Prevention of pre-eclampsia: status and perspectives 2000

Preeclampsia and its prediction: traditional versus contemporary predictive methods

OBJECTIVE

Preeclampsia (PE) poses a significant threat to maternal and perinatal health, so its early prediction, prevention, and management are of paramount importance to mitigate adverse pregnancy outcomes. This article provides a brief review spanning epidemiology, etiology, pathophysiology, and risk factors associated with PE, mainly discussing the emerging role of Artificial Intelligence (AI) deep learning (DL) technology in predicting PE, to advance the understanding of PE and foster the clinical application of early prediction methods.

METHODS

Our narrative review comprehensively examines the PE epidemiology, etiology, pathophysiology, risk factors and predictive approaches, including traditional models and AI deep learning technology.

RESULTS

Preeclampsia involves a wide range of biological and biochemical risk factors, among which poor uterine artery remodeling, excessive immune response, endothelial dysfunction, and imbalanced angiogenesis play important roles. Traditional PE prediction models exhibit significant limitations in sensitivity and specificity, particularly in predicting late-onset PE, with detection rates ranging from only 30% to 50%. AI models have exhibited a notable level of predictive accuracy and value across various populations and datasets, achieving detection rates of approximately 70%. Particularly, they have shown superior predictive capabilities for late-onset PE, thereby presenting novel opportunities for early screening and management of the condition.

CONCLUSION

AI DL technology holds promise in revolutionizing the prediction and management of PE. AI-based approaches offer a pathway toward more effective risk assessment methods by addressing the shortcomings of traditional prediction models. Ongoing research efforts should focus on expanding databases and validating the performance of AI in diverse populations, leading to the development of more sophisticated prediction models with improved accuracy.

Placenta-mediated pregnancy complications in women with a history of late fetal loss and placental infarction without thrombophilia: risk of recurrence and efficacy of pharmacological prophylactic interventions. A 10-year retrospective study

PURPOSE

To evaluate the risk of recurrence of severe placenta-mediated pregnancy complications and compare the efficacy of two different anti-thrombotic regimens in women with a history of late fetal loss without thrombophilia.

PATIENTS AND METHODS

We performed a 10-year retrospective observational study (2008-2018) analyzing a cohort of 128 women who suffered from pregnancy fetal loss (>20 weeks of gestational age) with histological evidence of placental infarction. All the women tested negative for congenital and/or acquired thrombophilia. In their subsequent pregnancies, 55 received prophylaxis with acetylsalicylic acid (ASA) only and 73 received ASA plus low molecular weight heparin (LMWH).

RESULTS

Overall, one-third of all pregnancies (31%) had adverse outcomes related to placental dysfunction: pre-term births (25% <37 weeks, 5.6% <34 weeks), newborns with birth weight <2500 g (17%), and newborns small for gestational age (5%). The prevalence of placental abruption, early and/or severe preeclampsia, and fetal loss >20 weeks were 6%, 5%, and 4% respectively. We found a risk reduction for combination therapy (ASA plus LMWH) compared with ASA alone for delivery <34 weeks (RR 0.11, 95% CI: 0.01-0.95 p = 0.045) and a trend for the prevention of early/severe preeclampsia (RR 0.14, 95% CI: 0.01-1.18, p = 0.0715), while no statistically significant difference was observed for composite outcomes (RR 0.51, 95%CI: 0.22-1.19, p = 0.1242). An absolute risk reduction of 5.31% was observed for the ASA plus LMWH group. Multivariate analysis confirmed a risk reduction for delivery <34 weeks (RR 0.32, 95% CI 0.16-0.96 p = 0.041).

CONCLUSION

In our study population, the risk of recurrence of placenta-mediated pregnancy complications is substantial, even in the absence of maternal thrombophilic conditions. A reduction of the risk of delivery <34 weeks was detected in the ASA plus LMWH group.

