The effects of sleep disturbance on dyspnoea and impaired lung function following COVID-19 hospitalisation: a prospective multi-centre cohort study

BackgroundSleep disturbance is common following hospitalisation both for COVID-19 and other causes. The clinical associations are poorly understood, despite it altering pathophysiology in other scenarios. We, therefore, investigated whether sleep disturbance is associated with dyspnoea along with relevant mediation pathways. MethodsSleep parameters were assessed in a prospective cohort of patients (n=2,468) hospitalised for COVID-19 in the United Kingdom in 39 centres using both subjective and device-based measures. Results were compared to a matched UK biobank cohort and associations were evaluated using multivariable linear regression. Findings64% (456/714) of participants reported poor sleep quality; 56% felt their sleep quality had deteriorated for at least 1-year following hospitalisation. Compared to the matched cohort, both sleep regularity (44.5 vs 59.2, p<0.001) and sleep efficiency (85.4% vs 88.5%, p<0.001) were lower whilst sleep period duration was longer (8.25h vs 7.32h, p<0.001). Overall sleep quality (effect estimate 4.2 (3.0-5.5)), deterioration in sleep quality following hospitalisation (effect estimate 3.2 (2.0-4.5)), and sleep regularity (effect estimate 5.9 (3.7-8.1)) were associated with both dyspnoea and impaired lung function (FEV1 and FVC). Depending on the sleep metric, anxiety mediated 13-42% of the effect of sleep disturbance on dyspnoea and muscle weakness mediated 29-43% of this effect. InterpretationSleep disturbance is associated with dyspnoea, anxiety and muscle weakness following COVID-19 hospitalisation. It could have similar effects for other causes of hospitalisation where sleep disturbance is prevalent. FundingUK Research and Innovation, National Institute for Health Research, and Engineering and Physical Sciences Research Council.

Nasal IgA wanes 9 months after hospitalisation with COVID-19 and is not induced by subsequent vaccination.

BackgroundMost studies of immunity to SARS-CoV-2 focus on circulating antibody, giving limited insights into mucosal defences that prevent viral replication and onward transmission. We studied nasal and plasma antibody responses one year after hospitalisation for COVID-19, including a period when SARS-CoV-2 vaccination was introduced. MethodsPlasma and nasosorption samples were prospectively collected from 446 adults hospitalised for COVID-19 between February 2020 and March 2021 via the ISARIC4C and PHOSP-COVID consortia. IgA and IgG responses to NP and S of ancestral SARS-CoV-2, Delta and Omicron (BA.1) variants were measured by electrochemiluminescence and compared with plasma neutralisation data. FindingsStrong and consistent nasal anti-NP and anti-S IgA responses were demonstrated, which remained elevated for nine months. Nasal and plasma anti-S IgG remained elevated for at least 12 months with high plasma neutralising titres against all variants. Of 180 with complete data, 160 were vaccinated between 6 and 12 months; coinciding with rises in nasal and plasma IgA and IgG anti-S titres for all SARS-CoV-2 variants, although the change in nasal IgA was minimal. Samples 12 months after admission showed no association between nasal IgA and plasma IgG responses, indicating that nasal IgA responses are distinct from those in plasma and minimally boosted by vaccination. InterpretationThe decline in nasal IgA responses 9 months after infection and minimal impact of subsequent vaccination may explain the lack of long-lasting nasal defence against reinfection and the limited effects of vaccination on transmission. These findings highlight the need to develop vaccines that enhance nasal immunity. Research in contextO_ST_ABSEvidence before the studyC_ST_ABSWhile systemic immunity to SARS-CoV-2 is important in preventing severe disease, mucosal immunity prevents viral replication at the point of entry and reduces onward transmission. We searched PubMed with search terms "mucosal", "nasal", "antibody", "IgA", "COVID-19", "SARS-CoV-2", "convalescent" and "vaccination" for studies published in English before 20th July 2022, identifying three previous studies examining the durability of nasal responses that generally show nasal antibody to persist for 3 to 9 months. However, these studies were small or included individuals with mild COVID-19. One study of 107 care-home residents demonstrated increased salivary IgG (but not IgA) after two doses of mRNA vaccine, and another examined nasal antibody responses after infection and subsequent vaccination in 20 cases, demonstrating rises in both nasal IgA and IgG 7 to 10 days after vaccination. Added value of this studyStudying 446 people hospitalised for COVID-19, we show durable nasal and plasma IgG responses to ancestral (B.1 lineage) SARS-CoV-2, Delta and Omicron (BA.1) variants up to 12 months after infection. Nasal antibody induced by infection with pre-Omicron variants, bind Omicron virus in vitro better than plasma antibody. Although nasal and plasma IgG responses were enhanced by vaccination, Omicron binding responses did not reach levels equivalent to responses for ancestral SARS-CoV-2. Using paired plasma and nasal samples collected approximately 12 months after infection, we show that nasal IgA declines and shows a minimal response to vaccination whilst plasma antibody responses to S antigen are well maintained and boosted by vaccination. Implications of all the available evidenceAfter COVID-19 and subsequent vaccination, Omicron binding plasma and nasal antibody responses are only moderately enhanced, supporting the need for booster vaccinations to maintain immunity against SARS-CoV-2 variants. Notably, there is distinct compartmentalisation between nasal IgA and plasma IgA and IgG responses after vaccination. These findings highlight the need for vaccines that induce robust and durable mucosal immunity.

