Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss

Contemporary Features Of Predicting The Development Of Luteal Insufficiency And Related Gestational Disorders

The goal of our study was a comprehensive assessment of obstetric, gynecological, somatic and genetic factors, contributing to high risk of insufficient luteal phase (ILP) and relating gestational disorders to the latter in relevant patients for further optimization of therapeutic and preventive measures. Material and Methods — A cohort study with a mixed cohort was carried out. The clinical material of the retrospective study was presented based on the results of analyzing 300 cases of patients with verified diagnoses of the threat of spontaneous abortion, miscarriage, and complete spontaneous abortion, who were hospitalized in the period of 2018-2020. As part of a prospective study, we analyzed 66 blood samples of women treated at the State Budgetary Healthcare Institution Simferopol Clinical Maternity Hospital No.2 in Crimea in 2020. The polymerase chain reaction method in real time mode, with the use of the developed kits, was used for CYP3A5 6986A> G polymorphism. Results — A comprehensive assessment of obstetric, gynecological, somatic and genetic factors allowed identifying the most informative prognostic markers for the risk of developing luteal phase insufficiency and related gestational disorders, including irregular menstrual cycle, cases of drug-induced abortion, preceding specific infectious diseases (chlamydia, Ureaplasma urealyticum infection), gynecological pathology (polycystic ovary syndrome), surgical interventions performed for gynecological pathology (ovarian resection and ovariectomy), as well as single nucleotide polymorphism rs776746 in the CYP3A5 gene. Conclusion — The identified prognostic criteria make it possible to identify a group of patients with a high risk of miscarriage even before the conception; such patients need more careful and systematic medical monitoring for the timely diagnosis of possible pregnancy complications. Early diagnosing of potential issues would allow clinicians to take preventive measures, along with initiating timely treatment. As a result, the percentage of reproductive losses would go down.

Potential Positive Association between Cytochrome P450 1A1 Gene Polymorphisms and Recurrent Pregnancy Loss: a Meta-Analysis

In order to discover the potential genetic risks associated with recurrent pregnancy loss (RPL), this meta-analysis was conducted to assess the association between CYP1A1 gene polymorphism and RPL. Studies were retrieved from the databases PubMed, Embase, HuGENet, and CNKI. Four models were then applied. Seven studies, including three datasets for the rs1048943 and five for the rs4646903 single-nucleotide polymorphism (SNP), were included in this analysis, involving 613 cases and 398 controls for the rs1048943; and 864 cases and 842 controls for the rs4646903 SNP. After comprehensive analysis, we found that rs4646903 was significantly associated with RPL [recessive (OR = 1.72, 95%CI: 1.13-2.61); codominant (CC vs TT; OR = 1.74, 95%CI: 1.12-2.71), (CC vs CT; OR = 1.67, 95%CI: 1.07-2.62) and allele analysis (OR = 1.27, 95%CI: 1.07-1.50)]. In the following subgroup analysis, a positive association was also discovered among people of Asian descent, especially South Asians. However, there was no obvious association between rs1048943 and RPL. In summary, our results suggest that CYP1A1 gene polymorphism (particularly for rs4646903) might be associated with RPL risk, especially among South Asians. Further studies are required to confirm this association.

Aryl hydrocarbon receptor and unexplained miscarriage

AIM

The aim of this study was to carry out a preliminary investigation of the expression of aryl hydrocarbon receptor (AhR) in decidua and villus and the relationship between AhR and unexplained miscarriage.

METHODS

The expression of AhR mRNA and protein from decidua and villus were measured using real-time reverse transcription-polymerase chain reaction, western blot and immunohistochemistry in 34 patients with unexplained miscarriage (miscarriage group) and 38 women with normal early pregnancy (control group).

RESULTS

The AhR mRNA and protein expression was increased significantly in the villus in both groups compared with decidua (P < 0.05, P < 0.05). In decidua, AhR mRNA and protein expression in the miscarriage group was increased significantly compared with the control group (P < 0.05, P < 0.05). In villus, AhR mRNA and protein expression in the miscarriage group was increased significantly compared with the control group (P < 0.05, P < 0.05). AhR is expressed mostly in the cytoplasm of syncytiotrophoblasts in villus, and also in the cytoplasm of decidual cells.

