A systematic review of the effect of HIV infection and antiretroviral therapy on the risk of pre-eclampsia

Antiretroviral Options and Treatment Decisions During Pregnancy

The majority of pediatric human immunodeficiency virus (HIV) infections are the result of vertical transmissions that occur during pregnancy, childbirth, and breastfeeding. The treatment of all pregnant persons living with HIV remains a global health initiative. Early and consistent use of antiretroviral therapy throughout pregnancy and childbirth drastically reduces the risk of perinatal transmission of HIV, resulting in fewer children living with the disease worldwide. Given that the maternal HIV viral load is the strongest predictor of perinatal transmission, suppressive antiretroviral treatment during pregnancy is the principal means to eliminate transmission of HIV from mother to child. With the use of combined antiretroviral therapy, typically with dual-nucleoside reverse transcriptase inhibitors plus an integrase strand transfer inhibitor or a ritonavir-boosted protease inhibitor, HIV-infected mothers can now achieve virologic suppression to undetectable levels and yield a perinatal transmission rate of less than 2%. Important considerations of HIV treatment in pregnancy include the safety and efficacy of antiretroviral drugs, altered pregnancy-related pharmacokinetics, potential for birth defects or adverse neonatal outcomes, and individualized delivery planning based on maternal viral load. This practical review article summarizes the options, considerations, and recommendations for antiretroviral treatment in pregnancy to reduce perinatal HIV transmission and optimize health outcomes for mothers and infants worldwide.

Maternal HIV Infection and Spontaneous Versus Provider-Initiated Preterm Birth in an Urban Zambian Cohort

OBJECTIVE

We investigated the effect of maternal HIV and its treatment on spontaneous and provider-initiated preterm birth (PTB) in an urban African cohort.

METHODS

The Zambian Preterm Birth Prevention Study enrolled pregnant women at their first antenatal visit in Lusaka. Participants underwent ultrasound, laboratory testing, and clinical phenotyping of delivery outcomes. Key exposures were maternal HIV serostatus and timing of antiretroviral therapy initiation. We defined the primary outcome, PTB, as delivery between 16 and 37 weeks' gestational age, and differentiated spontaneous from provider-initiated parturition.

RESULTS

Of 1450 pregnant women enrolled, 350 (24%) had HIV. About 1216 (84%) were retained at delivery, 3 of whom delivered <16 weeks. Of 181 (15%) preterm deliveries, 120 (66%) were spontaneous, 56 (31%) were provider-initiated, and 5 (3%) were unclassified. In standardized analyses using inverse probability weighting, maternal HIV increased the risk of spontaneous PTB [RR 1.68; 95% confidence interval (CI): 1.12 to 2.52], but this effect was mitigated on overall PTB [risk ratio (RR) 1.31; 95% CI: 0.92 to 1.86] owing to a protective effect against provider-initiated PTB. HIV reduced the risk of preeclampsia (RR 0.32; 95% CI: 0.11 to 0.91), which strongly predicted provider-initiated PTB (RR 17.92; 95% CI: 8.13 to 39.53). The timing of antiretroviral therapy start did not affect the relationship between HIV and PTB.

CONCLUSION

The risk of HIV on spontaneous PTB seems to be opposed by a protective effect of HIV on provider-initiated PTB. These findings support an inflammatory mechanism underlying HIV-related PTB and suggest that published estimates of PTB risk overall underestimate the risk of spontaneous PTB.

A Narrative Review of the Renin-Angiotensin-Aldosterone System in the Placenta and Placental Bed of HIV Infected Women of African Ancestry with Preeclampsia

PURPOSE OF REVIEW

Both HIV infection and preeclampsia (PE), a pregnancy-specific disorder of hypertension and multi-system organ involvement, have high prevalence rates especially in low-to-middle-income countries. The immunoexpression of specific renin-angiotensin-aldosterone system (RAAS) receptors in the placenta and placental bed interface may forecast the risk of PE.