Device-assessed sleep and physical activity in individuals recovering from a hospital admission for COVID-19: a prospective, multicentre study

ObjectivesTo describe physical behaviours following hospital admission for COVID-19 including associations with acute illness severity and ongoing symptoms. Methods1077 patients with COVID-19 discharged from hospital between March and November 2020 were recruited. Using a 14-day wear protocol, wrist-worn accelerometers were sent to participants after a five-month follow-up assessment. Acute illness severity was assessed by the WHO clinical progression scale, and the severity of ongoing symptoms was assessed using four previously reported data-driven clinical recovery clusters. Two existing control populations of office workers and type 2 diabetes were comparators. ResultsValid accelerometer data from 253 women and 462 men were included. Women engaged in a mean{+/-}SD of 14.9{+/-}14.7 minutes/day of moderate-to-vigorous physical activity (MVPA), with 725.6{+/-}104.9 minutes/day spent inactive and 7.22{+/-}1.08 hours/day asleep. The values for men were 21.0{+/-}22.3 and 755.5{+/-}102.8 minutes/day and 6.94{+/-}1.14 hours/day, respectively. Over 60% of women and men did not have any days containing a 30-minute bout of MVPA. Variability in sleep timing was approximately 2 hours in men and women. More severe acute illness was associated with lower total activity and MVPA in recovery. The very severe recovery cluster was associated with fewer days/week containing continuous bouts of MVPA, longer sleep duration, and higher variability in sleep timing. Patients post-hospitalisation with COVID-19 had lower levels of physical activity, greater sleep variability, and lower sleep efficiency than a similarly aged cohort of office workers or those with type 2 diabetes. ConclusionsPhysical activity and regulating sleep patterns are potential treatable traits for COVID-19 recovery programmes.

Clinical characteristics with inflammation profiling of Long-COVID and association with one-year recovery following hospitalisation in the UK: a prospective observational study

