Immune modulation in COVID-19: Strategic considerations for personalized therapeutic intervention

Precision Detection of Fungal Co-Infections for Enhanced COVID-19 Treatment Strategies Using FESEM Imaging

The treatment of fungal infections presents significant challenges due to the lack of standardized diagnostic procedures, a restricted range of antifungal treatments, and the risk of harmful interactions between antifungal medications and the immunosuppressive drugs used in anti-inflammatory treatment for critically ill patients with COVID-19. Mucormycosis and aspergillosis are the primary invasive fungal infections in patients with severe COVID-19, occurring singly or in combination. Histopathological examination is a vital diagnostic technique that details the presence and invasion of fungi within tissues and blood vessels, and the body's response to the infection. However, the pathology report omits information on the most common fungi associated with the observed morphology, as well as other potential fungi and parasites that ought to be included in the differential diagnosis. This research marks significance in diagnosing fungal infections, such as mucormycosis and aspergillosis associated to COVID-19 by field emission scanning electron microscopy (FESEM) imaging to examine unstained histopathology slides, allowing for a detailed morphological analysis of the fungus. FESEM provides an unprecedented resolution and detail, surpassing traditional Hematoxylin & Eosin (H&E) and Grocott's Methenamine Silver (GMS) staining methods in identifying and differentiating dual fungal infections and diverse fungal species. The findings underscore the critical need for individualized treatment plans for patients severely affected by COVID-19 and compounded by secondary fungal infections. The high-magnification micrographs reveal specific fungal morphology and reproductive patterns. Current treatment protocols largely depend on broad-spectrum antifungal therapies. However this FESEM guided diagnostic approach can help in targeted patient specific anti fungal therapies. Such precision could lead to more effective early interventions, addressing the complex management required for severe COVID-19 cases with coexisting fungal infections. This approach significantly advances disease management and patient recovery, advocating for personalized, precision medicine in tackling this multifaceted clinical challenge.

Graphical Abstract

Harnessing immunity: Immunomodulatory therapies in COVID-19

An overly exuberant immune response, characterized by a cytokine storm and uncontrolled inflammation, has been identified as a significant driver of severe coronavirus disease 2019 (COVID-19) cases. Consequently, deciphering the intricacies of immune dysregulation in COVID-19 is imperative to identify specific targets for intervention and modulation. With these delicate dynamics in mind, immunomodulatory therapies have emerged as a promising avenue for mitigating the challenges posed by COVID-19. Precision in manipulating immune pathways presents an opportunity to alter the host response, optimizing antiviral defenses while curbing deleterious inflammation. This review article comprehensively analyzes immunomodulatory interventions in managing COVID-19. We explore diverse approaches to mitigating the hyperactive immune response and its impact, from corticosteroids and non-steroidal drugs to targeted biologics, including anti-viral drugs, cytokine inhibitors, JAK inhibitors, convalescent plasma, monoclonal antibodies (mAbs) to severe acute respiratory syndrome coronavirus 2, cell-based therapies (i.e., CAR T, etc.). By summarizing the current evidence, we aim to provide a clear roadmap for clinicians and researchers navigating the complex landscape of immunomodulation in COVID-19 treatment.

Metagenomic next-generation sequencing of nasopharyngeal microbiota in COVID-19 patients with different disease severities

Throughout the COVID-19 pandemic, extensive research has been conducted on SARS-COV-2 to elucidate its genome, prognosis, and possible treatments. However, few looked at the microbial markers that could be explored in infected patients and that could predict possible disease severity. The aim of this study is to compare the nasopharyngeal microbiota of healthy subjects, moderate, under medication, and recovered SARS-COV-2 patients. In 2020, 38 nasopharyngeal swabs were collected from 6 healthy subjects, 14 moderates, 10 under medication and 8 recovered SARS-COV-2 patients at the Prince Mohammed Bin Abdulaziz Hospital Riyadh. Metatranscriptomic sequencing was performed using Minion Oxford nanopore sequencing. No significant difference in alpha as well as beta diversity was observed among all four categories. Nevertheless, we have found that Streptococcus spp including Streptococcus pneumoniae and Streptococcus thermophilus were among the top 15 most abundant species detected in COVID-19 patients but not in healthy subjects. The genus Staphylococcus was found to be associated with COVID-19 patients compared to healthy subjects. Furthermore, the abundance of Leptotrichia was significantly higher in healthy subjects compared to recovered patients. Corynebacterium on the other hand, was associated with under-medication patients. Taken together, our study revealed no differences in the overall microbial composition between healthy subjects and COVID-19 patients. Significant differences were seen only at specific taxonomic level. Future studies should explore the nasopharyngeal microbiota between controls and COVID-19 patients while controlling for confounders including age, gender, and comorbidities; since these latter could affect the results and accordingly the interpretation.IMPORTANCEIn this work, no significant difference in the microbial diversity was seen between healthy subjects and COVID-19 patients. Changes in specific taxa including Leptotrichia, Staphylococcus, and Corynebacterium were only observed. Leptotrichia was significantly higher in healthy subjects, whereas Staphylococcus and Corynebacterium were mostly associated with COVID-19, and specifically with under-medication SARS-COV-2 patients, respectively. Although the COVID-19 pandemic has ended, the SARS-COV-2 virus is continuously evolving and the emergence of new variants causing more severe disease should be always kept in mind. Microbial markers in SARS-COV-2 infected patients can be useful in the early suspicion of the disease, predicting clinical outcomes, framing hospital and intensive care unit admission as well as, risk stratification. Data on which microbial marker to tackle is still controversial and more work is needed, hence the importance of this study.

Clinical and immunological features of COVID-19 in patients with anti-MDA5 dermatomyositis during the omicron wave in Chongqing, China

Patients with anti-melanoma differentiation-associated gene 5 (anti-MDA5) dermatomyositis (DM) have a higher risk of coronavirus disease 2019 (COVID-19) infection. In this longitudinal observational study, we aimed to investigate the clinical and immunological features of these patients after COVID-19 infection. A total of 73 patients with anti-MDA5 DM were recruited from the Second Affiliated Hospital of Chongqing Medical University during the Omicron wave epidemic. Clinical data were collected by questionnaire survey and electronic medical records. Blood samples were used to determine the immunity responses. From December 9, 2022 to March 31, 2023, 67 patients were eligible for final analysis; 68.7% of them were infected with COVID-19. The most common symptoms observed in COVID-19 were upper respiratory symptoms, most cases were mild or moderate (97.8%). The clinical laboratory indexes were relativity stable in patients after infection (all p > 0.05). Vaccination is not a protective factor against the Omicron infection (odds ratio: 2.69, 95% confidence interval: 0.81-8.93, p = 0.105). Both wildtype (WT) neutralizing antibodies titer and BA.5-specific immunoglobulin G titer were significantly enhanced after infection (all p < 0.01), which was as high as healthy controls (HCs). The memory B-cell responses were similar between the patients with anti-MDA5 DM and HCs (p > 0.05). However, both the WT-specific CD8+ T cells and CD4+ T cells were reduced in patients with anti-MDA5 DM (all p < 0.05). In conclusion, patients with anti-MDA5 DM did not deteriorate the COVID-19, in turn, COVID-19 infection did not increase the risk of anti-MDA5 DM exacerbation. The humoral responses were robust but the cellular responses were weakened after COVID-19 infection.

