The interplay between the immune system and SARS-CoV-2 in COVID-19 patients

Association Between Altered Microbiota Composition and Immune System-Related Genes in COVID-19 Infection

Microbiota and immunity affect the host's susceptibility to SARS-CoV-2 infection and the severity of COVID-19. This study aimed to identify significant alterations in the microbiota composition, immune signaling pathways, their potential association, and candidate microRNA in COVID-19 patients using an in silico study model. Enrichment online databases and Python programming were utilized to analyze GSE164805, GSE180594, and GSE182279, as well as NGS data of microbiota composition (PRJNA650244 and PRJNA660302) associated with COVID-19, employing amplicon-based/marker gene sequencing methods. C1, TNF, C2, IL1, and CFH genes were found to have a significant impact on immune signaling pathways. Additionally, we observed a notable decrease in Bacteroides spp. and Faecalibacterium sp., while Escherichia coli, Streptococcus spp., and Akkermansia muciniphila showed increased abundance in COVID-19. Notably, A. muciniphila demonstrated an association with immunity through C1 and TNF, while Faecalibacterium sp. was linked to C2 and IL1. The correlation between E. coli and CFH, as well as IL1 and Streptococcus spp. with C2, was identified. hsa-let-7b-5p was identified as a potential candidate that may be involved in the interaction between the microbiota composition, immune response, and COVID-19. In conclusion, integrative in silico analysis shows that these microbiota members are potentially crucial in the immune responses against COVID-19.

Metabolism configures immune response across multi-systems: Lessons from COVID-19

Several studies over the last decade demonstrate the recruitment of immune cells, increased inflammatory cytokines, and chemokine in patients with metabolic diseases, including heart failure, parenchymal inflammation, obesity, tuberculosis, and diabetes mellitus. Metabolic rewiring of immune cells is associated with the severity and prevalence of these diseases. The risk of developing COVID-19/SARS-CoV-2 infection increases in patients with metabolic dysfunction (heart failure, diabetes mellitus, and obesity). Several etiologies, including fatigue, dyspnea, and dizziness, persist even months after COVID-19 infection, commonly known as Post-Acute Sequelae of CoV-2 (PASC) or long COVID. A chronic inflammatory state and metabolic dysfunction are the factors that contribute to long COVID. Here, this study explores the potential link between pathogenic metabolic and immune alterations across different organ systems that could underlie COVID-19 and PASC. These interactions could be utilized for targeted future therapeutic approaches.

Lack of a prompt normalization of immunological parameters is associated with long-term care and poor prognosis in COVID-19 affected patients receiving convalescent plasma: a single center experience

OBJECTIVES

Being COVID-19 convalescent plasma (CCP) a therapeutic option that can have a potential impact on the normalization of immunological parameters of COVID-19 affected patients, a detailed analysis of post-infusion immunological changes was conducted in CCP treated patients, aiming to identify possible predictive hallmarks of disease prognosis.

METHODS

This prospective observational study describes a cohort of 28 patients who received CCP shortly after being hospitalized for COVID-19 and diagnosed for Acute Respiratory Distress Syndrome. All patients were subjected to a detailed flow cytometry based evaluation of immunological markers at baseline and on days +3 and +7 after transfusion.

RESULTS

At baseline almost all patients suffered from lymphopenia (25/28 on T-cells and 16/28 on B-cells) coupled with neutrophil-lymphocyte ratio exceeding normal values (26/28). Lymphocyte subsets were generally characterized by increased percentages of CD19+CD20-CD38hiCD27+ plasmablasts and reduction of CD4+CD45RA+CCR7+CD31+ recent thymic emigrants, while monocytes presented a limited expression of CD4 and HLA-DR molecules. Amelioration of immunological parameters began to be evident from day +3 and became more significant at day +7 post-CCP transfusion in 18 patients who recovered within 30 days from hospitalization. Conversely, baseline immunological characteristics generally persisted in ten critical patients who eventually progressed to death (6) or long-term care (4).

CONCLUSIONS

This study demonstrates that proper immunophenotyping panels can be potentially useful for monitoring CCP treated patients from the first days after infusion in order to presume higher risk of medical complications.

Mild-to-Moderate COVID-19 Convalescents May Present Pro-Longed Endothelium Injury

Background: The SARS-CoV-2 pandemic posed a great threat to public health, healthcare systems and the economy worldwide. It became clear that, in addition to COVID-19 and acute disease, the condition that develops after recovery may also negatively impact survivors’ health and quality of life. The damage inflicted by the viral infection on endothelial cells was identified quite early on as a possible mechanism underlying the so-called post-COVID syndrome. It became an urgent matter to establish whether convalescents present chronic endothelial impairment, which could result in an increased risk of cardiovascular and thrombotic complications. Methods: In this study, we measured the levels of CRP, ICAM-1, VCAM-1, E-selectin and syndecan-1 as markers of inflammation and endothelial injury in generally healthy convalescents selected from blood donors and compared these to a healthy control group. Results: We found higher concentrations of E-selectin and a lower level of syndecan-1 in convalescents in comparison to those of the control group. Conclusion: Based on our results, it can be concluded that, at least 6 months after infection, there is only slight evidence of endothelial dysfunction in COVID-19 convalescents who do not suffer from other comorbidities related to endothelial impairment.