RECENT FINDINGS

Preeclampsia is a leading risk factor for mortality worldwide and remains a challenge in HIV-infected individuals especially those on antiretroviral therapy (ART). Irregular RAAS stimulation may be linked to the pathophysiology of hypertension in HIV infection and in PE. The AT1 receptor is expressed across all trimesters of pregnancy, within placental tissue, eliciting vasoconstriction. This increased expression is associated with the severity of PE, implying that the increased expression may be involved in the pathogenesis of this pregnancy disorder. The AT2 receptor expression in normotensive pregnancies was shown to be lower as compared to non-pregnant individuals. Furthermore, in the PE placental bed, the AT2 receptor is the predominant receptor subtype and is found in extravillous trophoblast cells where they facilitate vasodilation. However, AT4R in placentae of PE pregnancies are found to be significantly reduced compared to normotensives pregnancies. The data on the role played by the RAAS pathway in pregnancy is conflicting. Investigation into a tissue-based RAAS with emphasis on immune-expression within the placenta and placental bed may help resolve this conundrum.

High blood pressure at entry into antenatal care and birth outcomes among a cohort of HIV-uninfected women and women living with HIV initiating antiretroviral therapy in South Africa

OBJECTIVE

To examine associations between high blood pressure (BP) when entering antenatal care (ANC) and birth outcomes in a cohort of pregnant HIV- and women living with HIV (WLHIV) initiating antiretroviral treatment (ART).

STUDY DESIGN

Prospective cohort study.

MAIN OUTCOME MEASURES

Cesarean delivery, preterm birth (<37 weeks' gestation), low birthweight (LBW, <2500 g), small-for-gestational age (SGA, <10th percentile), and large-for-gestational age (LGA, >10th percentile for GA).

RESULTS

Of 1116 women (median GA 20 weeks; WLHIV 53%), 48% (53% WLHIV; 43% HIV-) entered ANC with high BP, defined as elevated (120-129 or < 80 mmHg), stage 1 (>130-139 or 80-89) or stage 2 hypertension (≥140 / or ≥ 90). WLHIV were more likely to have high BP (RR 1.32; 95%CI 1.12-1.57), controlling for pre-pregnancy body mass index and additional confounders. In multivariable analysis, there was no evidence that high BP increased the risk of cesarean delivery (RR 1.10, 95% CI 0.92-1.30), preterm birth (RR 1.15, 95% CI 0.81-1.62), LBW (RR 1.16, 95% CI 0.84-1.60) or SGA (RR 1.02, 0.72-1.44), overall or when stratified by HIV-status. High BP was associated with an increased risk of LGA (RR 1.43; 95% CI 1.00-2.03).

CONCLUSION

In this setting, half of women had high BP at entry into ANC, with WLHIV at increased risk of high BP. There was no strong evidence that high BP increased the risk of adverse birth outcomes overall, or by HIV-status, with the exception of LGA. WLHIV may be at high risk of high BP during pregnancy and should be monitored closely.

Does HIV infection modify the relationship between pre-pregnancy body mass index and adverse birth outcomes?

BACKGROUND

South Africa faces dual epidemics of HIV and obesity; however, little research has explored whether HIV status influences associations between pre-pregnancy body mass index (BMI) and adverse birth outcomes.

OBJECTIVES

To examine associations between pre-pregnancy body mass index (BMI) and adverse birth outcomes, and if they differ by HIV status.

METHODS

We followed HIV-uninfected and -infected pregnant women initiating antiretroviral therapy (ART) from first antenatal visit through delivery. HIV-infected women initiated ART (tenofovir-emtricitabine/lamivudine-efavirenz) in pregnancy. Estimated pre-pregnancy BMI (kg/m2 ) was categorised as underweight (<18.5), normal (18.5-24.9), overweight (25.0-29.9), and obese (≥30.0). We used modified Poisson regression to estimate risk ratios (RR) for associations between pre-pregnancy BMI and adverse birth outcomes and explored modification by HIV status.

