Role of IL-17 Variants in Preeclampsia in Chinese Han Women

Association of IL-17 and IL-27 polymorphisms with susceptibility to recurrent pregnancy loss and pre-eclampsia: A systematic review and meta-analysis

OBJECTIVE

Recurrent pregnancy loss (RPL) and pre-eclampsia (PE) are immune-related pregnancy complications that have been linked to CD4+ T cells and their cytokines, which can be influenced by genetic polymorphisms. This meta-analysis aimed to investigate the relationship between interleukin (IL)-17 and -27 polymorphisms and the susceptibility to RPL and PE.

METHODS

All eligible case-control studies published up to February 2023 were identified by searching PubMed, EMBASE, Cochrane, Web of Science, and Google Scholar. The risk of recurrent pregnancy loss and PE associated with the IL-17 rs2275913, IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were estimated for each study.

RESULTS

The meta-analysis incorporated a total of 13 studies. The overall analysis indicated that IL-17 rs2275913, IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were not significantly associated with immune-related pregnancy complications, including RPL and PE. However, when the analysis was stratified by disease type, the IL-17 rs2275913 polymorphism was found to be associated with an increased risk of RPL (recessive model AA/GA + GG: OR = 1.68, 95% confidence interval [CI]: 1.13-2.49, p = .01).

CONCLUSIONS

The IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were not significantly associated with RPL and PE, whereas the IL-17 rs2275913 polymorphism was associated with the susceptibility to recurrent miscarriage.

Association between polymorphisms rs2228001 and rs2228000 in XPC and genetic susceptibility to preeclampsia: a case control study

BACKGROUND

Xeroderma pigmentosum complementation group C (XPC) is a DNA damage recognition protein that plays an important role in nucleotide excision repair and can reduce oxidative stress, which may be involved in the development of preeclampsia (PE). Therefore, the aim of this study was to explore whether XPC polymorphisms were relevant to the genetic susceptibility to PE in Chinese Han women.

METHOD

A total of 1276 healthy pregnant women were included as the control group and 958 pregnant women with PE as the case group. DNA was extracted from peripheral blood samples to perform genotyping of loci rs2228001 and rs2228000 in XPC through real-time quantitative polymerase chain reaction (PCR). The relationship between XPC and susceptibility to PE was evaluated by comparing the genotypic and allelic frequencies between the two groups of pregnant women.

RESULTS

Polymorphism of rs2228000 may be associated with PE risk and allele T may play a protective role (genotype, χ2 = 38.961, P < 0.001 and allele χ2 = 21.746 P < 0.001, odds ratio (OR) = 0.885, 95% confidence interval (CI) = 0.840-0.932). No significant difference was found between the two groups in rs2228001,(genotype χ2 = 3.148, P = 0.207 and allele χ2 = 0.59, P = 0.442, OR = 1.017, 95% CI = 0.974-1.062). When the frequencies of genotypes and alleles for early- and late-onset PE, mild PE and severe PE were compared with those of controls, the results were consistent with the large clinical sample.

CONCLUSION

Our data suggest that the genetic variant rs2228000 in XPC may be associated with PE risk in Chinese Han women, and that pregnant women with the TT genotype have a reduced risk of PE. Further investigations are needed to confirm these findings in other regions or larger prospective populations.

A review of key cytokines based on gene polymorphism in the pathogenesis of pre-eclampsia

Although a number of theories have been suggested, including roles for oxidative stress, an abnormal maternal-fetal interface, and genetic and environmental factors, the etiopathology of pre-eclampsia (PE) remains unclear. Maternal immune tolerance is important for maintaining pregnancy, and researchers have increasingly focused on the critical roles of cytokines in the pathogenesis of PE in recent years. The assessment of candidate genetic polymorphisms in PE could partially elucidate the mechanisms of susceptibility to disease, and contribute to seeking for new diagnosis and treatment methods of PE. PE can lead to severe complications, and even the death of both mother and fetus. Although the complex pathology is not yet clear, some evidence suggested that the occurrence of PE is related to inflammatory factors. We reviewed the current understandings of roles of cytokines in PE, and provided an extensive overview of the role of single nucleotide chain polymorphisms (SNPs) in the genes potentially underlying the pathophysiology of PE.

