Navegando por Palavras-chave "CYP3A5"

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    Influence of the CYP3A4/5 genetic score and ABCB1 polymorphisms on tacrolimus exposure and renal function in Brazilian kidney transplant patients
    (Lippincott Williams & Wilkins, 2016) Genvigir, Fabiana D. V.; Salgado, Patricia C.; Felipe, Claudia Rosso [UNIFESP]; Luo, Elena Y. F.; Alves, Camila; Cerda, Alvaro; Tedesco-Silva Junior, Hélio [UNIFESP]; Pestana, Jose Osmar Medina [UNIFESP]; Oliveira, Nagilla Ione de [UNIFESP]; Rodrigues, Alice C.; Doi, Sonia Q.; Hirata, Mario H.; Hirata, Rosario D. C.
    BackgroundPolymorphisms in genes encoding transport proteins and metabolizing enzymes involved in tacrolimus (TAC) disposition may be important sources of individual variability during treatment.ObjectiveThe aim of this study was to investigate the effect of combined CYP3A4 and CYP3A5 variants, using a CYP3A4/5 genetic score, and ABCB1 polymorphisms on therapeutic TAC monitoring and their relationship with clinical outcomes.Material and methodsBrazilian kidney transplant recipients (n=151), who received TAC over 3 months after transplantation, were genotyped for CYP3A4 rs2242480 (g.20230G>A), CYP3A5 rs15524 (g.31611C>T) and rs776746 (g.6986A>G), ABCB1 rs1128503 (c.1236C>T), rs1045642 (c.3435C>T), and rs2032582 (c.2677G>T/A) polymorphisms.ResultsFrequencies of CYP3A4 g.20230A, CYP3A5 g.31611C, and g.6986A were 0.37, 0.26, and 0.28, respectively. These alleles were associated with TAC rapid metabolization and were used for CYP3A4/5 genetic score construction. A higher CYP3A4/5 genetic score was associated with higher TAC dose and lower concentrations for dose administered (Co/D, P<0.05). Ninety days after transplantation, the presence of two or more rapid metabolization alleles contributed toward 27.7% of Co/D variability and was associated with a lower estimated glomerular filtration rate values (P<0.05). For ABCB1, the frequencies of c.1236T, c.3435T, and c.2677T/A alleles were 0.42, 0.42, and 0.33/0.04. At 30 days after transplantation, patients carrying ABCB1 c.1236TT+c.3435TT+(c.2677TT+TA) genotypes had higher TAC Co/D than those with common or heterozygous genotypes (P<0.05).ConclusionThe results show the impact of the CYP3A4/5 genetic score on TAC exposure and renal function in Brazilian patients. Furthermore, ABCB1 polymorphisms, in a combined analysis, influenced TAC Co/D at 30 days after transplantation.
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    Pharmacogenetics of calcineurin inhibitors in Brazilian renal transplant patients
    (Future Medicine Ltd, 2011-09-01) Santoro, Ana; Felipe, Claudia Rosso [UNIFESP]; Tedesco-Silva, Helio [UNIFESP]; Medina-Pestana, Jose O. [UNIFESP]; Struchiner, Claudio J.; Ojopi, Elida B.; Suarez-Kurtz, Guilherme; Inst Nacl Canc; Universidade Federal de São Paulo (UNIFESP); Fundacao Oswaldo Cruz; Universidade de São Paulo (USP)
    Aim: Polymorphisms in the CYP3A5 and ABCB1 genes have been investigated as modulators of the pharmacokinetics and clinical effects of cyclosporine (CSA) and tacrolimus (TAC) in European, North American and Asian populations, with controversial results. the extensive variation in worldwide frequency distribution of CYP3A5 and ABCB1 polymorphisms is a caveat against the extrapolation of these data to the heterogeneous and admixed Brazilian population. We investigated the effect of CYP3A5 and ABCB1 polymorphisms on CSA and TAC dose-adjusted trough concentration (C(0)/dose) in Brazilian renal transplant recipients, during the first 3 months post-transplantation. Materials & methods: Patients receiving CSA (n = 150) or TAC (n = 151) were genotyped for CYP3A5(star)3 (rs776746, 6986A>G), (star)6(rs10264272, 14690G>A) and (star) 7 (rs41303343, 27131-27132insT) and for ABCB1 1236C>T (rs1128503), 2677G>T/A (rs2032582) and 3435C>T (rs1045642) polymorphisms. We explored the effects of CYP3A5 and ABCB1 polymorphisms, clinical and demographical characteristics on CSA and TAC C(0)/dose under a two-step data ana-lysis strategy by fitting a longitudinal mixed-effects model to the data; first to select the important covariates under a univariate setting and then to fit the final multivariate model. Results: C(0)/dose of TAC was associated with the number of CYP3A5-defective alleles, in a gene-dose manner, throughout the observation period, whereas C0/dose of CSA was associated with body surface area and prednisone dosing. No other significant associations were detected. Conclusion: Individual adjustment of the initial TAC dose according to the CYP3A5 haplotypes comprising the CYP3A5(star)3, (star)6 and (star)7 defective alleles might prove beneficial to Brazilian renal transplant recipients and should be further investigated in prospective trials. Original submitted 5 April 2011; Revision submitted 4 May 2011