First trimester preeclampsia screening and prediction

Preeclampsia is a major cause of maternal and perinatal morbidity and mortality. Early-onset disease requiring preterm delivery is associated with a higher risk of complications in both mothers and babies. Evidence suggests that the administration of low-dose aspirin initiated before 16 weeks' gestation significantly reduces the rate of preterm preeclampsia. Therefore, it is important to identify pregnant women at risk of developing preeclampsia during the first trimester of pregnancy, thus allowing timely therapeutic intervention. Several professional organizations such as the American College of Obstetricians and Gynecologists (ACOG) and National Institute for Health and Care Excellence (NICE) have proposed screening for preeclampsia based on maternal risk factors. The approach recommended by ACOG and NICE essentially treats each risk factor as a separate screening test with additive detection rate and screen-positive rate. Evidence has shown that preeclampsia screening based on the NICE and ACOG approach has suboptimal performance, as the NICE recommendation only achieves detection rates of 41% and 34%, with a 10% false-positive rate, for preterm and term preeclampsia, respectively. Screening based on the 2013 ACOG recommendation can only achieve detection rates of 5% and 2% for preterm and term preeclampsia, respectively, with a 0.2% false-positive rate. Various first trimester prediction models have been developed. Most of them have not undergone or failed external validation. However, it is worthy of note that the Fetal Medicine Foundation (FMF) first trimester prediction model (namely the triple test), which consists of a combination of maternal factors and measurements of mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor, has undergone successful internal and external validation. The FMF triple test has detection rates of 90% and 75% for the prediction of early and preterm preeclampsia, respectively, with a 10% false-positive rate. Such performance of screening is superior to that of the traditional method by maternal risk factors alone. The use of the FMF prediction model, followed by the administration of low-dose aspirin, has been shown to reduce the rate of preterm preeclampsia by 62%. The number needed to screen to prevent 1 case of preterm preeclampsia by the FMF triple test is 250. The key to maintaining optimal screening performance is to establish standardized protocols for biomarker measurements and regular biomarker quality assessment, as inaccurate measurement can affect screening performance. Tools frequently used to assess quality control include the cumulative sum and target plot. Cumulative sum is a sensitive method to detect small shifts over time, and point of shift can be easily identified. Target plot is a tool to evaluate deviation from the expected multiple of median and the expected median of standard deviation. Target plot is easy to interpret and visualize. However, it is insensitive to detecting small deviations. Adherence to well-defined protocols for the measurements of mean arterial pressure, uterine artery pulsatility index, and placental growth factor is required. This article summarizes the existing literature on the different methods, recommendations by professional organizations, quality assessment of different components of risk assessment, and clinical implementation of the first trimester screening for preeclampsia.

Prediction of pre-eclampsia

Pre-eclampsia is a leading cause of neonatal and maternal mortality and morbidity that complicates approximately 2-8% of all pregnancies worldwide. The precise cause of pre-eclampsia is not completely understood, with several environmental, genetic, and maternal factors involved in its pathogenesis and pathophysiology. An accurate predictor of pre-eclampsia will facilitate early recognition, close surveillance according to the individual risk and early intervention, and reduce the negative consequences of the disorder. Current evidence shows that no single test predicts pre-eclampsia with sufficient accuracy to be clinically useful. A combination of markers into multiparametric models may provide a more useful and feasible predictive tool for pre-eclampsia screening in the routine care setting than a test of either component alone. This review presents a summary of the current advances on prediction of pre-eclampsia, highlighting their performance and applicability. Key priorities when conducting research on predicting pre-eclampsia are also analyzed.