Association between interleukin-32 gene polymorphism and susceptibility to preeclampsia

OBJECTIVE

To determine association between IL-32 gene polymorphism, and serum levels of IL-32 and susceptibility to preeclampsia (PE).

METHODS

The frequency of IL-32 rs9927163 and rs4786370 polymorphisms was determined by PCR-RFLP. Also ELISA was used to determine the levels of serum IL-32.

RESULTS

Regarding rs4786370 C/T SNPs, the frequencies of CT, TT genotypes, and T allele were shown to be higher in the PE patients. IL-32 serum level significantly increased in the PE patients.

CONCLUSION

Variety of allele and genotype IL32 rs4786370 as well as a rise in serum level of IL-32 can be regarded as a risk factor for PE.

Are genetic variations in IL-1β and IL-6 cytokines associated with the risk of pre-eclampsia? Evidence from a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis study was performed to assess the potential association between interleukin-1 beta (IL-1β) single nucleotide polymorphisms (SNPs) (rs1143634 and rs16944) and interleukin-6 (IL-6) SNP (rs1800795) and pre-eclampsia (PE).

METHODS

A comprehensive literature search was conducted in the international search engines and databases, including MEDLINE (via PubMed), Scopus, and Web of Science (ISI) up to 9 March 2021. After retrieving relevant articles, data extraction was performed by four authors independently. Pooled ORs and corresponding 95% CIs were used to evaluate the association between IL-1β and IL-6 polymorphisms and PE risk. Cochran's Q test was used to check heterogeneity, and the I² index was calculated for measuring the heterogeneity between the estimations of included studies.

RESULTS

After reviewing fully published studies, 21 studies were included in this study based on the eligibility criteria. Our results showed that rs16944 and rs1143634 of IL-1β were significantly associated with the risk of PE. Regarding rs16944, the minor C allele significantly decreased the risk of PE (C vs. T: OR = 0.79, 95% CI = 0.69-0.90). In contrast, the minor T allele of rs1143634 significantly increased the risk of PE (T vs. C: OR = 1. 28, 95% CI = 1.04-1.58). There was no significant association between IL-6 rs1800795 (C vs. G: OR = 1.04, 95% CI = 0.93-1.16) polymorphism and PE risk.

CONCLUSIONS

In conclusion, this meta-analysis suggests rs1143634 and rs16944 polymorphisms of IL-1β are related to the risk of PE.

TIGIT and CD155 as Immune-Modulator Receptor and Ligand on CD4+ T cells in Preeclampsia Patients

One of the main characteristics of preeclampsia (PE) is systemic inflammation. CD4⁺ FoxP3⁺ cells play a critical role in both fetomaternal tolerance and successful pregnancy. T-cell immunoglobulin, as well as immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT)/CD155 pathway, possesses critical parts in the development of normal pregnancy by promoting regulatory T (Treg) cells. However, in PE, the relationship between TIGIT/CD155 and Treg differentiation has not been entirely clarified. In the current report, we aimed to assess the frequency of TIGIT and CD155 expressing TCD4⁺ cells in both PE and healthy pregnant women, as well as evaluating the amount of inflammatory and inhibitory cytokines at both mRNA and protein levels before and after blocking TIGIT and CD155. In the present report, 59 healthy, and 52 PE patients were designated to obtain their venous blood. The isolation of peripheral blood mononuclear cells (PBMCs) was performed from the blood samples, and PBMCs were then cultured in the RPMI1640 medium. The percentage of CD155⁺ and TIGIT⁺ CD4⁺ cells was assessed by flow cytometry in PBMCs. Cell culture supernatants were utilized to evaluate the secretory levels of transforming growth factor beta (TGF-β), interleukin (IL)-10, IL-17, tumor necrosis factor alpha (TNF-α), and IL-1 β, using enzyme-linked immunosorbent assay technique in pregnant women with or without PE both before and after blocking TIGIT and CD155. The mRNA expression of Foxp3, TIGIT, CD155, SHP-1, TGF-β, IL-10, IL-17, TNF-α, and IL-1β was also assessed by qRT-PCR in PBMCs before and after blocking TIGIT and CD155 in both populations. The data showed a significant decrease in the frequency of TIGIT⁺ CD4⁺ and CD155⁺ CD4⁺ T cells in PE women, compared to the control group. Our results showed decreased protein and mRNA levels of TIGIT, CD155, IL-10, FOXP3, and SHP-1 in PE patients. In addition, significant improvements in the levels of IL-17, TNF-α, and IL-1β were observed in PE patients, as compared with the controls. However, blocking TIGIT and CD155 could increase these inflammatory cytokines and decrease anti-inflammatory cytokines. The data obtained in this report illustrated that there existed an imbalance between inflammatory and anti-inflammatory profiles, with an inflammatory status polarization, in PE patients. Additionally, TIGIT/CD155 showed a positive effect on immune regulation by activating ITIM, demonstrating the potential therapeutic value of the TIGIT/CD155 pathway in PE treatment. Also, using some proteins or materials that increased TIGIT/CD155 pathways activity and can be a therapeutic approach in PE.

