Dysfunctional purinergic signaling correlates with disease severity in COVID-19 patients.

Ectonucleotidases modulate inflammatory responses by balancing extracellular ATP and adenosine (ADO) and might be involved in COVID-19 immunopathogenesis. Here, we explored the contribution of extracellular nucleotide metabolism to COVID-19 severity in mild and severe cases of the disease. We verified that the gene expression of ectonucleotidases is reduced in the whole blood of patients with COVID-19 and is negatively correlated to levels of CRP, an inflammatory marker of disease severity. In line with these findings, COVID-19 patients present higher ATP levels in plasma and reduced levels of ADO when compared to healthy controls. Cell type-specific analysis revealed higher frequencies of CD39+ T cells in severely ill patients, while CD4+ and CD8+ expressing CD73 are reduced in this same group. The frequency of B cells CD39+CD73+ is also decreased during acute COVID-19. Interestingly, B cells from COVID-19 patients showed a reduced capacity to hydrolyze ATP into ADP and ADO. Furthermore, impaired expression of ADO receptors and a compromised activation of its signaling pathway is observed in COVID-19 patients. The presence of ADO in vitro, however, suppressed inflammatory responses triggered in patients' cells. In summary, our findings support the idea that alterations in the metabolism of extracellular purines contribute to immune dysregulation during COVID-19, possibly favoring disease severity, and suggest that ADO may be a therapeutic approach for the disease.

Considerations on Immunization and Immunosuppression of Patients With Autoimmune Blistering Diseases During COVID-19 Pandemic in Brazil: Case Report.

Autoimmune blistering diseases comprise a rare group of potentially life-threatening dermatoses. Management of autoimmune disorders poses a challenge in terms of achieving disease control and preventing adverse events. Treatment often requires an individualized approach considering disease severity, age, comorbidities, and infectious risk especially in the context of the ongoing COVID-19 pandemic. Knowledge regarding SARS-CoV-2 infection is still evolving and no specific antiviral therapy is available yet. We report four patients with active disease that required adjustment of treatment during the pandemic to discuss the use of immunosuppressants and immunobiologics, weighing potential risks and benefits of each therapy modality and vaccination status.

Generation of Cytotoxic T Cells and Dysfunctional CD8 T Cells in Severe COVID-19 Patients.

COVID-19, the infectious disease caused by SARS-CoV-2, has spread on a pandemic scale. The viral infection can evolve asymptomatically or can generate severe symptoms, influenced by the presence of comorbidities. Lymphopenia based on the severity of symptoms in patients affected with COVID-19 is frequent. However, the profiles of CD4+ and CD8+ T cells regarding cytotoxicity and antiviral factor expression have not yet been completely elucidated in acute SARS-CoV-2 infections. The purpose of this study was to evaluate the phenotypic and functional profile of T lymphocytes in patients with moderate and severe/critical COVID-19. During the pandemic period, we analyzed a cohort of 62 confirmed patients with SARS-CoV-2 (22 moderate cases and 40 severe/critical cases). Notwithstanding lymphopenia, we observed an increase in the expression of CD28, a co-stimulator molecule, and activation markers (CD38 and HLA-DR) in T lymphocytes as well as an increase in the frequency of CD4+ T cells, CD8+ T cells, and NK cells that express the immunological checkpoint protein PD-1 in patients with a severe/critical condition compared to healthy controls. Regarding the cytotoxic profile of peripheral blood mononuclear cells, an increase in the response of CD4+ T cells was already observed at the baseline level and scarcely changed upon PMA and Ionomycin stimulation. Meanwhile, CD8+ T lymphocytes decreased the cytotoxic response, evidencing a profile of exhaustion in patients with severe COVID-19. As observed by t-SNE, there were CD4+ T-cytotoxic and CD8+ T with low granzyme production, evidencing their dysfunction in severe/critical conditions. In addition, purified CD8+ T lymphocytes from patients with severe COVID-19 showed increased constitutive expression of differentially expressed genes associated with the caspase pathway, inflammasome, and antiviral factors, and, curiously, had reduced expression of TNF-α. The cytotoxic profile of CD4+ T cells may compensate for the dysfunction/exhaustion of TCD8+ in acute SARS-CoV-2 infection. These findings may provide an understanding of the interplay of cytotoxicity between CD4+ T cells and CD8+ T cells in the severity of acute COVID-19 infection.

