Tocilizumab administration for the treatment of hospitalized patients with COVID-19: A systematic review and meta-analysis

Quantitative SARS-CoV-2 RT-PCR and Bronchoalveolar Cytokine Concentrations Redefine the COVID-19 Phenotypes in Critically Ill Patients

RATIONALE

Recent studies suggest that both hypo- and hyperinflammatory acute respiratory distress syndrome (ARDS) phenotypes characterize severe COVID-19-related pneumonia. The role of lung Severe Acute Respiratory Syndrome - Coronavirus 2 (SARS-CoV-2) viral load in contributing to these phenotypes remains unknown.

OBJECTIVES

To redefine COVID-19 ARDS phenotypes when considering quantitative SARS-CoV-2 RT-PCR in the bronchoalveolar lavage of intubated patients. To compare the relevance of deep respiratory samples versus plasma in linking the immune response and the quantitative viral loads.

METHODS

Eligible subjects were adults diagnosed with COVID-19 ARDS who required mechanical ventilation and underwent bronchoscopy. We recorded the immune response in the bronchoalveolar lavage and plasma and the quantitative SARS-CoV-2 RT-PCR in the bronchoalveolar lavage. Hierarchical clustering on principal components was applied separately on the 2 compartments' datasets. Baseline characteristics were compared between clusters.

MEASUREMENTS AND RESULTS

Twenty subjects were enrolled between August 2020 and March 2021. Subjects underwent bronchoscopy on average 3.6 days after intubation. All subjects were treated with dexamethasone prior to bronchoscopy, 11 of 20 (55.6%) received remdesivir and 1 of 20 (5%) received tocilizumab. Adding viral load information to the classic 2-cluster model of ARDS revealed a new cluster characterized by hypoinflammatory responses and high viral load in 23.1% of the cohort. Hyperinflammatory ARDS was noted in 15.4% of subjects. Bronchoalveolar lavage clusters were more stable compared to plasma.

CONCLUSIONS

We identified a unique group of critically ill subjects with COVID-19 ARDS who exhibit hypoinflammatory responses but high viral loads in the lower airways. These clusters may warrant different treatment approaches to improve clinical outcomes.

Tocilizumab in Severe and Critical COVID-19 Pneumonia: Streamlining the Mixed Signals