Maternal one carbon metabolism and interleukin-10 &-17 synergistically influence the mode of delivery in women with Early Onset Pre-Eclampsia

OBJECTIVE

Studies on One Carbon Metabolism (OCM), Interleukins-10 &-17 (IL-10/-17) & βhCG in pre-eclampsia and its delivery outcome (preterm birth) reveal contradictory results, attributed to clinical heterogeneity (early/late onset pre-eclampsia) or preterm/term birth. Disturbed OCM also influences IL-10 &-17 during pregnancy. We sought to investigate the synergism between OCM and IL-10/-17 mediated immune-regulation through βhCG in Early onset pre-eclampsia (EO-PE) patients, delivering preterm, among North Indian women.

STUDY DESIGN

Case-control study with a total of 399 pregnant women (EO-PE delivering preterm = 199; Normotensives delivering at term = 200). Maternal genotypes & biochemical estimations along with fetal genotypes on subset (n = 72) pertaining to OCM and IL-10/-17 regulation were assessed.

MAIN OUTCOME MEASURES

Association of 1) maternal plasma levels with EO-PE 2) maternal and fetal genotypes with EO-PE. 3) Effect of Hyper-homocysteinemia (surrogate of disturbed OCM) on differential immune regulation (IL10,-17, βhCG) in EO-PE and mode of delivery.

RESULTS

Hyper-homocysteinemia posed an increased risk of three folds for EO-PE. Both, folate and B12 deficiencies were associated with elevated homocysteine in EO-PE. Further, MTHFR 677TT homozygotes was present only in EO-PE indicating its detrimental role. However, maternal IL17-197AA genotype showed decreased risk for EO-PE. Furthermore, elevated maternal plasma IL-17 along with elevated IL-10 & βhCG were observed in EO-PE. Taken together, altered homocysteine metabolism was associated with high IL10 in EO-PE; and was more pronounced in spontaneous vaginal deliveries as compared to induced/caesarean section deliveries.

CONCLUSIONS

We report homocysteine mediated IL-10 &17 dysregulation and its influence on mode of delivery in EO-PE, possibly through initiation of cervical ripening. Further, these could serve potential biomarkers of EO-PE & its delivery outcome among vulnerable populations with similar nutritional & genetic predispositions.

IL-17A polymorphism (rs2275913) and levels are associated with preeclampsia pathogenesis in Chinese patients

BACKGROUND

Preeclampsia (PE) is a pregnancy-related condition that affects both the infant and the mother. Although the role of various inflammatory molecules in PE has been demonstrated, the importance of pro-inflammatory molecules such as IL-17A, IL-23 is not well understood. In the present investigation, a potential association of common genetic variants in the IL-17A and IL-23A genes with PE was investigated.

METHODS

115 PE clinically diagnosed patients who registered to the International Peace Maternity and Child Health Hospital were enrolled in this research. One hundred two pregnant women and 147 healthy Chinese women were also included. ELISA was used to measure IL-17A and IL-23 serum levels in all enrolled subjects. Common genetic polymorphisms in IL-17A (rs 2,275,913, rs1974226, and rs1974226), IL-23A (rs11171806), and IL-12B (rs3212227) were genotyped using the PCR-RFLP or TaqMan probe-based method.