BackgroundThere are currently no effective pharmacological or non-pharmacological interventions for Long-COVID. To identify potential therapeutic targets, we focussed on previously described four recovery clusters five months after hospital discharge, their underlying inflammatory profiles and relationship with clinical outcomes at one year. MethodsPHOSP-COVID is a prospective longitudinal cohort study, recruiting adults hospitalised with COVID-19 across the UK. Recovery was assessed using patient reported outcomes measures (PROMs), physical performance, and organ function at five-months and one-year after hospital discharge. Hierarchical logistic regression modelling was performed for patient-perceived recovery at one-year. Cluster analysis was performed using clustering large applications (CLARA) k-medoids approach using clinical outcomes at five-months. Inflammatory protein profiling from plasma at the five-month visit was performed. Findings2320 participants have been assessed at five months after discharge and 807 participants have completed both five-month and one-year visits. Of these, 35{middle dot}6% were female, mean age 58{middle dot}7 (SD 12{middle dot}5) years, and 27{middle dot}8% received invasive mechanical ventilation (IMV). The proportion of patients reporting full recovery was unchanged between five months 501/1965 (25{middle dot}5%) and one year 232/804 (28{middle dot}9%). Factors associated with being less likely to report full recovery at one year were: female sex OR 0{middle dot}68 (95% CI 0{middle dot}46-0{middle dot}99), obesity OR 0{middle dot}50 (95%CI 0{middle dot}34-0{middle dot}74) and IMV OR 0{middle dot}42 (95%CI 0{middle dot}23-0{middle dot}76). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate/cognitive, mild relating to the severity of physical, mental health and cognitive impairments at five months in a larger sample. There was elevation of inflammatory mediators of tissue damage and repair in both the very severe and the moderate/cognitive clusters compared to the mild cluster including interleukin-6 which was elevated in both comparisons. Overall, there was a substantial deficit in median (IQR) EQ5D-5L utility index from pre-COVID (retrospective assessment) 0{middle dot}88 (0{middle dot}74-1{middle dot}00), five months 0{middle dot}74 (0{middle dot}60-0{middle dot}88) to one year: 0{middle dot}74 (0{middle dot}59-0{middle dot}88), with minimal improvements across all outcome measures at one-year after discharge in the whole cohort and within each of the four clusters. InterpretationThe sequelae of a hospital admission with COVID-19 remain substantial one year after discharge across a range of health domains with the minority in our cohort feeling fully recovered. Patient perceived health-related quality of life remains reduced at one year compared to pre-hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials. FundingUKRI & NIHR Research in ContextO_ST_ABSEvidence before this studyC_ST_ABSWe systematically searched PubMed and Embase databases for large studies reporting one-year follow-up data for hospitalised COVID-19 patients published between January 1, 2021 and November 7, 2021, without language restrictions. Search terms related to COVID-19, hospitalisation and long-term follow-up were used. A large prospective cohort study from Wuhan, China (n = 1276) showed that 49% of patients reported at least one persistent symptom during a follow-up clinic visit at 12 months post COVID-19; no significant improvement in exercise capacity was observed between six- and 12-month visits. Another two large cohort studies in China (n = 2433) and Spain (n = 1950) with one-year follow-up data from telephone interviews showed that 45% and 81% of patients reported at least one residual COVID-19 symptom, respectively. However, no previous studies have compared the trajectories of COVID-19 recovery in patients classified by different clinical phenotypes, and there are no large studies investigating the relationship between systemic inflammation and ongoing health impairments post COVID-19. Added value of this studyIn a diverse population of adults post-hospital admission with COVID-19, our large UK prospective multi-centre study reports several novel findings: the minority felt fully recovered at one year with minimal recovery from five months across any health domain; female sex and obesity are associated with being less likely to feel fully recovered at one year; several inflammatory mediators were increased in individuals with the most severe physical, mental health, and cognitive impairments compared to individuals with milder ongoing impairments. Implications of all the available evidenceBoth pharmacological and non-pharmacological interventions are urgently needed to improve the ongoing burden following hospitalisation for COVID-19 both for individuals and healthcare systems; our findings support the use of a precision medicine approach with potential treatable traits of systemic inflammation and obesity.

Symptom Persistence Despite Improvement in Cardiopulmonary Health - Insights from longitudinal CMR, CPET and lung function testing post-COVID-19

