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Background: Reactivation of herpesviruses such as Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in COVID-19 patients reported in many studies in different countries during the pandemic. We aimed to measure prevalence of this coinfection in Egyptian COVID-19 patients with elevated liver enzymes and its relation to the severity and the outcome of COVID-19 infection in those patients. Methods: A cross-sectional study was carried out on 110 COVID-19 patients with elevated liver enzymes regardless the severity of COVID-19 disease. All patients were subjected to medical history, clinical examination, laboratory investigations, high-resolution computed tomography chest (HRCT chest). Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) were determined by VCA IgM and CMV IgM respectively by enzyme-linked immunosorbent assay (ELISA). Results: Of the included 110 patients with COVID-19 illness, 5 (4.5%) were Epstein-Barr virus seropositive and 5 (4.5%) were human cytomegalovirus seropositive. Regarding the symptoms, the incidence of fever in the EBV and CMV seropositive group was apparently higher than that in the EBV and CMV seronegative group. In lab tests, the platelets and albumin of EBV and CMV seropositive group decreased more significantly than EBV and HCMV seronegative group, and serum ferritin, D-dimer, and C-reactive protein show higher values in seropositive group than in seronegative group but not statistically significant. Seropositive group had received higher doses of steroids than seronegative group. The median of hospital stay in seropositive group was (15 days) nearly double that of seronegative group with statistically significant difference between both groups. Conclusion: Coinfection of EBV and CMV in COVID-19 Egyptian has no effect on the disease severity or the clinical outcome of the disease. But those patients had higher hospital stay duration.
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NK group 2 member A (NKG2A) receptor transduces inhibitory signaling; suppressing NK and T-cell cytokine secretion and cytotoxic function. This study aimed to assess the expression of NKG2A inhibitory receptor on natural killer (NK) cells and CD8+ T lymphocytes in COVID-19 patients and correlate the results with disease severity defined according to the criteria established by the world health organization, in a trial to understand the immunological response towards COVID-19 infection. The study enrolled 30 COVID-19 patients classified into 2 groups that comprised 15 subjects each; moderate and severe based on clinical, radiological, and laboratory findings. Ten age and sex matched apparently healthy individuals were included in this study as a control group. About 1 ml EDTA anti-coagulated blood samples were collected for measuring expression of NKG2A/CD159a on CD56+ CD3- NK and CD3+CD8+ T cells by flow cytometry. Results revealed that COVID-19 patients had significantly lower NK and CD8+ T cell counts compared to healthy subjects. Severe cases had significantly lower CD8+ T counts compared to moderate ones. Percentages of NK and CD8+T cells expressing NKG2A receptor were significantly higher in cases compared to controls. Comparison between severe and moderate cases revealed that although the percentages of NK cells expressing NKG2A receptor were not significantly higher in severe cases, the mean fluorescence intensity was significantly higher. The percentages of CD8 +T cells expressing NKG2A receptor were significantly higher in severe cases with higher mean fluorescence intensity. In conclusion, our results indicate that elevated NKG2A expression on cytotoxic lymphocytes correlates with disease severity in COVID-19 patients, and may serve as a potential marker for prognosis. Additionally, the blockade of NKG2A should be investigated as means of enhancing NK cell and cytotoxic T cells antiviral immunity in patients with severe COVID-19 infection.