Current Technologies and Future Perspectives in Immunotherapy towards a Clinical Oncology Approach

Immunotherapy is now established as a potent therapeutic paradigm engendering antitumor immune response against a wide range of malignancies and other diseases by modulating the immune system either through the stimulation or suppression of immune components such as CD4+ T cells, CD8+ T cells, B cells, monocytes, macrophages, dendritic cells, and natural killer cells. By targeting several immune checkpoint inhibitors or blockers (e.g., PD-1, PD-L1, PD-L2, CTLA-4, LAG3, and TIM-3) expressed on the surface of immune cells, several monoclonal antibodies and polyclonal antibodies have been developed and already translated clinically. In addition, natural killer cell-based, dendritic cell-based, and CAR T cell therapies have been also shown to be promising and effective immunotherapeutic approaches. In particular, CAR T cell therapy has benefited from advancements in CRISPR-Cas9 genome editing technology, allowing the generation of several modified CAR T cells with enhanced antitumor immunity. However, the emerging SARS-CoV-2 infection could hijack a patient's immune system by releasing pro-inflammatory interleukins and cytokines such as IL-1β, IL-2, IL-6, and IL-10, and IFN-γ and TNF-α, respectively, which can further promote neutrophil extravasation and the vasodilation of blood vessels. Despite the significant development of advanced immunotherapeutic technologies, after a certain period of treatment, cancer relapses due to the development of resistance to immunotherapy. Resistance may be primary (where tumor cells do not respond to the treatment), or secondary or acquired immune resistance (where tumor cells develop resistance gradually to ICIs therapy). In this context, this review aims to address the existing immunotherapeutic technologies against cancer and the resistance mechanisms against immunotherapeutic drugs, and explain the impact of COVID-19 on cancer treatment. In addition, we will discuss what will be the future implementation of these strategies against cancer drug resistance. Finally, we will emphasize the practical steps to lay the groundwork for enlightened policy for intervention and resource allocation to care for cancer patients.

Low Dose of Ti3 C2 MXene Quantum Dots Mitigate SARS-CoV-2 Infection

MXene QDs (MQDs) have been effectively used in several fields of biomedical research. Considering the role of hyperactivation of immune system in infectious diseases, especially in COVID-19, MQDs stand as a potential candidate as a nanotherapeutic against viral infections. However, the efficacy of MQDs against SARS-CoV-2 infection has not been tested yet. In this study, Ti3 C2 MQDs are synthesized and their potential in mitigating SARS-CoV-2 infection is investigated.  Physicochemical characterization suggests that MQDs are enriched with abundance of bioactive functional groups such as oxygen, hydrogen, fluorine, and chlorine groups as well as surface titanium oxides. The efficacy of MQDs is tested in VeroE6 cells infected with SARS-CoV-2. These data demonstrate that the treatment with MQDs is able to mitigate multiplication of virus particles, only at very low doses such as 0,15 µg mL-1 . Furthermore, to understand the mechanisms of MQD-mediated anti-COVID properties, global proteomics analysis are performed and determined differentially expressed proteins between MQD-treated and untreated cells. Data reveal that MQDs interfere with the viral life cycle through different mechanisms including the Ca2 + signaling pathway, IFN-α response, virus internalization, replication, and translation. These findings suggest that MQDs can be employed to develop future immunoengineering-based nanotherapeutics strategies against SARS-CoV-2 and other viral infections.

Inhaled Sargramostim (Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor) for COVID-19-Associated Acute Hypoxemia: Results of the Phase 2, Randomized, Open-Label Trial (iLeukPulm)

INTRODUCTION

Granulocyte-macrophage colony-stimulating factor (GM-CSF), a protein produced in the lung, is essential for pulmonary host defense and alveolar integrity. Prior studies suggest potential benefits in several pulmonary conditions, including acute respiratory distress syndrome and viral infections. This trial evaluated the effect of the addition of inhaled sargramostim (yeast-derived, glycosylated recombinant human GM-CSF) to standard of care (SOC) on oxygenation and clinical outcomes in patients with COVID-19-associated acute hypoxemia.

MATERIALS AND METHODS

A randomized, controlled, open-label trial of hospitalized adults with COVID-19-associated hypoxemia (oxygen saturation <93% on ≥2 L/min oxygen supplementation and/or PaO2/FiO2 <350) randomized 2:1 to inhaled sargramostim (125 mcg twice daily for 5 days) plus SOC versus SOC alone. Institutional SOC before and during the study was not limited. Primary outcomes were change in the alveolar-arterial oxygen gradient (P(A-a)O2) by day 6 and the percentage of patients intubated within 14 days. Safety evaluations included treatment-emergent adverse events. Efficacy analyses were based on the modified intent-to-treat population, the subset of the intent-to-treat population that received ≥1 dose of any study treatment (sargramostim and/or SOC). An analysis of covariance approach was used to analyze changes in oxygenation measures. The intubation rate was analyzed using the chi-squared test. All analyses are considered descriptive. The study was institutional review board approved.

RESULTS

In total, 122 patients were treated (sargramostim, n = 78; SOC, n = 44). The sargramostim arm experienced greater improvement in P(A-a)O2 by day 6 compared to SOC alone (least squares [LS] mean change from baseline [SE]: -102.3 [19.4] versus -30.5 [26.9] mmHg; LS mean difference: -71.7 [SE 33.2, 95% CI -137.7 to -5.8]; P = .033; n = 96). By day 14, 11.5% (9/78) of sargramostim and 15.9% (7/44) of SOC arms required intubation (P = .49). The 28-day mortality was 11.5% (9/78) and 13.6% (6/44) in the sargramostim and SOC arms, respectively (hazard ratio 0.85; P = .76). Treatment-emergent adverse events occurred in 67.9% (53/78) and 70.5% (31/44) on the sargramostim and SOC arms, respectively.