RESULTS

Among 1116 women (53% HIV-infected), 44% of HIV-uninfected women and 36% of HIV-infected women were classified as obese; 4% of women were underweight. Overall, 12% of infants were delivered preterm (<37 weeks), 10% small for gestational age (SGA, <10th percentile), and 9% large for gestational age (LGA, >90th percentile). Compared to HIV-uninfected women, HIV-infected women on ART had less LGA (5% vs 13%) but more SGA (12% vs 8%), and a similar proportion of preterm (13% vs 11%) infants. Pre-pregnancy BMI was not associated with preterm birth. Among HIV-uninfected women, obesity modestly increased the risk of LGA (RR 1.34, 95% confidence interval [CI] 0.82, 2.19), and underweight modestly elevated the risk of SGA (RR 1.66, 95% CI 0.79, 3.46). These associations were attenuated among HIV-infected women (RR 1.07, 95% CI 0.44, 2.64 for LGA, and RR 1.34, 95% CI 0.49, 3.64 for SGA).

CONCLUSIONS

In this urban African setting of high HIV prevalence, pre-pregnancy obesity was common and did not vary by HIV status. In HIV-uninfected women, obesity increased the risk of LGA and being underweight the risk of SGA, compared with among HIV-uninfected women.

Postpartum obesity and weight gain among human immunodeficiency virus-infected and human immunodeficiency virus-uninfected women in South Africa

In South Africa, up to 40% of pregnant women are living with human immunodeficiency virus (HIV), and 30-45% are obese. However, little is known about the dual burden of HIV and obesity in the postpartum period. In a cohort of HIV-uninfected and HIV-infected pregnant women initiating antiretroviral therapy in Cape Town, South Africa, we examined maternal anthropometry (weight and body mass index [BMI]) from 6 weeks through 12 months postpartum. Using multinomial logistic regression, we estimated associations between baseline sociodemographic, clinical, behavioural, and HIV factors and being overweight-obese I (BMI 25 to <35), or obese II-III (BMI >35), compared with being underweight or normal weight (BMI <25), at 12 months postpartum. Among 877 women, we estimated that 43% of HIV-infected women and 51% of HIV-uninfected women were obese I-III at enrollment into antenatal care, and 51% of women were obese I-III by 12 months postpartum. On average, both HIV-infected and HIV-uninfected women gained, rather than lost, weight between 6 weeks and 12 months postpartum, but HIV-uninfected women gained more weight (3.3 kg vs. 1.7 kg). Women who were obese I-III pre-pregnancy were more likely to gain weight postpartum. In multivariable analyses, HIV-infection status, being married/cohabitating, higher gravidity, and high blood pressure were independently associated with being obese II-III at 12 months postpartum. Obesity during pregnancy is a growing public health concern in low- and middle-income countries, including South Africa. Additional research to understand how obesity and HIV infection affect maternal and child health outcomes is urgently needed.

Prevention of cardiovascular disease among people living with HIV in sub-Saharan Africa

As longevity has increased for people living with HIV (PLWH) in the United States and Europe, there has been a concomitant increase in the prevalence of cardiovascular disease (CVD) risk factors and morbidity in this population. Whereas the availability of HIV antiretroviral therapy has resulted in dramatic increases in life expectancy in sub-Saharan Africa (SSA), where over two thirds of PLWH reside, if and how these trends impact the epidemiology of CVD is less clear. In this review, we describe the current state of the science on how both HIV and its treatment impact CVD risk factors and outcomes among PLWH in sub-Saharan Africa, including regional factors (unique to SSA) likely to differentiate these relationships from the global North. We then outline how current regional guidelines address CVD prevention among PLWH and which clinical and structural interventions are best poised to confront the co-epidemics of HIV and CVD in the region. We conclude with a discussion of key research gaps that need to be addressed to optimally develop an actionable public health response.

Risk factors during pregnancy and birth-related complications in HIV-positive versus HIV-negative women in Denmark, 2002-2014

OBJECTIVES

We aimed to compare risk factors for adverse pregnancy outcomes in women living with HIV (WLWH) with those in women of the general population (WGP) in Denmark. Further, we estimated risk of pregnancy- or birth-related complications.