CONCLUSIONS

AhR was expressed more in the villus than in the decidua, and the upregulation of AhR mRNA and protein expression is associated with the pathogenesis of unexplained miscarriage.

Dioxin-metabolizing genes in relation to effects of prenatal dioxin levels and reduced birth size: The Hokkaido study

OBJECTIVES

We investigated the effects of maternal polymorphisms in 3 genes encoding dioxin-metabolizing enzymes in relation to prenatal dioxin levels on infant birth size in Japan.

METHODS

We examined the relationship between dioxin exposure and birth size in relation to the polymorphisms in the genes encoding aromatic hydrocarbon receptor (AHR [G>A, Arg554Lys]), cytochrome P450 (CYP) 1A1 (T6235C), and glutathione S-transferase mu 1 (GSTM1; Non-null/null) in 421 participants using multiple linear regression models.

RESULTS

In mothers carrying the GSTM1 null genotype, a ten-fold increase in total dioxin toxic equivalency was correlated with a decrease in birth weight of -345g (95% confidence interval: -584, -105).

CONCLUSIONS

We observed adverse effects of maternal GSTM1 null genotype on birth weight in the presence of dioxins exposure during pregnancy.

Combined effects of AHR, CYP1A1, and XRCC1 genotypes and prenatal maternal smoking on infant birth size: Biomarker assessment in the Hokkaido Study

OBJECTIVES

We investigated the individual and combined effects of maternal polymorphisms encoding the aromatic hydrocarbon receptor (AHR; rs2066853), cytochrome P450 (CYP) 1A1 (rs1048963), and the X-ray-complementing gene 1 (XRCC1; rs1799782) and prenatal smoking in relation to infant birth size.

METHODS

Totally, 3263 participants (1998 non-smokers and 1265 smokers) were included in the study between 2003 and 2007. Two groups of mothers were distinguished by plasma cotinine levels by ELISA measured during the third trimester (cut-off=11.48ng/mL). We conducted data analysis using multiple linear regression models.

RESULTS

Infants whose mothers smoked and had AHR-GG, CYP1A1-AG/GG, and XRCC1-CT/TT genotypes weighed, -145g less than those born of mothers who did not smoke and had the AHR-GA/AA, CYP1A1-AA, and XRCC1-CC genotypes (95% CI: -241, -50).

CONCLUSIONS

We demonstrated that infants whose mothers smoked during pregnancy with the combination of AHR, CYP1A1, and XRCC1 polymorphisms had lower birth size.

Genetics of recurrent miscarriage: challenges, current knowledge, future directions

Recurrent miscarriage (RM) occurs in 1-3% of couples aiming at childbirth. Due to multifactorial etiology the clinical diagnosis of RM varies. The design of genetic/"omics" studies to identify genes and biological mechanisms involved in pathogenesis of RM has challenges as there are several options in defining the study subjects (female patient and/or couple with miscarriages, fetus/placenta) and controls. An ideal study would attempt a trio-design focusing on both partners as well as pregnancies of the couple. Application of genetic association studies focusing on pre-selected candidate genes with potential pathological effect in RM show limitations. Polymorphisms in ∼100 genes have been investigated and association with RM is often inconclusive or negative. Also, implication of prognostic molecular diagnostic tests in clinical practice exhibits uncertainties. Future directions in investigating biomolecular risk factors for RM rely on integrating alternative approaches (SNPs, copy number variations, gene/protein expression, epigenetic regulation) in studies of single genes as well as whole-genome analysis. This would be enhanced by collaborative network between research centers and RM clinics.

