Avaliação das populações de linfócitos T, B e NK e de marcadores de diferenciação, ativação e exaustão em linfócitos TCD4 e TCD8 de pacientes acometidos pela COVID-19
Data
2024-08-28
Autores
Eburneo, Gabriela Strafolino 
Orientadores
Salomão, Reinaldo
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: A COVID-19, causada pelo SARS-CoV-2 e declarada pandemia pela Organização Mundial de Saúde, causou enorme impacto da saúde global e economia mundial, com cerca de 775 milhões de casos, 7 milhões de mortes e 5,47 bilhões de doses de vacina aplicadas. A doença é caracterizada por disfunção da reposta imune, com intenso comprometimento das populações linfocitárias e produção de citocinas inflamatórias, que se associam com manifestações clínicas e desfechos dos pacientes. Objetivo: O objetivo do trabalho foi avaliar o comprometimento das populações linfocitárias e caracterizar, na população de linfócitos T de pacientes com COVID-19, a expressão de marcadores de diferenciação, ativação e exaustão, no período de internação e após alta hospitalar. Métodos: Trata-se de uma coorte prospectiva de pacientes com COVID-19, admitidos nas enfermarias do Hospital São Paulo e acompanhados durante a internação e convalescência (30 dias pós-alta), caracterizados clinicamente como críticos e não críticos conforme a resolução de sintomas ou deterioração clínica progressiva e necessidade de cuidados intensivos. Foi realizada uma análise longitudinal das populações de linfócitos T, B e NK, com coleta sequencial de amostras ao longo do tempo. A pesquisa focou na modulação de marcadores imunológicos e na correlação entre as contagens de linfócitos e a gravidade clínica da COVID-19. Os linfócitos T foram avaliados quanto à diferenciação celular (CD45RA e CCR7), ativação (HLA-DR e CD38), senescência/ exaustão (CD57 e PD-L1) por citometria de fluxo. A análise da imunofenotipagem estendida foi realizada pelo método convencional e por análise estocástica. Resultados: Os resultados mostraram que as contagens de linfócitos e suas subpopulações T, B e NK estão diminuídas nos pacientes em comparação aos indivíduos sadios e correlacionadas com a gravidade da doença.. A análise estocástica caracterizou 11 clones distintos, com marcadores de ativação, exaustão e senescência. Os dados foram corroborados na análise convencional, onde os marcadores de senescência e de exaustão estavam aumentados A exaustão celular em linfócitos T foi identificada como um fator que pode influenciar a eficácia da resposta imunológica. Conclusões: O estudo atendeu aos objetivos propostos, fornecendo informações valiosas sobre a resposta imunológica em pacientes com COVID-19. A diminuição das populações linfocitárias na circulação e alterações fenotípicas dos linfócitos T, principalmente TCD-8+, evidenciando ativação, exaustão e senescência evidencia a disfunção imune nesses pacientes e sugere que a avaliação dessas células pode ser uma ferramenta útil na prática clínica. As limitações do estudo indicam a necessidade de investigações futuras que considerem novas variantes do vírus e ampliem a amostragem.