Four years since the start of the pandemic, the first lockdown in Manila happened on March 15, 2020 causing a pandemonium in the metro as the Filipinos gear up for the unexpected. As the suspected and confirmed cases grew, case numbers of unidentified patients soon became friends, relatives, and loved ones. As of May 2023 1 , there have been more than 1.3 million confirmed COVID-19 cases in Metro Manila alone with almost 14,000 deaths from severe and critical cases. The current knowledge about the disease as well as the explanation of its widely varied symptomatology continues to evolve. 2-4 At the center of the discussion for severe and critical COVID-19 requiring hospitalization is the hyperactivation ofthe inflammatory response resulting to simultaneous increase in multiple cytokines. 4,5 Such an inflammatory cascade results in nonspecific inflammatory reaction from damaged or dysfunctional virus-infected host cells making it difficult to identify a specific mediator of inflammatory response. 5,6 It is therefore not surprising that multiple therapeutic trials done targeting specific cytokines such as IL-6 and TNF-a have also led to mixed results. 7-10 Since 2020, aggressive research has allowed both the development of new medications as well as repurposing of other molecules in the treatment of COVID-19. Antiviral drugs, monoclonal antibodies, IL-6R inhibitor/immune modulators, andsystemic corticosteroids have become household names. 6 IL-6, an identified key propagator of the cytokine storm in severe and critical COVID, has been the focus of the noise as mechanistically, IL-6 blockers including tocilizumab and sarilumabtheoretically disrupt the inflammatory cascade. 5-7 If mechanistically, IL-6 blockers, particularly tocilizumab can block the inflammatory cascade, why are there mixed signals on its benefit based on real-world evidence? 7-10 One of the largest and most recently published systematic review and meta-analysis of 15 randomized and two non- randomized clinical trials evaluating the effect of tocilizumab on the clinical outcomes of COVID-19 patients11 showed acombined cumulative risk of death in COVID-19 patients of 0.93 (RR 0.93, 95% CI 0.86 – 1.00, i 2 72.39%). The need for invasive ventilation, ICU admission was at 1.04 (RR 1.04, 95% CI 0.90 – 1.20, i 2 0.00). These figures indicate a 7% decreasedrisk of death with a 4% increased risk of ICU admission and need for invasive ventilation, again indicating mixed signals on the perceived benefit of tocilizumab. 11 Limitations in the study results compared to controlled clinical trials are probablydue to (1) heterogeneity of the patients with severe and critically ill COVID-19 patients potentially having different degrees of inflammatory activities; (2) timing of administration of tocilizumab; (3) different administrative and hospital policies inthe management of more ill patients suffering from COVID-19; and (4) presence of multiple inflammatory cytokines aside from IL-6, making it difficult to pinpoint the specific key mediator of inflammatory response on a per-patient basis. The local randomized controlled trial published by Amante et al.12 agree with these mixed signals from the published literature in COVID-19. In both intention-to-treat and per-protocol-analysis, there was no statistical significance and clinicalbenefit of using tocilizumab for severe and critically ill patients. Four years later, the picture is clearer now as real-world evidence coupled with carefully conducted clinical trials provide us a better understanding of the use of tocilizumab for current cases. However, back in 2020, when this mysterious respiratory illness is wreaking havoc, medications both newly developed and repurposed were offered as the medical research community was challenged by a pandemic in an unprecedented manner. As COVID-19 becomes endemic, the search for the cure for severe COVID-19 remains to be discovered. Given its mixed signals, shared decision making (pending confirmation in further studies) between the patient, caregiver, and the physician remains the cornerstone of management.

Alpha-1 adrenergic antagonists and the risk of hospitalization or death in non-hospitalized patients with COVID-19: A population-based study

BACKGROUND

Alpha-1 receptor antagonists may interfere with IL-6 signaling and could therefore be a potential treatment for COVID-19. However, the effectiveness of these drugs in mitigating the risk of clinical deterioration among non-hospitalized patients with COVID-19 is unknown.

OBJECTIVES

The aim of this study is to examine the association between alpha-1 antagonist exposure and the 30-day risk of a hospital encounter or death in nonhospitalized patients with COVID-19.

METHODS

We conducted a population-based cohort study of Ontario residents aged 35 years and older who were eligible for public drug coverage and who had a positive test for SARS-CoV-2 between January 1, 2020, and March 1, 2021. We matched each individual receiving an alpha-1 antagonist at the time of their positive test with two non-exposed individuals using propensity scores. Our outcome was a composite of a hospital admission, emergency department visit, or death, 1 to 30 days following the positive test.

RESULTS

We matched 3289 alpha-1 antagonist exposed patients to 6189 unexposed patients. Overall, there was no difference in the 30-day risk of the primary outcome among patients exposed to alpha-1 antagonists at the time of their diagnosis relative to unexposed individuals (28.8% vs. 28.0%; OR 1.00, 95% CI 0.91 to 1.11). In a secondary analysis, individuals exposed to alpha-1 antagonists had a lower risk of death in the 30 days following a COVID diagnosis (OR 0.79; 95% CI 0.66 to 0.93).

CONCLUSION

Alpha-1 antagonists did not mitigate the 30-day risk of clinical deterioration in non-hospitalized patients with COVID-19. Our findings do not support the general repurposing of alpha-1 antagonists as a treatment for such patients, although there may be subgroups of patients in whom further research is warranted.