CONCLUSIONS

The addition of inhaled sargramostim to SOC improved P(A-a)O2, a measure of oxygenation, by day 6 in hospitalized patients with COVID-19-associated acute hypoxemia and was well tolerated. Inhaled sargramostim is delivered directly to the lung, minimizing systemic effects, and is simple to administer making it a feasible treatment option in patients in settings where other therapy routes may be difficult. Although proportionally lower rates of intubation and mortality were observed in sargramostim-treated patients, this study was insufficiently powered to demonstrate significant changes in these outcomes. However, the significant improvement in gas exchange with sargramostim shows this inhalational treatment enhances pulmonary efficiency in this severe respiratory illness. These data provide strong support for further evaluation of sargramostim in high-risk patients with COVID-19.

[Exosomes in the life cycle of viruses and the pathogenesis of viral infections]

Exosomes are extracellular vesicles of endosomal origin, with a bilayer membrane, 30160 nm in diameter. Exosomes are released from cells of different origins and are detected in various body fluids. They contain nucleic acids, proteins, lipids, metabolites and can transfer the contents to recipient cells. Exosome biogenesis involves cellular proteins of the Rab GTPase family and the ESCRT system, which regulate budding, vesicle transport, molecule sorting, membrane fusion, formation of multivesicular bodies and exosome secretion. Exosomes are released from cells infected with viruses and may contain viral DNA and RNA, as well as mRNA, microRNA, other types of RNA, proteins and virions. Exosomes are capable of transferring viral components into uninfected cells of various organs and tissues. This review analyzes the impact of exosomes on the life cycle of widespread viruses that cause serious human diseases: human immunodeficiency virus (HIV-1), hepatitis B virus, hepatitis C virus, SARS-CoV-2. Viruses are able to enter cells by endocytosis, use molecular and cellular pathways involving Rab and ESCRT proteins to release exosomes and spread viral infections. It has been shown that exosomes can have multidirectional effects on the pathogenesis of viral infections, suppressing or enhancing the course of diseases. Exosomes can potentially be used in noninvasive diagnostics as biomarkers of the stage of infection, and exosomes loaded with biomolecules and drugs - as therapeutic agents. Genetically modified exosomes are promising candidates for new antiviral vaccines.

Pharmacological approaches to pulmonary fibrosis following COVID-19

Background: In the past few years, COVID-19 became the leading cause of morbidity and mortality worldwide. Although the World Health Organization has declared an end to COVID-19 as a public health emergency, it can be expected, that the emerging new cases at the top of previous ones will result in an increasing number of patients with post-COVID-19 sequelae. Despite the fact that the majority of patients recover, severe acute lung tissue injury can in susceptible individuals progress to interstitial pulmonary involvement. Our goal is to provide an overview of various aspects associated with the Post-COVID-19 pulmonary fibrosis with a focus on its potential pharmacological treatment options. Areas covered: We discuss epidemiology, underlying pathobiological mechanisms, and possible risk and predictive factors that were found to be associated with the development of fibrotic lung tissue remodelling. Several pharmacotherapeutic approaches are currently being applied and include anti-fibrotic drugs, prolonged use or pulses of systemic corticosteroids and non-steroidal anti-inflammatory and immunosuppressive drugs. In addition, several repurposed or novel compounds are being investigated. Fortunately, clinical trials focused on pharmacological treatment regimens for post-COVID-19 pulmonary fibrosis have been either designed, completed or are already in progress. However, the results are contrasting so far. High quality randomised clinical trials are urgently needed with respect to the heterogeneity of disease behaviour, patient characteristics and treatable traits. Conclusion: The Post-COVID-19 pulmonary fibrosis contributes to the burden of chronic respiratory consequences among survivors. Currently available pharmacotherapeutic approaches mostly comprise repurposed drugs with a proven efficacy and safety profile, namely, corticosteroids, immunosuppressants and antifibrotics. The role of nintedanib and pirfenidone is promising in this area. However, we still need to verify conditions under which the potential to prevent, slow or stop progression of lung damage will be fulfilled.

In vitro high-content tissue models to address precision medicine challenges

The field of precision medicine allows for tailor-made treatments specific to a patient and thereby improve the efficiency and accuracy of disease prevention, diagnosis, and treatment and at the same time would reduce the cost, redundant treatment, and side effects of current treatments. Here, the combination of organ-on-a-chip and bioprinting into engineering high-content in vitro tissue models is envisioned to address some precision medicine challenges. This strategy could be employed to tackle the current coronavirus disease 2019 (COVID-19), which has made a significant impact and paradigm shift in our society. Nevertheless, despite that vaccines against COVID-19 have been successfully developed and vaccination programs are already being deployed worldwide, it will likely require some time before it is available to everyone. Furthermore, there are still some uncertainties and lack of a full understanding of the virus as demonstrated in the high number new mutations arising worldwide and reinfections of already vaccinated individuals. To this end, efficient diagnostic tools and treatments are still urgently needed. In this context, the convergence of bioprinting and organ-on-a-chip technologies, either used alone or in combination, could possibly function as a prominent tool in addressing the current pandemic. This could enable facile advances of important tools, diagnostics, and better physiologically representative in vitro models specific to individuals allowing for faster and more accurate screening of therapeutics evaluating their efficacy and toxicity. This review will cover such technological advances and highlight what is needed for the field to mature for tackling the various needs for current and future pandemics as well as their relevancy towards precision medicine.

Short-term complications and post-acute sequelae in hospitalized paediatric patients with COVID-19 and obesity: A multicenter cohort study

BACKGROUND

Obesity increases the severity of coronavirus disease 2019 illness in adults. The role of obesity in short-term complications and post-acute sequelae in children is not well defined.

OBJECTIVE

To evaluate the relationship between obesity and short-term complications and post-acute sequelae of SARS-CoV-2 infection in hospitalized paediatric patients.

METHODS

An observational study was conducted in three tertiary hospitals, including paediatric hospitalized patients with a confirmatory SARS-CoV-2 RT-PCR from March 2020 to December 2021. Obesity was defined according to WHO 2006 (0-2 years) and CDC 2000 (2-20 years) growth references. Short-term outcomes were intensive care unit admission, ventilatory support, superinfections, acute kidney injury, and mortality. Neurological, respiratory, and cardiological symptoms and/or delayed or long-term complications beyond 4 weeks from the onset of symptoms were considered as post-acute sequalae. Adjusted linear, logistic regression and generalized estimating equations models were performed.

RESULTS

A total of 216 individuals were included, and 67 (31.02%) of them had obesity. Obesity was associated with intensive care unit admission (aOR = 5.63, CI95% 2.90-10.94), oxygen requirement (aOR = 2.77, CI95% 1.36-5.63), non-invasive ventilatory support (aOR = 6.81, CI95% 2.11-22.04), overall superinfections (aOR = 3.02 CI95% 1.45-6.31), and suspected bacterial pneumonia (aOR = 3.00 CI95% 1.44-6.23). For post-acute sequalae, obesity was associated with dyspnea (aOR = 9.91 CI95% 1.92-51.10) and muscle weakness (aOR = 20.04 CI95% 2.50-160.65).

