Respiratory Immune Responses during Infection and Pollution Inhalation.

The COVID-19 pandemic highlighted the importance of lung immune responses to pathogens and environmental factors [...].

COVID-19 in patients with pulmonary alveolar proteinosis: a European multicentre study.

Adult PAP patients experience similar #COVID19 rates to the general population, and high rates of hospitalisation and deaths, underscoring their vulnerability and the need for measures to prevent infection. The impact of iGM-CSF must be considered. https://bit.ly/3M0wKnZ.

Prediction of low pulse oxygen saturation in COVID-19 using remote monitoring post hospital discharge.

BACKGROUND: Monitoring systems have been developed during the COVID-19 pandemic enabling clinicians to remotely monitor physiological measures including pulse oxygen saturation (SpO2), heart rate (HR), and breathlessness in patients after discharge from hospital. These data may be leveraged to understand how symptoms vary over time in COVID-19 patients. There is also potential to use remote monitoring systems to predict clinical deterioration allowing early identification of patients in need of intervention. METHODS: A remote monitoring system was used to monitor 209 patients diagnosed with COVID-19 in the period following hospital discharge. This system consisted of a patient-facing app paired with a Bluetooth-enabled pulse oximeter (measuring SpO2 and HR) linked to a secure portal where data were available for clinical review. Breathlessness score was entered manually to the app. Clinical teams were alerted automatically when SpO2 < 94 %. In this study, data recorded during the initial ten days of monitoring were retrospectively examined, and a random forest model was developed to predict SpO2 < 94 % on a given day using SpO2 and HR data from the two previous days and day of discharge. RESULTS: Over the 10-day monitoring period, mean SpO2 and HR increased significantly, while breathlessness decreased. The coefficient of variation in SpO2, HR and breathlessness also decreased over the monitoring period. The model predicted SpO2 alerts (SpO2 < 94 %) with a mean cross-validated. sensitivity of 66 ± 18.57 %, specificity of 88.31 ± 10.97 % and area under the receiver operating characteristic of 0.80 ± 0.11. Patient age and sex were not significantly associated with the occurrence of asymptomatic SpO2 alerts. CONCLUSION: Results indicate that SpO2 alerts (SpO2 < 94 %) on a given day can be predicted using SpO2 and heart rate data captured on the two preceding days via remote monitoring. The methods presented may help early identification of patients with COVID-19 at risk of clinical deterioration using remote monitoring.

A Man With Malaise, Myalgia, and Rapidly Progressive Interstitial Lung Disease.

CASE PRESENTATION: A 45-year-old man sought treatment at the ED during the third wave of the COVID-19 pandemic with a month-long history of fatigue, cough, myalgia, and hand stiffness. He did not report dyspnea. He had no past medical history and previously was fit and active, working as a farmer. He was a lifelong nonsmoker and had no family history of lung disease.

COVID-19 in patients with Pulmonary Alveolar Proteinosis A European multicenter study

Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) signaling is essential in both alveolar macrophages (AMs) differentiation and activation of lung immune cells [1]. Differentiated AMs are crucial in both the elimination of alveolar microbes and surfactant clearance. The disruption of the GM-CSF axis in alveolar macrophages leads to the development of pulmonary alveolar proteinosis (PAP) [1]. In the majority of patients this relates to the presence of autoantibodies against GM-CSF autoimmune (a)PAP but there are multiple other causes [1, 2, 3]. GM-CSF deficient animals may have impaired lung inflammatory response to commensal microbes and humans with PAP may occasionally develop opportunistic lung infections [4]. The mainstay of pharmacological treatment in aPAP is inhaled GM-CSF which is off-label but increasingly used worldwide [5, 6, 7, 8, 9].

Contemporary Concise Review 2021: Interstitial lung disease.

The last 2 years have presented previously unforeseen challenges in pulmonary medicine. Despite the significant impact of the SARS-CoV-2 pandemic on patients, clinicians and communities, advances in the care and understanding of interstitial lung disease (ILD) continued unabated. Recent studies have led to improved guidelines, better understanding of the role for antifibrotics in fibrosing ILDs, prognostic indicators and novel biomarkers. In this concise contemporary review, we summarize many of the important studies published in 2021, highlighting their relevance and impact to the management and knowledge of ILD.

A Review of Alpha-1 Antitrypsin Binding Partners for Immune Regulation and Potential Therapeutic Application.

Alpha-1 antitrypsin (AAT) is the canonical serine protease inhibitor of neutrophil-derived proteases and can modulate innate immune mechanisms through its anti-inflammatory activities mediated by a broad spectrum of protein, cytokine, and cell surface interactions. AAT contains a reactive methionine residue that is critical for its protease-specific binding capacity, whereby AAT entraps the protease on cleavage of its reactive centre loop, neutralises its activity by key changes in its tertiary structure, and permits removal of the AAT-protease complex from the circulation. Recently, however, the immunomodulatory role of AAT has come increasingly to the fore with several prominent studies focused on lipid or protein-protein interactions that are predominantly mediated through electrostatic, glycan, or hydrophobic potential binding sites. The aim of this review was to investigate the spectrum of AAT molecular interactions, with newer studies supporting a potential therapeutic paradigm for AAT augmentation therapy in disorders in which a chronic immune response is strongly linked.

Protease-anti-protease compartmentalization in SARS-CoV-2 ARDS: Therapeutic implications.

