-resistant pathways involving neutrophils and CD8+ T-cells. Extensive murine data reveal the plasticity of CD8+ T-cells and their capacity to enhance airway inflammation and airway dysfunction. In humans, Tc2 cells are predominant in fatal asthma, while in stable state, severe eosinophilic asthma is associated with greater numbers of Tc2 than Th2 cells in blood, bronchoalveolar lavage fluid and bronchial biopsies. Tc2 cells strongly express CRTH2, the receptor for prostaglandin D2, the cysteinyl leukotriene receptor 1 and the leukotriene B4 receptor. When activated, these elicit Tc2 cell chemotaxis and production of chemokines and type 2 and other cytokines, resulting directly or indirectly in eosinophil recruitment and survival. These factors position CD8+ Tc2 cells as important and underappreciated effector cells contributing to asthma pathogenesis. Here, we review recent advances and new insights in understanding the pro-asthmatic functions of CD8+ T-cells in eosinophilic asthma, especially corticosteroid-resistant asthma, and the molecular mechanisms underlying their pathologic effector function.

Coal workers' pneumoconiosis (CWP), as part of the spectrum of coal mine dust lung disease (CMDLD), is a preventable but incurable lung disease that can be complicated by respiratory failure and death. Recent increases in coal production from the financial incentive of economic growth lead to higher respirable coal and quartz dust levels, often associated with mechanization of longwall coal mining. In Australia, the observed increase in the number of new CWP diagnoses since the year 2000 has necessitated a review of recommended respirable dust exposure limits, where exposure limits and monitoring protocols should ideally be standardized. Evidence that considers the regulation of engineering dust controls in the mines is lacking even in high-income countries, despite this being the primary preventative measure. Also, it is a global public health priority for at-risk miners to be systemically screened to detect early changes of CWP and to include confirmed patients within a central registry; a task limited by financial constraints in less developed countries. Characteristic X-ray changes are usually categorized using the International Labour Office classification, although future evaluation by low-dose HRCT) chest scanning may allow for CWP detection and thus avoidance of further exposure, at an earlier stage. Preclinical animal and human organoid-based models are required to explore potential re-purposing of anti-fibrotic and related agents with potential efficacy. Epidemiological patterns and the assessment of molecular and genetic biomarkers may further enhance our capacity to identify susceptible individuals to the inhalation of coal dust in the modern era.

Introduction: CRTH2 antagonists are a promising therapy for T2-high disorders, particularly uncontrolled eosinophilic asthma. Biomarkers to identify patients likely to respond to treatment would be a useful advance. We set out to investigate the relationship between the effect of 12 weeks’ treatment with the CRTH2 antagonist timapiprant on the induced sputum eosinophil count and a range of blood and sputum biomarkers. Methods and Materials: Peripheral blood and induced sputum samples were collected from 20 patients with severe eosinophilic asthma at baseline and 12 weeks after oral treatment with 50 mg timapiprant daily. Immune cell counts in blood were determined with flow cytometry. Cell numbers in sputum were determined by slide counting. Correlations were assessed non-parametrically using Prism 7. Results: Timapiprant treatment reduced the geometric mean sputum eosinophils from 11% to 2.5% (Fold reduction 4.5; 95% CI 1.9 to 9.7; p=0.001). Baseline blood total CRTH2+ cells (r=0.75; p Conclusion: High levels of blood total CRTH2+ cells, eosinophils, basophils, Tc2 cells, and sputum eosinophils are associated with the anti-inflammatory effect of timapiprant treatment and could be potential predictive biomarkers of response.