Clinical Manifestations and Outcomes of Older Patients with COVID-19: A Comprehensive Review

The consequences of coronavirus disease 2019 (COVID-19) are particularly severe in older adults with a disproportionate number of severe and fatal outcomes. Therefore, this integrative review aimed to provide a comprehensive overview of the clinical characteristics, management approaches, and prognosis of older patients diagnosed with COVID-19. Common clinical presentations in older patients include fever, cough, and dyspnea. Additionally, preexisting comorbidities, especially diabetes and pulmonary and cardiovascular diseases, were frequently observed and associated with adverse outcomes. Management strategies varied, however, early diagnosis, vigilant monitoring, and multidisciplinary care were identified as key factors for enhancing patient outcomes. Nonetheless, the prognosis remains guarded for older patients, with increased rates of hospitalization, mechanical ventilation, and mortality. However, timely therapeutic interventions, especially antiviral and supportive treatments, have demonstrated some efficacy in mitigating the severe consequences in this age group. In conclusion, while older adults remain highly susceptible to severe outcomes from COVID-19, early intervention, rigorous monitoring, and comprehensive care can play a pivotal role in improving their clinical outcomes.

Cardiovascular Disease from Pathophysiology to Risk Estimation: Is Inflammation Estimated through Perivascular Attenuation on Computed Tomography the Key?

(1) Background: Systemic inflammation stands as a well-established risk factor for ischemic cardiovascular disease, as well as a contributing factor in the development of cardiac arrhythmias, notably atrial fibrillation. Furthermore, scientific studies have brought to light the pivotal role of localized vascular inflammation in the initiation, progression, and destabilization of coronary atherosclerotic disease. (2) Methods: We comprehensively review recent, yet robust, scientific evidence elucidating the use of perivascular adipose tissue attenuation measurement on computed tomography applied to key anatomical sites. Specifically, the investigation extends to the internal carotid artery, aorta, left atrium, and coronary arteries. (3) Conclusions: The examination of perivascular adipose tissue attenuation emerges as a non-invasive and indirect means of estimating localized perivascular inflammation. This measure is quantified in Hounsfield units, indicative of the inflammatory response elicited by dense adipose tissue near the vessel or the atrium. Particularly noteworthy is its potential utility in assessing inflammatory processes within the coronary arteries, evaluating coronary microvascular dysfunction, appraising conditions within the aorta and carotid arteries, and discerning inflammatory states within the atria, especially in patients with atrial fibrillation. The widespread applicability of perivascular adipose tissue attenuation measurement underscores its significance as a diagnostic tool with considerable potential for enhancing our understanding and management of cardiovascular diseases.

Coronary inflammation on chest computed tomography and COVID-19 mortality

OBJECTIVES

The main factors associated with coronavirus disease-19 (COVID-19) mortality are age, comorbidities, pattern of inflammatory response, and SARS-CoV-2 lineage involved in infection. However, the clinical course of the disease is extremely heterogeneous, and reliable biomarkers predicting adverse prognosis are lacking. Our aim was to elucidate the prognostic role of a novel marker of coronary artery disease inflammation, peri-coronary adipose tissue attenuation (PCAT), available from high-resolution chest computed tomography (HRCT) in COVID-19 patients with severe disease requiring hospitalization.

METHODS

Two distinct groups of patients were admitted to Parma University Hospital in Italy with COVID-19 in March 2020 and March 2021 (first- and third-wave peaks of the COVID-19 pandemic in Italy, with the prevalence of wild-type and B.1.1.7 SARS-CoV-2 lineage, respectively) were retrospectively enrolled. The primary endpoint was in-hospital mortality. Demographic, clinical, laboratory, HRCT data, and coronary artery HRCT features (coronary calcium score and PCAT attenuation) were collected to show which variables were associated with mortality.

RESULTS

Among the 769 patients enrolled, 555 (72%) were discharged alive, and 214 (28%) died. In multivariable logistic regression analysis age (p < 0.001), number of chronic illnesses (p < 0.001), smoking habit (p = 0.006), P/F ratio (p = 0.001), platelet count (p = 0.002), blood creatinine (p < 0.001), non-invasive mechanical ventilation (p < 0.001), HRCT visual score (p < 0.001), and PCAT (p < 0.001), but not the calcium score, were independently associated with in-hospital mortality.

