Análise da contribuição do inflamassoma na heterogeneidade clínica de pacientes com doença falciforme

• Ano de defesa: 2019
• Autor(a) principal: Dutra, Valeria De Freitas [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Sickle Cell Disease; Inflammasome; Monocytes; Polymorphisms; Doença Falciforme; Inflamassoma; Monócitos; Polimorfismos
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=8399842; https://repositorio.unifesp.br/handle/11600/59544

In spite of having a molecular basis, Sickle cell disease (SCD) is an inflammatory state with abnormal cell activation. Physiopathological factors are not completely understood, but it is known that interleukins plays an important role in inflammation. Inflammasome complex is an innate immune pathway involved in the production of active IL-1β and IL-18. The participation of this complex in sickle cell disease is still not clear. Polymorphisms of inflammasome are simple amino acid substitution that can lead to a loss or gain of function and may be associated with clinical manifestations. NLRP3 is the most studied and well-known inflammasome, associated especially to auto-inflammatory diseases. Aim: To analyze the contribution of inflammasome to the clinical heterogeneity of SCD. To this, the association of inflammasome gene polymorphisms and a functional in vitro study were performed. Methods: In the association study 161 patients were included. Retrospective data were collected to fill clinical and laboratorial information. Patients were classified in two different groups: mild (0-1) or severe (> 2 organ damage). DNA samples were collected from 88 patients and 73 were used from a biorepository (BR- 116). Minor allelic frequency and literature information were used to choose 10 SNPs. Real-time PCR technique with allele and specific probes was used in TaqMan® assays (Applied Biosystms, Thermo Fisher Scientific). To functional study (n=7), PBMC and monocytes from healthy patients and controls were challenged with LPS and / or ATP, with subsequent IL-1β dosage by the ELISA method. All volunteers received a free and informed consent form. Multivariate analysis were performed by the software R Studio 3.5.3 (www.r-project.org), SNP association package. Mann-Whitney test was applied to group comparison. Results: The gain-offunction polymorphism rs16944 has resulted in a significant protection factor for SCD severity. The loss of function variant in the IL18 gene (rs1834481) was associated to high count of monocytes and leucocytes. In the functional test, patients with SCD tend to have less inflammasome activation when compared to controls. Conclusion: The promoter variant -511 C>T in IL1β resulted significantly associated to mild presentation in SCD patients (padj=0.001). PBM analysis showed that SCD cells seems to be less prone to activate inflammasome than HD.