The International Federation of Gynecology and Obstetrics (FIGO) initiative on pre-eclampsia: A pragmatic guide for first-trimester screening and prevention

Pre‐eclampsia (PE) is a multisystem disorder that typically affects 2%–5% of pregnant women and is one of the leading causes of maternal and perinatal morbidity and mortality, especially when the condition is of early onset. Globally, 76 000 women and 500 000 babies die each year from this disorder. Furthermore, women in low‐resource countries are at a higher risk of developing PE compared with those in high‐resource countries. Although a complete understanding of the pathogenesis of PE remains unclear, the current theory suggests a two‐stage process. The first stage is caused by shallow invasion of the trophoblast, resulting in inadequate remodeling of the spiral arteries. This is presumed to lead to the second stage, which involves the maternal response to endothelial dysfunction and imbalance between angiogenic and antiangiogenic factors, resulting in the clinical features of the disorder. Accurate prediction and uniform prevention continue to elude us. The quest to effectively predict PE in the first trimester of pregnancy is fueled by the desire to identify women who are at high risk of developing PE, so that necessary measures can be initiated early enough to improve placentation and thus prevent or at least reduce the frequency of its occurrence. Furthermore, identification of an “at risk” group will allow tailored prenatal surveillance to anticipate and recognize the onset of the clinical syndrome and manage it promptly. PE has been previously defined as the onset of hypertension accompanied by significant proteinuria after 20 weeks of gestation. Recently, the definition of PE has been broadened. Now the internationally agreed definition of PE is the one proposed by the International Society for the Study of Hypertension in Pregnancy (ISSHP). According to the ISSHP, PE is defined as systolic blood pressure at ≥140 mm Hg and/or diastolic blood pressure at ≥90 mm Hg on at least two occasions measured 4 hours apart in previously normotensive women and is accompanied by one or more of the following new‐onset conditions at or after 20 weeks of gestation: 1.Proteinuria (i.e. ≥30 mg/mol protein:creatinine ratio; ≥300 mg/24 hour; or ≥2 + dipstick); 2.Evidence of other maternal organ dysfunction, including: acute kidney injury (creatinine ≥90 μmol/L; 1 mg/dL); liver involvement (elevated transaminases, e.g. alanine aminotransferase or aspartate aminotransferase >40 IU/L) with or without right upper quadrant or epigastric abdominal pain; neurological complications (e.g. eclampsia, altered mental status, blindness, stroke, clonus, severe headaches, and persistent visual scotomata); or hematological complications (thrombocytopenia–platelet count <150 000/μL, disseminated intravascular coagulation, hemolysis); or 3.Uteroplacental dysfunction (such as fetal growth restriction, abnormal umbilical artery Doppler waveform analysis, or stillbirth). It is well established that a number of maternal risk factors are associated with the development of PE: advanced maternal age; nulliparity; previous history of PE; short and long interpregnancy interval; use of assisted reproductive technologies; family history of PE; obesity; Afro‐Caribbean and South Asian racial origin; co‐morbid medical conditions including hyperglycemia in pregnancy; pre‐existing chronic hypertension; renal disease; and autoimmune diseases, such as systemic lupus erythematosus and antiphospholipid syndrome. These risk factors have been described by various professional organizations for the identification of women at risk of PE; however, this approach to screening is inadequate for effective prediction of PE. PE can be subclassified into: 1.Early‐onset PE (with delivery at <34+0 weeks of gestation); 2.Preterm PE (with delivery at <37+0 weeks of gestation); 3.Late‐onset PE (with delivery at ≥34+0 weeks of gestation); 4.Term PE (with delivery at ≥37+0 weeks of gestation). These subclassifications are not mutually exclusive. Early‐onset PE is associated with a much higher risk of short‐ and long‐term maternal and perinatal morbidity and mortality. Obstetricians managing women with preterm PE are faced with the challenge of balancing the need to achieve fetal maturation in utero with the risks to the mother and fetus of continuing the pregnancy longer. These risks include progression to eclampsia, development of placental abruption and HELLP (hemolysis, elevated liver enzyme, low platelet) syndrome. On the other hand, preterm delivery is associated with higher infant mortality rates and increased morbidity resulting from small for gestational age (SGA), thrombocytopenia, bronchopulmonary dysplasia, cerebral palsy, and an increased risk of various chronic diseases in