CONCLUSION

Coronary inflammation, measured with PCAT on non-triggered HRCT, appeared to be independently associated with higher mortality in patients with severe COVID-19, while the pre-existent coronary atherosclerotic burden was not associated with adverse outcomes after adjustment for covariates.

CLINICAL RELEVANCE STATEMENT

The current study demonstrates that a relatively simple measurement, peri-coronary adipose tissue attenuation (PCAT), available ex-post from standard high-resolution computed tomography, is strongly and independently associated with in-hospital mortality.

KEY POINTS

• Coronary inflammation can be measured by the attenuation of peri-coronary adipose tissue (PCAT) on high-resolution CT (HRCT) without contrast media. • PCAT is strongly and independently associated with in-hospital mortality in SARS-CoV-2 patients. • PCAT might be considered an independent prognostic marker in COVID-19 patients if confirmed in other studies.

Cytokine storm and translating IL-6 biology into effective treatments for COVID-19

As of May 3, 2023, the Coronavirus disease 2019 (COVID-19) pandemic has resulted in more than 760 million confirmed cases and over 6.9 million deaths. Several patients have developed pneumonia, which can deteriorate into acute respiratory distress syndrome. The primary etiology may be attributed to cytokine storm, which is triggered by the excessive release of proinflammatory cytokines and subsequently leads to immune dysregulation. Considering that high levels of interleukin-6 (IL-6) have been detected in several highly pathogenic coronavirus-infected diseases, such as severe acute respiratory syndrome in 2002, the Middle East respiratory syndrome in 2012, and COVID-19, the IL-6 pathway has emerged as a key in the pathogenesis of this hyperinflammatory state. Thus, we review the history of cytokine storm and the process of targeting IL-6 signaling to elucidate the pivotal role played by tocilizumab in combating COVID-19.

Insights into COVID-19: Perspectives on Drug Remedies and Host Cell Responses

In light of the COVID-19 global pandemic caused by SARS-CoV-2, ongoing research has centered on minimizing viral spread either by stopping viral entry or inhibiting viral replication. Repurposing antiviral drugs, typically nucleoside analogs, has proven successful at inhibiting virus replication. This review summarizes current information regarding coronavirus classification and characterization and presents the broad clinical consequences of SARS-CoV-2 activation of the angiotensin-converting enzyme 2 (ACE2) receptor expressed in different human cell types. It provides publicly available knowledge on the chemical nature of proposed therapeutics and their target biomolecules to assist in the identification of potentially new drugs for the treatment of SARS-CoV-2 infection.

Should We Interfere with the Interleukin-6 Receptor During COVID-19: What Do We Know So Far?

Severe manifestations of COVID-19 consist of acute respiratory distress syndrome due to an initially local reaction leading to a systemic inflammatory response that results in hypoxia. Many therapeutic approaches have been attempted to reduce the clinical consequences of an excessive immune response to viral infection. To date, systemic corticosteroid therapy is still the most effective intervention. More recently, new hope has emerged with the use of interleukin (IL)-6 receptor inhibitors (tocilizumab and sarilumab). However, the great heterogeneity of the methodology and results of published studies obfuscate the true value of this treatment, leading to a confusing synthesis in recent meta-analyses, and the persistence of doubts in terms of patient groups and the appropriate time to treat. Moreover, their effects on the anti-infectious or pro-healing response are still poorly studied. This review aims to clarify the potential role of IL-6 receptor inhibitors in the treatment of severe forms of COVID-19.