BackgroundThe longitudinal trajectories of cardiopulmonary abnormalities and symptoms following infection with coronavirus disease (COVID-19) are unclear. We sought to describe their natural history in previously hospitalised patients, compare this with controls, and assess the relationship between symptoms and cardiopulmonary impairment at 6 months post-COVID-19. MethodsFifty-eight patients and thirty matched controls underwent symptom-questionnaires, cardiac and lung magnetic resonance imaging (CMR), cardiopulmonary exercise test (CPET), and spirometry at 3 months following COVID-19. Of them, forty-six patients returned for follow-up assessments at 6 months. FindingsAt 2-3 months, 83% of patients had at least one cardiopulmonary symptom versus 33% of controls. Patients and controls had comparable biventricular volumes and function. Native cardiac T1 (marker of inflammation) and late gadolinium enhancement (LGE, marker of focal fibrosis) were increased in patients. Sixty percent of patients had lung parenchymal abnormalities on CMR and 55% had reduced peak oxygen consumption (pVO2) on CPET. By 6 months, 53% of patients remained symptomatic. On CMR, indexed right ventricular (RV) end-diastolic volume (-4{middle dot}3 mls/m2, P=0{middle dot}005) decreased and RV ejection fraction (+3{middle dot}2%, P=0{middle dot}0003) increased. Native T1 and LGE improved and was comparable to controls. Lung parenchymal abnormalities and peak VO2, although better, were abnormal in patients versus controls. 31% had reduced pVO2 secondary to fatigue and submaximal tests. Cardiopulmonary symptoms in patients did not associate with CMR, lung function, or CPET measures. InterpretationIn patients, cardiopulmonary abnormalities improve over time, though some measures remain abnormal relative to controls. Persistent symptoms at 6 months post-COVID-19 did not associate with objective measures of cardiopulmonary health. FundingNIHR Oxford and Oxford Health BRC, Oxford BHF CRE, UKRI and Wellcome Trust.

Namilumab or infliximab compared to standard of care in hospitalised patients with COVID-19 (CATALYST): a phase 2 randomised adaptive trial

BackgroundDysregulated inflammation is associated with poor outcomes in Coronavirus disease 2019 (COVID-19). We assessed the efficacy of namilumab, a granulocyte-macrophage colony-stimulating factor inhibitor and infliximab, a tumour necrosis factor inhibitor in hospitalised patients with COVID-19 in order to prioritise agents for phase 3 trials. MethodsIn this randomised, multi-arm, parallel group, open label, adaptive phase 2 proof-of-concept trial (CATALYST) we recruited hospitalised patients [≥] 16 years with COVID-19 pneumonia and C-reactive protein (CRP) [≥] 40mg/L in nine UK hospitals. Participants were randomly allocated with equal probability to usual care, or usual care plus a single 150mg intravenous dose of namilumab (150mg) or infliximab (5mg/kg). Randomisation was stratified for ward versus ICU. The primary endpoint was improvement in inflammation in intervention arms compared to control as measured by CRP over time, analysed using Bayesian multi-level models. ISRCTN registry number 40580903. FindingsBetween 15th June 2020 and 18th February 2021 we randomised 146 participants: 54 to usual care, 57 to namilumab and 35 to infliximab. The probabilities that namilumab and infliximab were superior to usual care in reducing CRP over time were 97% and 15% respectively. Consistent effects were seen in ward and ICU patients and aligned with clinical outcomes, such that the probability of discharge (WHO levels 1-3) at day 28 was 47% and 64% for ICU and ward patients on usual care, versus 66% and 77% for patients treated with namilumab. 134 adverse events occurred in 30/55 (54.5%) namilumab patients compared to 145 in 29/54 (53.7%) usual care patients. 102 events occurred in 20/29 (69.0%) infliximab patients versus 112 events in 17/34 (50.0%) usual care patients. InterpretationNamilumab, but not infliximab, demonstrated proof-of-concept evidence for reduction in inflammation in hospitalised patients with COVID-19 pneumonia which was consistent with secondary clinical outcomes. Namilumab should be prioritised for further investigation in COVID-19. FundingMedical Research Council.