CONCLUSIONS

In paediatric hospitalized patients with COVID-19, severe short-term outcomes and post-acute sequelae are associated with obesity. Recognizing obesity as a key comorbidity is essential to develop targeted strategies for prevention of COVID-19 complications in children.

Air-permeable redox mediated transcutaneous CO2 sensor

Standard clinical care of neonates and the ventilation status of human patients affected with coronavirus disease involves continuous CO2 monitoring. However, existing noninvasive methods are inadequate owing to the rigidity of hard-wired devices, insubstantial gas permeability and high operating temperature. Here, we report a cost-effective transcutaneous CO2 sensing device comprising elastomeric sponges impregnated with oxidized single-walled carbon nanotubes (oxSWCNTs)-based composites. The proposed device features a highly selective CO2 sensing response (detection limit 155 ± 15 ppb), excellent permeability and reliability under a large deformation. A follow-up prospective study not only offers measurement equivalency to existing clinical standards of CO2 monitoring but also provides important additional features. This new modality allowed for skin-to-skin care in neonates and room-temperature CO2 monitoring as compared with clinical standard monitoring system operating at high temperature to substantially enhance the quality for futuristic applications.

The Deceptive COVID-19: Lessons from Common Molecular Diagnostics and a Novel Plan for the Prevention of the Next Pandemic

The COVID-19 pandemic took place during the years 2020-2022 and the virus, named SARS-CoV-2, seems likely to have resulted in an endemic disease. Nevertheless, widespread COVID-19 has given rise to several major molecular diagnostics' facts and concerns that have emerged during the overall management of this disease and the subsequent pandemic. These concerns and lessons are undeniably critical for the prevention and control of future infectious agents. Furthermore, most populaces were introduced to several new public health maintenance strategies, and again, some critical events arose. The purpose of this perspective is to thoroughly analyze all these issues and the concerns, such as the molecular diagnostics' terminologies, their role, as well as the quantity and quality issues with a molecular diagnostics' test result. Furthermore, it is speculated that society will be more vulnerable in the future and prone to emerging infectious diseases; thus, a novel preventive medicine's plan for the prevention and control of future (re)emerging infectious diseases is presented, so as to aid the early prevention of future epidemics and pandemics.

Recombinant GM-CSF for diseases of GM-CSF insufficiency: Correcting dysfunctional mononuclear phagocyte disorders

Introduction

Endogenous granulocyte-macrophage colony-stimulating factor (GM-CSF), identified by its ability to support differentiation of hematopoietic cells into several types of myeloid cells, is now known to support maturation and maintain the metabolic capacity of mononuclear phagocytes including monocytes, macrophages, and dendritic cells. These cells sense and attack potential pathogens, present antigens to adaptive immune cells, and recruit other immune cells. Recombinant human (rhu) GM-CSF (e.g., sargramostim [glycosylated, yeast-derived rhu GM-CSF]) has immune modulating properties and can restore the normal function of mononuclear phagocytes rendered dysfunctional by deficient or insufficient endogenous GM-CSF.

Methods

We reviewed the emerging biologic and cellular effects of GM-CSF. Experts in clinical disease areas caused by deficient or insufficient endogenous GM-CSF examined the role of GM-CSF in mononuclear phagocyte disorders including autoimmune pulmonary alveolar proteinosis (aPAP), diverse infections (including COVID-19), wound healing, and anti-cancer immune checkpoint inhibitor therapy.

Results

We discuss emerging data for GM-CSF biology including the positive effects on mitochondrial function and cell metabolism, augmentation of phagocytosis and efferocytosis, and immune cell modulation. We further address how giving exogenous rhu GM-CSF may control or treat mononuclear phagocyte dysfunction disorders caused or exacerbated by GM-CSF deficiency or insufficiency. We discuss how rhu GM-CSF may augment the anti-cancer effects of immune checkpoint inhibitor immunotherapy as well as ameliorate immune-related adverse events.

Discussion

We identify research gaps, opportunities, and the concept that rhu GM-CSF, by supporting and restoring the metabolic capacity and function of mononuclear phagocytes, can have significant therapeutic effects. rhu GM-CSF (e.g., sargramostim) might ameliorate multiple diseases of GM-CSF deficiency or insufficiency and address a high unmet medical need.

Incidence, Outcomes and Risk Factors of Recurrent Ventilator Associated Pneumonia in COVID-19 Patients: A Retrospective Multicenter Study

Background: High incidence of ventilator associated pneumonia (VAP) has been reported in critically ill patients with COVID-19. Among these patients, we aimed to assess the incidence, outcomes and risk factors of VAP recurrences. Methods: We conducted an observational retrospective study in three French intensive care units (ICUs). Patients admitted for a documented COVID-19 from March 2020 to May 2021 and requiring mechanical ventilation (MV) for ≥48 h were included. The study main outcome was the incidence of VAP recurrences. Secondary outcomes were the duration of MV, ICU and hospital length of stay and mortality according to VAP and recurrences. We also assessed the factors associated with VAP recurrences. Results: During the study period, 398 patients met the inclusion criteria. A total of 236 (59%) of them had at least one VAP episode during their ICU stay and 109 (46%) of these patients developed at least one recurrence. The incidence of VAP recurrence considering death and extubation as competing events was 29.6% (IC = [0.250−0.343]). Seventy-eight percent of recurrences were due to the same bacteria (relapses). Patients with a VAP recurrence had a longer duration of MV as compared with one VAP and no VAP patients (41 (25−56) vs. 16 (8−30) and 10 (5−18) days; p < 0.001) and a longer ICU length of stay (46 (29−66) vs. 22 (12−36) and 14 (9−25) days; p < 0.001). The 90-day mortality was higher in the recurrence group as compared with the no VAP group only (31.2 vs. 21.0% (p = 0.021)). In a multivariate analysis including bacterial co-infection at admission, the use of immunosuppressive therapies and the bacteria responsible for the first VAP episode, the duration of MV was the only factor independently associated with VAP recurrence. Conclusion: In COVID-19 associated respiratory failure, recurrences affected 46% of patients with a first episode of VAP. VAP recurrences were mainly relapses and were associated with a prolonged duration of MV and ICU length of stay but not with a higher mortality. MV duration was the only factor associated with recurrences.

Overview of Antiviral Drug Therapy for COVID-19: Where Do We Stand?

