Avaliação do perfil inflamatório na doença falciforme: neutrófilos de baixa densidade (LDNs) e CD177
Data
2023-08-17
Autores
Leal, Bruno Cardoso 
Orientadores
Bordin, José Orlando
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: Os neutrófilos são células do sistema imunológico essenciais na resposta a infecções e inflamação. Descobriu-se que eles podem ser divididos em subpopulações com funções distintas, como os neutrófilos de baixa densidade (LDNs), relacionados a câncer e doenças inflamatórias como lúpus e artrite reumatóide. É crucial compreender e identificar melhor essas subpopulações de neutrófilos, pois não existem marcadores específicos e sua separação se baseia apenas na densidade.
Objetivos: Estudar os neutrófilos de baixa densidade e neutrófilos de densidade normal em pacientes com anemia falciforme quanto à representatividade de cada população e avaliação destas células quanto ao grau de maturação de cada população bem como a expressão da glicoproteína CD177; comparar o perfil de inflamação no grupo de pacientes com anemia falciforme de acordo com a variável de tratamento.
Casuística e métodos: Foram analisadas amostras de 63 indivíduos, divididos em grupo controle (21 participantes) e grupo doença falciforme (42 participantes). As amostras foram separadas usando a metodologia de Ficoll por gradiente de densidade e posteriormente analisadas por citometria de fluxo para a caracterização das populações de LDNs e HDNs quanto a estágio maturativo destas células (utilizando os marcadores CD13, C11b e CD16); e expressão da glicoproteína de membrana CD177, utilizando o marcador desta proteína (CD177). Também foram realizados hemograma para a obtenção dos resultados de hemoglobina, hematócrito, plaquetas, reticulócitos, contagem global de leucócitos e neutrófilos; e dosagens bioquímicas dos parâmetros, bilirrubina indireta, proteína c reativa e desidrogenase lática.
Resultados: Os resultados foram divididos em quatro análises: grupo inteiro de pacientes com anemia falciforme x grupo controle de indivíduos saudáveis; pacientes tratados com hidroxiureia x grupo controle; pacientes tratados com transfusão x grupo controle; pacientes em tratamento expectante x grupo controle. Na avaliação do parâmetro LDNs, observamos resultados aumentados estatisticamente relevantes nos grupo de pacientes tratado com hidroxiureia (p<0,05) e no grupo tratado com transfusão crônica (p<0,01) quando comparados ao grupo controle. Também foi possível observar um aumento não significativo no grupo geral de pacientes com anemia falciforme (p= 0,12) e no grupo de pacientes em tratamento expectante (p= 0,85) quando comparados ao grupo controle. No parâmetro CD177, ainda que os valores de tendência central estejam aumentados nos diferentes tratamentos: hidroxiureia (47,81%); transfusão (39,4%) e expectante (42,41%), em comparação ao grupo controle (27,3), a análise não apresentou relevância estatística nos dados obtidos. Além disso, observou-se heterogeneidade na maturação dos neutrófilos de baixa densidade, com a presença de neutrófilos maduros e imaturos nesta camada em todos os grupos estudados, porém, embora o valor médio apresentado de neutrófilos, apesar disto, a análise realizada não mostrou diferença estatisticamente relevante nos parâmetros neutrófilos maduros e neutrófilos imaturos nos grupos de pacientes com anemia falciforme quando comparados ao grupo controle.
Conclusão: Portanto, este estudo destaca a relevância dos LDNs na inflamação da anemia falciforme, uma informação inédita na literatura científica. Esses resultados abrem caminho para futuras pesquisas sobre a função dos LDNs na anemia falciforme e sua potencialidade como alvo terapêutico.