Spatial transcriptomic characterization of COVID-19 pneumonitis identifies immune pathways related to tissue injury

Severe lung damage in COVID-19 involves complex interactions between diverse populations of immune and stromal cells. In this study, we used a spatial transcriptomics approach to delineate the cells, pathways and genes present across the spectrum of histopathological damage in COVID-19 lung tissue. We applied correlation network-based approaches to deconvolve gene expression data from areas of interest within well preserved post-mortem lung samples from three patients. Despite substantial inter-patient heterogeneity we discovered evidence for a common immune cell signaling circuit in areas of severe tissue that involves crosstalk between cytotoxic lymphocytes and pro-inflammatory macrophages. Expression of IFNG by cytotoxic lymphocytes was associated with induction of chemokines including CXCL9, CXCL10 and CXCL11 which are known to promote the recruitment of CXCR3+ immune cells. The tumour necrosis factor (TNF) superfamily members BAFF (TNFSF13B) and TRAIL (TNFSF10) were found to be consistently upregulated in the areas with severe tissue damage. We used published spatial and single cell SARS-CoV-2 datasets to confirm our findings in the lung tissue from additional cohorts of COVID-19 patients. The resulting model of severe COVID-19 immune-mediated tissue pathology may inform future therapeutic strategies. One Sentence SummarySpatial analysis identifies IFN{gamma} response signatures as focal to severe alveolar damage in COVID-19 pneumonitis.

A blood atlas of COVID-19 defines hallmarks of disease severity and specificity

Treatment of severe COVID-19 is currently limited by clinical heterogeneity and incomplete understanding of potentially druggable immune mediators of disease. To advance this, we present a comprehensive multi-omic blood atlas in patients with varying COVID-19 severity and compare with influenza, sepsis and healthy volunteers. We identify immune signatures and correlates of host response. Hallmarks of disease severity revealed cells, their inflammatory mediators and networks as potential therapeutic targets, including progenitor cells and specific myeloid and lymphocyte subsets, features of the immune repertoire, acute phase response, metabolism and coagulation. Persisting immune activation involving AP-1/p38MAPK was a specific feature of COVID-19. The plasma proteome enabled sub-phenotyping into patient clusters, predictive of severity and outcome. Tensor and matrix decomposition of the overall dataset revealed feature groupings linked with disease severity and specificity. Our systems-based integrative approach and blood atlas will inform future drug development, clinical trial design and personalised medicine approaches for COVID-19.

Physical, cognitive and mental health impacts of COVID-19 following hospitalisation: a multi-centre prospective cohort study

BackgroundThe impact of COVID-19 on physical and mental health, and employment following hospitalisation is poorly understood. MethodsPHOSP-COVID is a multi-centre, UK, observational study of adults discharged from hospital with a clinical diagnosis of COVID-19 involving an assessment between two- and seven-months later including detailed symptom, physiological and biochemical testing. Multivariable logistic regression was performed for patient-perceived recovery with age, sex, ethnicity, body mass index (BMI), co-morbidities, and severity of acute illness as co-variates. Cluster analysis was performed using outcomes for breathlessness, fatigue, mental health, cognition and physical function. FindingsWe report findings of 1077 patients discharged in 2020, from the assessment undertaken a median 5 [IQR4 to 6] months later: 36% female, mean age 58 [SD 13] years, 69% white ethnicity, 27% mechanical ventilation, and 50% had at least two co-morbidities. At follow-up only 29% felt fully recovered, 20% had a new disability, and 19% experienced a health-related change in occupation. Factors associated with failure to recover were female, middle-age, white ethnicity, two or more co-morbidities, and more severe acute illness. The magnitude of the persistent health burden was substantial and weakly related to acute severity. Four clusters were identified with different severities of mental and physical health impairment: 1) Very severe (17%), 2) Severe (21%), 3) Moderate with cognitive impairment (17%), 4) Mild (46%), with 3%, 7%, 36% and 43% feeling fully recovered, respectively. Persistent systemic inflammation determined by C-reactive protein was related to cluster severity, but not acute illness severity. InterpretationWe identified factors related to recovery from a hospital admission with COVID-19 and four different phenotypes relating to the severity of physical, mental, and cognitive health five months later. The implications for clinical care include the potential to stratify care and the need for a pro-active approach with wide-access to COVID-19 holistic clinical services. Funding: UKRI and NIHR

Medium-term effects of SARS-CoV-2 infection on multiple vital organs, exercise capacity, cognition, quality of life and mental health, post-hospital discharge

