Genetic variants, immune function, and risk of pre-eclampsia among American Indians

Individual- and community-level risk factors for maternal morbidity and mortality among Native American women in the USA: a systematic review

INTRODUCTION AND OBJECTIVE

Maternal morbidity and mortality (MMM) is a public health concern in the USA, with Native American women experiencing higher rates than non-Hispanic White women. Research on risk factors for MMM among Native American women is limited. This systematic review comprehensively synthesizes and critically appraises the literature on risk factors for MMM experienced by Native American women.

METHODS AND ANALYSIS

A systematic search was conducted on 10 October 2022 in PubMed, Embase, CINAHL and Scopus for articles published since 2012. Selection criteria included observational studies set in the USA, involving Native American women in the perinatal period, and examining the relationship between risk factors and MMM outcomes. Three reviewers screened and extracted data from the included studies, with risk of bias assessed using the National Institutes of Health Quality Assessment Tools. Data were analysed descriptively.

RESULTS

15 studies were included. All studies used administrative databases, with settings, including nationwide (seven studies), statewide (four studies) and Indian reservations (four studies). The majority of studies focused on hypertensive disorders of pregnancy (eight studies) and severe maternal morbidity (SMM) (four studies). 26 risk factors were identified. Key risk factors included Native American race (six studies), rural maternal residency (four studies), overweight/obese body mass index (two studies), maternal age (two studies), nulliparity (two studies) and pre-existing medical conditions (one study).

CONCLUSION

This review identified risk factors associated with MMM among Native American women, including rural residency, overweight or obesity and advanced maternal age. However, the findings also reveal a scarcity of research specific to this population, limiting the ability to fully understand these risk factors and develop effective interventions. These results emphasise the need for further research and culturally relevant studies to inform public health and address disparities for Native American women, particularly those in rural areas.

PROSPERO REGISTRATION NUMBER

CRD42022363405.

Genetic variant rs1205 is associated with COVID-19 outcomes: The Strong Heart Study and Strong Heart Family Study

BACKGROUND

Although COVID-19 infection has been associated with a number of clinical and environmental risk factors, host genetic variation has also been associated with the incidence and morbidity of infection. The CRP gene codes for a critical component of the innate immune system and CRP variants have been reported associated with infectious disease and vaccination outcomes. We investigated possible associations between COVID-19 outcome and a limited number of candidate gene variants including rs1205.

METHODOLOGY/PRINCIPAL FINDINGS

The Strong Heart and Strong Heart Family studies have accumulated detailed genetic, cardiovascular risk and event data in geographically dispersed American Indian communities since 1988. Genotypic data and 91 COVID-19 adjudicated deaths or hospitalizations from 2/1/20 through 3/1/23 were identified among 3,780 participants in two subsets. Among 21 candidate variants including genes in the interferon response pathway, APOE, TMPRSS2, TLR3, the HLA complex and the ABO blood group, only rs1205, a 3' untranslated region variant in the CRP gene, showed nominally significant association in T-dominant model analyses (odds ratio 1.859, 95%CI 1.001-3.453, p = 0.049) after adjustment for age, sex, center, body mass index, and a history of cardiovascular disease. Within the younger subset, association with the rs1205 T-Dom genotype was stronger, both in the same adjusted logistic model and in the SOLAR analysis also adjusting for other genetic relatedness.

CONCLUSION

A T-dominant genotype of rs1205 in the CRP gene is associated with COVID-19 death or hospitalization, even after adjustment for relevant clinical factors and potential participant relatedness. Additional study of other populations and genetic variants of this gene are warranted.

Efficacy of Magnesium Sulfate and Labetalol in the Treatment of Pregnancy-Induced Hypertension and Its Effect on Anxiety and Depression: A Retrospective Cohort Study

Background

In this study, the effect of magnesium sulfate and labetalol in treating pregnancy-induced hypertension (PIH) and its influence on anxiety and depression in patients are observed, and new ideas for treating anxiety and depression in PIH are introduced.

