Surfactant in SARS-CoV-2 - a therapeutic option based on underlying lung cell damage?

Introduction: the severe acute respiratory syndrome – coronavirus 2 (SARS Cov-2), leads to a diffuse alveolar deterioration due infection of type II pneumocytes. The type II pneumocytes are involved in synthesis and secretion of pulmonary surfactant in pulmonary alveoli. Objective: the purpose of this study is to discuss the indication of surfactant replacement as a potential adjunctive treatment modality for SARS CoV-2, similarly treatment to neonatal respiratory distress syndrome. Methodology: we argue that SARS can be triggered by surfactant deficiency secondary to production deficiency determined by type 2 pneumocyte injuries. In this sense, we carried out a bibliographic review. Conclusion: thus, the replacement of human surfactant could be a potential treatment modality for SARS CoV-2, in the same way that it is indicated for the treatment of neonatal respiratory distress syndrom

SEQUENCE SIMILARITY BETWEEN THYROID SELF-PROTEIN AND HEPATITIS C VIRUS POLYPROTEIN: possible triggering mechanism of autoimmune thyroiditis

ABSTRACT Background - Exposure to viral antigens that share amino acid sequence similar with self- antigens might trigger autoimmune diseases in genetically predisposed individuals, and the molecular mimicry theory suggests that epitope mimicry between the virus and human proteins can activate autoimmune disease. Objective - The purpose of this study is to explore the possible sequence similarity between the amino acid sequences of thyroid self-protein and hepatitis C virus proteins, using databanks of proteins and immunogenic peptides, to explain autoimmune thyroid disease. Methods - Were performed the comparisons between the amino acid sequence of the hepatitis C virus polyprotein and thyroid self-protein human, available in the database of National Center for Biotechnology Information on Basic Local Alignment Search Tool. Results - The sequence similarity was related each hepatitis C virus genotype to each thyroid antigen. The similarities between the thyroid and the viral peptides ranged from 21.0 % (31 identical residues out of 147 amino acid in the sequence) to 71.0% (5 identical residues out of 7 amino acid in the sequence). Conclusion - Bioinformatics data, suggest a possible pathogenic link between hepatitis C virus and autoimmune thyroid disease. Through of molecular mimicry is observed that sequences similarities between viral polyproteins and self-proteins thyroid could be a mechanism of induction of crossover immune response to self-antigens, with a breakdown of self-tolerance, resulting in autoimmune thyroid disease