Padronização e validação de ensaios sorológicos para o diagnóstico da Hepatite C.

• Ano de defesa: 2024
• Autor(a) principal: Laís Dias Ribeiro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais
• Link de acesso: https://hdl.handle.net/1843/77604
• topic: Diagnóstico; Hepatite C; ELISA; DBS; Teste rápido; Validação

Hepatitis C is caused by a virus from the Flaviviridae family, genus Hepacivirus, called Hepatitis C Virus (HCV). In most cases, the infection has no symptoms in the acute phase but becomes chronic in 75 to 85% of the affected ones. It is estimated that 71 million people live with chronic hepatitis C worldwide, leading to liver fibrosis, cirrhosis, hepatocarcinoma, and various other associated extra-hepatic conditions. The initial diagnosis of HCV infection is usually made by detecting antibodies in serum and plasma samples. However, the use of dried blood samples impregnated in filter paper (DBS) and point-of-care methodologies are alternatives for screening individuals at high risk of infection in places with poor laboratory infrastructure. This study aimed to standardize and validate an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-HCV antibodies in serum, plasma, and DBS samples and to standardize an immunochromatographic test for the detection of anti-HCV antibodies in serum, plasma, and blood samples. For ELISA, 237 serum and plasma samples and 185 DBS samples were used. The assay developed demonstrated a sensitivity and specificity of >99.99%. In the comparative analytical sensitivity, the DBS samples obtained a kappa index of 0.41, with regular agreement. The repeatability, reproducibility, and inter-assay analyses showed results with a coefficient of variation of <20%. For the immunochromatographic test, 90 serum samples were used, showing a sensitivity and specificity of >99.99%. In comparative analytical sensitivity, the rapid test with serum samples obtained a kappa of 1.0, with perfect agreement, while the use of blood samples obtained a kappa of 0.61, representing good agreement. These results support the good functioning of the assays developed for the serological diagnosis of HCV infection both in serum/plasma samples and in DBS and blood samples, in the ELISA and rapid test methodologies.