ELIDA PAULA BENQUIQUE OJOPI
Projetos de Pesquisa
Unidades Organizacionais
LIM/27 - Laboratório de Neurociências, Hospital das Clínicas, Faculdade de Medicina
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- Global pharmacogenomics: Impact of population diversity on the distribution of polymorphisms in the CYP2C cluster among Brazilians(2012) SUAREZ-KURTZ, G.; GENRO, J. P.; MORAES, M. O. de; OJOPI, E. B.; PENA, S. D. J.; PERINI, J. A.; RIBEIRO-DOS-SANTOS, A.; ROMANO-SILVA, M. A.; SANTANA, I.; STRUCHINER, C. J.The impact of biogeographical ancestry, self-reported 'race/color' and geographical origin on the frequency distribution of 10 CYP2C functional polymorphisms (CYP2C8*2, *3, *4, CYP2C9*2, *3, *5, *11, CYP2C19*2, *3 and *17) and their haplotypes was assessed in a representative cohort of the Brazilian population (n = 1034). TaqMan assays were used for allele discrimination at each CYP2C locus investigated. Individual proportions of European, African and Amerindian biogeographical ancestry were estimated using a panel of insertion-deletion polymorphisms. Multinomial log-linear models were applied to infer the statistical association between the CYP2C alleles and haplotypes (response variables), and biogeographical ancestry, self-reported Color and geographical origin (explanatory variables). The results showed that CYP2C19*3, CYP2C9*5 and CYP2C9*11 were rare alleles (<1%), the frequency of other variants ranged from 3.4% (CYP2C8*4) to 17.3% (CYP2C19*17). Two distinct haplotype blocks were identified: block 1 consists of three single nucleotide polymorphisms (SNPs) (CYP2C19*17, CYP2C19*2 and CYP2C9*2) and block 2 of six SNPs (CYP2C9*11, CYP2C9*3, CYP2C9*5, CYP2C8*2, CYP2C8*4 and CYP2C8*3). Diplotype analysis generated 41 haplotypes, of which eight had frequencies greater than 1% and together accounted for 96.4% of the overall genetic diversity. The distribution of CYP2C8 and CYP2C9 (but not CYP2C19) alleles, and of CYP2C haplotypes was significantly associated with self-reported Color and with the individual proportions of European and African genetic ancestry, irrespective of Color self-identification. The individual odds of having alleles CYP2C8*2, CYP2C8*3, CYP2C9*2 and CYP2C9*3, and haplotypes including these alleles, varied continuously as the proportion of European ancestry increased. Collectively, these data strongly suggest that the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of pharmacogenomic studies of the CYP2C cluster in order to avoid spurious conclusions based on improper matching of study cohorts. This conclusion extends to other polymorphic pharmacogenes among Brazilians, and most likely to other admixed populations of the Americas. The Pharmacogenomics Journal (2012) 12, 267-276; doi: 10.1038/tpj.2010.89; published online 21 December 2010
- Pharmacogenetics of calcineurin inhibitors in Brazilian renal transplant patients(2011) SANTORO, Ana; FELIPE, Claudia R.; TEDESCO-SILVA, Helio; MEDINA-PESTANA, Jose O.; STRUCHINER, Claudio J.; OJOPI, Elida B.; SUAREZ-KURTZ, GuilhermeAim: 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