Acute liver injury in COVID-19 patients hospitalized in the intensive care unit: Narrative review

In recent years, humanity has been confronted with a global pandemic due to coronavirus disease 2019 (COVID-19), which has caused an unprecedented health and economic crisis worldwide. Apart from the respiratory symptoms, which are considered the principal manifestations of COVID-19, it has been recognized that COVID-19 constitutes a systemic inflammatory process affecting multiple organ systems. Across the spectrum of organ involvement in COVID-19, acute liver injury (ALI) has been gradually gaining increasing attention by the international scientific community. COVID-19 associated liver impairment can affect a considerable proportion of COVID-19 patients and seems to correlate with the severity of the disease course. Indeed, COVID-19 patients hospitalized in the intensive care unit (ICU) run a greater risk of developing ALI due to the severity of their clinical condition and in the context of multi-organ failure. The putative pathophysiological mechanisms of COVID-19 induced ALI in ICU patients remain poorly understood and appear to be multifactorial in nature. Several theories have been proposed to explain the occurrence of ALI in the ICU setting, such as hypoperfusion and ischemia due to hemodynamic instability, passive liver congestion as a result of congestive heart failure, ischemia-reperfusion injury, hypoxia due to respiratory failure, mechanical ventilation itself, sepsis and septic shock, cytokine storm, endotheliitis with concomitant coagulopathy, drug-induced liver injury, parenteral nutrition and direct cytopathic viral effect. It should be noted that no specific therapy for COVID-19 induced ALI exists. Therefore, the therapeutic approach lies in preventive measures and is exclusively supportive once ALI ensues. The aim of the current review is to scrutinize the existing evidence on COVID-19 associated ALI in ICU patients, explore its clinical implications, shed light on the underlying pathophysiological mechanisms and propose potential therapeutic approaches. Ongoing research on the particular scientific field will further elucidate the pathophysiology behind ALI and address unresolved issues, in the hope of mitigating the tremendous health consequences imposed by COVID-19 on ICU patients.

Drug-Induced Liver Injury in Hospitalized Patients during SARS-CoV-2 Infection

In the last few years, the world has had to face the SARS-CoV-2 infection and its multiple effects. Even though COVID-19 was first considered to be a respiratory disease, it has an extended clinical spectrum with symptoms occurring in many tissues, and it is now identified as a systematic disease. Therefore, various drugs are used during the therapy of hospitalized COVID-19 patients. Studies have shown that many of these drugs could have adverse side-effects, including drug-induced liver injury-also known as DILI-which is the focus of our review. Despite the consistent findings, the pathophysiological mechanism behind DILI in COVID-19 disease is still complex, and there are a few risk factors related to it. However, when it comes to the diagnosis, there are specific algorithms (including the RUCAM algorithm) and biomarkers that can assist in identifying DILI and which we will analyze in our review. As indicated by the title, a variety of drugs are associated with this COVID-19-related complication, including systemic corticosteroids, drugs used for the therapy of uncontrolled cytokine storm, as well as antiviral, anti-inflammatory, and anticoagulant drugs. Bearing in mind that hepatotoxicity is very likely to occur during COVID-19, especially in patients treated with multiple medications, we will also refer to the use of other drugs used for DILI therapy in an effort to control and prevent a severe and long-term outcome.

Experience of anticipatory therapy with IL-6 receptor inhibitors and perspectives for its use in the evolution of COVID-19

The Advisory Board chaired by the chief specialist in infectious diseases of the Ministry of Health of Russian Federation, Professor V.P. Chulanov was held on June 18, 2022 in Saint Petersburg. Aim. The main purpose of the Board was following discussion: the analysis of the real-world data of levilimab as an anticipatory therapy for COVID-19 in hospitalized patients; the review of the experience and perspectives of levilimab as an anticipatory anti-inflammatory option for outpatient patients who meet defined clinical and laboratory criteria. Results. The analyzed data on clinical efficacy and safety formed the basis of recommendations proposed by experts for the use of levilimab in the inpatient and outpatient medical care for COVID-19.