The vaccine weapon has resulted in being essential in fighting the COVID-19 outbreak, but it is not fully preventing infection due to an alarming spreading of several identified variants of concern. In fact, the recent emergence of variants has pointed out how the SARS-CoV-2 pandemic still represents a global health threat. Moreover, oral antivirals also develop resistance, supporting the need to find new targets as therapeutic tools. However, cocktail therapy is useful to reduce drug resistance and maximize vaccination efficacy. Natural products and metal-drug-based treatments have also shown interesting antiviral activity, representing a valid contribution to counter COVID-19 outbreak. This report summarizes the available evidence which supports the use of approved drugs and further focuses on significant clinical trials that have investigated the safety and efficacy of repurposing drugs and new molecules in different COVID-19 phenotypes. To date, there are many individuals vulnerable to COVID-19 exhibiting severe symptoms, thus characterizing valid therapeutic strategies for better management of the disease is still a challenge.

A primer on Post-COVID-19 conditions and implications for clinical pharmacists

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and is largely viewed as an acute illness involving multiple organ systems. In the wake of the acute illness, many survivors fully recover and return to baseline, while others suffer from a wide range of lingering symptoms collectively known as "post-COVID conditions". The recognition of these conditions as a clinical entity represents the first step in developing a targeted plan for recovery and symptom mitigation. While interventions to directly minimize or reduce new, recurrent, or persistent symptoms are currently unknown, pharmacists can play a key role in optimizing management of these patients.

Immune Targeted Therapies for COVID-19 Infection: A Narrative Review

In December 2019, the coronavirus disease-2019 (COVID-19) outbreak emerged in Wuhan, China. The World Health Organization officially declared it a pandemic on March 11, 2020. Reports indicated that the associated mortality of the infection is quite higher in the elderly, individuals with specific comorbidities (such as diabetes mellitus), and generally the ones with a compromised immune system. A cohort study in Wuhan, China, reported a dysregulated immune response in 452 patients with laboratory-confirmed COVID-19. As a result of this suppressed immune response, an increase in neutrophil to lymphocyte ratio, T lymphopenia, and a decrease in CD4⁺ T cells were all common laboratory findings, especially in severe cases. On the other hand, there is substantial evidence of T cell exhaustion in critically ill patients. Accordingly, the immune system seems to play an important role in the prognosis and pathogenesis of the disease. Therefore, this study aims to review the evidence on the immune response dysregulation in COVID-19 infection and the potential role of immunoregulatory treatments such as immune checkpoint inhibitors, interferons, and CD200 inhibitors in altering disease prognosis, especially in critically ill patients.

Vitamin D prescribing practices among clinical practitioners during the COVID-19 pandemic

Background and Aims

COVID-19 has caused devastation globally. Low vitamin D status, particularly during the winter months, remains commonplace around the world, and it is thought to be one of the contributing factors toward causation and severity of COVID-19. Many guidelines do not recommend vitamin D for the treatment or prevention of the disease. Hence, we set out to conduct a global survey to understand the use and prescribing habits of vitamin D among clinicians for COVID-19.

Methods

An online anonymous questionnaire was sent to clinicians enquiring about their prescribing habits of vitamin D and personal use of vitamin D. Data of the survey were collected between January 15, 2021, and February 13, 2021.

Results

Four thousand four hundred forty practicing clinicians were included in the analysis, with the majority of those responding from Asia, followed by Europe. 82.9% prescribed vitamin D before COVID-19, more commonly among general practitioners (GPs) in comparison with medical specialists, and Asian clinicians were more likely to prescribe vitamin D in comparison with Caucasian physicians (p < 0.01). GPs were also more likely to prescribe vitamin D prophylactically to prevent COVID-19 in comparison with medical specialists (OR 1.47, p < 0.01). Most GPs (72.8%) would also prescribe vitamin D to treat COVID-19 in comparison with medical specialists (OR 1.81, p < 0.01), as well as more Asian in comparison with Caucasian physicians (OR 4.57, p < 0.01). 80.4% of respondents were taking vitamin D, more so in the 45-54 and 65-74 age groups in comparison with the 18-24 years category (OR 2.15 and 2.40, respectively, both p < 0.05), many of whom did so before COVID-19 (72.1%).

Conclusion

This survey has shown that many clinicians would prescribe vitamin D for the prevention and treatment of COVID-19. The majority would also recommend measuring vitamin D levels, but not so in patients with COVID-19.

Concurrent Infection with SARS-CoV-2 and Pneumocystis jirovecii in Immunocompromised and Immunocompetent Individuals

Coronavirus disease 2019 (COVID-19) may occur with concurrent infections caused by bacterial and fungal microorganisms. This systematic review evaluated studies reporting concomitant COVID-19 and Pneumocystis jirovecii pneumonia (PJP). We found 39 patients (74% male, median age: 56.8 (range: 11-83) years), including 66% immunosuppressed individuals (23% HIV-infected and 41% on long-term corticosteroid therapy). Patients were characteristically severely ill (mechanical ventilation: 70%), associated with 41% mortality. The median lymphocyte count was 527 cells/mm3 (range: 110-2200), and the median CD4+ T cell count was 206 cells/mm3 (range: 8-1021). We identified three patterns of concurrent COVID-19 and P. jirovecii infection. The first pattern (airway colonization with a low burden of P. jirovecii) does not seem to modify the COVID-19 course of illness. However, P. jirovecii superinfection, typically occurring weeks after COVID-19 diagnosis as a biphasic illness, and P. jirovecii coinfection characteristically results in progressive multilobar pneumonia, which is associated with poor outcomes. To support this categorization, we reported three patients with concurrent PJP and COVID-19 identified in our institution, presenting these clinical scenarios. The diagnosis of PJP requires a high index of suspicion, since clinical and radiological characteristics overlap with COVID-19. Observational studies are necessary to determine the PJP burden in patients with COVID-19 requiring hospitalization.

SARS-CoV-2 and HIV co-infection; clinical features, diagnosis, and treatment strategies: A systematic review and meta-analysis

Background and aim

Coronavirus disease 2019 (COVID-19) in people living with human immunodeficiency virus (HIV) who has a compromised immune system can be associated with more significant risks for severe complications. To date, no comprehensive study has been performed to evaluate HIV in patients with COVID-19. In the present study, we assessed the status of patients co-infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HIV as a systematic review and meta-analysis.

Methods

A systematic literature search strategy was conducted via reviewing original research articles published in Medline, Web of Science, and Embase databases in 2019 and 2020. Statistical analysis was performed using STATA software, version 14.0 (Stata Corporation, College Station, Texas, USA), to report the prevalence of HIV among patients with COVID-19. Case reports/case series were also evaluated as a systematic review.

Results

Sixty-three studies (53 case reports/case series and ten prevalence studies) were included in our study. A meta-analysis of prevalence studies showed that HIV infection among patients with COVID-19 was reported in 6 countries (Uganda, China, Iran, USA, Italy, and Spain) with an overall frequency of 1.2% [(95% CI) 0.8–1.7] among 14,424 COVID-19 patients. According to the case reports and case series, 111 patients with HIV have been reported among 113 patients with COVID-19 from 19 countries. Most of the cases were in the USA, China, Italy, and Spain.