Introduction: Prostaglandin D2 acting via the DP2 receptor plays an important role in the pathogenesis of the steroid-resistant airway inflammation in severe eosinophilic asthma. We tested this hypothesis in a randomised, placebo-controlled, double-blind, parallel group proof of concept study of the effects of the DP2 antagonist timapiprant (OC459) on sputum eosinophil counts in patients with severe eosinophilic asthma. Methods: Patients meeting the ERS/ATS criteria for severe asthma, prior evidence of eosinophilic airway inflammation and screening sputum eosinophil count >3% were randomised to timapiprant 50 mg or placebo once daily for 12 weeks. Induced sputum eosinophil counts, lung function parameters, symptoms and quality of life were assessed at baseline and at 4, 8 and 12 weeks. Results: 68 patients were screened and 40 randomised. The geometric mean induced sputum eosinophil count reduced from 11.0% at baseline to 2.5% at 12 weeks with timapiprant (n=20) and from 10.7% to 6.2% with placebo (n=19). A 2.3-fold reduction (p=0.151) in sputum eosinophil level at week 12 for timapiprant compared to placebo was observed. The difference between groups for change from baseline in pre-bronchodilator FEV1 at week 12 was 127 ml (95% CI: -77 to 330 ml; p=0.214). The safety profile of timapiprant was comparable to that of placebo. Conclusions: Treatment for 12 weeks with timapiprant in severe eosinophilic asthma patients was associated with an evident reduction of airway eosinophilic inflammation and an increase in FEV1 (although not statistically significant due to the limited sample size). Studies in larger population are needed to confirm these effects.

Rationale: Severe asthma is a heterogeneous disease with different inflammatory phenotypes based on blood or sputum measures. Increasingly blood eosinophils (Eos) are used to direct therapy choice but there is limited information how stable inflammatory measures in sputum and blood are over time and how they relate. Method: Sputum was successfully induced in 48 severe asthma patients at 2 timepoints within 2 years. At each timepoint a full blood count was completed. Patients were at least 4-weeks clear of exacerbation and considered stable. The percentage of granulocytes were reported and the stability at these two timepoints was assessed using Spearman’s rho. Results: In this cohort the sputum Eos and blood Eos significantly correlated between the two timepoints (sputum r=0.739,p= Discussion: These results demonstrate that airway neutrophilic inflammation is more dynamic than eosinophilic inflammation and poorly reflected in peripheral blood. A greater understanding of the underlying factors responsible for airway neutrophilic changes is needed if progress is to be made in addressing this severe asthma phenotype.

Background: Severe asthma with persistent airway eosinophilia despite high-intensity inhaled corticosteroids is a phenotype associated with high exacerbation risk. A major barrier to progress is poor understanding of the pathogenic mechanisms and cell types contributing to the disease. Aims and objectives: To determine the function of type-2 cytokine producing CD8+ T cells in severe eosinophilic asthma, and investigate their contribution to pathogenesis of the disease. Methods: Profiles of type-2 CD8+ T cells (Tc2) and type-2 T helper (Th2), in different asthma phenotypes were analysed with flow cytometry. Tc2 cells were isolated and cultured in vitro. Effects of prostaglandin D2 (PGD2) and leukotriene E4 (LTE4) on Tc2 cells were defined using chemotaxis assays, Luminex, quantitative RT-PCR, PrimeFlow RNA assay and microarray. Effects of Tc2 supernatants were determined on eosinophil shape change and apoptosis, and on eosinophil chemokine production from airway epithelial cells. Results: In two independent patient cohorts we show that, in contrast to Th2 cells, type-2 cytokine-secreting CD8+CRTH2+ Tc2 cells are enriched in blood and airways, and concentrations of prostaglandin D2 (PGD2) and cysteinyl leukotriene E4 (LTE4) are also increased in the airways in severe eosinophilic asthma. In vitro PGD2 and LTE4 function synergistically to enhance Tc2 cell recruitment and activation. They regulate diverse genes in Tc2 cells inducing type-2 cytokines and many other pro-inflammatory cytokines and chemokines which could contribute to eosinophilia. Conclusions: These finding are consistent with an important role for human Tc2 cells in severe eosinophilic asthma.