Methods

A retrospective cohort study was conducted to select patients with PlH diagnosed from July 2020 to July 2023 from Affiliated Hospital of Electronic Science and Technology University and Chengdu Women' s and Children's Central Hospital in Chengdu of Sichuan Province. The changes in blood pressure, Edinburgh Postnatal Depression Scale (EPDS), and generalized anxiety disorder 7 (GAD-7) in patients with hypertensive pregnancy were collected and analyzed.

Results

In our investigation, 219 patients completed the study, and 36.1% (79/219) of them developed anxiety and depression. According to whether the patients were treated with magnesium sulfate and labetalol, 49 cases were assigned to the magnesium sulfate and labetalol treatment (MSLT) group, and 30 cases were assigned to the conventional treatment (CT) group. Edinburgh Postnatal Depression Scale scores and GAD-7 scores in the MSLT group were significantly lower than those in the CT group, indicating that magnesium sulfate and labetalol can improve anxiety and depression in hypertensive patients during pregnancy. The difference was statistically significant (P < .05). According to the changes in systolic blood pressure, the clinical efficacy of patients was evaluated, and no significant difference in efficacy existed between the MSLT and CT groups.

Conclusion

Magnesium sulfate and labetalol can control the blood pressure of patients with PIH and indirectly improve anxiety and depression in patients with PIH, thereby introducing new ideas for the treatment of PIH accompanied by anxiety and depression.

Genomics and inclusion of Indigenous peoples in high income countries

Genomics research related to Indigenous people has been at worst exploitative and at best, retrospectively on a journey to improve effective engagement of Indigenous individuals and communities. Genomics can positively impact all stages of clinical management, and to improve genomic effectiveness researchers aggregate genomic data from diverse global sub-populations, such as shared ancestry groupings, as people within these groupings will have a greater proportion of shared DNA traits. While genomics is already being used worldwide to improve lives, its utility and effectiveness has not been maximized for individuals with Indigenous ancestry. Several large datasets of human genetic variation have been made publicly available, of which the most widely used is the Genome Aggregation Database (gnomAD), but none of these databases currently contain any population-specific data for Indigenous populations. There are many reasons why Indigenous people have been largely left out of genomics research and, because of this, miss out on the benefits offered. It is also clear that if research is to be effective, it needs to be done 'with' and not 'on' Indigenous communities. This systematic review of the literature regarding Indigenous peoples (in high income countries) and genomics aims to review the existing literature and identify areas of strength and weakness in study design and conduct, focusing on the effectiveness of Indigenous community engagement.

Does race or ethnicity play a role in the origin, pathophysiology, and outcomes of preeclampsia? An expert review of the literature

The burden of preeclampsia, a substantial contributor to perinatal morbidity and mortality, is not born equally across the population. Although the prevalence of preeclampsia has been reported to be 3% to 5%, racial and ethnic minority groups such as non-Hispanic Black women and American Indian or Alaskan Native women are widely reported to be disproportionately affected by preeclampsia. However, studies that add clarity to the causes of the racial and ethnic differences in preeclampsia are limited. Race is a social construct, is often self-assigned, is variable across settings, and fails to account for subgroups. Studies of the genetic structure of human populations continue to find more variations within racial groups than among them. Efforts to examine the role of race and ethnicity in biomedical research should consider these limitations and not use it as a biological construct. Furthermore, the use of race in decision making in clinical settings may worsen the disparity in health outcomes. Most of the existing data on disparities examine the differences between White and non-Hispanic Black women. Fewer studies have enough sample size to evaluate the outcomes in the Asian, American Indian or Alaskan Native, or mixed-race women. Racial differences are noted in the occurrence, presentation, and short-term and long-term outcomes of preeclampsia. Well-established clinical risk factors for preeclampsia such as obesity, diabetes, and chronic hypertension disproportionately affect non-Hispanic Black, American Indian or Alaskan Native, and Hispanic populations. However, with comparable clinical risk factors for preeclampsia among women of different race or ethnic groups, addressing modifiable risk factors has not been found to have the same protective effect for all women. Abnormalities of placental formation and development, immunologic factors, vascular changes, and inflammation have all been identified as contributing to the pathophysiology of preeclampsia. Few studies have examined race and the pathophysiology of preeclampsia. Despite attempts, a genetic basis for the disease has not been identified. A number of genetic variants, including apolipoprotein L1, have been identified as possible risk modifiers. Few studies have examined race and prevention of preeclampsia. Although low-dose aspirin for the prevention of preeclampsia is recommended by the US Preventive Service Task Force, a population-based study found racial and ethnic differences in preeclampsia recurrence after the implementation of low-dose aspirin supplementation. After implementation, recurrent preeclampsia reduced among Hispanic women (76.4% vs 49.6%; P<.001), but there was no difference in the recurrent preeclampsia in non-Hispanic Black women (13.7 vs 18.1; P=.252). Future research incorporating the National Institute on Minority Health and Health Disparities multilevel framework, specifically examining the role of racism on the burden of the disease, may help in the quest for effective strategies to reduce the disproportionate burden of preeclampsia on a minority population. In this model, a multilevel framework provides a more comprehensive approach and takes into account the influence of behavioral factors, environmental factors, and healthcare systems, not just on the individual.