Conclusion

The small number of SARS-CoV-2-HIV co-infected patients reported in the literature makes it difficult to draw precise conclusions. However, since people with HIV are more likely to develop more severe complications of COVID-19, targeted policies to address this raised risk in the current pandemic should be considered. Our findings highlight the importance of identifying underlying diseases, co-infections, co-morbidities, laboratory findings, and beneficial treatment strategies for HIV patients during the COVID-19 pandemic.

GM-CSF: Orchestrating the Pulmonary Response to Infection

This review summarizes the structure and function of the alveolar unit, comprised of alveolar macrophage and epithelial cell types that work in tandem to respond to infection. Granulocyte-macrophage colony-stimulating factor (GM-CSF) helps to maintain the alveolar epithelium and pulmonary immune system under physiological conditions and plays a critical role in restoring homeostasis under pathologic conditions, including infection. Given the emergence of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and global spread of coronavirus disease 2019 (COVID-19), with subsequent acute respiratory distress syndrome, understanding basic lung physiology in infectious diseases is especially warranted. This review summarizes clinical and preclinical data for GM-CSF in respiratory infections, and the rationale for sargramostim (yeast-derived recombinant human [rhu] GM-CSF) as adjunctive treatment for COVID-19 and other pulmonary infectious diseases.

Detection of Lophomonas in pericardial effusion sample in a COVID-19 patient with systemic sclerosis: An unusual case report

Systemic sclerosis is a connective tissue disorder that involves the skin and many other organs, such as the heart, skin, and gastrointestinal tract. Cardiac involvement is in the form of pericarditis, pericardial effusion, and pulmonary hypertension. Several complications and super infections post-COVID-19 have been reported, such as fungal, bacterial infections, and Lophomonas blattarum. Lophomoniasis is an emerging pulmonary infection that mainly involves the lower respiratory tract. Herein, we present an ectopic Lophomonas infection in an unusual location (pericardial effusion) in a COVID-19 patient who had systemic sclerosis.

Missed opportunities to identify cryptococcosis in COVID-19 patients: a case report and literature review

SARS-CoV-2 may activate both innate and adaptive immune responses ultimately leading to a dysregulated immune response prompting the use of immunomodulatory therapy. Although viral pneumonia increases the risk of invasive fungal infections, it remains unclear whether SARS-CoV-2 infection, immunomodulatory therapy, or a combination of both are responsible for the increased recognition of opportunistic infections in COVID-19 patients. Cases of cryptococcosis have previously been reported following treatment with corticosteroids, interleukin (IL)-6 inhibitors, and Janus kinase (JAK) inhibitors, for patients with autoimmune diseases, but their effect on the immunologic response in patients with COVID-19 remains unknown. Herein, we present the case of a patient with COVID-19 who received high-dose corticosteroids and was later found to have cryptococcosis despite no traditional risk factors. As our case and previous cases of cryptococcosis in patients with COVID-19 demonstrate, clinicians must be suspicious of cryptococcosis in COVID-19 patients who clinically deteriorate following treatment with immunomodulatory therapies.

Evaluating the Effects of Curcumin on the Cytokine Storm in COVID-19 Using a Chip-Based Multiplex Analysis

SARS-CoV-2 can stimulate the expression of various inflammatory cytokines and induce the cytokine storm in COVID-19 patients leading to multiple organ failure and death. Curcumin as a polyphenolic compound has been shown to have anti-inflammatory properties and inhibit the release of numerous pro-inflammatory cytokines. We present multiplex analysis using the Evidence Investigator biochip system to determine the effect of curcumin on serum level of cytokines which are typically elevated in cytokine storm events, including tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and IL-10.

An Overview of COVID-19 and Its Vaccines

Coronavirus pandemic, is a continuing catastrophe (COVID-19) triggered by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The virus passes into the target cells by attaching itself to a receptor i.e., Human Angiotensin-converting enzyme 2 (hACE2). It consists of Spike structures created from glycoproteins that promote the virus entry into the target cells of host. The RBD of the S1 subunit on Spike proteins binds to the hACE2 receptor, which is mostly found in the lungs, particularly type-2 pneumocytes, causing human ACE2 receptors to be downregulated. Apart from nausea, vomiting, and chest tightness, which are unusual symptoms of COVID-19, the most common causes of death and severity are respiratory failure (69.5%), sepsis or multi-organ failure (28%), cardiac failure (14.6%), and renal failure (14.6%). Viral antigen-based or viral nucleic acid-based real-time RT-PCR is recommended for the diagnosis of COVID-19 suspects. Vaccination is essential for antiviral treatment. The study was conducted on viruses based on live-attenuated or non-activated viruses, recombinant viral vectors, DNA, VLPs and soluble proteins. Vaccine from Pfizer and BioNTech was the first that showed promising data on effectiveness. 90% efficacy of the vaccine was reported. BNT-162b2 (Pfizer, BioNTech) & mRNA-1273 (Moderna) are mRNA based; AZD-1222 Ad5‑CoV (AstraZeneca; Oxford University); Ad26.COV2.S (Johnson & Johnson) are viral vector based and other vaccines have been granted emergency use authorization by FDA. Since RNA viruses are able to mutate readily and quickly the mutation in the existing strain can be Variants of concern (VOCs) that might diminish vaccine effectiveness. The latest Delta variant (B.1.671.2) has rapidly spread in India is emerging in the United States in mid-2021. It turns out to be the chief which is 6–8 fold more resistant to neutralization by sera from COVID-19 convalescent and mRNA vaccinated individuals.

Therapeutic approaches for SARS-CoV-2 infection

Therapeutic approaches to COVID-19 treatment require appropriate inhibitors to target crucial proteins of SARS-CoV-2 replication machinery. It's been approximately 12 months since the pandemic started, yet no known specific drugs are available. However, research progresses with time in terms of high throughput virtual screening (HTVS) and rational design of repurposed, novel synthetic and natural products discovery by understanding the viral life cycle, immuno-pathological and clinical outcomes in patients based on host's nutritional, metabolic, and lifestyle status. Further, complementary and alternative medicine (CAM) approaches have also improved resiliency and immune responses. In this article, we summarize all the therapeutic antiviral strategies for COVID-19 drug discovery including computer aided virtual screening, repurposed drugs, immunomodulators, vaccines, plasma therapy, various adjunct therapies, and phage technology to unravel insightful mechanistic pathways of targeting SARS-CoV-2 and host's intrinsic, innate immunity at multiple checkpoints that aid in the containment of the disease.

Sargramostim (rhu GM-CSF) as Cancer Therapy (Systematic Review) and An Immunomodulator. A Drug Before Its Time?