Introduction: Neutrophils are essential immune system cells in responding to infections and inflammation. It has been discovered that they can be divided into subpopulations with distinct functions, such as low-density neutrophils (LDNs), high-density granulocytes (HDNs), and normal-density granulocytes (NDNs). Neutrophils express a unique protein on their membrane, called CD177. Understanding and better identifying these neutrophil subpopulations, as well as the expression of CD177 in these cells, in sickle cell anemia patients is crucial. Aims: To evaluate low-density neutrophils in patients with sickle cell anemia regarding their representation, maturation, and expression of the CD177 glycoprotein. Samples and methods: Samples from 63 individuals were analyzed, divided into a control group (21 participants) and a sickle cell disease group (42 participants). The samples were separated using the Ficoll density gradient methodology and subsequently analyzed by flow cytometry to characterize the populations of LDNs and HDNs in terms of their maturation stage (using the markers CD13, C11b, and CD16); and expression of the CD177 membrane glycoprotein, using its specific marker (CD177). Hemogram tests were also conducted to obtain results for hemoglobin, hematocrit, platelets, reticulocytes, overall white blood cell and neutrophil counts, as well as biochemical measurements of parameters including indirect bilirubin, C-reactive protein, and lactate dehydrogenase. Results: The results were divided into four analyses: whole group of sickle cell anemia patients vs. healthy individuals control group; patients treated with hydroxyurea vs. control group; patients treated with transfusion vs. control group; patients on expectant treatment vs. control group. In the evaluation of the LDNs parameter, we observed statistically significant increases in the group of patients treated with hydroxyurea (p<0.05) and in the group treated with chronic transfusion (p<0.01) when compared to the control group. It was also possible to observe a non-significant increase in the overall sickle cell anemia patient group (p=0.12) and in the expectant treatment patient group (p=0.85) when compared to the control group. Regarding the CD177 parameter, even though the central tendency values are increased in the different treatments: hydroxyurea (47.81%), transfusion (39.4%), and expectant (42.41%), compared to the control group (27.3), the analysis did not show statistical significance in the obtained data. Furthermore, there was heterogeneity in the maturation of low-density neutrophils, with the presence of mature and immature neutrophils in this layer in all studied groups. The analysis performed did not show statistically significant differences in the parameters of mature neutrophils and immature neutrophils in the sickle cell anemia patient groups when compared to the control group. Conclusion: Therefore, this study highlights the relevance of LDNs in the inflammation of sickle cell anemia, novel information in the scientific literature. These findings pave the way for future research on the role of LDNs in sickle cell anemia and their potential as a therapeutic target.
Introduction: Neutrophils are essential immune system cells in responding to infections and inflammation. It has been discovered that they can be divided into subpopulations with distinct functions, such as low-density neutrophils (LDNs), high-density granulocytes (HDNs), and normal-density granulocytes (NDNs). Neutrophils express a unique protein on their membrane, called CD177. Understanding and better identifying these neutrophil subpopulations, as well as the expression of CD177 in these cells, in sickle cell anemia patients is crucial. Aims: To evaluate low-density neutrophils in patients with sickle cell anemia regarding their representation, maturation, and expression of the CD177 glycoprotein. Samples and methods: Samples from 63 individuals were analyzed, divided into a control group (21 participants) and a sickle cell disease group (42 participants). The samples were separated using the Ficoll density gradient methodology and subsequently analyzed by flow cytometry to characterize the populations of LDNs and HDNs in terms of their maturation stage (using the markers CD13, C11b, and CD16); and expression of the CD177 membrane glycoprotein, using its specific marker (CD177). Hemogram tests were also conducted to obtain results for hemoglobin, hematocrit, platelets, reticulocytes, overall white blood cell and neutrophil counts, as well as biochemical measurements of parameters including indirect bilirubin, C-reactive protein, and lactate dehydrogenase. Results: The results were divided into four analyses: whole group of sickle cell anemia patients vs. healthy individuals control group; patients treated with hydroxyurea vs. control group; patients treated with transfusion vs. control group; patients on expectant treatment vs. control group. In the evaluation of the LDNs parameter, we observed statistically significant increases in the group of patients treated with hydroxyurea (p<0.05) and in the group treated with chronic transfusion (p<0.01) when compared to the control group. It was also possible to observe a non-significant increase in the overall sickle cell anemia patient group (p=0.12) and in the expectant treatment patient group (p=0.85) when compared to the control group. Regarding the CD177 parameter, even though the central tendency values are increased in the different treatments: hydroxyurea (47.81%), transfusion (39.4%), and expectant (42.41%), compared to the control group (27.3), the analysis did not show statistical significance in the obtained data. Furthermore, there was heterogeneity in the maturation of low-density neutrophils, with the presence of mature and immature neutrophils in this layer in all studied groups. The analysis performed did not show statistically significant differences in the parameters of mature neutrophils and immature neutrophils in the sickle cell anemia patient groups when compared to the control group. Conclusion: Therefore, this study highlights the relevance of LDNs in the inflammation of sickle cell anemia, novel information in the scientific literature. These findings pave the way for future research on the role of LDNs in sickle cell anemia and their potential as a therapeutic target.
Descrição
Citação
LEAL, Bruno Cardoso. Avaliação do perfil inflamatório na doença falciforme: neutrófilos de baixa densidade (LDNs) e CD177. 2023. 72 f. Dissertação (Mestrado em Hematologia) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP). São Paulo, 2023.