The lymphopenia exhibited in patients with COVID-19 has been associated with a worse prognosis in the development of the disease. To understand the factors associated with a worse evolution of COVID-19, we analyzed comorbidities, indicators of inflammation such as CRP and the ratio of neutrophils/lymphocytes, as well as the count of blood cells with T-lymphocyte subtypes in 172 hospitalized patients with COVID-19 pneumonia. Patients were grouped according to their needs for mechanical ventilation (ICU care) or not. Within the comorbidities studied, obesity was the only associated with greater severity and ICU admission. Both the percentage and the absolute number of neutrophils were higher in patients needing ICU care than non-ICU patients, whereas absolute lymphocyte count, and especially the percentage of lymphocytes, presented a deep decline in critical patients. There was no difference between the two groups of patients for CD4 T-lymphocytes, neither in percentage of lymphocyte nor in absolute number, however for CD8 T-cells the differences were significant for both parameters which were in decline in ICU patients. There was a firm correlation between the highest values of inflammation indicators with the decrease in percentage of CD8 T-lymphocytes. This effect was not seen with CD4 cells. Obesity together with lymphopenia, especially whether preferentially affects to CD8 T-lymphocytes, are factors that can predict a poor prognosis in patients with COVID-19.

The rush protocol described is useful and safe for achieving tolerance to egg within a few days but it should always be performed in a highly supervised setting. A high proportion of patients allergic to egg can effectively be desensitized using the described schedule, with the advantage of shortening the time to become protected from reactions after inadvertent ingestion of egg, with no increase in the risk compared with the earlier reported slower protocols.

Highlights The serum IL-6 level is the best marker for the severity of COVID-19 of those tested. IL-6 values greater than 35 pg/mL can differentiate between mild and severe COVID-19. High serum IL-6 values are associated with increased risk of mortality and ICU admission.

The coronavirus disease 19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people worldwide. The characterization of the immunological mechanisms involved in disease symptomatology and protective response is important to advance in disease control and prevention. Humans evolved by losing the capacity to synthesize the glycan Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal), which resulted in the development of a protective response against pathogenic viruses and other microorganisms containing this modification on membrane proteins mediated by anti-α-Gal IgM/IgG antibodies produced in response to bacterial microbiota. In addition to anti-α-Gal antibody-mediated pathogen opsonization, this glycan induces various immune mechanisms that have shown protection in animal models against infectious diseases without inflammatory responses. In this study, we hypothesized that the immune response to α-Gal may contribute to the control of COVID-19. To address this hypothesis, we characterized the antibody response to α-Gal in patients at different stages of COVID-19 and in comparison with healthy control individuals. The results showed that while the inflammatory response and the anti-SARS-CoV-2 (Spike) IgG antibody titers increased, reduction in anti-α-Gal IgE, IgM and IgG antibody titers and alteration of anti-α-Gal antibody isotype composition correlated with COVID-19 severity. The results suggested that the inhibition of the α-Gal-induced immune response may translate into more aggressive viremia and severe disease inflammatory symptoms. These results support the proposal of developing interventions such as probiotics based on commensal. CC-BY-NC-ND 4.0 International license (which was not certified by peer review) is the author/funder. It is made available under a The copyright holder for this preprint this version posted July 14, 2020. bacteria with α-Gal epitopes to modify the microbiota and increase the α-Gal-induced protective immune response and reduce the severity of COVID-19.