BACKGROUND

Sargramostim [recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF)] was approved by US FDA in 1991 to accelerate bone marrow recovery in diverse settings of bone marrow failure and is designated on the list of FDA Essential Medicines, Medical Countermeasures, and Critical Inputs. Other important biological activities including accelerating tissue repair and modulating host immunity to infection and cancer via the innate and adaptive immune systems are reported in pre-clinical models but incompletely studied in humans.

OBJECTIVE

Assess safety and efficacy of sargramostim in cancer and other diverse experimental and clinical settings.

METHODS AND RESULTS

We systematically reviewed PubMed, Cochrane and TRIP databases for clinical data on sargramostim in cancer. In a variety of settings, sargramostim after exposure to bone marrow-suppressing agents accelerated hematologic recovery resulting in fewer infections, less therapy-related toxicity and sometimes improved survival. As an immune modulator, sargramostim also enhanced anti-cancer responses in solid cancers when combined with conventional therapies, for example with immune checkpoint inhibitors and monoclonal antibodies.

CONCLUSIONS

Sargramostim accelerates hematologic recovery in diverse clinical settings and enhances anti-cancer responses with a favorable safety profile. Uses other than in hematologic recovery are less-well studied; more data are needed on immune-enhancing benefits. We envision significantly expanded use of sargramostim in varied immune settings. Sargramostim has the potential to reverse the immune suppression associated with sepsis, trauma, acute respiratory distress syndrome (ARDS) and COVID-19. Further, sargramostim therapy has been promising in the adjuvant setting with vaccines and for anti-microbial-resistant infections and treating autoimmune pulmonary alveolar proteinosis and gastrointestinal, peripheral arterial and neuro-inflammatory diseases. It also may be useful as an adjuvant in anti-cancer immunotherapy.

Impact of dexamethasone on the incidence of ventilator-associated pneumonia and blood stream infections in COVID-19 patients requiring invasive mechanical ventilation: a multicenter retrospective study

Background

Dexamethasone decreases mortality in patients with severe coronavirus disease 2019 (COVID-19) and has become the standard of care during the second wave of pandemic. Dexamethasone is an immunosuppressive treatment potentially increasing the risk of secondary hospital acquired infections in critically ill patients. We conducted an observational retrospective study in three French intensive care units (ICUs) comparing the first and second waves of pandemic to investigate the role of dexamethasone in the occurrence of ventilator-associated pneumonia (VAP) and blood stream infections (BSI). Patients admitted from March to November 2020 with a documented COVID-19 and requiring mechanical ventilation (MV) for ≥ 48 h were included. The main study outcomes were the incidence of VAP and BSI according to the use of dexamethasone. Secondary outcomes were the ventilator-free days (VFD) at day-28 and day-60, ICU and hospital length of stay and mortality.

Results

Among the 151 patients included, 84 received dexamethasone, all but one during the second wave. VAP occurred in 63% of patients treated with dexamethasone (DEXA+) and 57% in those not receiving dexamethasone (DEXA−) (p = 0.43). The cumulative incidence of VAP, considering death, duration of MV and late immunosuppression as competing factors was not different between groups (p = 0.59). A multivariate analysis did not identify dexamethasone as an independent risk factor for VAP occurrence. The occurrence of BSI was not different between groups (29 vs. 30%; p = 0.86). DEXA+ patients had more VFD at day-28 (9 (0–21) vs. 0 (0–11) days; p = 0.009) and a reduced ICU length of stay (20 (11–44) vs. 32 (17–46) days; p = 0.01). Mortality did not differ between groups.

Conclusions

In this cohort of COVID-19 patients requiring invasive MV, dexamethasone was not associated with an increased incidence of VAP or BSI. Dexamethasone might not explain the high rates of VAP and BSI observed in critically ill COVID-19 patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00876-8.

Nanomaterials-Mediated Immunomodulation for Cancer Therapeutics

Immunotherapy holds great promise in overcoming the limitations of conventional regimens for cancer therapeutics. There is growing interest among researchers and clinicians to develop novel immune-strategies for cancer diagnosis and treatment with better specificity and lesser adversity. Immunomodulation-based cancer therapies are rapidly emerging as an alternative approach that employs the host's own defense mechanisms to recognize and selectively eliminate cancerous cells. Recent advances in nanotechnology have pioneered a revolution in the field of cancer therapy. Several nanomaterials (NMs) have been utilized to surmount the challenges of conventional anti-cancer treatments like cytotoxic chemotherapy, radiation, and surgery. NMs offer a plethora of exceptional features such as a large surface area to volume ratio, effective loading, and controlled release of active drugs, tunable dimensions, and high stability. Moreover, they also possess the inherent property of interacting with living cells and altering the immune responses. However, the interaction between NMs and the immune system can give rise to unanticipated adverse reactions such as inflammation, necrosis, and hypersensitivity. Therefore, to ensure a successful and safe clinical application of immunomodulatory nanomaterials, it is imperative to acquire in-depth knowledge and a clear understanding of the complex nature of the interactions between NMs and the immune system. This review is aimed at providing an overview of the recent developments, achievements, and challenges in the application of immunomodulatory nanomaterials (iNMs) for cancer therapeutics with a focus on elucidating the mechanisms involved in the interplay between NMs and the host's immune system.

Clinical significance of measuring serum cytokine levels as inflammatory biomarkers in adult and pediatric COVID-19 cases: A review

Coronavirus disease 2019 (COVID-19) is a rapidly evolving infectious/inflammatory disorder which has turned into a global pandemic. With severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as its etiologic agent, severe COVID-19 cases usually develop uncontrolled inflammatory responses and cytokine storm-like syndromes. Measuring serum levels of pro-inflammatory cytokines (e.g., IL-6 and others) as inflammatory biomarkers may have several potential applications in the management of COVID-19, including risk assessment, monitoring of disease progression, determination of prognosis, selection of therapy and prediction of response to treatment. This is especially true for pediatric patients with COVID-19 associated Kawasaki-like disease and similar syndromes. In this report, we review the current knowledge of COVID-19 associated cytokines, their roles in host immune and inflammatory responses, the clinical significance and utility of cytokine immunoassays in adult and pediatric COVID-19 patients, as well as the challenges and pitfalls in implementation and interpretation of cytokine immunoassays. Given that cytokines are implicated in different immunological disorders and diseases, it is challenging to interpret the multiplex cytokine data for COVID-19 patients. Also, it should be taken into consideration that biological and technical variables may affect the commutability of cytokine immunoassays and enhance complexity of cytokine immunoassay interpretation. It is recommended that the same method, platform and laboratory should be used when monitoring differences in cytokine levels between groups of individuals or for the same individual over time. It may be important to correlate cytokine profiling data with the SARS-CoV-2 nucleic acid amplification testing and imaging observations to make an accurate interpretation of the inflammatory status and disease progression in COVID-19 patients.