Dysfunctional purinergic signaling correlates with disease severity in COVID-19 patients

Ectonucleotidases modulate inflammatory responses by balancing extracellular ATP and adenosine (ADO) and might be involved in COVID-19 immunopathogenesis. Here, we explored the contribution of extracellular nucleotide metabolism to COVID-19 severity in mild and severe cases of the disease. We verified that the gene expression of ectonucleotidases is reduced in the whole blood of patients with COVID-19 and is negatively correlated to levels of CRP, an inflammatory marker of disease severity. In line with these findings, COVID-19 patients present higher ATP levels in plasma and reduced levels of ADO when compared to healthy controls. Cell type-specific analysis revealed higher frequencies of CD39+ T cells in severely ill patients, while CD4+ and CD8+ expressing CD73 are reduced in this same group. The frequency of B cells CD39+CD73+ is also decreased during acute COVID-19. Interestingly, B cells from COVID-19 patients showed a reduced capacity to hydrolyze ATP into ADP and ADO. Furthermore, impaired expression of ADO receptors and a compromised activation of its signaling pathway is observed in COVID-19 patients. The presence of ADO in vitro, however, suppressed inflammatory responses triggered in patients’ cells. In summary, our findings support the idea that alterations in the metabolism of extracellular purines contribute to immune dysregulation during COVID-19, possibly favoring disease severity, and suggest that ADO may be a therapeutic approach for the disease.

Long-term effects of COVID-19 in diabetic and non-diabetic patients.

The literature presents several reports of the impact of glycemic control and diabetes in the inflammatory and coagulatory response during coronavirus disease 2019 (COVID-19). Nevertheless, the long-term impact of the COVID-19 in diabetic patients is still to be explored. Therefore, we recruited 128 patients and performed a longitudinal analysis on COVID-19-associated biomarkers of patients with COVID-19, tree and 6 months after COVID-19 recovery and put into perspective the possible long-term complication generated after COVID-19. In our investigation, we failed to verify any long-term modification on inflammatory biomarkers, but detected an increase in the glycemia and glycated hemoglobin in patients without any pre-existing history or diagnosis of diabetes (non-diabetic patients). Although diabetic and non-diabetic patients presented elevated levels of glycated hemoglobin, the c-peptide test indicated a normal beta cell function in all patients.

Resveratrol Downmodulates Neutrophil Extracellular Trap (NET) Generation by Neutrophils in Patients with Severe COVID-19.

The formation of microthrombi in lung autopsies indicates the involvement of NETs in the immunopathogenesis of severe COVID-19. Therefore, supplements inhibiting NET formation, in association with drugs with fewer adverse effects, should be a relevant strategy to attenuate the disease. Resveratrol (RESV) is a natural polyphenol with an important antiviral and antioxidant role. To modulate neutrophils from patients infected with SARS-CoV-2, we evaluated the in vitro effect of RESV on NET formation. Herein, we investigated 190 patients hospitalized with moderate, severe, and critical symptoms at Hospital das Clínicas, Brazil. We observed that neutrophilia in patients with severe COVID-19 infection is composed of neutrophils with activated profile able to release NET spontaneously. Notably, RESV decreased the neutrophil-activated status and the release of free DNA, inhibiting NET formation even under the specific PMA stimulus. At present, there is no evidence of the role of RESV in neutrophils from patients with COVID-19 infection. These findings suggest that adjunctive therapies with RESV may help decrease the inflammation of viral or bacterial infection, improving patient outcomes.