adult life, particularly type 2 diabetes, cardiovascular disease, and obesity. Women who have experienced PE may also face additional health problems in later life, as the condition is associated with an increased risk of death from future cardiovascular disease, hypertension, stroke, renal impairment, metabolic syndrome, and diabetes. The life expectancy of women who developed preterm PE is reduced on average by 10 years. There is also significant impact on the infants in the long term, such as increased risks of insulin resistance, diabetes mellitus, coronary artery disease, and hypertension in infants born to pre‐eclamptic women. The International Federation of Gynecology and Obstetrics (FIGO) brought together international experts to discuss and evaluate current knowledge on PE and develop a document to frame the issues and suggest key actions to address the health burden posed by PE. FIGO's objectives, as outlined in this document, are: (1) To raise awareness of the links between PE and poor maternal and perinatal outcomes, as well as to the future health risks to mother and offspring, and demand a clearly defined global health agenda to tackle this issue; and (2) To create a consensus document that provides guidance for the first‐trimester screening and prevention of preterm PE, and to disseminate and encourage its use. Based on high‐quality evidence, the document outlines current global standards for the first‐trimester screening and prevention of preterm PE, which is in line with FIGO good clinical practice advice on first trimester screening and prevention of pre‐eclampsia in singleton pregnancy.1 It provides both the best and the most pragmatic recommendations according to the level of acceptability, feasibility, and ease of implementation that have the potential to produce the most significant impact in different resource settings. Suggestions are provided for a variety of different regional and resource settings based on their financial, human, and infrastructure resources, as well as for research priorities to bridge the current knowledge and evidence gap. To deal with the issue of PE, FIGO recommends the following: Public health focus: There should be greater international attention given to PE and to the links between maternal health and noncommunicable diseases (NCDs) on the Sustainable Developmental Goals agenda. Public health measures to increase awareness, access, affordability, and acceptance of preconception counselling, and prenatal and postnatal services for women of reproductive age should be prioritized. Greater efforts are required to raise awareness of the benefits of early prenatal visits targeted at reproductive‐aged women, particularly in low‐resource countries. Universal screening: All pregnant women should be screened for preterm PE during early pregnancy by the first‐trimester combined test with maternal risk factors and biomarkers as a one‐step procedure. The risk calculator is available free of charge at https://fetalmedicine.org/research/assess/preeclampsia. FIGO encourages all countries and its member associations to adopt and promote strategies to ensure this. The best combined test is one that includes maternal risk factors, measurements of mean arterial pressure (MAP), serum placental growth factor (PLGF), and uterine artery pulsatility index (UTPI). Where it is not possible to measure PLGF and/or UTPI, the baseline screening test should be a combination of maternal risk factors with MAP, and not maternal risk factors alone. If maternal serum pregnancy‐associated plasma protein A (PAPP‐A) is measured for routine first‐trimester screening for fetal aneuploidies, the result can be included for PE risk assessment. Variations to the full combined test would lead to a reduction in the performance screening. A woman is considered high risk when the risk is 1 in 100 or more based on the first‐trimester combined test with maternal risk factors, MAP, PLGF, and UTPI. Contingent screening: Where resources are limited, routine screening for preterm PE by maternal factors and MAP in all pregnancies and reserving measurements of PLGF and UTPI for a subgroup of the population (selected on the basis of the risk derived from screening by maternal factors and MAP) can be considered. Prophylactic measures: Following first‐trimester screening for preterm PE, women identified at high risk should receive aspirin prophylaxis commencing at 11–14+6 weeks of gestation at a dose of ~150 mg to be taken every night until 36 weeks of gestation, when delivery occurs, or when PE is diagnosed. Low‐dose aspirin should not be prescribed to all pregnant women. In women with low calcium intake (<800 mg/d), either calcium replacement (≤1 g elemental calcium/d) or calcium supplementation (1.5–2 g elemental calcium/d) may reduce the burden of both early‐ and late‐onset PE.

