Estudo da rela??o entre o polimorfismo c.98T>C do gene UGT1A9 e n?veis plasm?ticos de ?cido micofen?lico em pacientes transplantados renais

• Main Author: Ruschel , Lizania Rodrigues
• Other Authors: Thiesen , Flavia Vallad?o
• Format: Others
• Language: Portuguese
• Published: Pontif?cia Universidade Cat?lica do Rio Grande do Sul 2015
• Subjects: FARMACOLOGIA; BIOTECNOLOGIA - F?RMACOS; PREPARA??ES FARMAC?UTICAS; FARMACOGEN?TICA; RINS - TRANSPLANTE; CIENCIAS DA SAUDE::FARMACIA
• Online Access: http://tede2.pucrs.br/tede2/handle/tede/6357

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS ([e-mail]) on 2015-10-20T10:56:16Z No. of bitstreams: 1 475810 Texto Completo.pdf: 380863 bytes, checksum: d1fcdd6e53d6287f6c48e59678eb0404 (MD5) === Made available in DSpace on 2015-10-20T10:56:16Z (GMT). No. of bitstreams: 1 475810 Texto Completo.pdf: 380863 bytes, checksum: d1fcdd6e53d6287f6c48e59678eb0404 (MD5) Previous issue date: 2015-05-15 === Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq === After the proceeding of a transplant, it is of huge concem the use of all therapeutic resource available in order to prevent graft rejection. The incidence and severity of acute rejection have been reduced along time due to the development of new immunosuppressive agents such as cyclosporin, tacrolimus, mycophenolate mofetil (MMF), specific polyclonal and monoclonal antibodies. Mofetil mycophenolate (MMF) is a prodrug active only after its hydrolysis to mycophenolic acid (MPA). Once it, has a large variability on inter-individual response, an increasing need of therapeutic monitoring arises. This will permit an individualization of MMF therapy, optimizing immunosuppression and minimizing potential toxic effects.The aim of pharmacogenetics is to evaluate the association between individual genetic characteristics and different responses to the same therapeutic regimen. When considering immunosuppressive drugs, genetic changes on a single nucleotide (single nucleotide polymorphisms - SNPs) of genes encoding proteins involved in transport or drug metabolism may affect patient?s response to therapy. UDP-glucuronosyltransferases (UGTs) belong to a group of enzymes involved in phase II reactions, responsible for the detoxification of endogenous and exogenous substrates. UGT1A9 is of particular interest once it is the primary enzyme involved in the metabolism of the MPA. This enzyme is encoded by the UGT1A9 gene.In the present study, we investigated the effect of UGT1A9 c.98T>C (rs72551330; g. 87289T>C) allelic variants on MMF metabolism in 39 renal transplant volunteers. MPA levels were measured by high pressure liquid chromatography using ultraviolet detection (HPLC/UV). The analysis of c.98T>C polymorphism was performed by polymerase chain reaction (PCR), followed by fragment purification and sequencing. All investigated individuals showed having the same polymorphism genotype (c.98TT) evaluation of variants or genotype influence on plasma levels of MPA and MPAG was not possible, even though different levels were observed in the study. === Ao realizar um transplante, ? de fundamental import?ncia que, seja utilizado todo o arsenal terap?utico dispon?vel e cuidados para evitar a rejei??o do enxerto. A incid?ncia e a intensidade da rejei??o aguda t?m sido reduzidas gra?as ao uso de f?rmacos imunossupressores, como ciclosporina, tacrolimus, micofenolato de mofetil (MMF), anticorpos monoclonais e policlonais. O MMF ? um pr?-f?rmaco com atividade ap?s sua hidr?lise a ?cido micofen?lico (MPA). No entanto, possui grande variabilidade inter-individual de resposta e por isso ? crescente a import?ncia da realiza??o de seu monitoramento terap?utico, o qual permite individualizar a dose de MMF e otimizar a imunossupress?o, minimizando os potenciais efeitos t?xicos. A farmacogen?tica estuda a rela??o entre as caracter?sticas gen?ticas do indiv?duo e as diferentes respostas a uma mesma terapia farmacol?gica.No caso de f?rmacos imunossupressores, altera??es gen?ticas de um ?nico nucleot?deo (single nucleotide polymorphisms - SNPs) em genes que codificam prote?nas envolvidas no transporte ou no metabolismo do f?rmaco podem modificar a resposta do paciente ? terap?utica. As UDP-glucuronosiltransferases (UGTs) pertencem a um grupo de enzimas envolvidas na fase II, respons?vel pela detoxifica??o de subst?ncias end?genas e ex?genas. A UGT1A9 ? de especial interesse por ser a principal enzima envolvida no metabolismo do ?cido micofen?lico. Esta enzima ? codificada pelo gene UGT1A9. No presente estudo, foi investigado o efeito das variantes al?licas de UGT1A9 c.98T>C (rs72551330; g. 87289T>C) no metabolismo de MMF em 39 pacientes volunt?rios transplantados renais.Foram dosados os n?veis de MPA por cromatografia l?quida de alta efici?ncia utilizando detec??o com ultravioleta (HPLC/UV) e a an?lise do polimorfismo c.98T>C do gene UGT1A9 foi realizada utilizando rea??o em cadeia de polimerase (PCR), seguida de purifica??o do fragmento e sequenciamento. Todos os indiv?duos investigados apresentaram o mesmo gen?tipo (c.98TT) para este polimorfismo, n?o possibilitando a avalia??o da influ?ncia das variantes ou gen?tipos deste polimorfismo sobre os n?veis plasm?ticos de MPA e MPAG, apesar de n?veis diversos destes compostos terem sido identificados nos pacientes.