Considerations on Immunization and Immunosuppression of Patients With Autoimmune Blistering Diseases During COVID-19 Pandemic in Brazil: Case Report

Autoimmune blistering diseases comprise a rare group of potentially life-threatening dermatoses. Management of autoimmune disorders poses a challenge in terms of achieving disease control and preventing adverse events. Treatment often requires an individualized approach considering disease severity, age, comorbidities, and infectious risk especially in the context of the ongoing COVID-19 pandemic. Knowledge regarding SARS-CoV-2 infection is still evolving and no specific antiviral therapy is available yet. We report four patients with active disease that required adjustment of treatment during the pandemic to discuss the use of immunosuppressants and immunobiologics, weighing potential risks and benefits of each therapy modality and vaccination status.

Platelet-Based Biomarkers for Diagnosis and Prognosis in COVID-19 Patients.

Coronavirus disease 2019 (COVID-19) caused millions of deaths worldwide. COVID-19's clinical manifestations range from no symptoms to a severe acute respiratory syndrome, which can result in multiple organ failure, sepsis, and death. Severe COVID-19 patients develop pulmonary and extrapulmonary infections, with a hypercoagulable state. Several inflammatory or coagulatory biomarkers are currently used with predictive values for COVID-19 severity and prognosis. In this manuscript, we investigate if a combination of coagulatory and inflammatory biomarkers could provide a better biomarker with predictive value for COVID-19 patients, being able to distinguish between patients that would develop a moderate or severe COVID-19 and predict the disease outcome. We investigated 306 patients with COVID-19, confirmed by severe acute respiratory syndrome coronavirus 2 RNA detected in the nasopharyngeal swab, and retrospectively analyzed the laboratory data from the first day of hospitalization. In our cohort, biomarkers such as neutrophil count and neutrophil-to-lymphocyte ratio from the day of hospitalization could predict if the patient would need to be transferred to the intensive care unit but failed to identify the patients´ outcomes. The ratio between platelets and inflammatory markers such as creatinine, C-reactive protein, and urea levels is associated with patient outcomes. Finally, the platelet/neutrophil-to-lymphocyte ratio on the first day of hospitalization can be used with predictive value as a novel severity and lethality biomarker in COVID-19. These new biomarkers with predictive value could be used routinely to stratify the risk in COVID-19 patients since the first day of hospitalization.

COVID-19 Severity and Mortality in Solid Organ Transplantation: Differences between Liver, Heart, and Kidney Recipients

The infection by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can generate a wide spectrum of clinical manifestations ranging from asymptomatic to severe respiratory and systemic disease with coagulation disorder named coronavirus disease 2019 (COVID-19). Patients with comorbidities have been identified as risk groups for severe COVID-19, also having a higher death risk. Previous reports have conflicting results regarding if solid organ transplant recipients present an increased risk for COVID-19. Nevertheless, previous investigations failed to distinguish between different organs received or made a longitudinal investigation on those patients. We recruited 39 solid organ transplant recipients: 25 kidney transplant recipients, 7 heart transplant recipients, and 7 liver transplant recipients and 25 age-matched non-transplant COVID-19 patients without comorbidities (control group) and compared daily laboratory data in addition to performing survival analysis. Heart and kidney transplant recipients presented an increase in several COVID-19 severity-associated biomarkers, such as neutrophil-to-lymphocyte ratio and thrombocytopenia, in comparison to the control group and liver transplant recipients. Heart and kidney transplant recipients also presented an increase in the need for intensive care and invasive mechanical ventilation during the disease’s course. Importantly, heart and kidney transplant recipients presented a higher mortality rate in comparison to liver transplant recipients and non-transplant recipients. In our cohort, heart and kidney transplant recipients presented a difference in clinical characteristics and survival rate in comparison to liver transplant recipients. Further investigation involving immune response to SARS-CoV-2 in solid organ recipients should consider and separate patients according to the organ grafted.