Calcium supplementation and prevention of preeclampsia: a meta-analysis

BACKGROUND

Since the early 1980s, epidemiological evidence has suggested a connection between low calcium intake and preeclampsia The purpose of this meta-analysis is to summarize current evidence regarding calcium supplementation during pregnancy in predicting preeclampsia and associated maternal-fetal complications.

METHODS

Literature revision of all RCT (random allocation of calcium versus placebo) available in MEDLINE/PUBMED up to 2/29/2012 regarding calcium supplementation during pregnancy for preventing preeclampsia. We used the Mantel-Haenszel's Method for four subgroup of patients: Adequate calcium intake; Low calcium intake; Low risk of preeclampsia; High risk of preeclampsia. We considered p < 0.05 as significant.

RESULTS

There is no consensus in Literature about: (1) the efficacy of calcium supplementation in the prevention of preeclampsia, (2) other/adverse/long-term effects of calcium supplementation in pregnancy.

CONCLUSIONS

Preeclampsia is likely to be a multifactorial disease. However, inadequate calcium intake represents a factor associated with an increased incidence of hypertensive disease. The results of our meta-analysis demonstrate that the additional intake of calcium during pregnancy is an effective measure to reduce the incidence of preeclampsia, especially in populations at high risk of preeclampsia due to ethnicity, gender, age, high BMI and in those with low baseline calcium intake.

Polymorphisms of FAS and FAS ligand genes in preeclamptic women

OBJECTIVES

This study investigated the influence that Fas and Fas ligand gene polymorphisms might have on preeclampsia. The pathogenesis of preeclampsia is still enigmatic and several studies have proposed that it may, in part, be determined by genetic susceptibility. Therefore, the identification of a gene polymorphism associated with an increased risk of preeclampsia might well represent a useful tool in the identification of at risk pregnant women enabling the setup of preventive therapy. Apoptosis has also been implied in the pathogenesis of preeclampsia and since Fas and Fas ligand are the main apoptotic pathway members, they may represent candidate genes involved in the development of preeclampsia. A polymorphism at the 670 position (A-G) in the Fas gene has been found more frequently in Hungarian women with preeclampsia.

STUDY DESIGN

The study cohort was a group of 50 women with preeclampsia and 142 healthy control subjects from the general Italian population. They were studied, by RFLP analysis, to validate the role that the 670 G Fas gene polymorphism plays in preeclampsia, and to evaluate the Fas ligand IVS2nt 124 G polymorphism. The Fisher's exact test was used to compute the statistical difference between groups.

RESULTS

The presence of the 670 G Fas gene variant was observed in 42 preeclamptic patients (84%) and 96 members of the general population control group (67.6%) (p=0.029). Regarding the Fas ligand gene, the IVS2nt 124 G variant was present in 14 preeclamptic patients (28%) and in 47 of the general population control subjects (33.1%) (p=0.6).

CONCLUSIONS

The present study validated the hypothesis that the Fas 670 G variant may have an influencing role in preeclampsia.

Prevention of preeclampsia with low-dose aspirin -- a systematic review and meta-analysis of the main randomized controlled trials

The purpose of this paper is to evaluate the effectiveness of low-dose aspirin in the prevention of preeclampsia in low-risk and high-risk women. We identified randomized clinical trials of the use of low-dose aspirin to prevent preeclampsia through the PUBMED search engine, and through the Cochran Library database. Twenty-two studies met our inclusion criteria, and were divided according to the studied population into 2 groups: trials with women at low risk for preeclampsia and trials with women at high risk. Effects were measured through the incidence of preeclampsia in women taking either placebo or aspirin, in studies where the relative risks and the 95% confidence intervals were calculated for both groups. A total of 33,598 women were studied, comprising 5 trials with 16,700 women at low-risk and 17 trials including 16,898 women at high risk. The incidence of preeclampsia was 3.75% (626/17,700), in the low-risk group, 9.01% (1,524/16,898) in the high-risk group, and 6.40% (2,150/33,598) overall. Low-dose aspirin had no statistically significantly effect on the incidence of preeclampsia in the low-risk group (RR = 0.95, 95% CI = 0.81-1.11), but had a small beneficial effect in the high-risk group (RR = 0.87, 95% CI = 0.79-0.96). Therefore, low-dose aspirin is mildly beneficial in terms of reducing the incidence of preeclampsia in women at high risk of developing preeclampsia.