Current treatment in COVID-19 disease: a rapid review

The world has faced the most challenging pandemic of the modern era, that of severe acute respiratory syndrome coronavirus 2 infection, causing coronavirus disease and affecting over 35 million people globally. The wide range of clinical manifestations associated with this viral disease is thought to be related to the overexpression of inflammatory markers. Due to a dysregulated host response, the most severe form involves multi-organ failure and thromboembolic complications. Immunomodulatory therapies may help prevent its progression and anticoagulation has been shown to reduce the risk of thrombotic complications. As this is a new entity for the medical world, there are no known therapeutic options nor has the prevention of complications been established. Anti-inflammatory agents, antimicrobial therapy, and vitamin supplements are short of clear benefits, but there is limited data to review. Other agents, such as convalescent plasma, eculizumab, immunoglobulins, neutralizing IgG1 monoclonal antibodies, remdesivir, steroids, and tocilizumab, have shown a possible impact on inpatient length of stay and mortality rate. This review aims to assess the efficacy and safety of these available therapies in light of current evidence. We compare these treatment options based on their impact on symptom management, inpatient length of stay, and overall morbidity and mortality.

Epidemiology and pathobiology of SARS-CoV-2 (COVID-19) in comparison with SARS, MERS: An updated overview of current knowledge and future perspectives

Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) is the causative etiology of ‘Corona Virus Disease-2019’ (COVID-19); formerly referred as ‘novel-Coronavirus-2019’. It was originated in Wuhan city, Hubei province, China in early December 2019. The World Health Organization (WHO) declared it as ‘Public Health Emergency of International Concern’ due to their rapid transmission and causing public and health-care-related casualties worldwide. This review provides an updated overview of COVID-19 (SARS-CoV-2), in comparison with the etiologies of the same group viz. SARS and MERS and also its future perspectives for planning appropriate strategies for prevention, control and treatment modalities to avert similar catastrophe in near future.

SARS-CoV-2-Induced ARDS Associates with MDSC Expansion, Lymphocyte Dysfunction, and Arginine Shortage

Purpose

The SARS-CoV-2 infection can lead to a severe acute respiratory distress syndrome (ARDS) with prolonged mechanical ventilation and high mortality rate. Interestingly, COVID-19-associated ARDS share biological and clinical features with sepsis-associated immunosuppression since lymphopenia and acquired infections associated with late mortality are frequently encountered. Mechanisms responsible for COVID-19-associated lymphopenia need to be explored since they could be responsible for delayed virus clearance and increased mortality rate among intensive care unit (ICU) patients.

Methods

A series of 26 clinically annotated COVID-19 patients were analyzed by thorough phenotypic and functional investigations at days 0, 4, and 7 after ICU admission.

Results

We revealed that, in the absence of any difference in demographic parameters nor medical history between the two groups, ARDS patients presented with an increased number of myeloid-derived suppressor cells (MDSC) and a decreased number of CD8^pos effector memory cell compared to patients hospitalized for COVID-19 moderate pneumonia. Interestingly, COVID-19-related MDSC expansion was directly correlated to lymphopenia and enhanced arginase activity. Lastly, T cell proliferative capacity in vitro was significantly reduced among COVID-19 patients and could be restored through arginine supplementation.

Conclusions

The present study reports a critical role for MDSC in COVID-19-associated ARDS. Our findings open the possibility of arginine supplementation as an adjuvant therapy for these ICU patients, aiming to reduce immunosuppression and help virus clearance, thereby decreasing the duration of mechanical ventilation, nosocomial infection acquisition, and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-020-00920-5.

Role of Host Immune and Inflammatory Responses in COVID-19 Cases with Underlying Primary Immunodeficiency: A Review

Coronavirus disease 2019 (COVID-19) has spread rapidly and become a pandemic. Caused by a novel human coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), severe COVID-19 is characterized by cytokine storm syndromes due to innate immune activation. Primary immunodeficiency (PID) cases represent a special patient population whose impaired immune system might make them susceptible to severe infections, posing a higher risk to COVID-19, but this could also lead to suppressed inflammatory responses and cytokine storm. It remains an open question as to whether the impaired immune system constitutes a predisposing or protective factor for PID patients when facing SARS-CoV-2 infection. After literature review, it was found that, similar to other patient populations with different comorbidities, PID patients may be susceptible to SARS-CoV-2 infection. Their varied immune status, however, may lead to different disease severity and outcomes after SARS-CoV-2 infection. PID patients with deficiency in antiviral innate immune signaling [eg, Toll-like receptor (TLR)3, TLR7, or interferon regulatory factor 7 (IRF7)] or interferon signaling (IFNAR2) may be linked to severe COVID-19. Because of its anti-infection, anti-inflammatory, and immunomodulatory effects, routine intravenous immunoglobulin therapy may provide some protective effects to the PID patients.

The anti-inflammatory cytokine response characterized by elevated interleukin-10 is a stronger predictor of severe disease and poor outcomes than the pro-inflammatory cytokine response in coronavirus disease 2019 (COVID-19)

OBJECTIVES

Severe coronavirus disease 2019 (COVID-19) is associated with a dysregulated immune state. While research has focused on the hyperinflammation, little research has been performed on the compensatory anti-inflammatory response. The aim of this study was to evaluate the anti-inflammatory cytokine response to COVID-19, by assessing interleukin-10 (IL-10) and IL-10/lymphocyte count ratio and their association with outcomes.

METHODS

Adult patients presenting to the emergency department (ED) with laboratory-confirmed COVID-19 were recruited. The primary endpoint was maximum COVID-19 severity within 30 days of index ED visit.

RESULTS

A total of 52 COVID-19 patients were enrolled. IL-10 and IL-10/lymphocyte count were significantly higher in patients with severe disease (p<0.05), as well as in those who developed severe acute kidney injury (AKI) and new positive bacterial cultures (all p≤0.01). In multivariable analysis, a one-unit increase in IL-10 and IL-10/lymphocyte count were associated with 42% (p=0.031) and 32% (p=0.013) increased odds, respectively, of severe COVID-19. When standardized to a one-unit standard deviations scale, an increase in the IL-10 was a stronger predictor of maximum 30-day severity and severe AKI than increases in IL-6 or IL-8.

CONCLUSIONS

The hyperinflammatory response to COVID-19 is accompanied by a simultaneous anti-inflammatory response, which is associated with poor outcomes and may increase the risk of new positive bacterial cultures. IL-10 and IL-10/lymphocyte count at ED presentation were independent predictors of COVID-19 severity. Moreover, elevated IL-10 was more strongly associated with outcomes than pro-inflammatory IL-6 or IL-8. The anti-inflammatory response in COVID-19 requires further investigation to enable more precise immunomodulatory therapy against SARS-CoV-2.