Imunopatologia da COVID-19 e suas implicações clínicas / COVID-19 immunopathology and its clinical implications

Compreender os mecanismos imunopatológicos envolvidos na evolução da COVID-19 é um desafio para a ciência mundial. A observação da existência de formas clínicas diferentes da doença, podendo ocorrer desde manifestações leves até formas graves, demonstra a complexidade da resposta imune desenvolvida frente à infecção pelo SARS-CoV-2. Nesta revisão da literatura, utilizamos as bases de dados PubMed, MEDLINE, LILACS, SciELO a partir de dezembro de 2019, quando surgiram os primeiros casos da doença. A relação entre as diferentes formas clínicas da COVID-19 com o desenvolvimento da resposta imune foi amplamente discutida. As diferenças da evolução da COVID-19 em crianças e idosos foram avaliadas focalizando aspectos da resposta imune que podem conferir prognóstico favorável ou risco de desenvolvimento de formas clínicas graves. Particularidades da infecção pelo SARS-CoV-2 em pacientes com imunossupressão e em portadores de asma foram analisadas. Os mecanismos imunopatológicos envolvidos no desenvolvimento das formas graves da COVID-19 foram abordados com ênfase no fenômeno "tempestade de citocinas".

Understanding the immunopathological mechanisms involved in the evolution of COVID-19 is a challenge for science worldwide. The observed existence of several clinical forms of the disease with mild to severe manifestations demonstrates the complexity of the immune response to SARS-CoV-2 infection. In this literature review, we searched the PubMed, MEDLINE, LILACS, SciELO databases for studies published after December 2019, when the first cases of the disease were described. The relationship between the different clinical forms of COVID-19 and the development of immune response was widely discussed. The differences in the evolution of COVID-19 in children and elderly were evaluated focusing aspects of the immune response that may confer favorable prognosis or risk of developing severe clinical forms. Particularities of SARS-CoV-2 infection in patients with immunosuppression and in asthma patients were analyzed. The immunopathological mechanisms involved in the development of severe forms of COVID-19 were addressed, with emphasis on the cytokine storm phenomenon.

The effect of essential oil of Syzygium cumini on the development of granulomatous inflammation in mice

The anti-inflammatory and apoptotic activity of the essential oil of Syzygium cumini (L.) Skeels, Myrtaceae, leaves was investigated in vivo. The anti-inflammatory action and chronic granulomatous inflammation in BALB/c mice, intravenously infected with Mycobacterium bovis, BCG, (Bacillo Calmet Guerim), was judged by measuring and classifying the granulomas formed in the hepatic parenchyma. The degree of apoptosis in the inflammatory cells was also measured. A reduction in the granulomatous area and a change in the pattern of the granulomas were found. Anti-mycobacterial activity of the essential oil against M. bovis was detected in vitro by an interferometric method in liquid culture medium. The chemical constituents of the essential oil were determined by GC/MS. Higher yields of the essential oil of S. cumini leaves were obtained by extraction in a Clevenger apparatus when the fresh leaves were previously frozen as a pre-processing step. The essential oil obtained from this plant demonstrated a statistically significant and dramatic effect in the chosen model system.