BackgroundThe medium-term effects of Coronavirus disease (COVID-19) on multiple organ health, exercise capacity, cognition, quality of life and mental health are poorly understood. MethodsFifty-eight COVID-19 patients post-hospital discharge and 30 comorbidity-matched controls were prospectively enrolled for multiorgan (brain, lungs, heart, liver and kidneys) magnetic resonance imaging (MRI), spirometry, six-minute walk test, cardiopulmonary exercise test (CPET), quality of life, cognitive and mental health assessments. FindingsAt 2-3 months from disease-onset, 64% of patients experienced persistent breathlessness and 55% complained of significant fatigue. On MRI, tissue signal abnormalities were seen in the lungs (60%), heart (26%), liver (10%) and kidneys (29%) of patients. COVID-19 patients also exhibited tissue changes in the thalamus, posterior thalamic radiations and sagittal stratum on brain MRI and demonstrated impaired cognitive performance, specifically in the executive and visuospatial domain relative to controls. Exercise tolerance (maximal oxygen consumption and ventilatory efficiency on CPET) and six-minute walk distance (405{+/-}118m vs 517{+/-}106m in controls, p<0.0001) were significantly reduced in patients. The extent of extra-pulmonary MRI abnormalities and exercise tolerance correlated with serum markers of ongoing inflammation and severity of acute illness. Patients were more likely to report symptoms of moderate to severe anxiety (35% versus 10%, p=0.012) and depression (39% versus 17%, p=0.036) and a significant impairment in all domains of quality of life compared to controls. InterpretationA significant proportion of COVID-19 patients discharged from hospital experience ongoing symptoms of breathlessness, fatigue, anxiety, depression and exercise limitation at 2-3 months from disease-onset. Persistent lung and extra-pulmonary organ MRI findings are common. In COVID-19 survivors, chronic inflammation may underlie multiorgan abnormalities and contribute to impaired quality of life. FundingNIHR Oxford and Oxford Health Biomedical Research Centres, British Heart Foundation Centre for Research Excellence, UKRI, Wellcome Trust, British Heart Foundation.

Recovery of monocyte exhaustion is associated with resolution of lung injury in COVID-19 convalescence.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection resulting in the clinical syndrome COVID-19 is associated with an exaggerated immune response and monocyte infiltrates in the lungs and other peripheral tissues. It is now increasingly recognised that chronic morbidity persists in some patients. We recently demonstrated profound alterations of monocytes in hospitalised COVID-19 patients. It is currently unclear whether these abnormalities resolve or progress following patient discharge. We show here that blood monocytes in convalescent patients at their 12 week follow up, have a greater propensity to produce pro-inflammatory cytokines TNF and IL-6, which was consistently higher in patients with resolution of lung injury as indicated by a normal chest X-ray and no shortness of breath (a key symptom of lung injury). Furthermore, monocytes from convalescent patients also displayed enhanced levels of molecules involved in leucocyte migration, including chemokine receptor CXCR6, adhesion molecule CD31/PECAM and integrins VLA-4 and LFA-1. Expression of migration molecules on monocytes was also consistently higher in convalescent patients with a normal chest X-ray. These data suggest persistent changes in innate immune function following recovery from COVID-19 and indicate that immune modulating therapies targeting monocytes and leucocyte migration may be useful in recovering COVID-19 patients with persistent symptoms.

Outcome of hospitalisation for COVID-19 in patients with Interstitial Lung Disease: An international multicentre study.