Efficacy of human papillomavirus type 16/18 AS04-adjuvanted vaccine in Japanese women aged 20 to 25 years: final analysis of a phase 2 double-blind, randomized controlled trial

BACKGROUND

Human papillomavirus (HPV) type 16/18 AS04-adjuvanted vaccine was shown to be highly immunogenic and generally well tolerated in the interim analysis of a phase 2 double-blind, randomized controlled multicenter study in Japanese healthy women aged 20 to 25 years. Vaccine efficacy, immunogenicity, and safety are assessed in this study through 24 months after the first vaccination.

METHODS

Japanese women aged 20 to 25 years were randomly assigned to receive either HPV-16/18 AS04-adjuvanted vaccine (n = 519) or hepatitis A vaccine (n = 521) at 0, 1, and 6 months. Women were assessed for virological, cytological, and histological end points associated with HPV-16/18 and 12 other oncogenic HPV types (types 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) in cervical specimens and for the vaccine safety and immunogenicity. Antibody concentrations were measured by an enzyme-linked immunosorbent assay. Primary efficacy analysis was performed in the according-to-protocol cohort for efficacy, primary immunogenicity analysis was performed in the according-to-protocol cohort for immunogenicity, and primary safety analysis was done in the total vaccinated cohort.

RESULTS

Vaccine efficacy against persistent infections (6 month definition) associated with HPV-16/18 was 100% (95.5% confidence interval, 71.3-100; P < 0.0001). Vaccine efficacy against cervical intraepithelial neoplasia 1+ associated with 14 oncogenic HPV types was 64.9% (95.5% confidence interval, 4.9-89.0; P = 0.02). At 24 months after the first dose of the vaccine, geometric mean antibody titers against HPV-16 and HPV-18 were 1521.5 enzyme-linked immunosorbent assay U/mL and 627.4 enzyme-linked immunosorbent assay U/mL, respectively. The HPV-16/18 AS04-adjuvanted vaccine had a clinically acceptable safety profile.

CONCLUSIONS

The HPV-16/18 AS04-adjuvanted vaccine showed excellent prophylactic efficacy against 6-month persistent infection with HPV-16/18. The HPV-16/18 AS04-adjuvanted vaccine was generally well tolerated and immunogenic in the study population of healthy Japanese women aged 20 to 25 years.

Genetic association of phase I and phase II detoxification genes with recurrent miscarriages among North Indian women

Allelic variants of the detoxification genes that have impaired biotransformation functions may increase susceptibility to reproductive toxicity leading to endometriosis, recurrent miscarriage (RM) or poor pregnancy outcome. In the present study, we have investigated CYP1A1, CYP2D6, GSTT1, GSTP1 and GSTM1, which are involved in the phase I and phase II detoxification systems, in relation to their role in the etiology of unexplained RMs. In a case-control study, we have investigated 200 females with RM and 300 age and ethnically matched healthy controls with successful reproductive history from North India. The frequencies of phase I wild-type genotypes of CYP1A1 and CYP2D6 in RM cases were 0.56 and 0.60, whereas in controls these were 0.68 and 0.65, respectively (both P < 0.05). The GSTM1 null-genotype frequencies were 0.66 and 0.84 among RM cases and controls, respectively, the GSTT1 null-genotype frequencies were 0.52 and 0.45 (P < 0.005) and the GSTP1 variant allele frequencies were 0.23 and 0.20, respectively. In conclusion, we observed significant protective effects of phase I wild-type genotypes and association of the GSTT1 null genotype with RM. Through combined analyses we have highlighted the importance of the balance of phase I/phase II detoxification systems, in the etiology of RM.

Immunogenicity, reactogenicity, and safety of human papillomavirus 16/18 AS04-adjuvanted vaccine in Japanese women: interim analysis of a phase II, double-blind, randomized controlled trial at month 7