Unactivated leukocyte expression of C-reactive protein is minimal and not dependent on rs1205 genotype

C-reactive protein (CRP), a prominent component of the innate immune system, is implicated in the pathophysiology of many conditions. CRP production primarily occurs in the liver; but contributions from other tissues is unclear. The Genotype-Tissue Expression Portal shows essentially no expression in whole blood and reports in the literature are conflicting. Multiple genomic variants influence serum levels of CRP. We measured CRP mRNA expression in leukocytes and sought to determine if rs1205 genotype influences leukocyte expression. Leukocytes were obtained from 20 women differing by genotype. Quantitative, real-time PCR (RT-qPCR) detected CRP and reference gene (GAPDH) mRNA. Leukocyte expression was calculated by the 2^ΔCT method, and against a standard curve. Digital drop PCR was also used to calculate expression ratios. Student's t test and linear regression methods examined possible differences between genotypes. During 32 runs (10 replicates each), the RT-qPCR mean (SD) CRP/GAPDH ratio was 3.39 × 10^–4 (SD 1.73 × 10^–4) and 3.15 × 10^–4 (SD 1.64 × 10^–4) for TT and CC genotypes respectively, p = 0.76; and digital drop PCR results were similar. Serum CRP was not significantly different between genotypes, nor correlated with leukocyte expression. CRP is minimally expressed in unactivated leukocytes and this expression is not likely influenced by rs1205 genotype.

Analysis of Complement C3 Gene Reveals Susceptibility to Severe Preeclampsia

Preeclampsia (PE) is a common vascular disease of pregnancy with genetic predisposition. Dysregulation of the complement system has been implicated, but molecular mechanisms are incompletely understood. In this study, we determined the potential linkage of severe PE to the most central complement gene, C3. Three cohorts of Finnish patients and controls were recruited for a genetic case-control study. Participants were genotyped using Sequenom genotyping and Sanger sequencing. Initially, we studied 259 Finnish patients with severe PE and 426 controls from the Southern Finland PE and the Finnish population-based PE cohorts. We used a custom-made single nucleotide polymorphism (SNP) genotyping assay consisting of 98 SNPs in 18 genes that encode components of the complement system. Following the primary screening, C3 was selected as the candidate gene and consequently Sanger sequenced. Fourteen SNPs from C3 were also genotyped by a Sequenom panel in 960 patients with severe PE and 705 controls, including already sequenced individuals. Three of the 43 SNPs observed within C3 were associated with severe PE: rs2287845 (p = 0.038, OR = 1.158), rs366510 (p = 0.039, OR = 1.158), and rs2287848 (p = 0.041, OR = 1.155). We also discovered 16 SNP haplotypes with extreme linkage disequilibrium in the middle of the gene with a protective (p = 0.044, OR = 0.628) or a predisposing (p = 0.011, OR = 2.110) effect to severe PE depending on the allele combination. Genetic variants associated with PE are located in key domains of C3 and could thereby influence the function of C3. This is, as far as we are aware, the first candidate gene in the complement system with an association to a clinically relevant PE subphenotype, severe PE. The result highlights a potential role for the complement system in the pathogenesis of PE and may help in defining prognostic and therapeutic subgroups of preeclamptic women.