Introduction: COVID19, caused by SARSCoV2 and declared a pandemic by the World Health Organization, has had a massive impact on global health and the world economy, with around 775 million cases, 7 million deaths, and 5.47 billion vaccine doses administered. The disease is characterized by dysfunction in the immune response, with significant impairment of lymphocyte populations and production of inflammatory cytokines, which are associated with clinical manifestations and patient outcomes. Objective: The objective of this study was to evaluate the impairment of lymphocyte populations and characterize, within the T lymphocyte population of patients with COVID19, the expression of differentiation, activation, and exhaustion markers during hospitalization and after hospital discharge. Methods: This was a prospective cohort study of COVID19 patients admitted to the wards of Hospital São Paulo, followed during hospitalization and convalescence (30 days postdischarge), clinically classified as critical and noncritical based on the resolution of symptoms or progressive clinical deterioration and the need for intensive care. A longitudinal analysis of T, B, and NK lymphocyte populations was conducted, with sequential sample collection over time. The research focused on the modulation of immunological markers and the correlation between lymphocyte counts and the clinical severity of COVID19. T lymphocytes were evaluated for cellular differentiation (CD45RA and CCR7), activation (HLADR and CD38), and senescence/exhaustion (CD57 and PDL1) by flow cytometry. Extended immunophenotyping analysis was performed using conventional and stochastic analysis methods. Results: The results showed that lymphocyte counts and their T, B, and NK subpopulations were decreased in patients compared to healthy individuals and correlated with disease severity. Stochastic analysis characterized 11 distinct clones with activation, exhaustion, and senescence markers. The data were corroborated in the conventional analysis, where senescence and exhaustion markers were increased. T lymphocyte exhaustion was identified as a factor that may influence the effectiveness of the immune response. Conclusions: The study met its proposed objectives, providing valuable information on the immune response in COVID19 patients. The reduction of circulating lymphocyte populations and phenotypic alterations of T lymphocytes, particularly TCD8+, showing activation, exhaustion, and senescence, highlight immune dysfunction in these patients and suggest that the evaluation of these cells may be a useful tool in clinical practice. The study's limitations indicate the need for future investigations that consider new virus variants and broaden the sample size.
Introduction: COVID19, caused by SARSCoV2 and declared a pandemic by the World Health Organization, has had a massive impact on global health and the world economy, with around 775 million cases, 7 million deaths, and 5.47 billion vaccine doses administered. The disease is characterized by dysfunction in the immune response, with significant impairment of lymphocyte populations and production of inflammatory cytokines, which are associated with clinical manifestations and patient outcomes. Objective: The objective of this study was to evaluate the impairment of lymphocyte populations and characterize, within the T lymphocyte population of patients with COVID19, the expression of differentiation, activation, and exhaustion markers during hospitalization and after hospital discharge. Methods: This was a prospective cohort study of COVID19 patients admitted to the wards of Hospital São Paulo, followed during hospitalization and convalescence (30 days postdischarge), clinically classified as critical and noncritical based on the resolution of symptoms or progressive clinical deterioration and the need for intensive care. A longitudinal analysis of T, B, and NK lymphocyte populations was conducted, with sequential sample collection over time. The research focused on the modulation of immunological markers and the correlation between lymphocyte counts and the clinical severity of COVID19. T lymphocytes were evaluated for cellular differentiation (CD45RA and CCR7), activation (HLADR and CD38), and senescence/exhaustion (CD57 and PDL1) by flow cytometry. Extended immunophenotyping analysis was performed using conventional and stochastic analysis methods. Results: The results showed that lymphocyte counts and their T, B, and NK subpopulations were decreased in patients compared to healthy individuals and correlated with disease severity. Stochastic analysis characterized 11 distinct clones with activation, exhaustion, and senescence markers. The data were corroborated in the conventional analysis, where senescence and exhaustion markers were increased. T lymphocyte exhaustion was identified as a factor that may influence the effectiveness of the immune response. Conclusions: The study met its proposed objectives, providing valuable information on the immune response in COVID19 patients. The reduction of circulating lymphocyte populations and phenotypic alterations of T lymphocytes, particularly TCD8+, showing activation, exhaustion, and senescence, highlight immune dysfunction in these patients and suggest that the evaluation of these cells may be a useful tool in clinical practice. The study's limitations indicate the need for future investigations that consider new virus variants and broaden the sample size.
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Citação
EBURNEO, Gabriela Strafolino . Avaliação das populações de linfócitos T, B e NK e de marcadores de diferenciação, ativação e exaustão em linfócitos TCD4 e TCD8 de pacientes acometidos pela COVID-19. 2024. 112 f. Dissertação (Mestrado em Infectologia) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP). São Paulo, 2024.