A phase II, double-blind, controlled randomized multicenter study with human papillomavirus (HPV) 16/18 AS04 (3-O-desacyl-4'-monophosphoryl lipid A and aluminum hydroxide)-adjuvanted vaccine is ongoing in Japanese women aged 20 to 25 years. An interim analysis was performed at month 7 (1 month after the third dose of vaccine) to determine reactogenicity, safety, and immunogenicity of the vaccine and to evaluate the baseline HPV-16/18 seropositivity and DNA status of women. In the HPV-16/18 group (according-to-protocol cohort for immunogenicity analysis), 100% seroconversion was observed against HPV-16 and HPV-18 at month 6 (5 months after the second dose) and at month 7. At month 7, anti-HPV-16 geometric mean titer (GMT) was 7441.0 enzyme-linked immunosorbent assay units/mL and anti-HPV-18 GMT was 3805.4 enzyme-linked immunosorbent assay units/mL, which is, respectively, 250- and 168-fold higher than GMTs observed after natural infection with HPV-16 or HPV-18. In the total vaccinated cohort, the seropositivity rates against HPV-16 and HPV-18 at study entry were 17.3% and 15.8%, respectively. At the same time point, HPV-16 and HPV-18 DNA was detected in 6.5% and 4.0% of the women, respectively. The immunogenicity of the HPV-16/18 vaccine and the HPV prevalence before vaccination in Japanese women are in line with what was observed in other populations. Injection site symptoms and some general symptoms were reported more frequently in the HPV-16/18 group than in the hepatitis A vaccine group but had no impact on compliance with completion of the vaccination course. Overall, the HPV-16/18 vaccine had a good safety profile, was well tolerated, and is highly immunogenic in the study population of Japanese women.

Effects of the Interaction between Interleukin-6-634C/G Polymorphism and Smoking on Serum C-Reactive Protein Concentrations

Smoking and interleukin-6 (IL-6) are major factors in inflammation. The aim of this study was to investigate whether or not the IL6 -634C/G polymorphism (rs1800796) and its interaction with smoking influence serum C-reactive protein (CRP) concentrations. The subjects were 347 Japanese male employees of a transit company. CRP and conventional cardiovascular risk factors were evaluated. IL6 -634C/G polymorphisms were genotyped by allelic discrimination using fluorogenic probes and the 5' nuclease assay. The mean values of CRP were significantly higher in current smokers than in nonsmokers after adjustment for age, body mass index (BMI), systolic blood pressure, total cholesterol, log triglycerides, high-density lipoprotein cholesterol (HDL-C), fasting glucose, and drinking habit (p=0.011). Comparison of three genotypes revealed significant interaction between smoking and the IL6 -634C/G genotype manifested by CRP concentrations (p=0.007) after the adjustments cited above. After stratification by smoking status, CRP differed significantly among IL6 -634C/G genotypes groups in nonsmokers (p=0.010, p for trend=0.007), whereas no significant difference was found in current smokers. Comparison between -634C/C and C/G+G/G groups revealed also a significant interaction between smoking and the IL6 -634C/G genotype (p=0.007). These findings suggest that the impact of the -634G allele on CRP elevation is greater in nonsmokers than in current smokers. Since gene-environment interactions have been insufficiently examined, further studies are required to clarify their effect on inflammation, including CRP elevation.

Association of cytochrome P450 1B1 polymorphism with first-trimester miscarriage

OBJECTIVE

To determine whether the cytochrome P450 1B1 (CYP1B1) Val432Leu polymorphism is associated with risk of miscarriage. We also analyzed the possible interaction between this polymorphism and caffeine intake.

DESIGN

The population-based case-control study included 507 women with miscarriage in the first trimester of pregnancy and 908 controls with a normal first-trimester pregnancy. The controls were frequency matched to cases. The material was analyzed taking maternal age, smoking habits, alcohol intake, caffeine intake, fetal karyotype, nausea, and vomiting into consideration.

SETTING

University hospital and primary care facility.

MAIN OUTCOME MEASURE(S)

CYP1B1 Val432Leu genotype frequencies in cases and controls.

RESULT(S)

Carriers of the CYP1B1 432 Val/Val genotype were at a higher risk of miscarriage in the first trimester of pregnancy (odds ratio = 1.46; 95% confidence interval, 1.02-2.08). We also found a significant interaction between genotype and caffeine intake.