Background: Mucosal associated invariant T (MAIT) cells are evolutionarily-conserved, innate-like lymphocytes which are abundant in human lungs and can contribute to protection against pulmonary bacterial infection. However, whilst they are also activated during human viral infections, it is unknown whether MAIT cells play a significant protective or even detrimental role during viral infections in vivo. Aims and objectives: To determine whether MAIT cells play a significant role – either protective or detrimental – during influenza A infection in vivo. Methods: We used major histocompatibility complex–related protein 1 (MR1) tetramers and intracellular cytokine staining to track MAIT cell frequencies and activation during in vivo murine experimental challenge with two strains of influenza A virus in immunocompetent (C57BL/6), MAIT-cell deficient (MR1-/-) and immunodeficient (Rag2-/-γC-/-) mice. Results: MAIT cells accumulated and were activated early in infection, with upregulation of CD25, CD69 and Granzyme B peaking at 5 days post infection. Activation was modulated via cytokines interleukin (IL)-12, -15, -18 and type I interferon, independent of MR1. MR1-/- mice, which lack MAIT cells, showed enhanced body weight loss and mortality to severe (H1N1) influenza. This was ameliorated by prior adoptive transfer of pulmonary MAIT cells in both immunocompetent and immunodeficient Rag2-/-γC-/- mice which lack T, B and NK cells. Conclusions: MAIT cells contribute to protection during respiratory viral infections, and constitute a potential target for therapeutic manipulation.

The functions and in vivo roles of type-2 CD8+ T cells in humans have not been well defined and this cell type has been largely overlooked in models of disease. We investigated this in the context of severe asthma with persistent airway eosinophilia - a phenotype associated with high exacerbation risk and responsiveness to type-2 cytokine-targeted therapies. In two independent cohorts we show that, in contrast to Th2 cells, type-2 cytokine-secreting CD8+CRTH2+ (Tc2) cells are enriched in blood and airways in severe eosinophilic asthma. Concentrations of prostaglandin D2 (PGD2) and cysteinyl leukotriene E4 (LTE4) are also increased in the airways of the same group of patients. In vitro PGD2 and LTE4 function synergistically to trigger Tc2 cell recruitment and activation in a TCR-independent manner. These lipids regulate diverse genes in Tc2 cells inducing type-2 cytokines and many other pro-inflammatory cytokines and chemokines which could contribute to eosinophilia. These findings are consistent with an important innate-like role for human Tc2 cells in severe eosinophilic asthma and suggest a potential target for therapeutic intervention in this and other diseases.

RATIONALE: Mucosal-associated invariant T (MAIT) cells are a recently described abundant, proinflammatory T-cell subset with unknown roles in pulmonary immunity. Nontypeable Haemophilus influenzae (NTHi) is the leading bacterial pathogen during chronic obstructive pulmonary disease (COPD) exacerbations and is a plausible target for MAIT cells. OBJECTIVES: To investigate whether MAIT cells respond to NTHi and the effects of inhaled corticosteroids (ICS) on their frequency and function in COPD. METHODS: Eleven subjects with COPD receiving ICS, 8 steroid-naive subjects with COPD, and 21 healthy control subjects underwent phlebotomy, sputum induction, bronchoalveolar lavage, and endobronchial biopsy. Pulmonary and monocyte-derived macrophages were cultured in vitro with NTHi. MEASUREMENTS AND MAIN RESULTS: Frequencies of Vα7.2(+)CD161(+) MAIT cells, surface expression of the major histocompatibility complex-related protein 1 (MR1), and intracellular IFN-γ expression were measured by flow cytometry. MAIT-cell frequencies were reduced in peripheral blood of ICS-treated subjects with COPD (median 0.38%; interquartile range [IQR], 0.25-0.96) compared with healthy control subjects (1.8%; IQR, 1.4-2.5; P = 0.001) or steroid-naive patients with COPD (1.8%; IQR, 1.2-2.3; P = 0.04). MAIT cells were reduced in bronchial biopsies from subjects with COPD treated with steroids (0.73%; IQR, 0.46-1.3) compared with healthy control subjects (4.0%; IQR, 1.6-5.0; P = 0.02). Coculture of live NTHi increased macrophage surface expression of MR1 and induced IFN-γ from CD4 cells and CD8 cells, but most potently from MAIT cells (median IFN-γ-positive frequencies, 2.9, 8.6, and 27.6%, respectively). In vitro fluticasone and budesonide reduced MR1 surface expression twofold and decreased NTHi-induced IFN-γ secretion eightfold. CONCLUSIONS: MAIT cells are deficient in blood and bronchial tissue in steroid-treated, but not steroid-naive, COPD. NTHi constitutes a target for pulmonary MAIT-cell immune responses, which are significantly impaired by corticosteroids.