A small randomised trial of low-dose aspirin in women at high risk of pre-eclampsia

OBJECTIVE

To determine if aspirin (ASA) therapy reduces the incidence of pre-eclampsia in women at high risk of this condition.

STUDY DESIGN

Randomised clinical trial. We recruited pregnant women with gestational age at randomisation <14 weeks, who satisfied the following criteria: chronic hypertension, history of severe pre-eclampsia or eclampsia or intrauterine growth retardation (IUGR) or intrauterine foetal death. Nineteen women in the no-treatment group and 16 in the ASA group were successfully followed up.

RESULTS

The mean birthweight was higher in the ASA group than in the no-treatment group (2790 g (S.D. 340 g) versus 2616 g (S.D. 779 g)), but the difference was not statistically significant. We found no statistically significant differences between the groups in the proportion of infants with birthweight below 2500 g (13.3% versus 29.4%) and the number of cases with pregnancy-induced hypertension (PIH)/pre-eclampsia (31.3% versus 36.8%).

CONCLUSION

These limited data give some support to the potential favourable effect of early treatment with ASA in pregnant women at risk of PIH and IUGR.

Low-dose aspirin in pregnancy: maternal and neonatal aspirin concentrations and neonatal prostanoid formation

OBJECTIVE

To evaluate maternal and neonatal plasma concentrations of acetylsalicylic acid and salicylic acid and the neonatal endogenous prostanoid formation during low-dose aspirin prophylaxis (LDA; 100 mg daily) in pregnant women.

METHODS

Concentrations of acetylsalicylic acid and salicylic acid in maternal plasma after at least 4 weeks of LDA (n = 14) and in umbilical cord plasma of newborns after maternal LDA (n = 7) were determined by gas chromatography-mass spectrometry. Platelet and renal formation of thromboxane A2 and the formation of prostaglandin E2 and prostacyclin were evaluated in vivo by quantification of index metabolites in plasma and urine by gas chromatography-mass spectrometry in neonates after maternal LDA (n = 14) and in a control group.

RESULTS

In the pregnant women, acetylsalicylic acid and salicylic acid concentrations rapidly increased after ingestion of LDA. Acetylsalicylic acid was completely eliminated within 4 hours, whereas salicylic acid was detected with low concentrations at 18 and 21 hours after dosing. In the neonates, acetylsalicylic acid was not detected. Salicylic acid was detected in 1 infant only. Platelet thromboxane A2 formation in the newborn infants was significantly suppressed but recovered within 2 to 3 days after discontinuation of LDA. Renal thromboxane A2 formation and the formation of prostaglandin E2 and prostacyclin were not affected by LDA.

CONCLUSION

In pregnant women who are treated with LDA, acetylsalicylic acid is not completely inactivated in the portal circulation but reaches the uteroplacental circulation and exerts antiplatelet effects in the fetus and newborn.