METHODS

A retrospective cohort study including all WLWH who delivered a live-born child from 2002 to 2014 and WGP, matched by origin, age, year and parity, was carried out. We compared risk factors during pregnancy and estimated risk of pregnancy- and birth-related complications using multivariate logistic regression.

RESULTS

A total of 2334 pregnancies in 304 WLWH and 1945 WGP were included in the study. WLWH had more risk factors present than WGP during pregnancy: previous caesarean section (CS) (24.7% versus 16.3%, respectively; P = 0.0001), smoking (14.2% versus 7.5%, respectively; P = 0.0001) and previous perinatal/neonatal death (2.3% versus 0.9%, respectively; P = 0.03). We found no difference between groups regarding gestational diabetes, hypertensive disorders, low birth weights or premature delivery. More children of WLWH had intrauterine growth retardation (IUGR) [adjusted odds ratio (aOR) 1.9; 95% confidence interval (CI) 1.1-3.2; P = 0.02]. Median gestational age and birth weight were lower in children born to WLWH. WLWH had a higher risk of emergency CS (EmCS) (aOR 1.6; 95% CI 1.2-2.1; P = 0.0005) and postpartum haemorrhage (aOR 1.4; 95% CI 1.0-1.9; P = 0.02) but not infection, amniotomy, failure to progress, low activity-pulse-grimace-appearance-respiration (APGAR) score or signs of asphyxia.

CONCLUSIONS

WLWH had more risk factors present during pregnancy, similar risks of most pregnancy- and birth-related complications but a higher risk of postpartum haemorrhage and EmCS compared with WGP. Children born to WLWH had lower median birth weights and gestational ages and were at higher risk of IUGR.

Human Immunodeficiency Virus and risk of pre-eclampsia and eclampsia in pregnant women: A meta-analysis on cohort studies

Maternal HIV infection is related to several perinatal adverse outcomes. This study is aimed at establishing whether maternal HIV infection is associated with the development of pre-eclampsia (PE) and eclampsia. We comprehensively searched MEDLINE/PubMed, Web of Science, SCOPUS and Embase databases for relevant studies published up to 20 November 2018, without time and language restrictions. We have limited our literature searches to observational studies in humans. We applied a random-effects model to calculate the relative risks (RR) and 95% confidence intervals (CI) for the meta-analyses. We also systematically reviewed eligible studies to determine the effects of HIV infection on imbalance of angiogenic and anti-angiogenic factors, which are effective in increased risk of PE or eclampsia. We identified a total of 11,186 publications, out of which 22 eligible studies (11 prospective and 11 retrospective cohort studies) comprising 90,514 HIV-positive and 66,085,278 HIV-negative pregnant women were included in meta-analysis. Results of the meta-analyses suggested that maternal HIV infection is not significantly associated with the development of PE (RR, 1.04; 95%CI, 0.89-1.21) and eclampsia (RR, 1.05; 95%CI, 0.63-1.75). Six studies were included to understand the effects of HIV infection on imbalance of angiogenic and anti-angiogenic factors. All six studies demonstrated that HIV infection had no significant effect on expression levels of these factors in pre-eclamptic and normotensive pregnant women. Our study showed that maternal HIV infection was not significantly associated with increased or reduced risks of pre-eclampsia and eclampsia. More well-designed studies with large sample size and well defined outcomes are recommended to confirm or refute the present findings.

Combined antiretroviral therapy for HIV and the risk of hypertensive disorders of pregnancy: A systematic review

OBJECTIVE

To assess if there is a relationship between use of combined antiretroviral therapy among pregnant women living with HIV and hypertensive disorders of pregnancy (HDP).

DESIGN

Due to the heterogeneity of study designs in the literature and the utilization of different outcome measures in regards to assessing the presence of HDP, a systematic review was performed.