RationaleThe impact of COVID-19 on patients with Interstitial Lung Disease (ILD) has not been established. ObjectivesTo assess outcomes following COVID-19 in patients with ILD versus those without in a contemporaneous age, sex and comorbidity matched population. MethodsAn international multicentre audit of patients with a prior diagnosis of ILD admitted to hospital with COVID-19 between 1 March and 1 May 2020 was undertaken and compared with patients, without ILD obtained from the ISARIC 4C cohort, admitted with COVID-19 over the same period. The primary outcome was survival. Secondary analysis distinguished IPF from non-IPF ILD and used lung function to determine the greatest risks of death. Measurements and Main ResultsData from 349 patients with ILD across Europe were included, of whom 161 were admitted to hospital with laboratory or clinical evidence of COVID-19 and eligible for propensity-score matching. Overall mortality was 49% (79/161) in patients with ILD with COVID-19. After matching ILD patients with COVID-19 had higher mortality (HR 1.60, Confidence Intervals 1.17-2.18 p=0.003) compared with age, sex and comorbidity matched controls without ILD. Patients with a Forced Vital Capacity (FVC) of <80% had an increased risk of death versus patients with FVC [≥]80% (HR 1.72, 1.05-2.83). Furthermore, obese patients with ILD had an elevated risk of death (HR 1.98, 1.13-3.46). ConclusionsPatients with ILD are at increased risk of death from COVID-19, particularly those with poor lung function and obesity. Stringent precautions should be taken to avoid COVID-19 in patients with ILD.

Longitudinal immune profiling reveals distinct features of COVID-19 pathogenesis

BackgroundThe pathogenesis of COVID-19, caused by a novel strain of coronavirus (SARS-CoV-2), involves a complex host-virus interaction and is characterised by an exaggerated immune response, the specific components of which are poorly understood. Here we report the outcome of a longitudinal immune profiling study in hospitalised patients during the peak of the COVID-19 pandemic in the UK and show the relationship between immune responses and severity of the clinical presentation. MethodsThe Coronavirus Immune Response and Clinical Outcomes (CIRCO) study was conducted at four hospitals in Greater Manchester. Patients with SARS-CoV-2 infection, recruited as close to admission as possible, provided peripheral blood samples at enrolment and sequentially thereafter. Fresh samples were assessed for immune cells and proteins in whole blood and serum. Some samples were also stimulated for 3 hours with LPS and analysed for intracellular proteins. Results were stratified based on patient-level data including severity of symptoms and date of reported symptom onset. FindingsLongitudinal analysis showed a very high neutrophil to T cell ratio and abnormal activation of monocytes in the blood, which displayed high levels of the cell cycle marker, Ki67 and low COX-2. These properties all reverted in patient with good outcome. Unexpectedly, multiple aspects of inflammation were diminished as patients progressed in severity and time, even in ITU patients not recovering. InterpretationThis is the first detailed longitudinal analysis of COVID-19 patients of varying severity and outcome, revealing common features and aspects that track with severity. Patients destined for a severe outcome can be identified at admission when still displaying mild-moderate symptoms. We provide clues concerning pathogenesis that should influence clinical trials and therapeutics. Targeting pathways involved in neutrophil and monocyte release from the bone marrow should be tested in patients with COVID-19. FundingThe Kennedy Trust for Rheumatology Research, The Wellcome Trust, The Royal Society, The BBSRC, National Institute for Health Research (NIHR) Biomedical Research Centres (BRC). Research in contextO_ST_ABSEvidence before this studyC_ST_ABSAnalysis of the literature before the study via pubmed and bioRxiv searches using the terms COVID-19, SARS-CoV2, immune and inflammation (with the last search performed on 27th April 2020) showed evidence of an overactive immune response in a handful of studies in cross-sectional analyses all done at a single time point. Added value of this studyTo determine the role of the immune response in a disease process, it is necessary to correlate immune activity with clinical parameters dynamically. In this study patients presented to hospital at different stages of disease so we took samples at different time-points to provide an accurate picture of the relevant pathobiology. In order to avoid loss of large components of the immune system due to the processes of storage, longitudinal samples were interrogated in real time to reveal the full immune alterations in COVID-19. Implications of all the available evidenceRespiratory viruses continue to cause devastating global disease. The finding of altered myelopoiesis, with excess neutrophils and altered monocyte function, as dominant features in our study provides an incentive for clinical testing of therapeutics that specifically target this pathobiology. Given that inflammation is greatest prior to admission to intensive care, trials of specific immune-modulating therapies should be considered earlier in admission. Future studies of COVID-19 mechanisms should place more emphasis on longitudinal analyses since disease changes dramatically over time.