Pathogenesis and genetics of pre-eclampsia

After more than a century of intensive research, pre-eclampsia and eclampsia remain an enigmatic set of conditions. Aberration of the interaction between placental and maternal tissue is probably the primary cause, but the exact nature of the differences from normal pregnancy remain elusive. In this review attempts to understand the sequence of physiological changes have concentrated on vascular endothelium and oxidative stress issues. There are genetic components to susceptibility, but the relative contributions of maternal and fetal genotypes are still unclear. Whole-genome mapping could ultimately define the causative genes.

Malaria control in Bungoma District, Kenya: a survey of home treatment of children with fever, bednet use and attendance at antenatal clinics

OBJECTIVE

To lay the basis for planning an improved malaria control programme in Bungoma District, Kenya.

METHODS

By means of a cluster sample household survey an investigation was conducted into the home management of febrile children, the use of bednets, and attendance at antenatal clinics.

FINDINGS

Female carers provided information on 314 recently febrile children under 5 years of age, of whom 43% received care at a health facility, 47% received an antimalarial drug at home, and 25% received neither. Of the antimalarial treatments given at home, 91% were started by the second day of fever and 92% were with chloroquine, the nationally recommended antimalarial at the time. The recommended dosage of chloroquine to be administered over three days was 25 mg/kg but the median chloroquine tablet or syrup dosage given over the first three days of treatment was 15 mg/kg. The total dosages ranged from 2.5 mg/kg to 82 mg/kg, administered over one to five days. The dosages were lower when syrup was administered than when tablets were used. Only 5% of children under 5 years of age slept under a bednet. No bednets had been treated with insecticide since purchase. At least two antenatal visits were made by 91% of pregnant women.

CONCLUSIONS

Carers are major and prompt providers of antimalarial treatment. Home treatment practices should be strengthened and endorsed when prompt treatment at a health facility is impossible. The administration of incorrect dosages, which proved common with chloroquine, may occur less frequently with sulfadoxine-pyrimethamine, as its dosage regimen is simpler. High levels of utilization of antenatal clinics afford the opportunity to achieve good coverage with presumptive intermittent malaria treatments during pregnancy, and to reach the goal of widespread bednet use by pregnant women and children by distributing nets during antenatal clinic visits.

The preterm prediction study: quantitative fetal fibronectin values and the prediction of spontaneous preterm birth. The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network

OBJECTIVE

A cervicovaginal fetal fibronectin value of >/=50 ng/mL has been used to define women at risk of having a preterm birth. We evaluated the relationship between quantitative fetal fibronectin values and spontaneous preterm birth.

STUDY DESIGN

Cervical and vaginal specimens for fetal fibronectin were obtained at 24, 26, 28, and 30 weeks' gestation from 2926 women. Quantitative fetal fibronectin values were calculated by using absorbances determined by enzyme-linked immunosorbent assay. The highest fetal fibronectin value (cervical or vaginal) for each woman at each visit was evaluated in relation to spontaneous preterm birth at <35 weeks' gestation. Receiver operating characteristic curves were constructed to determine the optimal cutoff point for fetal fibronectin values to predict spontaneous preterm birth at <35 weeks' gestation and within 4 weeks of testing.

RESULTS

The risk of spontaneous preterm birth increased as a function of increasing fetal fibronectin values from approximately 20 to 300 ng/mL. Fetal fibronectin values > or =300 ng/mL were not associated with a further increase in spontaneous preterm birth. Examination of the receiver operating characteristic curve indicates that the optimal cutoff point for a positive fetal fibronectin test result at 24 to 30 weeks' gestation to predict spontaneous preterm birth at <35 weeks is between 45 and 60 ng/mL.

CONCLUSION

Increasing levels of cervicovaginal fetal fibronectin up to 300 ng/mL are associated with an increasing risk of spontaneous preterm birth. Nevertheless, at 24 to 30 weeks, the value currently used, 50 ng of fetal fibronectin per milliliter, appears to be a reasonable cutoff point for predicting spontaneous preterm birth at <35 weeks' gestation.

Dendritic cell elimination as an assay of cytotoxic T lymphocyte activity in vivo

We show in this paper that the survival of antigen-loaded dendritic cells in vivo may be used as a sensitive readout of CTL activity. We have previously shown that dendritic cells labeled with the fluorescent dye CFSE and injected sub-cutaneously into mice migrate spontaneously to the draining lymph node where they persist for several days. In the presence of effector CTL responses, dendritic cells loaded with specific antigen rapidly disappear from the draining lymph node. In this paper we extend the above observations and set up a simple and sensitive method to reveal CTL activity in individual mice in vivo. Dendritic cells were labeled with two different fluorochromes, loaded with antigen or left untreated, and mixed together before injection into mice. We show that only the dendritic cells loaded with specific antigen were cleared from the draining lymph node, while dendritic cells not loaded with antigen remained unaffected. Cytotoxic responses generated by immunization with peptide-loaded dendritic cells, or by infection with influenza virus, could be revealed using this method. Comparison of the differential survival of dendritic cells populations mixed together also allowed us to accurately evaluate the disappearance of dendritic cells, irrespective of variability in the injection site and other parameters. Given the ability of dendritic cells to efficiently take up and present complex antigens, nucleic acids and apoptotic bodies, this method may also allow the evaluation of cytotoxic activity against antigens that are not characterized in terms of peptide epitopes.

