Influence of ABCC2, CYP2C8, and CYP2J2 polymorphisms on tacrolimus and mycophenolate sodium-based treatment in brazilian kidney transplant recipients

STUDY OBJECTIVE: To investigate the influence of single nucleotide polymorphisms (SNPs) in genes encoding metabolizing enzymes (CYP2C8, CYP2J2, and UGT2B7) and transporters (ABCC2 and ABCG2) on dose and dose-adjusted trough blood concentrations (C:D ratio), clinical outcomes, and occurrence of adverse events of tacrolimus and mycophenolate sodium in Brazilian kidney transplant recipients. DESIGN: Pharmacogenetic analysis of patients enrolled in a previously published study. PATIENTS: One hundred forty-eight adult kidney transplant recipients treated with tacrolimus, enteric-coated mycophenolate sodium, and prednisone for 90 days posttransplantation.MEASUREMENTS AND MAIN RESULTS:ABCC2 c.-24C>T and c.3972C>T, ABCG2 c.421C>A, CYP2C8*3, CYP2J2 c.-76G>T, and UGT2B7 c.372A>G SNPs were determined by real-time polymerase chain reaction. The CYP3A5*3C SNP data were used to eliminate the confounding effect of this variant on the results. ABCC2 c.3972T allele carriers showed higher tacrolimus C:D values than did carriers of the c.3972CC genotype. The CYP2C8*3 variant was also associated with slightly higher tacrolimus C:D values and higher estimated glomerular filtration rate but only in CYP3A5-nonexpressing patients (CYP3A5*3C/*3C carriers). None of the SNPs were associated with mycophenolate sodium dose or episodes of biopsy-confirmed acute rejection or delayed graft function. The CYP2J2 c.-76T allele was associated with increased risk for treatment-induced nausea and/or vomiting (OR: 5.30, 95% confidence interval 1.49-18.79, p<0.05)...

Differentiation of african components of ancestry to stratify groups in a Case–control study of a brazilian urban population

Background: Balancing the subject composition of case and control groups to create homogenous ancestries between each group is essential for medical association studies. Methods: We explored the applicability of single-tube 34-plex ancestry informative markers (AIM) single nucleotide polymorphisms (SNPs) to estimate the African Component of Ancestry (ACA) to design a future case-control association study of a Brazilian urban sample. Results: One hundred eighty individuals (107 case group; 73 control group) self-described as white, brown-intermediate or black were selected. The proportions of the relative contribution of a variable number of ancestral population components were similar between case and control groups. Moreover, the case and control groups demonstrated similar distributions for ACA 0.50 categories. Notably a high number of outlier values (23 samples) were observed among individuals with ACA <0.25. These individuals presented a high probability of Native American and East Asian ancestral components; however, no individuals originally giving these self-described ancestries were observed in this study. Conclusions: The strategy proposed for the assessment of ancestry and adjustment of case and control groups for an association study is an important step for the proper construction of the study, particularly when subjects are taken from a complex urban population. This can be achieved using a straight forward multiplexed AIM-SNPs assay of highly discriminatory ancestry markers.

Atorvastatin and hormone therapy effects on APOE mRNA expression in hypercholesterolemic postmenopausal women

Menopause is associated with changes in lipid levels resulting in increased risk of atherosclerosis andcardiovascular events. Hormone therapy (HT) and atorvastatin have been used to improve lipid profilein postmenopausal women.Effects of HT, atorvastatin and APOE polymorphisms on serum lipids and APOE and LXRA expressionwere evaluated in 87 hypercholesterolemic postmenopausal women, randomly selected for treatmentwith atorvastatin (AT, n = 17), estrogen or estrogen plus progestagen (HT, n = 34) and estrogen or estrogenplus progestagen associated with atorvastatin (HT + AT, n = 36). RNA was extracted from peripheralblood mononuclear cells (PBMC) and mRNA expression was measured by TaqMan® PCR. APOE 2/ 3/ 4genotyping was performed using PCR-RFLP.Total cholesterol (TC), LDL-c and apoB were reduced after each treatment (p < 0.001). Triglycerides,VLDL-c and apoAI were reduced only after atorvastatin (p < 0.05), whereas triglycerides and VLDL-c wereincreased after HT (p = 0.01). HT women had lower reduction on TC, LDL-c and apoB than AT and HT + ATgroups (p < 0.05). APOE mRNA expression was reduced after atorvastatin treatment (p = 0.03). AlthoughLXRA gene expression was not modified by atorvastatin, it was correlated with APOE mRNA before andafter treatments. Basal APOE mRNA expression was not influenced by gene polymorphisms, however thereduction on APOE expression was more pronounced in 3 3 than in 3 4 carriers.Atorvastatin down-regulates APOE mRNA expression and it is modified by APOE genotypes in PBMCfrom postmenopausal women.

Pharmacogenetics of OATP Transporters Reveals That SLCO1B1 c.388A>G Variant Is Determinant of Increased Atorvastatin Response

Aims: The relationship between variants in SLCO1B1 and SLCO2B1 genes and lipid-lowering response to atorvastatin was investigated. Material and Methods: One-hundred-thirty-six unrelated individuals with hypercholesterolemia were selected andOPEN ACCESStreated with atorvastatin (10 mg/day/4 weeks). They were genotyped with a panel of ancestry informative markers for individual African component of ancestry (ACA) estimation by SNaPshot® and SLCO1B1 (c.388A>G, c.463C>A and c.521T>C) and SLCO2B1 (−71T>C) gene polymorphisms were identified by TaqMan® Real-time PCR. Results: Subjects carrying SLCO1B1 c.388GG genotype exhibited significantly high low-density lipoprotein (LDL) cholesterol reduction relative to c.388AA+c.388AG carriers (41 vs. 37%, p = 0.034). Haplotype analysis revealed that homozygous of SLCO1B1*15 (c.521C and c.388G) variant had similar response to statin relative to heterozygous and non-carriers. A multivariate logistic regression analysis confirmed that c.388GG genotype was associated with higher LDL cholesterol reduction in the study population (OR: 3.2, CI95%:1.3–8.0, p G polymorphism causes significant increase in atorvastatin response and may be an important marker for predicting efficacy of lipid-lowering therapy.