Position of the American Dietetic Association: nutrition and lifestyle for a healthy pregnancy outcome

It is the position of the American Dietetic Association that women of childbearing potential should maintain good nutritional status through a lifestyle that optimizes maternal health and reduces the risk of birth defects, suboptimal fetal growth and development, and chronic health problems in their children. The key components of a health-promoting lifestyle during pregnancy include appropriate weight gain; consumption of a variety of foods in accordance with the Food Guide Pyramid; appropriate and timely vitamin and mineral supplementation; avoidance of alcohol, tobacco, and other harmful substances; and safe food-handling. Prenatal weight gain within the Institute of Medicine (IOM) recommended ranges is associated with better pregnancy outcomes. The total energy needs during pregnancy range between 2,500 to 2,700 kcal a day for most women, but prepregnancy body mass index, rate of weight gain, maternal age, and physiological appetite must be considered in tailoring this recommendation to the individual. The consumption of more food to meet energy needs and the increased absorption and efficiency of nutrient utilization that occurs in pregnancy are generally adequate to meet the needs for most nutrients. However, vitamin and mineral supplementation is appropriate for some nutrients and situations. This statement also includes recommendations pertaining to use of alcohol, tobacco, caffeine, street drugs, and other substances during pregnancy; food safety; and management of common complaints during pregnancy and specific health problems. In particular for medical nutrition therapy, pregnant women with inappropriate weight gain, hyperemesis, poor dietary patterns, phenylketonuria (PKU), certain chronic health problems, or a history of substance abuse should be referred to a qualified dietetics professional.

Symposium on 'nutritional adaptation to pregnancy and lactation'. Pregnancy as a time for dietary change?

It is thought that nutrition during pregnancy plays a key role in the well-being of the mother and the newborn infant, and further influences health during childhood and adulthood. Pregnancy is a time of increased nutritional requirements, but many of these requirements will be met by adaptive physiological changes that occur during gestation, with little need to alter maternal dietary intake. A modest increment of food which provides 0.8 MJ/d (above prepregnant requirements) during the third trimester is considered adequate to meet the needs of fetal and maternal growth, and to satisfy the small increase in requirements of many macro- and micronutrients. However, requirements for vitamin D and folic acid increase substantially, and should be met primarily by supplementation. Food selection may also be altered to avoid a range of food-borne diseases and toxic constituents. There are a number of psycho-social reasons why pregnancy might be considered a good time for promoting changes in dietary behaviour for the health of the wider family. However, pregnancy may be a bad time to promote dietary change if it is perceived to involve slimming, if nutritional requirements are greatest before pregnancy, or if dietary changes made are harmful. There is little evidence to support educational interventions as successful at changing dietary behaviour during pregnancy. Pregnancy may be best viewed as an opportunity for maintaining good dietary selections and for building knowledge for future action, and should not be seen as the only opportunity for promoting dietary change within the life course.

Release of tumor necrosis factor-alpha and prostanoids in whole blood cultures after in vivo exposure to low-dose aspirin

BACKGROUND

The preventive effect of low-dose aspirin in cardiovascular disease is generally attributed to its antiplatelet action caused by differential inhibition of platelet cyclooxygenase-1. However, there is evidence that aspirin also affects release of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha). It is not known whether this is caused by direct action on the cytokine pathway or indirectly through cyclooxygenase inhibition and altered prostanoid synthesis, or both.

METHODS

We assessed the capacity of lipopolysaccharide-activated leukocytes in whole blood cultures of eight healthy subjects following a single oral dose of 80 mg aspirin to release TNF-alpha, prostanoid E2 (PGE2) and prostanoid I2 (PGI2), and thromboxane A2 (TXA2). TNF-alpha and prostanoids were determined by enzyme-linked immunoassays.

RESULTS

In seven subjects, TNF-alpha release in blood cultures decreased 24h after intake of aspirin. The effect of aspirin on prostanoid release was assessed in three individuals: PGE2 increased in all subjects, PGI2 increased in two and remained unchanged in one, and TXA2 was reduced in two and unchanged in one individual The presence of DFU, a specific inhibitor of cyclooxygenase 2, did not affect the reduction of TNF-alpha release by aspirin, but abolished prostanoid production in all three individuals.

CONCLUSION

The capacity of activated leukocytes to release TNF-alpha is reduced by ingestion of low-dose aspirin, independent of changes in prostanoid biosynthesis.