RESUMO
Resistance-associated variants (RAVs) represent a challenge to the success of new HCV therapies. The aim of this study was to describe the prevalence of naturally occurring NS5B RAVs in Brazilian direct acting antivirals (DAA)-naïve patients infected with HCV genotype 1, or co-infected with HIV. Patient enrollment and sample collection were performed between 2011 and 2013. Using Sanger-based sequencing, 244 sequences were obtained. RAVs detected in HCV-1a sequences were V321A (1.6 %), M414V (1.3 %), A421V (21.4-23.7 %), A421G (1.3 %) and Y448H (1.3 %); and in HCV-1b sequences were L159F (16.1 %), C316N (7.1-16.3 %) and A421V (3.2-6.3 %). Understanding the real RAVs scenario in patients is fundamental to establishing the most effective therapeutic strategy and in minimizing the risks for their selection.
Assuntos
Antivirais/farmacologia , Farmacorresistência Viral , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/virologia , Mutação de Sentido Incorreto , Proteínas não Estruturais Virais/genética , Brasil , Frequência do Gene , Infecções por HIV/complicações , Hepacivirus/genética , Humanos , Análise de Sequência de DNARESUMO
CONTEXT: The use of thiopurine drugs such as azathioprine and 6-mercaptopurine has become quite common in the treatment of inflammatory bowel disease, transplantation and acute leukemias. Despite their effectiveness, these drugs are capable of causing drug-induced toxicity with the risk of death by myelosuppression. It is now known that these complications occur because of genetic polymorphisms of the thiopurinemethyltransferase (TPMT) enzyme, responsible for its metabolism. OBJECTIVE: To assess the prevalence of thiopurine methyltransferase polymorphisms in the population of Joinville, SC, Brazil. METHODS: We analyzed the frequency of four main allelic variants of the TPMT gene in 199 blood donors from Joinville, from February to April 2010. RESULTS: The normal allele ("wild-type") was found in 93.9% of subjects studied. TPMT variants were detected in 12 subjects (6.03%). CONCLUSIONS: From this study, it was estimated at 6% the risk of toxicity by the administration of azathioprine and 6-mercaptopurine to patients in Joinville.
Assuntos
Azatioprina/efeitos adversos , Mercaptopurina/efeitos adversos , Metiltransferases/genética , Polimorfismo Genético/genética , Adulto , Brasil , Feminino , Genótipo , Humanos , Masculino , Fatores de RiscoRESUMO
CONTEXT: The use of thiopurine drugs such as azathioprine and 6-mercaptopurine has become quite common in the treatment of inflammatory bowel disease, transplantation and acute leukemias. Despite their effectiveness, these drugs are capable of causing drug-induced toxicity with the risk of death by myelosuppression. It is now known that these complications occur because of genetic polymorphisms of the thiopurinemethyltransferase (TPMT) enzyme, responsible for its metabolism. OBJECTIVE: To assess the prevalence of thiopurine methyltransferase polymorphisms in the population of Joinville, SC, Brazil. METHODS: We analyzed the frequency of four main allelic variants of the TPMT gene in 199 blood donors from Joinville, from February to April 2010. RESULTS: The normal allele ("wild-type") was found in 93.9% of subjects studied. TPMT variants were detected in 12 subjects (6.03%). CONCLUSIONS: From this study, it was estimated at 6% the risk of toxicity by the administration of azathioprine and 6-mercaptopurine to patients in Joinville.
CONTEXTO: A utilização de drogas tiopurinas como a azatioprina e a 6-mercaptopurina tem se tornado bastante frequente no tratamento de doenças inflamatórias intestinais, transplantes e leucemias agudas. Apesar de sua efetividade, estas drogas são capazes de causar toxicidade droga-induzida com risco de morte através de mielossupressão. Sabe-se hoje que estas complicações ocorrem em decorrência de polimorfismos genéticos da enzima tiopurina metiltransferase (TPMT), responsável por sua metabolização. OBJETIVOS: Avaliar a prevalência do polimorfismo do gene da TPMT na população de Joinville, SC. MÉTODOS: Foi analisada a frequência das quatro principais variantes alélicas do gene da TPMT em 199 doadores de sangue da cidade de Joinville, SC, no período de fevereiro a abril de 2010. RESULTADOS: O alelo normal ("selvagem") foi encontrado em 93,9% dos indivíduos estudados. Variantes da TPMT foram detectadas em 12 sujeitos (6,03%). CONCLUSÕES: A partir do presente estudo, pode-se estimar em cerca de 6% o risco de toxicidade na administração de azatioprina e 6-mercaptopurina a pacientes em Joinville.