Clinical Characteristics and Survival Analysis in Frequent Alcohol Consumers With COVID-19.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection can generate a systemic disease named coronavirus disease-2019 (COVID-19). Currently, the COVID-19 pandemic has killed millions worldwide, presenting huge health and economic challenges worldwide. Several risk factors, such as age, co-infections, metabolic syndrome, and smoking have been associated with poor disease progression and outcomes. Alcohol drinking is a common social practice among adults, but frequent and/or excessive consumption can mitigate the anti-viral and anti-bacterial immune responses. Therefore, we investigated if patients with self-reported daily alcohol consumption (DAC) presented alteration in the immune response to SARS-CoV-2. We investigated 122 patients with COVID-19 (101 male and 46 females), in which 23 were patients with DAC (18 men and 5 women) and 99 were non-DAC patients (58 men and 41 women), without other infections, neoplasia, or immunodeficiencies. Although with no difference in age, patients with DAC presented an increase in severity-associated COVID-19 markers such as C-reactive protein (CRP), neutrophil count, and neutrophil-to-lymphocyte ratio. In addition, patients with DAC presented a reduction in the lymphocytes and monocytes counts. Importantly, the DAC group presented an increase in death rate in comparison with the non-DAC group. Our results demonstrated that, in our cohort, DAC enhanced COVID-19-associated inflammation, and increased the number of deaths due to COVID-19.

Impact of Inflammatory Immune Dysfunction in Psoriasis Patients at Risk for COVID-19.

Psoriasis is an immune-mediated dermatosis usually associated with comorbidities. Treatment varies from topicals to systemic drugs and data on susceptibility to viral infections in psoriatic patients are scarce. The objectives of this study were to analyze psoriatic patients on different therapies who were at risk for COVID-19 for seroprevalence of SARS-COV-2, pro-inflammatory cytokine profile, comorbidities and outcomes in order to unveil the immunological mechanisms involved in the anti-viral response in patients with psoriasis. Seventy-five patients with psoriasis were divided according to treatment: immunobiologics, methotrexate, topicals and acitretin. Twenty healthy controls were included. Plasma samples were collected for: IgG SARS-COV-2 (ELISA); IL-27, IL-29 and IL-18 (ELISA); and IL-1ß, IL-17A, IL-6 and TNF (cytometric array). Seropositivity for SARS-COV-2 was detected in 24 out of 75 psoriasis patients and did not relate to COVID-19 symptoms and/or hospitalization, despite associated comorbidities. Psoriasis patients who were asymptomatic for SARS-COV-2 exhibited immune imbalance with high levels of IL-18, IL-17A and IL-6, and low levels of IL-27 compared to healthy controls. Psoriasis groups showed significant increased cytokine levels only in the group with immunobiologics. Despite immune deviations and lower IL-27, which has a potential antiviral impact, psoriatic patients did not exhibit complications related to COVID-19. An understanding of this kind of proinflammatory profile of psoriatic patients and of the lack of severe outcomes for COVID-19 is essential to establish novel therapeutic approaches and preventive measures, including with regard to the concomitance of viral infections.

Case Report: COVID-19 and Chagas Disease in Two Coinfected Patients.

American trypanosomiasis, also named Chagas disease (CD), is an anthropozoonosis caused by the protozoan parasite Trypanosoma cruzi. The disease affects millions of people worldwide, leading yearly to approximately 50,000 deaths. COVID-19, generated by SARS-CoV-2, can lead to lymphopenia and death. We hereby describe the first report of two patients with CD and COVID-19 coinfection, from hospitalization until patients' death.

Frequencies of CD33+CD11b+HLA-DR-CD14-CD66b+ and CD33+CD11b+HLA-DR-CD14+CD66b- Cells in Peripheral Blood as Severity Immune Biomarkers in COVID-19.

Common clinical features of patients with Coronavirus disease-2019 (COVID-19) vary from fever, to acute severe respiratory distress syndrome. Several laboratory parameters are reported as indicators of COVID-19 severity. We hereby describe the possible novel severity biomarkers for COVID-19, CD11b+CD33+HLA-DR-CD14+ cells and CD11b+CD33+HLA-DR-CD66b+ cells.