RESULTS

Elevated serum IL-17A levels were found in PE patients compared to pregnant (P < 0.0001) and healthy women (P < 0.0001). However, IL-23 levels were comparable across various clinical groups. In addition, heterozygous (GA) and minor allele (A) for IL-17A (rs2275913) and IL-23A (rs11171806) were more prevalent in PE patients compared to pregnant women indicating an important role in the predisposition to PE growth. Interestingly, IL-17A (r 2,275,913) mutants were associated with elevated IL-17A levels relative to wild type (GG).

CONCLUSIONS

IL-17A (rs2275913) variants are associated with higher serum levels of cytokine, and predisposed PE development.

Haplotype Analysis of Candidate Genes Involved in Inflammation and Oxidative Stress and the Susceptibility to Preeclampsia

Unbalanced inflammatory reactions and oxidative stress are inseparably interconnected, and both may play crucial roles in the pathophysiological mechanisms of preeclampsia (PE). In the published previous studies, we have genotyped for SNPs that related to inflammation (rs2227485, rs153109, rs17855750, rs2027432, rs2275913, rs763780, rs4819554, and rs13015714) and oxidative stress (rs1695, rs4680, rs1800566, rs4807542, rs713041, rs7579, rs230813, rs1004467, rs3824755, and rs9932581) to investigate whether these polymorphisms were associated with susceptibility to PE in a Chinese Han population. In this present study, we collected these data of experimental and clinical from above studies for haplotype analysis of inflammation-related SNPs in 631 PE patients and 720 normal pregnancy and oxidative stress-related SNPs in 342 PE patients and 457 normal pregnancies for susceptibility to PE. The data of genotype distribution and allele frequency comparisons after correction for multiple comparisons (P/8 or P/10) showed 2 among the 8 candidate inflammation-related SNPs have significant differences (rs2027432 genotype χ² = 407.377, p < 0.001, p < 0.00625). Moreover, the minor alleles of rs2027432 T (minor allele χ² = 450.923, p < 0.001, p < 0.00625; OR = 21.439, 95%CI = 15.181‐30.278) and rs4819554 G (minor allele χ² = 163.465, p < 0.001, p < 0.00625; OR = 5.814, 95%CI = 4.380‐7.719) were confirmed as risk allele of PE, respectively. Our analysis revealed rs2027432 (TT) of NLRP3 and rs4819554 (GG) of IL-17RA are risk factors for PE. However, no significant difference was found at the oxidative stress-related SNPs. In the candidate loci for oxidative stress, we also identified 3 SNP matches (rs4807542 and rs713041, rs230813 and rs75799, rs1004467 and rs3824755) that had high linkage disequilibrium (LD) with each other and were selected as a block (r² = 0.98, r² = 0.97, r² = 0.97, r² > 0.9), and the GT and GC haplotypes of rs4807542 and rs713041 in GPX4 showed significant differences between the PE and control groups (χ² = 5.143, p = 0.0233, p < 0.05; χ² = 6.373, p = 0.0116, p < 0.05). So, we inferred that polymorphisms of NLRP3 rs2027432 and IL-17RA rs4819554, which are related to inflammation, and the rs713041 variant of GPX4, which is related to oxidative stress, were associated with susceptibility to PE. The GT and GC haplotypes of rs4807542 and rs713041 in GPX4 may increase the risk of PE in the Chinese Han population.

Role of maternal serum interleukin 17 in preeclampsia: diagnosis and prognosis

Background

Immunological factors play a unique role in the setting of preeclampsia; there is a rising debate about the performance of interleukin 17 (IL-17) as inflammatory mediator in its pathogenesis. The purpose of this paper was to evaluate the significance of IL-17 in the diagnosis and prognosis of preeclampsia and estimate a cutoff value for better prediction.

Methods

A prospective case control study, 40 patient were enrolled in the study, two groups were designed: a normotensive (control) group (n=20) and preeclampsia group (n=20). Both groups were compared regarding serum IL-17 level to clarify its significance, then ROC curve analysis was done to establish the best cutoff level to predict preeclampsia, with further assessment of its relation to blood pressure to determine its prognostic value.

Results

We noted a statistically significant difference in serum IL-17 (pg/mL) level between the preeclampsia and control group (P<0.05). The best cutoff value of serum IL-17 in preeclampsia was (8.2 pg/mL) with a sensitivity of 100%, specificity 80% and accuracy 89%. There was also significant variation in its concentrations before and after control of blood pressure and a significant positive correlation with systolic blood pressure level (r=0.9).

