Pharmacogenetics in the treatment of pre-eclampsia: current findings, challenges and perspectives.

Pre-eclampsia (PE) is defined as pregnancy-induced hypertension and proteinuria, and is a major cause of maternal and perinatal morbidity and mortality. A large subgroup of pregnant women with PE is nonresponsive to antihypertensive drugs, including methyldopa, nifedipine and hydralazine. Pharmacogenomics may help to guide the individualized therapy for this nonresponsive subgroup. However, just a few pharmacogenetic studies examined the effects of genetic polymorphisms on response to antihypertensive drugs in PE, and the criteria of responsiveness used to define responsive or nonresponsive subgroups to antihypertensive therapy should be replicated by others. We review these gene-drugs interactions, novel approaches to pharmacogenomics research and potential novel drugs for PE therapy. Finally, we discuss the challenges and perspectives of pharmacogenetics in the treatment of PE.

Effects of NAMPT polymorphisms and haplotypes on circulating visfatin/NAMPT levels in hypertensive disorders of pregnancy.

Dysregulation of adipocytokines may be associated with endothelial dysfunction in women with preeclampsia (PE), who are at increased risk of future cardiovascular disease. Visfatin, an adipocytokine with a potential cardiovascular role, is also known as nicotinamide phosphorybosil transferase (NAMPT). NAMPT gene polymorphisms affect circulating visfatin/NAMPT levels in obesity. Most findings provide evidence for increased visfatin/NAMPT circulating levels in PE. However, no previous study has tested the hypothesis that NAMPT polymorphisms affect visfatin/NAMPT levels in hypertensive disorders of pregnancy. We studied the effects of the NAMPT polymorphisms T>C (rs1319501) and A>G (rs3801266), and the haplotypes formed by them on visfatin/NAMPT levels and whether these genetic markers are associated with gestational hypertension (GH) and PE. We studied 212 healthy pregnant (HP), 181 patients with GH and 208 with PE. Genotypes were determined by Taqman allele discrimination assays. Plasma visfatin/NAMPT levels were measured by ELISA. No significant differences in visfatin/NAMPT levels were found among the groups. However, higher visfatin/NAMPT levels (P<0.05) were found in GH patients carrying the AG or the GG genotypes for the rs3801266 polymorphism or the 'T, G' haplotype. The TC and CC genotypes and the C allele for the rs1319501 polymorphism were more frequent in the HP than in the PE group (P<0.05). Moreover, the 'C, A' haplotype was also more frequent in the HP than in the PE group (P<0.01). Our findings suggest that although the rs3801266 polymorphism and the 'T, G' haplotype affect visfatin/NAMPT levels in GH, the rs1319501 polymorphism and the 'C, A' haplotype affect the susceptibility to PE.

Epistasis among eNOS, MMP-9 and VEGF maternal genotypes in hypertensive disorders of pregnancy.

Polymorphisms of the endothelial nitric oxide synthase (eNOS), matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) genes were shown to be associated with hypertensive disorders of pregnancy. However, epistasis is suggested to be an important component of the genetic susceptibility to preeclampsia (PE). The aim of this study was to characterize the interactions among these genes in PE and gestational hypertension (GH). Seven clinically relevant polymorphisms of eNOS (T-786C, rs2070744, a variable number of tandem repeats in intron 4 and Glu298Asp, rs1799983), MMP-9 (C-1562T, rs3918242 and -90(CA)13-25, rs2234681) and VEGF (C-2578A, rs699947 and G-634C, rs2010963) were genotyped by TaqMan allelic discrimination assays or PCR and fragment separation by electrophoresis in 122 patients with PE, 107 patients with GH and a control group of 102 normotensive pregnant (NP) women. A robust multifactor dimensionality reduction analysis was used to characterize gene-gene interactions. Although no significant genotype combinations were observed for the comparison between the GH and NP groups (P>0.05), the combination of MMP-9-1562CC with VEGF-634GG was more frequent in NP women than in women with PE (P<0.05). Moreover, the combination of MMP-9-1562CC with VEGF-634CC or MMP-9-1562CT with VEGF-634CC or-634GG was more frequent in women with PE than in NP women (P<0.05). These results are obscured when single polymorphisms in these genes are considered and suggest that specific genotype combinations of MMP-9 and VEGF contribute to PE susceptibility.

eNOS haplotypes associated with gestational hypertension or preeclampsia.

AIMS: Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene have been inconsistently associated with preeclampsia. We compared genotype and haplotype frequencies of three eNOS gene polymorphisms in normotensive and hypertensive pregnancies. METHODS: Genotypes and haplotypes for eNOS polymorphisms (T-786C, Glu298Asp and intron 4 b/a) were determined in 326 pregnant women (110 healthy pregnancies, 103 gestational hypertensives and 113 preeclamptic). RESULTS: No differences were observed in the frequencies of genotypes and alleles of the three polymorphisms among the groups (all p > 0.05). However, the haplotype 'T Glu a' was more common in healthy pregnancies than in gestational hypertensives or preeclamptic (20 vs 6 and 6%, respectively; p < 0.0032). Conversely, the haplotype 'C Glu a' was more common in gestational hypertensives and preeclamptic than in healthy pregnancies (17 vs 17 and 5%; p = 0.0061). CONCLUSION: These findings suggest a contribution of eNOS haplotypes to the development of hypertensive disorders of pregnancy that is obscured when specific eNOS genotypes alone are considered.