BACKGROUND: Interleukin-6 (IL-6) is elevated in SARS-CoV-2 infection. IL-6 regulates acute-phase proteins, such as alpha-1 antitrypsin (AAT), a key lung anti-protease. We investigated the protease-anti-protease balance in the circulation and pulmonary compartments in SARS-CoV-2 acute respiratory distress syndrome (ARDS) compared to non-SARS-CoV-2 ARDS (nsARDS) and the effects of tocilizumab (IL-6 receptor antagonist) on anti-protease defence in SARS-CoV-2 infection. METHODS: Levels and activity of AAT and neutrophil elastase (NE) were measured in plasma, airway tissue and tracheal secretions (TA) of people with SARS-CoV-2 ARDS or nsARDS. AAT and IL-6 levels were evaluated in people with moderate SARS-CoV-2 infection who received standard of care +/- tocilizumab. FINDINGS: AAT plasma levels doubled in SARS-CoV-2 ARDS. In lung parenchyma AAT levels were increased, as was the percentage of neutrophils involved in NET formation. A protease-anti-protease imbalance was detected in TA with active NE and no active AAT. The airway anti-protease, secretory leukoprotease inhibitor was decreased in SARS-CoV-2-infected lungs and cleaved in TA. In nsARDS, plasma AAT levels were elevated but TA samples had less AAT cleavage, with no detectable active NE in most samples. Induction of AAT in ARDS occurred mainly through IL-6. Tocilizumab down-regulated AAT during SARS-CoV-2 infection. INTERPRETATION: There is a protease-anti-protease imbalance in the airways of SARS-CoV-2-ARDS patients. This imbalance is a target for anti-protease therapy. FUNDING: NIH Serological Sciences Network, National Heart, Lung, and Blood Institute and National Institute of Diabetes and Digestive and Kidney Diseases.

The COVIRL002 Trial-Tocilizumab for management of severe, non-critical COVID-19 infection: A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: Tocilizumab is a humanized monoclonal antibody which targets and inhibits interleukin-6 (IL-6) and has demonstrated efficacy in treating diseases associated with hyper-inflammation. Data are suggestive of tocilizumab as a potential treatment for patients with COVID-19 infection. The aim of this study is to determine the safety and efficacy of standard dose versus low dose tocilizumab in adults with severe, non-critical, PCR-confirmed COVID-19 infection with evidence of progressive decline in respiratory function and evolving systemic inflammation on time to intubation, non-invasive ventilation and/or all-cause mortality. TRIAL DESIGN: This trial is a phase 2, open label, two-stage, multicentre, randomised trial. PARTICIPANTS: Adult subjects with severe, non-critical, PCR-confirmed COVID-19 infection with evidence of progressive decline in respiratory function and evolving systemic inflammation requiring admission to hospital at St. Vincent's University Hospital and Mater Misericordiae University Hospital, Dublin, Ireland. Inclusion criteria Aged 18 years or older. Confirmed SARS-CoV2 infection (as defined by positive PCR). Evidence of hyper inflammatory state as evidenced by at least three of the following: Documented temperature >38°C in the past 48 hours, IL6 >40 pg/ml, or in its absence D-dimer >1.5 µgFEU /ml, Elevated CRP (>100mg/L) and/or a three-fold increase since presentation, Elevated ferritin X5 ULN, Elevated LDH (above the ULN), Elevated fibrinogen (above the ULN). Pulmonary infiltrates on chest imaging. Moderate to severe respiratory failure as defined by PaO2/FiO2≤300mmHg. INTERVENTION AND COMPARATOR: Intervention for participants in this trial is SOC plus Tocilizumab compared to SOC alone (comparator). For Stage 1, following randomisation, subjects will receive either (Arm 1) SOC alone or (Arm 2) SOC plus Tocilizumab (standard single dose - 8mg/kg, infused over 60 minutes. Once stage 1 has fully recruited, subsequent participants will be enrolled directly into Stage 2 and receive either (Arm 1) SOC plus Tocilizumab (standard single dose - 8mg/kg, infused over 60 minutes or (Arm 2) SOC plus Tocilizumab (standard single dose - 4mg/kg, infused over 60 minutes). MAIN OUTCOMES: The primary endpoint for this study is the time to a composite primary endpoint of progression to intubation and ventilation, non-invasive ventilation or death within 28 days post randomisation. RANDOMISATION: Eligible patients will be randomised (1:1) using a central register. Randomisation will be performed through an interactive, web-based electronic data capturing database. In stage 1, eligible participants will be randomised (1:1) to (Arm 1) SOC alone or to (Arm 2) SOC with single dose (8mg/kg, maximum 800mg) intravenous tocilizumab infused over 60 minutes. In stage 2, eligible participants will be randomised (1:1) to receive either (Arm 1) single, standard dose (8mg/kg, maximum 800mg) intravenous tocilizumab infused over 60 minutes or (Arm 2) reduced dose (4mg/kg, maximum 800mg) intravenous tocilizumab infused over 60 minutes. BLINDING: This study is open label. The study will not be blinded to investigators, subjects, or medical or nursing staff. The trial statistician will be blinded for data analysis and will be kept unaware of treatment group assignments. To facilitate this, the randomisation schedule will be drawn up by an independent statistician and objective criteria were defined for the primary outcome to minimize potential bias. NUMBERS TO BE RANDOMISED: In stage 1, 90 subjects will be randomised 1:1, 45 to SOC and 45 subjects to SOC plus Tocilizumab (8mg/kg, infused over 60 minutes). In stage 2, sample size calculation for the dose evaluation stage will use data generated from stage 1 using the same primary endpoint as in stage 1. TRIAL STATUS: The COVIRL002 trial (Protocol version 1.4, 13th May 2020) commenced in May 2020 at St. Vincent's University Hospital and Mater Misericordiae University Hospital, Dublin, Ireland. Recruitment is proceeding with the aim to achieve the target sample size on or before April 2021. TRIAL REGISTRATION: COVIRL002 was registered 25 June 2020 under EudraCT number: 2020-001767-86 and Protocol identification: UCDCRC/20/02. FULL PROTOCOL: The full protocol for COVIRL002 is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2).