Conclusion

IL-17 is a significant inflammatory biomarker in preeclampsia with useful prognostic power to predict severity of disease.

Interleukin-23 receptor (IL-23R) gene polymorphisms and haplotypes associated with the risk of preeclampsia: evidence from cross-sectional and in silico studies

PURPOSE

Pre-eclampsia is a relatively common pregnancy disorder. Serum concentrations of certain pro-inflammatory molecules and cytokines like interleukin-23 may affect the pathogenesis of pre-eclampsia. The interleukin-23 receptor (IL-23R) gene plays an important role in the progression of inflammatory and autoimmune diseases and IL-23 polymorphisms might influence the susceptibility of pre-eclampsia. The aim of the recent study was to establish the association between IL-23R gene polymorphisms and the susceptibility for developing of pre-eclampsia.

METHODS

One hundred and fifty-eight pregnant patients with pre-eclampsia and 153 controls were genotyped using RFLP-PCR and AS-PCR. Also, an in silico analysis was performed to predict possible effects of these variations on IL-23R mRNA and protein structures.

RESULTS

The frequency of the AG genotype of rs11209026 is related to a higher risk of pre-eclampsia. The mutant C and A allele in rs10889677 and rs11209026 SNPs, respectively, are correlated with the risk of pre-eclampsia and they are more frequent in severe late onset PE. We found higher frequency of the haplotype CG in patients with pre-eclampsia in comparison to healthy controls, as well as, the CG haplotype frequency significantly increased the risk of PE in severe, early onset, and late onset sub-groups. The results of computational analysis predicted rs11209026 and rs10889677 SNPs as functional variations, which can influence IL-23R mRNA and protein.

CONCLUSIONS

The results of present study show positive association between polymorphisms in the IL-23R gene and pre-eclampsia. Therefore, the presence of IL-23R rs11209026, rs10889677 polymorphism might be markers for the genetic susceptibility to pre-eclampsia.

Methylation profile of genes involved in inflammation, in the blood from pregnancies with maternal preeclampsia due to untreated gestational diabetes mellitus

PURPOSE

To investigate DNA methylation changes in peripheral blood from patients with gestational diabetes mellitus (GDM) and preeclampsia (PE) due to poorly treated GDM.

METHODS

Eighteen pregnant women participated in the study: 6 with GDM, 6 with PE, and 6 healthy controls. The promoter methylation status of genes was profiled using the Human Inflammatory Response and Autoimmunity EpiTect Methyl II Signature PCR Array profiles. The results were validated with quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Fewer inflammation-related genes were significantly hypomethylated in PE cases compared to healthy subjects than in GDM cases. Some of the examined genes show different methylation patterns between GDM and PE.

CONCLUSIONS

The epigenetic changes observed in this study indicate that GDM and PE exhibit specific DNA methylation profiles, with possible clinical applications.

The imbalance of Th17/Treg axis involved in the pathogenesis of preeclampsia

PROBLEM

Inappropriate activation of the immune system, particularly the imbalance of T-helper type 17 (Th17)/regulatory T (Treg) cells is thought to play considerable roles in preeclampsia (PE). To investigate the probable effects of the adaptive immune system in the pathophysiology of PE, we analyzed the dynamic changes of Th17/Treg cells, cytokines profile, and transcription pattern of Th17/Treg-related genes and microRNAs (miRNAs) in 50 women suffering from PE in comparison with 50 healthy pregnant women.

METHODS

Expressions of cytokines, specific transcription factors, and related miRNAs were measured by real-time polymerase chain reaction (PCR). Enzyme-linked immunosorbent assay (ELISA) was used to test the interleukin (IL)-17, IL-23, IL-6, and IL-10 and transforming growth factor β in serum and supernatant of peripheral blood mononuclear cells (PBMCs). The frequency of Th17 and Treg cells were determined by flow cytometry.