Lessons from SARS-CoV, MERS-CoV, and SARS-CoV-2 Infections: What We Know So Far

Within past decades, human infections with emerging and reemerging zoonotic viral pathogens have raised the eminent public health concern. Since November 2002, three highly pathogenic and major deadly human coronaviruses of the βετα-genera (β-hCoVs), namely, severe acute respiratory distress syndrome-coronavirus (SARS-CoV), middle east respiratory syndrome-coronavirus (MERS-CoV), and SARS-CoV-2, have been globally emerged and culminated in the occurrence of SARS epidemic, MERS outbreak, and coronavirus disease 19 (COVID-19) pandemic, respectively. The global emergence and spread of these three major deadly β-hCoVs have extremely dreadful impacts on human health and become an economic burden. Unfortunately, clear specific and highly efficient medical countermeasures for these three β-hCoVs and their underlying fatal illnesses remain under development. Although they belong to the same family and share many features and convergent evolution, these three deadly β-hCoVs have some important and obvious differences. By utilizing their lessons and gaining a deeper understanding of these β-hCoVs, we can identify areas of improvement and provide preparedness plans for fighting and controlling the future reemerging human infections that might arise from them or from other potential pathogenic hCoVs. Therefore, this review summarizes the state-of-the-art information and compares the similarities and dissimilarities between SARS-CoV, MERS-CoV, and SARS-CoV-2, in terms of their evolution trait, genome organization, host cell entry mechanisms, tissue infectivity tropisms, transmission routes and contagiousness, and the clinical characteristics, laboratory features, and immunological abnormalities of their related illnesses. It also provides an overview of the emerging SARS-CoV-2 variants. Additionally, it discusses the challenges of the most proposed treatment options for SARS-CoV-2 infections.

COVID-19 in Patients with Hematologic Malignancies: Clinical Manifestations, Persistence, and Immune Response

BACKGROUND

The clinical presentation of coronavirus disease 19 (COVID-19) is the result of intricate interactions between the novel coronavirus and the immune system. In patients with hematologic malignancies (HM), these interactions dramatically change the clinical course and outcomes of COVID-19.

SUMMARY

Patients with HM and COVID-19 are at an increased risk for prolonged viral shedding, more protracted and severe presentation, and death, even when compared to other immunocompromised hosts. HM (e.g., multiple myeloma, chronic lymphocytic leukemia) and anticancer treatments (e.g., anti-CD20 agents) that impair humoral immunity markedly increase the risk of severe COVID-19 as well as protracted viral shedding and possibly longer infectivity. Cytokine release syndrome (CRS) is an important player in the pathophysiology of severe and fatal COVID-19. Treatments targeting specific cytokines involved in CRS such as interleukin-6 and Janus kinase have proven beneficial in COVID-19 patients but were not assessed specifically in HM patients. Although neutropenia (as well as neutrophilia) was associated with increased COVID-19 mortality, granulocyte colony-stimulating factors were not beneficial in patients with COVID-19 and may have been associated with worse outcomes. Decreased levels of T lymphocytes and especially decreased CD4+ counts, and depletion of CD8+ lymphocytes, are a hallmark of severe COVID-19, and even more so among patients with HM, underlying the important role of T-helper dysfunction in severe COVID-19. In HM patients with intact cellular immunity, robust T-cell responses may compensate for an impaired humoral immune system. Further prospective studies are needed to evaluate the mechanisms of severe COVID-19 among patients with HM and assess the efficacy of new immunomodulating COVID-19 treatments in this population.

KEY MESSAGES

Understanding the immunopathology of COVID-19 has greatly benefited from the previous research in patients with HM. So far, no COVID-19 treatments were properly evaluated in patients with HM. Patients with HM should be included in future RCTs assessing treatments for COVID-19.

Superiority of lymphocyte ratio over total leukocyte count in detecting the severity of COVID- 19 pneumonia

BACKGROUND

Coronavirus disease (COVID-19) is an infectious disease caused by a recently discovered coronavirus. Blood test including complete blood count is crucial in diagnosing of several viral and bacterial infection.

AIMS

This study aimed to assess the association between lymphocyte ratio and other WBC types and severity of COVID-19 pneumonia.

METHODS

The design of this study was a cross-sectional study. A complete blood count and erythrocyte sedimentation rate (ESR) was done for one hundred twenty-six COVID-19 patients (76 males and 50 females; aged 20-70 years). Patients were randomly recruited from multicenter in Al-Najaf Governorate, Iraq.

RESULTS

The study had revealed an inverse correlation between severity of COVID-19 infection and both lymphocytes and monocytes ratio even in patients with normal WBC count. Additionally, there was a direct correlation between platelets and leukocyte count. The relation between leukocyte count and ESR level was significant in a patient with elevated WBC only.

CONCLUSION

Lymphocytes and monocyte ratios inpatient with COVID-19 infection can be used as predictors for the severity of infection. Increased leukocyte count resulted in increases in platelets inpatient with COVID-19.