Pre-eclampsia in American Indians/Alaska Natives and Whites: The Significance of Body Mass Index

Introduction The prevalence of pre-eclampsia, a major cause of maternal morbidity, varies by race, being greater in African Americans, and lower in Asians and Hispanics than in White women. Little is known about its prevalence in American Indians/Alaska Natives (AI/ANs). We estimated pre-eclampsia risk in AI/ANs compared to Whites, with consideration of the potential effect of obesity, a major risk factor for pre-eclampsia, and a condition disproportionately affecting AI/AN women. Methods This retrospective cohort study of linked birth-hospital discharge data from Washington State (2003-2013) included all AI/AN women and a sample of White first-time mothers with singleton deliveries. Logistic regression was used to estimate odds ratio (OR) and 95 % confidence intervals (CI) for pre-eclampsia risk in AI/ANs compared to Whites, first controlling for several important risk factors, and subsequently with additional adjustment for pre-pregnancy body mass index (BMI). Results AI/ANs had an increased risk of pre-eclampsia compared to Whites after controlling for all covariates except BMI (OR 1.17, 95 % CI 1.06-1.29). After further adjustment for BMI, the racial disparity in pre-eclampsia risk was greatly attenuated (OR 1.05, 95 % CI 0.95-1.16). Discussion This population-based study suggests that any increased risk in AI/ANs relative to Whites may be at least partly due to differences in BMI.

FoxP3 gene promoter polymorphism affects susceptibility to preeclampsia

BACKGROUND

Preeclampsia (PE) is a multifactorial pregnancy disorder and is a major cause of maternal morbidity and mortality. Despite intense study, the pathophysiology of preeclampsia remains enigmatic. Recent studies have reported that regulatory T cells (Tregs) is linked with PE. It is well identified that FoxP3/Scurfin is involved in development and function of Tregs. However, the association between PE and the FoxP3 gene polymorphism has not been sufficiently investigated. In this study, we hypothesized that polymorphisms of the FoxP3 may be related to PE.

METHODS

We assessed the relationship between four single-nucleotide polymorphisms (SNPs) in the FoxP3 genes with sequence-specific primers (PCR-SSP) in 81 PE patients and 90 age-matched controls.

RESULT

We identified significant difference of rs4824747 GG genotype frequency between the PE and control groups. Women with GG genotypes exhibited higher (OR=6.25, 95% CI=2.63-14.85; P<0.0001) risk of developing PE. None of the other investigated SNPs (rs2232365, rs3761547 and rs3761548) showed significant association with PE.

CONCLUSION

We suggest that FoxP3 polymorphisms (rs4824747) could be a potential contributor for the development of PE in Iranian women.

Association between CRP gene polymorphisms and the risk of preeclampsia in Han Chinese women

BACKGROUND

As an inflammatory marker, C-reactive protein (CRP) has elevated expression in preeclampsia (PE), which is implicated in the pathogenesis of PE, but there has been a lack of information on the possible association between genetic variants of CRP and PE. In this study, we aimed to assess the genetic association between CRP polymorphisms and the risk of PE in Han Chinese Women.

METHODS

Five single-nucleotide polymorphisms of CRP, rs2794521 (T>C), rs3091244 (C>T>A), rs3093068 (C>G), rs876538 (C>T), and rs1205 (C>T) were genotyped using the Sequenom method in 181 PE patients and 203 controls.

RESULTS

The T allele frequency for rs2794521 was significantly higher in PE patients than in controls (odds ratios [OR]=4.091; 95% confidence interval [CI]: 1.533-10.917; p=0.002). The TT genotype of rs2794521 conferred a risk for PE (TT vs. TC+CC: OR=4.062; 95% CI: 1.499-11.008; p=0.003) and severe PE (TT vs. TC+CC: OR=9.577; 95% CI: 1.267-72.397; p=0.006). The other four polymorphic loci were not different between the groups. The CRP H2 haplotype (T-C-C-G-C) was associated with PE (OR=2.129; 95% CI: 1.47-3.085; p<0.001), whereas the H1 haplotype (C-C-C-G-C) offered protection (OR=0.23; 95% CI: 0.066-0.8; p=0.01).