Summary New T cell-based blood tests for tuberculosis infection could improve diagnosis of tuberculosis but their clinical utility remains unknown. We describe the role of the ELISpot test in the diagnostic work-up of 13 patients presenting with suspected tuberculosis in routine practice. Of the seven patients with a final diagnosis of active tuberculosis, all were positive by ELISpot including three with false-negative tuberculin skin test results. Rapid determination of tuberculosis infection by ELISpot accelerated the diagnosis of tuberculosis, enabling early treatment initiation.

Introduction: Sputum inflammometry has been used to describe asthma phenotypes and severe asthma is associated with neutrophilia based on the percentage of cells present. Sputum density is not accounted for in clinical practice. Methods: Induced sputum was obtained from 110 severe asthmatics (BTS step 4/5) of the Wessex Severe Asthma Cohort. Inflammatory biological markers were measured in sputum supernatant with Multiplex ELISA. Biomarker concentrations were compared to sputum neutrophil density using Spearmans correlation. Results: The median [IQR] cell number (x 106/g sputum) was significantly lower in P phenotype (n=41 0.64 \[0.96]) than N (n=29 2.1 [2.6\] (p

Central nervous system tuberculosis remains a clinical diagnostic challenge. The ex vivo Mycobacterium tuberculosis-specific enzyme-linked immunospot assay (ELISPOT) is a novel assay for the rapid detection of M. tuberculosis-specific T-lymphocytes in the peripheral blood. However, when performed on peripheral blood, this assay cannot distinguish between active tuberculosis or latent tuberculosis infection. On the assumption that M. tuberculosis-specific T-lymphocytes migrate to sites of infection, we were able to demonstrate high levels of M. tuberculosis-specific cells by ELISPOT in the cerebrospinal fluid of a patient with tuberculous meningitis and intracerebral tuberculoma four weeks before cerebrospinal fluid culture became positive for M. tuberculosis by culture.

Background: The role of new T-cell–based blood tests for tuberculosis in the diagnosis of active tuberculosis is unclear. Objective: To compare the performance of 2 interferon-? assays and tuberculin skin testing in adults with suspected tuberculosis. Design: Prospective study conducted in routine practice. Setting: 2 urban hospitals in the United Kingdom. Patients: 389 adults, predominantly of South Asian and black ethnicity, with moderate to high clinical suspicion of active tuberculosis. Intervention: Tuberculin skin testing, the enzyme-linked immunospot assay (ELISpot) incorporating early secretory antigenic target-6 and culture filtrate protein-10 (standard ELISpot), and ELISpot incorporating a novel antigen, Rv3879c (ELISpotPLUS) were performed during diagnostic assessment by independent persons who were blinded to results of the other test. Measurements: Sensitivity, specificity, predictive values, and likelihood ratios. Results: 194 patients had a final diagnosis of active tuberculosis, of which 79% were culture-confirmed. Sensitivity for culture confirmed and highly probable tuberculosis was 89% (95% CI, 84% to 93%) with ELISpotPLUS, 85% (CI, 79% to 90%) with standard ELISpot, 79% (CI, 72% to 85%) with 15-mm threshold tuberculin skin testing, and 83% (CI, 77% to 89%) with stratified thresholds of 15 and 10 mm in vaccinated and unvaccinated patients, respectively. The ELISpotPLUS assay was more sensitive than tuberculin skin testing with 15-mm cutoff points (P = 0.01) but not with stratified cutoff points (P = 0.10). The ELISpotPLUS assay had 4% higher diagnostic sensitivity than standard ELISpot (P = 0.02). Combined sensitivity of ELISpotPLUS and tuberculin skin testing was 99% (CI, 95% to 100%), conferring a negative likelihood ratio of 0.02 (CI, 0 to 0.06) when both test results were negative. Limitations: Local standards for tuberculin skin testing differed from others used internationally. The study sample included few immunosuppressed patients. Conclusion: The ELISpotPLUS assay is more sensitive than standard ELISpot and, when used in combination with tuberculin skin testing, enables rapid exclusion of active infection in patients with moderate to high pretest probability of tuberculosis.