METHODS

ClinicalTrials.gov and MEDLINE, via PubMed, EMBASE, Scopus, CINAHL, ProQuest Dissertations & Theses Global, EBSCOHost, DARE, and the Cochrane Library, were queried from January 1997 to October 2017. Studies were included if they reported HDP and focused on pregnant women living with HIV who used combined antiretroviral therapy. The Cochrane Collaboration's tool for assessment of risk of bias and the U.S. Preventive Services Task Force grading scale were used to assess the studies.

RESULTS

Of 1055 abstracts, 28 articles met inclusion criteria. The data are marked by multiple biases and poor study design. All studies demonstrate an increased risk of HDP among pregnant women living with HIV who used combined antiretroviral therapy when compared to seropositive pregnant women not using antiretroviral therapy. Three studies suggest protease inhibitors may be associated with a higher risk of HDP.

CONCLUSION

Despite all studies indicating a higher frequency of HDP among pregnant women living with HIV using combined antiretroviral therapy when compared with seropositive pregnant women not using antiretroviral therapy, the quality of the studies is mixed, necessitating further research.

Prediction of pre-eclampsia: review of reviews

OBJECTIVE

Primary studies and systematic reviews provide estimates of varying accuracy for different factors in the prediction of pre-eclampsia. The aim of this study was to review published systematic reviews to collate evidence on the ability of available tests to predict pre-eclampsia, to identify high-value avenues for future research and to minimize future research waste in this field.

METHODS

MEDLINE, EMBASE and The Cochrane Library including DARE (Database of Abstracts of Reviews of Effects) databases, from database inception to March 2017, and bibliographies of relevant articles were searched, without language restrictions, for systematic reviews and meta-analyses on the prediction of pre-eclampsia. The quality of the included reviews was assessed using the AMSTAR tool and a modified version of the QUIPS tool. We evaluated the comprehensiveness of search, sample size, tests and outcomes evaluated, data synthesis methods, predictive ability estimates, risk of bias related to the population studied, measurement of predictors and outcomes, study attrition and adjustment for confounding.

RESULTS

From 2444 citations identified, 126 reviews were included, reporting on over 90 predictors and 52 prediction models for pre-eclampsia. Around a third (n = 37 (29.4%)) of all reviews investigated solely biochemical markers for predicting pre-eclampsia, 31 (24.6%) investigated genetic associations with pre-eclampsia, 46 (36.5%) reported on clinical characteristics, four (3.2%) evaluated only ultrasound markers and six (4.8%) studied a combination of tests; two (1.6%) additional reviews evaluated primary studies investigating any screening test for pre-eclampsia. Reviews included between two and 265 primary studies, including up to 25 356 688 women in the largest review. Only approximately half (n = 67 (53.2%)) of the reviews assessed the quality of the included studies. There was a high risk of bias in many of the included reviews, particularly in relation to population representativeness and study attrition. Over 80% (n = 106 (84.1%)) summarized the findings using meta-analysis. Thirty-two (25.4%) studies lacked a formal statement on funding. The predictors with the best test performance were body mass index (BMI) > 35 kg/m² , with a specificity of 92% (95% CI, 89-95%) and a sensitivity of 21% (95% CI, 12-31%); BMI > 25 kg/m² , with a specificity of 73% (95% CI, 64-83%) and a sensitivity of 47% (95% CI, 33-61%); first-trimester uterine artery pulsatility index or resistance index > 90^th centile (specificity 93% (95% CI, 90-96%) and sensitivity 26% (95% CI, 23-31%)); placental growth factor (specificity 89% (95% CI, 89-89%) and sensitivity 65% (95% CI, 63-67%)); and placental protein 13 (specificity 88% (95% CI, 87-89%) and sensitivity 37% (95% CI, 33-41%)). No single marker had a test performance suitable for routine clinical use. Models combining markers showed promise, but none had undergone external validation.

