Clinical Profile of SARS-CoV-2 Infection: Mechanisms of the Cellular Immune Response and Immunogenetic Markers in Patients from Brazil.

OBJECTIVES: The aim of this study is to evaluate some mechanisms of the immune response of people infected with SARS-CoV-2 in both acute infection and early and late convalescence phases. METHODS: This is a cohort study of 70 cases of COVID-19, confirmed by RT-PCR, followed up to 60 days. Plasma Samples and clinical data were. Viral load, blood count, indicators inflammation were the parameters evaluated. Cellular immune response was evaluated by flow cytometry and Luminex immunoassays. RESULTS: In the severe group, hypertension was the only reported comorbidity. Non severe patients have activated memory naive CD4+ T cells. Critically ill patients have central memory CD4+ T cell activation. Severe COVID-19 patients have both central memory and activated effector CD8+ T cells. Non-severe COVID-19 cases showed an increase in IL1ß, IL-6, IL-10 and TNF and severely ill patients had higher levels of the cytokines IL-6, IL-10 and CXCL8. CONCLUSIONS: The present work showed that different cellular responses are observed according to the COVID-19 severity in patients from Brazil an epicenter the pandemic in South America. Also, we notice that some cytokines can be used as predictive markers for the disease outcome, possibility implementation of strategies effective by health managers.

Late-Relapsing Hepatitis after Yellow Fever.

One patient presented hyporexia, asthenia, adynamia, and jaundice two months after acute yellow fever (YF) onset; plus laboratory tests indicating hepatic cytolysis and a rebound of alanine and aspartate transaminases, and total and direct bilirubin levels. Laboratory tests discarded autoimmune hepatitis, inflammatory or metabolic liver disease, and new infections caused by hepatotropic agents. Anti-YFV IgM, IgG and neutralizing antibodies were detected in different times, but no viremia. A liver biopsy was collected three months after YF onset and tested positive for YFV antigens and wild-type YFV-RNA (364 RNA-copies/gram/liver). Transaminases and bilirubin levels remained elevated for five months, and the arresting of symptoms persisted for six months after the acute YF onset. Several serum chemokines, cytokines, and growth factors were measured. A similar immune response profile was observed in the earlier phases of the disease, followed by more pronounced changes in the later stages, when transaminases levels returned to normal. The results indicated viral persistence in the liver and continual liver cell damage three months after YF onset and reinforced the need for extended follow-ups of YF patients. Further studies to investigate the role of possible viral persistence and the immune response causing relapsing hepatitis following YF are also necessary.