CONCLUSIONS

The CRP variant rs2794521 shows a strong association with PE in Han Chinese women. Pregnant women with the TT genotype of rs2794521 have higher odds of having PE, which further supports a possible role for CRP in PE.

IBC CARe microarray allelic population prevalences in an American Indian population

Background

The prevalence of variant alleles among single nucleotide polymorphisms (SNPs) is not well known for many minority populations. These population allele frequencies (PAFs) are necessary to guide genetic epidemiology studies and to understand the population specific contribution of these variants to disease risk. Large differences in PAF among certain functional groups of genes could also indicate possible selection pressure or founder effects of interest. The 50K SNP, custom genotyping microarray (CARe) was developed, focusing on about 2,000 candidate genes and pathways with demonstrated pathophysiologic influence on cardiovascular disease (CVD).

Methods

The CARe microarray was used to genotype 216 unaffected controls in a study of pre-eclampsia among a Northern Plains, American Indian tribe. The allelic prevalences of 34,240 SNPs suitable for analysis, were determined and compared with corresponding HapMap prevalences for the Caucasian population. Further analysis was conducted to compare the frequency of statistically different prevalences among functionally related SNPs, as determined by the DAVID Bioinformatics Resource.

Results

Of the SNPs with PAFs in both datasets, 9.8%,37.2% and 47.1% showed allele frequencies among the American Indian population greater than, less than and either greater or less than (respectively) the HapMap Caucasian population. The 2,547 genes were divided into 53 functional groups using the highest stringency criteria. While none of these groups reached the Bonferroni corrected p value of 0.00094, there were 7 of these 53 groups with significantly more or less differing PAFs, each with a probability of less than 0.05 and an overall probability of 0.0046.

Conclusion

In comparison to the HapMap Caucasian population, there are substantial differences in the prevalence among an American Indian community of SNPs related to CVD. Certain functional groups of genes and related SNPs show possible evidence of selection pressure or founder effects.

Two variants of the C-reactive protein gene are associated with risk of pre-eclampsia in an American Indian population

BACKGROUND

The etiology of pre-eclampsia (PE) is unknown; but it is accepted that normal pregnancy represents a distinctive challenge to the maternal immune system. C-reactive protein is a prominent component of the innate immune system; and we previously reported an association between PE and the CRP polymorphism, rs1205. Our aim was to explore the effects of additional CRP variants. The IBC (Cardiochip) genotyping microarray focuses on candidate genes and pathways related to the pathophysiology of cardiovascular disease.

METHODS

This study recruited 140 cases of PE and 270 matched controls, of which 95 cases met criteria as severe PE, from an American Indian community. IBC array genotypes from 10 suitable CRP SNPs were analyzed. A replication sample of 178 cases and 427 controls of European ancestry was also genotyped.

RESULTS

A nominally significant difference (p value <0.05) was seen in the distribution of discordant matched pairs for rs3093068; and Bonferroni corrected differences (P<0.005) were seen for rs876538, rs2794521, and rs3091244. Univariate conditional logistic regression odds ratios (OR) were nominally significant for rs3093068 and rs876538 models only. Multivariate logistic models with adjustment for mother's age, nulliparity and BMI attenuated the effect (OR 1.58, P = 0.066, 95% CI 0.97-2.58) for rs876538 and (OR 2.59, P = 0.050, 95% CI 1.00-6.68) for rs3093068. An additive risk score of the above two risk genotypes shows a multivariate adjusted OR of 2.04 (P = 0.013, 95% CI 1.16-3.56). The replication sample also demonstrated significant association between PE and the rs876538 allele (OR = 1.55, P = 0.01, 95% CI 2.16-1.10). We also show putative functionality for the rs876538 and rs3093068 CRP variants.

CONCLUSION

The CRP variants, rs876538 and rs3093068, previously associated with other cardiovascular disease phenotypes, show suggestive association with PE in this American Indian population, further supporting a possible role for CRP in PE.