Inflammatory pathways in COVID‐19: Mechanism and therapeutic interventions

The 2019 coronavirus disease (COVID‐19) pandemic has become a global crisis. In the immunopathogenesis of COVID‐19, SARS‐CoV‐2 infection induces an excessive inflammatory response in patients, causing an inflammatory cytokine storm in severe cases. Cytokine storm leads to acute respiratory distress syndrome, pulmonary and other multiorgan failure, which is an important cause of COVID‐19 progression and even death. Among them, activation of inflammatory pathways is a major factor in generating cytokine storms and causing dysregulated immune responses, which is closely related to the severity of viral infection. Therefore, elucidation of the inflammatory signaling pathway of SARS‐CoV‐2 is important in providing otential therapeutic targets and treatment strategies against COVID‐19. Here, we discuss the major inflammatory pathways in the pathogenesis of COVID‐19, including induction, function, and downstream signaling, as well as existing and potential interventions targeting these cytokines or related signaling pathways. We believe that a comprehensive understanding of the regulatory pathways of COVID‐19 immune dysregulation and inflammation will help develop better clinical therapy strategies to effectively control inflammatory diseases, such as COVID‐19.

The safety and effectiveness of tocilizumab in older adult critically ill patients with COVID-19: a multicenter, cohort study

OBJECTIVES

Evidence supports tocilizumab (TCZ) benefit and safety in adult patients with severe COVID-19. However, its effectiveness in critically ill older adult patients remains questionable. Thus, the study aimed to evaluate the safety and effectiveness of TCZ in older critically ill patients with COVID-19.

METHODS

A multicenter, retrospective study for all critically ill older adults (aged ≥65 years) with confirmed COVID-19 infection and admitted to the intensive care units (ICUs). Eligible patients were categorized into two groups based on TCZ use during ICU stay (control vs TCZ). Propensity score (PS) matching was used (1:1 ratio) based on the selected criteria. The primary outcome was the in-hospital mortality.

RESULTS

A total of 368 critically ill older adult patients were included in the study. Fifty one patients (13.8%) received TCZ. The in-hospital mortality was lower in the TCZ group (HR 0.41; 95% CI 0.22-0.76, P-value = 0.005). Patients who received TCZ had lower odds of respiratory failure requiring mechanical ventilation (OR [95% CI]: 0.32 [0.10-0.98], P-value = 0.04). No statistically significant differences were found between the two groups for 30-days mortality, ventilator-free days, length of stay, and complications during ICU stay.

CONCLUSION

Tocilizumab use in critically ill older adult patients with COVID-19 is associated with lower in-hospital mortality and a similar safety profile.

Proteomic analysis and identification reveal the anti-inflammatory mechanism of clofazimine on lipopolysaccharide-induced acute lung injury in mice

Background and objective

Acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS) was increasingly recognized as one of the most severe acute hyperimmune response of coronavirus disease 2019 (COVID-19). Clofazimine (CFZ) has attracted attention due to its anti-inflammatory property in immune diseases as well as infectious diseases. However, the role and potential molecular mechanism of CFZ in anti-inflammatory responses remain unclear.

Methods

We analyze the protein expression profiles of CFZ and LPS from Raw264.7 macrophages using quantitative proteomics. Next, the protective effect of CFZ on LPS-induced inflammatory model is assessed, and its underlying mechanism is validated by molecular biology analysis.

Results

LC–MS/MS-based shotgun proteomics analysis identified 4746 (LPS) and 4766 (CFZ) proteins with quantitative information. The key proteins and their critical signal transduction pathways including TLR4/NF-κB/HIF-1α signaling was highlighted, which was involved in multiple inflammatory processes. A further analysis of molecular biology revealed that CFZ could significantly inhibit the proliferation of Raw264.7 macrophages, decrease the levels of TNF-α and IL-1β, alleviate lung histological changes and pulmonary edema, improve the survival rate, and down-regulate TLR4/NF-κB/HIF-1α signaling in LPS model.

Conclusion

This study can provide significant insight into the proteomics-guided pharmacological mechanism study of CFZ and suggest potential therapeutic strategies for infectious disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00011-022-01623-w.