Incomplete understanding of mechanisms and clinicopathobiological heterogeneity in asthma hinders research progress. Pathogenic roles for T-helper-type 17 (Th17) cells and invariant T cells implied by murine data have yet to be assessed in man. We aimed to investigate the role of Th17 and mucosal associated invariant T (MAIT) cells in airway inflammation; to characterise associations between diverse clinical and immunological features of asthma; and to identify novel multidimensional asthma endotypes.In this single-centre, cross-sectional observational study in the UK, we assessed volunteers with mild-to-severe asthma and healthy non-atopic controls using clinical and physiological assessment and immunological sampling of blood, induced sputum, endobronchial biopsy, and bronchoalveolar lavage for flow cytometry and multiplex-electrochemiluminescence assays. Primary outcomes were changes in frequencies of Th17 and MAIT cells between health and asthma using Mann-Whitney U tests and the Jonckheere-Terpstra test (linear trend across ranked groups). The study had 80% power to detect 60% differences in T-cell frequencies at p0·05. Bayesian Network Analysis (BNA) was used to explore associations between parameters. Topological Data Analysis (TDA) was used to identify multidimensional endotypes. The study had local research ethics approval. All participants provided informed consent.Participants were 84 male and female volunteers (60 with mild-to-severe asthma and 24 healthy, non-atopic controls) aged 18-70 years recruited from clinics and research cohorts. Th17 cells and γδ17 cells were not associated with asthma, even in severe neutrophilic forms. MAIT-cell frequencies were strikingly reduced in asthma compared with health (median frequency in blood 0·9% of CD3+ cells [IQR 0·3-1·8] in asthma vs 1·6 [1·2-2·6] in health, p=0·005; in sputum 1·1 [0·7-2·0] vs 1·8 [1·6-2·3], p=0·002; and in biopsy samples 1·3 [0·7-2·3] vs 3·9% [1·3-5·3%], p=0·02), especially in severe asthma where BAL regulatory T cells were also reduced compared with those in health (4·4, 3·1-6·1, vs 8·1, 5·6-10; p=0·02). BNA and TDA identified six novel clinicopathobiological clusters of underlying disease mechanisms, with elevated mast cell mediators tryptase (p0·0001), chymase (p=0·02), and carboxypeptidase A3 (p=0·02) in severe asthma.This study suggests that Th17 cells do not have a major pathogenic role in human asthma. We describe a novel deficiency of MAIT cells in severe asthma. We also provide proof of concept for application of TDA to identification of multidimensional clinicopathobiological endotypes. Endotypes will require validation in further cohorts.Wellcome Trust.

T-cell responses during tuberculosis (TB) help contain Mycobacterium tuberculosis in vivo but also cause collateral damage to host tissues. Immune regulatory mechanisms may limit this immunopathology, and suppressed cellular immune responses in patients with TB suggest the presence of regulatory activity. CD4+CD25(high) regulatory T cells mediate suppressed cellular immunity in several chronic infections but have not been described in TB.To determine whether regulatory T cells are increased in patients with TB and whether they suppress cellular immune responses.We compared the frequency of circulating regulatory T cells in 27 untreated patients with TB and 23 healthy control subjects using two specific markers: cell-surface CD25 expression and FoxP3 mRNA expression in peripheral blood mononuclear cells.We detected a threefold increase in the frequency of CD4 + CD25(high) T cells (p0.001) and a 2.2-fold increase in FoxP3 expression (p = 0.006) in patients with TB, and there was a positive correlation between these markers (r = 0.58, p0.001). Increased expression of interleukin-10 and transforming growth factor-beta1 mRNA was also detected in patients with TB but did not correlate with regulatory T-cell markers. Ex vivo depletion of CD4 + CD25(high) cells from peripheral blood mononuclear cells resulted in increased numbers of M. tuberculosis antigen-specific IFN-gamma-producing T cells in seven of eight patients with TB (p = 0.005). Finally, FoxP3 expression was increased 2.3-fold in patients with extrapulmonary TB compared with patients with purely pulmonary TB (p = 0.01) and was amplified 2.6-fold at disease sites relative to blood (p = 0.043).Regulatory T cells are expanded in patients with TB and may contribute to suppression of Th1-type immune responses.

