Genetic association of ERAP1 and ERAP2 with eclampsia and preeclampsia in northeastern Brazilian women.

The clinical spectrum of hypertensive disorders of pregnancy (HDP) is determined by the interplay between environmental and genetic factors, most of which remains unknown. ERAP1, ERAP2 and LNPEP genes code for multifunctional aminopeptidases involved with antigen processing and degradation of small peptides such as angiotensin II (Ang II), vasopressin and oxytocin. We aimed to test for associations between genetic variants in aminopeptidases and HDP. A total of 1282 pregnant women (normotensive controls, n = 693; preeclampsia, n = 342; chronic hypertension with superimposed preeclampsia, n = 61; eclampsia, n = 74; and HELLP syndrome, n = 112) were genotyped for variants in LNPEP (rs27300, rs38034, rs2303138), ERAP1 (rs27044, rs30187) and ERAP2 (rs2549796 rs2927609 rs11135484). We also evaluated the effect of ERAP1 rs30187 on plasma Ang II levels in an additional cohort of 65 pregnant women. The genotype C/C, in ERAP1 rs30187 variant (c.1583 T > C, p.Lys528Arg), was associated with increased risk of eclampsia (OR = 1.85, p = 0.019) whereas ERAP2 haplotype rs2549796(C)-rs2927609(C)-rs11135484(G) was associated with preeclampsia (OR = 1.96, corrected p-value = 0.01). Ang II plasma levels did not differ across rs30187 genotypic groups (p = 0.895). In conclusion, ERAP1 gene is associated with eclampsia whereas ERAP2 is associated with preeclampsia, although the mechanism by which genetic variants in ERAPs influence the risk of preeclampsia and eclampsia remain to be elucidated.

Cytokine gene polymorphisms in preeclampsia and eclampsia.

The clinical spectrum of preeclampsia (PE) ranges from mild hypertension to severe vasospasm associated with convulsions and multiple organ damage. The biological factors that determine the progression of PE to eclampsia (E) are unknown. Endothelial cell activation seems related to an impaired maternal immune response. The production of cytokines, IL-10 and TGF-beta1, is apparently suppressed, and altered IL-2/IL-10 and TNF-alpha/IL-10 ratios have been reported in preeclamptic cases. The relationship between PE and cytokine gene polymorphism has been studied, but there are few studies that include eclamptic patients. This study aimed at investigating whether polymorphisms in genes, TNF-alpha promoter (-308 G>A), IL6 promoter (-174 G>C), IFN-gamma intron 1 (+874 A>T), IL10 promoters (-1082 A>G), (-819 C>T) and (-592 C>A) and TGF-beta1 codon 10 (+869 T>C) and codon 25 (+915 G>C) are associated with E and/or PE. Genotyping was carried out in 266 Mulatto women from the northeastern region of Brazil who were referred to a single maternity hospital: 92 with PE, 73 with E and 101 normotensive controls. The chi(2) or Fisher's exact tests were used to compare genotype frequencies. Among the six single-nucleotide polymorphisms (SNPs) studied, we found no difference in genotype frequencies between the groups. There was a higher frequency of IFN-gamma (+874 A) in eclamptic patients in comparison with that in controls. (70.3 vs. 57.8%, respectively; P=0.02). There were no other significant differences in allelic frequencies between eclamptic, preeclamptic and control groups We found no independent association between any single SNP and PE or E risk in this population of Mulatto women from the northeastern region of Brazil.

Complexity and complicity in eclampsia: barriers or bridges?

The aetiology of pre-eclampsia-eclampsia remains largely unclarified, despite over 100 years of systematic study. The assumption that the triggering event is linear and amenable to reductionist techniques has characterized these efforts. The main purpose of this paper is to show that complexity and complicity characterize most pathophysiological processes in pre-eclampsia-eclampsia, a situation suggesting that similar mechanisms must exist at the origin of the disease. The unique configuration of the intervillous space and the intensity of energy transference through the fetomaternal interface offer many dysfunctional possibilities, even in clinically normal pregnancies. The most characteristic seem to be: the shedding and deportation of trophoblast, the fragmentation of villi, the escape of fetal blood, and events associated with trophoblast damage, degeneration and death. The pathogenic potential of these natural processes seems to depend on the association with amplifiers and permissive factors, which vary from person to person and from time to time. Thus, considering the convergence of multiple factors and the presence of nonlinearity in some of their interactions as a plausible working hypothesis, further exploration on this subject should adhere to the rules of this different reality. To find the best possible method of inquiry and to recognize its limitations will be the surest way to avoid failure.

Aspectos imunogenéticos da gestose hipertensiva / Immunogenetic aspects of hypertension in pregnancy

O autor discute, com base em trabalhos recentes, a possibilidade hipertensiva ter seu aparecimento influenciado por um gen único recessivo e tece consideraçöes sobre o aspecto imunogenético da doença