RESULTS

PE patients exhibited a decreased number of Treg cells (p = 0.006), while Th17 cells were increased ( p = 0.004). Forkhead box P3 and IL-10 mRNA expressions were reduced ( p = 0.0001 and 0.0028, respectively), while expressions of retinoic acid receptor-related orphan nuclear receptor γt, IL-17, IL-23, and IL-6 were enhanced ( p < 0.0001, 0.0018, 0.0014, and 0.027, respectively). ELISA results also showed increased levels of IL-6, IL-17, and IL-23 ( p = 0.022, 0.0005, 0.0081, respectively), and decreased levels of IL-10 in the supernatant of PBMCs of PE patients compared with control group ( p = 0.0011). There was significant upregulation of miR-106b and miR-326 ( p = 0.0048 and 0.028, respectively) in PE patients in comparison with the control group.

CONCLUSIONS

These findings suggest that imbalance of Th17/Treg cells, regulated possibly via microRNAs, may be involved in the pathogenesis of PE, emphasizing on the importance of these cells in feto-maternal immune cross-talk.

The role of interleukins in preeclampsia: A comprehensive review

Preeclampsia is a multi-system hypertensive disorder of pregnancy, with significant rates of maternal and neonatal morbidity. It represents a major cause of preterm birth, as definitive treatment demands fetal delivery. Although its pathophysiology is complicated, placental hypoxia and endothelial dysfunction constitute established pathogenetic steps of the disease. Inflammation is considered to be a crucial mediator of preeclampsia process, as an imbalance between T_H 1, T_H 2, and T_H 17 immune responses is observed. The present review accumulates current knowledge about the contribution of interleukins in preeclampsia, summarizing the pathways through which each interleukin exerts its function in the disease. Also, the role of genetic polymorphisms is explored and the predictive efficacy of maternal serum interleukin levels is evaluated. Finally, recommendations about the safe interpretation of the outcomes, as well as guidance for future research, are provided.

Salt and miscarriage: Is there a link?

Salt is a major mineral element that plays fundamental roles in health and disease. Excessive salt intake is a major cause of hypertension, cardiovascular disease and stroke. Miscarriage and preeclampsia are the most common pregnancy complications with multiple etiological factors, including inflammatory and autoimmune conditions. More recently, different studies indicated that excessive salt intake is involved in the development of inflammatory processes through induction of T helper-17 pathway and their inflammatory cytokines. On the other hand, several studies indicated the pivotal role of inflammation in the etiology of miscarriage, preeclampsia and adverse pregnancy outcome. Here, it is hypothesized that excessive salt intake around the time of conception or during pregnancy can trigger inflammatory processes, which consequently associated with increased risk of miscarriage, preeclampsia or adverse pregnancy outcome. Thus, this hypothesis suggests that low salt intake around the time of conception or during pregnancy can decrease the risk of miscarriage or adverse pregnancy outcome. This hypothesis also offers new insights about the role of salt in the etiology of miscarriage and preeclampsia.

A Dormant Microbial Component in the Development of Preeclampsia

Preeclampsia (PE) is a complex, multisystem disorder that remains a leading cause of morbidity and mortality in pregnancy. Four main classes of dysregulation accompany PE and are widely considered to contribute to its severity. These are abnormal trophoblast invasion of the placenta, anti-angiogenic responses, oxidative stress, and inflammation. What is lacking, however, is an explanation of how these themselves are caused. We here develop the unifying idea, and the considerable evidence for it, that the originating cause of PE (and of the four classes of dysregulation) is, in fact, microbial infection, that most such microbes are dormant and hence resist detection by conventional (replication-dependent) microbiology, and that by occasional resuscitation and growth it is they that are responsible for all the observable sequelae, including the continuing, chronic inflammation. In particular, bacterial products such as lipopolysaccharide (LPS), also known as endotoxin, are well known as highly inflammagenic and stimulate an innate (and possibly trained) immune response that exacerbates the inflammation further. The known need of microbes for free iron can explain the iron dysregulation that accompanies PE. We describe the main routes of infection (gut, oral, and urinary tract infection) and the regularly observed presence of microbes in placental and other tissues in PE. Every known proteomic biomarker of "preeclampsia" that we assessed has, in fact, also been shown to be raised in response to infection. An infectious component to PE fulfills the Bradford Hill criteria for ascribing a disease to an environmental cause and suggests a number of treatments, some of which have, in fact, been shown to be successful. PE was classically referred to as endotoxemia or toxemia of pregnancy, and it is ironic that it seems that LPS and other microbial endotoxins really are involved. Overall, the recognition of an infectious component in the etiology of PE mirrors that for ulcers and other diseases that were previously considered to lack one.