(2004). Spinal cord infarction caused by malignant intramedullary glioma: the traps of epidemiology and travel history. British Journal of Neurosurgery: Vol. 18, No. 2, pp. 199-200.

Introduction The background rate of latent tuberculosis infection (LTBI) in low prevalence regions of the UK is unknown. Interferon γ release assays (IGRAs) are sensitive and specific methods for detecting LTBI, and have accurately characterised the epidemiology of LTBI among high risk populations such as recent TB contacts or immigrants. However there are no current data on the incidence of IGRA positivity among the general adult population in the UK. Such data would be valuable for interpreting the significance of a positive IGRA result, and guiding cost-benefit analyses of new diagnostics. Methods A TB outbreak occurred within a rural DGH. 481 individuals were identified as potential contacts and were tested by IGRA (TSpot. TB ). Uniquely, for comparison, we recruited an additional large cohort of age matched controls from the same general wards but with no exposure to the outbreak. Results 456 staff and patients were tested including 148 unexposed age-matched patient controls. Rates of positivity were 22% (95%CI, 14 to 29), 11% (6.1 to 16), 8.8% (4.2 to 13) and 9.5% (3.0 to 22) among exposed patients, exposed staff, unexposed patients and unexposed staff respectively. 8 cases of active TB (identical VNTR profile) and an estimated 35 cases of recently acquired LTBI can be attributed to exposure to the index case, out of 481 contacts. Characteristics of the unexposed controls are in Abstract S40 table 1. IGRA positivity was associated in multivariate analyses with history of previous TB treatment (OR 11, p=0.04) and use of corticosteroids (OR 5.9, p=0.02), but not with age. The age specific prevalences of IGRA positivity were 0 (N/A) for ages Conclusions We observed a surprisingly high background rate of IGRA positivity among an unselected population typical of respiratory and general medical inpatients in a rural DGH. All controls were white-Caucasians, who comprise 92% of the UK population, and may represent a current minimum UK background rate. As rates were highest in the 5th and 6th decade, in the context of ageing populations and increasing iatrogenic immunosuppression, reactivation of LTBI may be a persistent hazard for several decades to come.

Background Background rates of latent tuberculosis infection in low prevalence regions of Britain are unknown. These would be valuable data for interpreting positive IGRA results, and guiding cost-benefit analyses. The management of a large outbreak of tuberculosis occurring in a rural district hospital provided an opportunity to determine the background rates and epidemiology of IGRA-positivity amongst unselected hospital patients in a low-prevalence region of U.K. Methods As part of a public health surveillance project we identified 445 individuals exposed to the index cases for clinical assessment and testing by a TB-specific interferon-γ release assay (IGRA): T-Spot.TB. Uniquely, an additional comparator group of 191 age-matched individuals without specific recent exposure, but with a similar age distribution and demographic, were recruited from the same wards where exposure had previously occurred, to undergo assessment by questionnaire and IGRA. Results Rates of IGRA positivity were 8.7% (95%CI, 4.2-13, n=149) amongst unexposed patients, 9.5%(3.0-22, n=21) amongst unexposed staff, 22%(14–29, n=130) amongst exposed patients, 11%(6.1-16, n=142) amongst exposed staff. Amongst the individuals without history of recent exposure to the outbreak, IGRA-positivity was associated with prior TB treatment (OR11, P.04) and corticosteroid use (OR5.9, P.02). Background age-specific prevalences of IGRA-positivity amongst unexposed individuals were: age Conclusions Background rates of IGRA-positivity remain high amongst unselected white-Caucasian hospital inpatients in U.K. These data will aid interpretation of future outbreak studies. As rates peak in the 5th and 6th decade, given an ageing population and increasing iatrogenic immunosuppression, reactivation of LTBI may be a persistent hazard in this population for several decades to come.