Lack of Difference in Tocilizumab Efficacy in the Treatment of Severe COVID-19 Caused by Different SARS-CoV-2 Variants

Tocilizumab (TOC) is presumed to be an effective and safe treatment for severe COVID-19, but its usefulness has not been yet investigated for different SARS-CoV-2 variants. This study aimed to evaluate the influence of TOC on mortality in patients with severe COVID-19 caused by Delta and non-Delta SARS-CoV-2 variants. In a retrospective analysis, we compared the medical records of 78 and 224 patients with severe COVID-19 due to Delta and non-Delta variants, respectively. A total of 30 patients with Delta and 84 with non-Delta variants were treated with TOC in addition to standard therapy. There were no statistically significant differences in mortality rate when comparing Delta vs. non-Delta patients nor when comparing those treated with TOC vs. not treated with TOC in both variants. Using a logistic regression model, in the examined population as a whole, we found an increased (p < 0.05) risk of death as leukocyte and erythrocyte counts decreased and as procalcitonin increased. Increased procalcitonin was significant for mortality in the Delta group, while decreased IL-6, leukocytes, and platelets and increased fibrinogen and procalcitonin were significant in the non-Delta group. Tocilizumab efficacy in severe COVID-19 does not differ between Delta or non-Delta virus variants. The Delta variant of SARS-CoV-2 does not increase mortality when compared to other virus strains.

Contemporary Concise Review 2021: COVID-19 and other respiratory infections

Bats are likely the primary source of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2).

Minks are highly susceptible to infection by SARS‐CoV‐2.

Transmission from asymptomatic individuals was estimated to account for over 50% of all transmissions of coronavirus disease 2019 (COVID‐19) cases.

SARS‐CoV‐2 is evolving towards more efficient aerosol transmission.

Remdesivir, baricitinib, tocilizumab and dexamethasone are frequently used for the treatment of patients with respiratory failure due to COVID‐19.

There is a rising incidence of non‐tuberculous Mycobacterium pulmonary disease globally, with a higher prevalence in Asian countries than in the Western world.

Protracted bacterial bronchitis is a common cause of chronic productive cough in childhood.

Re‐emergence of respiratory syncytial virus may occur after the relaxation of infection control measures and the reopening of borders during COVID‐19 pandemic.

The Central Role of Extracellular Vesicles in the Mechanisms of Thrombosis in COVID-19 Patients With Cancer and Therapeutic Strategies

Cancer patients have increased SARS-CoV-2 susceptibility and are prone to developing severe COVID-19 infections. The incidence of venous thrombosis is approximately 20% in COVID-19 patients with cancer. It has been suggested that thrombus formation has been suggested to correlate with severe clinical manifestations, mortality, and sequelae. In this review, we primarily elaborate on the pathophysiological mechanisms of thrombosis in COVID-19 patients with cancer, emphasize the role of microparticles (MPs) and phosphatidylserine (PS) in coagulation, and propose an antithrombotic strategy. The coagulation mechanisms of COVID-19 and cancer synergistically amplify the coagulation cascade, and collectively promotes pulmonary microvascular occlusion. During systemic coagulation, the virus activates immune cells to release abundant proinflammatory cytokines, referred to as cytokine storm, resulting in the apoptosis of tumor and blood cells and subsequent MPs release. Additionally, we highlight that tumor cells contribute to MPs and coagulation by apoptosis owing to insufficient blood supply. A positive feedback loop of cytokines storm and MPs storm promotes microvascular coagulation storm, leading to microthrombi formation and inadequate blood perfusion. Microthrombi-damaged endothelial cells (ECs), tumor, and blood cells further aggravate the apoptosis of the cells and facilitate MPs storm. PS, especially on MPs, plays a pivotal role in the blood coagulation process, contributing to clot initiation, amplification, and propagation. Since coagulation is a common pathway of COVID-19 and cancer, and associated with mortality, patients would benefit from antithrombotic therapy. The above results lead us to assert that early stage antithrombotic therapy is optimal. This strategy is likely to maintain blood flow patency contributing to viral clearance, attenuating the formation of cytokines and MPs storm, maintaining oxygen saturation, and avoiding the progress of the disease.