CONCLUSION(S)

CYP1B1 Val432Leu polymorphism is associated with first-trimester miscarriage, and it may also modify the risk among coffee drinkers.

Maternal smoking during pregnancy and genetic polymorphisms in the Ah receptor, CYP1A1 and GSTM1 affect infant birth size in Japanese subjects

Genetic susceptibility to tobacco smoke might have relation to adverse pregnancy outcomes. To estimate the effects of maternal smoking and genetic polymorphisms on infant birth weight and length, we conducted a prospective cohort study of 293 women who delivered singleton live births in Sapporo, Japan. Birth weight and length were significantly lower among infants born to continuously smoking women having the aryl hydrocarbon receptor (AhR) wild type genotype (Arg/Arg; 211 g +/- 76 g; 1.2 cm +/- 0.4 cm, p < 0.01 and p < 0.01, respectively), the CYP1A1 variant genotype (m1/m2 + m2/m2; 170 g +/- 64 g, 0.8 cm +/- 0.3 cm, p < 0.01 and p < 0.05, respectively), or the GSTM1 null genotype (171 g +/- 58 g, 0.6 cm +/- 0.3 cm, p < 0.01 and p < 0.05, respectively). When combinations of these genotypes were considered, birth weight and length were significantly lower for infants of continuously smoking women in the AhR wild type + CYP1A1 variant group (315 g +/- 116 g; 1.7 cm +/- 0.6 cm, p < 0.01 and p < 0.01, respectively) and in the CYP1A1 variant + GSTM1 null group (237 g +/- 92 g; 1.3 cm +/- 0.5 cm, p < 0.05 and p < 0.01, respectively). These genotypes did not confer adverse effects among women who had never smoked; therefore, maternal smoking in combination with maternal AhR, CYP1A1 and GSTM1 genetic polymorphisms may adversely affect infant birth size.

Polymorphisms of human nuclear receptors that control expression of drug-metabolizing enzymes

Phenotypic variation in human drug metabolism frequently can be attributed to polymorphisms in genes that encode drug-metabolizing enzymes (DMEs). However, levels of Phase I and Phase II DMEs also vary because many of these enzymes are induced by a myriad of xenobiotic chemicals. Individual differences in the capacity for induction contribute to variation in drug metabolism in human populations. Induction is mediated by intracellular receptors that act as ligand-dependent transcription factors, including several members of the nuclear receptor (NR) superfamily and the aryl hydrocarbon receptor (AHR). Genetic variations (SNPs and others) exist in genes that encode these human receptors but few of the known polymorphisms have any significant effect on enzyme induction. We suggest that the current scarcity of SNPs that are able to alter function in the DME-regulating NRs reflects considerable evolutionary selective pressures that conserve the key functional domains in these receptors.

Caffeine intake, CYP1A2 polymorphism and the risk of recurrent pregnancy loss

Some case-control studies have demonstrated that caffeine intake and high CYP1A2 activity increase risks of recurrent pregnancy loss (RPL) but the multifactorial effect is obscure. To investigate whether susceptible women who have more caffeine intake are at high risk of RPL, a case-control study of 58 cases with two or more RPL and fertile 147 controls was performed. The association between daily caffeine intake together with CYP1A21F (AA versus CA and CC) genotype and RPL was assessed. Without consideration of the genotype, there were no significant differences of the RPL risk in proportion to daily caffeine intake [less than 100 mg (reference); 100-299 mg: odds ratio (OR), 1.29; 95% confidence interval (CI), 0.66-2.50; 300 mg or more: OR, 1.82; 95% CI, 0.72-4.58; P for trend, 0.20]. However, the RPL risk significantly increased only among women who had homozygous CYP1A21F alleles with a dosage effect of daily caffeine intake [less than 100 mg (reference); 100-299 mg: OR, 1.94; 95% CI, 0.57-6.66; 300 mg or more: OR, 5.23; 95% CI, 1.05-25.9; P for trend, 0.03]. It was demonstrated for the first time that an increase in caffeine intake deteriorates the fecundity among susceptible women.