CONCLUSIONS

This review of reviews calls into question the need for further aggregate meta-analysis in this area given the large number of published reviews subject to the common limitations of primary predictive studies. Prospective, well-designed studies of predictive markers, preferably randomized intervention studies, and combined through individual-patient data meta-analysis are needed to develop and validate new prediction models to facilitate the prediction of pre-eclampsia and minimize further research waste in this field. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

The role of the complement system in HIV infection and preeclampsia

BACKGROUND

The complement system is a key component of the innate immune system that plays a vital role in host defense, maintains homeostasis and acts as a mediator of the adaptive immune response. The complement system could possibly play a role in the pathogenesis of HIV infection and preeclampsia (PE), both of which represent major causes of maternal death in South Africa.

RECENT FINDINGS

The relationship between PE and HIV infection is unclear as PE represents an exaggerated immune response, while HIV infection is associated with a decline in immune activity. Although the complement system works to clear and neutralize HIV, it could also enhance the infectivity of HIV by various other mechanisms. It has been suggested that the dysregulation of the complement system is associated with the development of PE.

CONCLUSION

There is currently a paucity of information on the combined effect of the complement system in HIV-associated PE. This review highlights the role of the complement system in the duality of HIV infection and PE and provides new insights into this relationship whilst also elucidating potential therapeutic targets.

Genetic and non-genetic risk factors for pre-eclampsia: umbrella review of systematic reviews and meta-analyses of observational studies

OBJECTIVE

To summarize evidence from the literature on genetic and non-genetic risk factors associated with pre-eclampsia (PE), assess the presence of statistical bias in the studies and identify risk factors for which there is robust evidence supporting their association with PE.

METHODS

PubMed and ISI Web of Science were searched from inception to October 2016, to identify systematic reviews and meta-analyses of observational studies examining associations between genetic or non-genetic risk factors and PE. For each meta-analysis, the summary-effect size was estimated using random-effects and fixed-effects models, along with 95% CIs and the 95% prediction interval. Between-study heterogeneity was expressed using the I2 statistic, and evidence of small-study effects (large studies had significantly more conservative results than smaller studies) and evidence of excess significance bias (too many studies with statistically significant results) were estimated.

RESULTS

Fifty-eight eligible meta-analyses were identified, which included 1466 primary studies and provided data on 130 comparisons of risk factors associated with PE, covering a wide range of comorbid diseases, genetic factors, exposure to environmental agents and biomarkers. Sixty-five (50%) associations had nominally statistically significant findings at P < 0.05, while 16 (12%) were significant at P < 10-6 . Sixty-five (50%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 10 (8%) and 26 (20%) associations, respectively. The only non-genetic risk factor with convincing evidence for an association with PE was oocyte donation vs spontaneous conception, which had a summary odds ratio of 4.33 (95% CI, 3.11-6.03), was supported by 2712 cases with small heterogeneity (I2  = 26%) and 95% prediction intervals excluding the null value, and without hints of small-study effects (P for Egger's test > 0.10) or excess of significance (P > 0.05). Of the statistically significant (P < 0.05) genetic risk factors for PE, only PAI-1 4G/5G (recessive model) polymorphism was supported by strong evidence for a contribution to the pathogenesis of PE. Eleven factors (serum iron level, pregnancy-associated plasma protein-A, chronic kidney disease, polycystic ovary syndrome, mental stress, bacterial and viral infections, cigarette smoking, oocyte donation vs assisted reproductive technology, obesity vs normal weight, severe obesity vs normal weight and primiparity) presented highly suggestive evidence for an association with PE.

CONCLUSIONS

A large proportion of meta-analyses of genetic and non-genetic risk factors for PE have caveats that threaten their validity. Oocyte donation vs spontaneous conception and PAI-1 4G/5G polymorphism (recessive model) showed the strongest consistent evidence for an association with risk for PE. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

10 workshops on Immunology of preeclampsia

For the 10th issue of the « island workshops », now the Reunion Workshops, organised by Pierre Yves Robillard since the first one in Tahiti challenging the "vascular disease only" theory of pre eclampsia and introducing the primipaternity concept, we examined the reasons for considering an Immunological approach to the disease. This (brief) overview thus examines several important topics in an Immunological framework. I have chosen to present here the evolution of the main themes rather than a purely chronological vision.

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.