Liver Injury in Patients Hospitalized for COVID-19: Possible Role of Therapy

Patients with COVID-19 show a high prevalence of liver injury. The pattern of this liver damage is still not fully understood. Different etiopathogenetic factors may concur; from a direct cytopathic effect, once the virus binds to the ACE-2 receptors, to the immune-mediated collateral damage, due to cytokine storm. The presence of pre-existing chronic liver disease is a contributing factor for acute organ damage during SARS-CoV2 infection. Last but not least, treatments probably play a role, also, in determining hepatotoxicity: many of the drugs we have used or are still using to treat COVID-19, combined with non-invasive ventilation, are known to sometimes determine acute liver injury. Although liver damage associated with COVID-19 is often transient and can resolve without any special treatment, it is important to understand the underlying mechanisms, particularly to better treat its more severe forms.

Tocilizumab improves 28-day survival in hospitalized patients with severe COVID-19: an open label, prospective study

BACKGROUND

Data on the safety and efficacy profile of tocilizumab in patients with severe COVID-19 needs to be enriched.

METHODS

In this open label, prospective study, we evaluated clinical outcomes in consecutive patients with COVID-19 and PaO2/FiO2 < 200 receiving tocilizumab plus usual care versus usual care alone. Tocilizumab was administered at the time point that PaO2/FiO2 < 200 was observed. The primary outcome was 28-day mortality. Secondary outcomes included time to discharge, change in PaO2/FiO2 at day 5 and change in WHO progression scale at day 10.

FINDINGS

Overall, 114 patients were included in the analysis (tocilizumab plus usual care: 56, usual care: 58). Allocation to usual care was associated with significant increase in 28-day mortality compared to tocilizumab plus usual care [Cox proportional-hazards model: HR: 3.34, (95% CI: 1.21-9.30), (p = 0.02)]. There was not a statistically significant difference with regards to hospital discharge over the 28 day period for patients receiving tocilizumab compared to usual care [11.0 days (95% CI: 9.0 to 16.0) vs 14.0 days (95% CI: 10.0-24.0), HR: 1.32 (95% CI: 0.84-2.08), p = 0.21]. ΔPaO2/FiO2 at day 5 was significantly higher in the tocilizumab group compared to the usual care group [42.0 (95% CI: 23.0-84.7) vs 15.8 (95% CI: - 19.4-50.3), p = 0.03]. ΔWHO scale at day 10 was significantly lower in the tocilizumab group compared to the usual care group (-0.5 ± 2.1 vs 0.6 ± 2.6, p = 0.005).

CONCLUSION

Administration of tocilizumab, at the time point that PaO2/FiO2 < 200 was observed, improved survival and other clinical outcomes in hospitalized patients with severe COVID-19 irrespective of systemic inflammatory markers levels.

Metabolic reprograming shapes neutrophil functions in severe COVID-19

To better understand the mechanisms at the basis of neutrophil functions during SARS-CoV-2, we studied patients with severe COVID-19 pneumonia. They had high blood proportion of degranulated neutrophils and elevated plasma levels of myeloperoxidase (MPO), elastase, and MPO-DNA complexes, which are typical markers of neutrophil extracellular traps (NET). Their neutrophils display dysfunctional mitochondria, defective oxidative burst, increased glycolysis, glycogen accumulation in the cytoplasm, and increase glycogenolysis. Hypoxia-inducible factor 1α (ΗΙF-1α) is stabilized in such cells, and it controls the level of glycogen phosphorylase L (PYGL), a key enzyme in glycogenolysis. Inhibiting PYGL abolishes the ability of neutrophils to produce NET. Patients displayed significant increases of plasma levels of molecules involved in the regulation of neutrophils' function including CCL2, CXCL10, CCL20, IL-18, IL-3, IL-6, G-CSF, GM-CSF, IFN-γ. Our data suggest that metabolic remodelling is vital for the formation of NET and for boosting neutrophil inflammatory response, thus, suggesting that modulating ΗΙF-1α or PYGL could represent a novel approach for innovative therapies.