Prostitution and the sex discrepancy in reported number of sexual partners

One of the most reliable and perplexing findings from surveys of sexual behavior is that men report substantially more sexual partners than women do. We use data from national sex surveys and studies of prostitutes and their clients in the United States to examine sampling bias as an explanation for this disparity. We find that prostitute women are underrepresented in the national surveys. Once their undersampling and very high numbers of sexual partners are factored in, the discrepancy disappears. Prostitution's role in the discrepancy is not readily apparent because men are reluctant to acknowledge that their reported partners include prostitutes.

Hypertension in pregnancy

Hypertension arising during pregnancy remains one of the two most frequently-cited causes of maternal death in the UK. In some cases, pregnancy is unmasking underlying hypertension, which manifests itself in later life. Pregnant women who develop de novo proteinuric hypertension (pre-eclampsia, PE) can share many risk factors with patients with the metabolic syndrome, such as obesity, dyslipidaemia and insulin resistance. However, more than half the women who develop PE remain normotensive thereafter. There is a genetic component(s) to the disease, but it is most improbable that there is a 'PE gene'. Rather, there are factors such as genetically-determined thrombophilias which are predisposers but not prerequisites. Impaired placentation is a feature, with inadequate invasion of the spiral arteries by syncytiotrophoblast and poor remodelling. However, similar features are found in association with non-hypertensive fetal growth restriction. Prospective studies have suggested a hyperdynamic circulation in early pregnancy, with cardiac output only falling in established disease. Baroreflex sensitivity is decreased in normal pregnancy, and still further decreased in established PE. Activation of endothelial cell function antedates the clinical diagnosis, and has features in common with atherosclerosis. Dyslipidaemia is common in PE and, via oxidation of susceptible lipids, may contribute to endothelial activation. Oxidative 'stress' is increased in PE, perhaps through a variant of the hypoxia-reperfusion phenomenon in the developing intervillous spaces. Such early changes might then lead to the clinically-evident syndrome in susceptible women. PE is a protean, multisystem, multifactorial disease, the causes of which are only slightly less enigmatic than a decade ago.

The impact of digital cervical examination on expectantly managed preterm rupture of membranes

OBJECTIVE

The purpose of this study was to examine the effects of digital cervical examination on maternal and neonatal outcomes among women with preterm rupture of membranes.

STUDY DESIGN

This analysis includes data from a previously reported trial of antibiotic treatment during expectant management of rupture of membranes at 24 to 32 weeks' gestation in singleton and twin gestations. Patients from both the randomized trial (n = 299 in the antibiotic group and n = 312 in the placebo group) and the observational component (n = 183) are included in this analysis. The groups were divided into those with one (n = 161) or two digital cervical examinations (n = 27) and those with no digital cervical examinations (n = 606).

RESULTS

The gestational ages at enrollment were similar in the two groups (29 +/- 2 weeks' gestation for one or two examinations vs 29 +/- 2 weeks' gestation for no examinations; P =.85). There were no differences in chorioamnionitis (27% vs 29%; P =.69), endometritis (13% vs 11%; P =.5), or wound infection (0.5% vs 1%; P >.999) between the group with one or two examinations and the no-examination group. Infant outcomes were also similar in the two groups, including early sepsis (6% vs 5%; P =.68), respiratory distress syndrome (51% vs 45%; P =.18), intraventricular hemorrhage (7% vs 7%; P =.67), necrotizing enterocolitis (5% vs 3%; P =.19), and perinatal death (7% vs 5%; P =.45). A composite outcome made up of these neonatal outcomes was not different (56% vs 48%; P =.10) between the group with one or two examinations and the no-examination group. The time from rupture to delivery was shorter in the digital examination group (median value, 3 vs 5 days; P <. 009). Multivariable analysis to adjust for antibiotic study group, group B streptococcal culture status, race, and maternal transfer did not modify these results.

CONCLUSION

Performance of one or two digital cervical examinations during the course of expectant management of rupture of membranes between 24 and 32 weeks' gestation was associated with shorter latency but did not appear to worsen either maternal or neonatal outcome.

Interval nodes: the forgotten sentinel nodes in patients with melanoma

BACKGROUND

Any sentinel lymph node that receives lymph drainage directly from a primary melanoma site, regardless of its location, may contain metastatic disease. This is true even if the sentinel node does not lie in a recognized node field. Interval (in-transit) nodes that lie along the course of a lymphatic vessel between a primary melanoma site and a recognized node field are sometimes seen during lymphatic mapping for sentinel node biopsy. If drainage to such interval nodes is ignored by the surgeon during sentinel node biopsy, metastatic melanoma will be missed in some patients.

HYPOTHESIS

When lymph drains directly from a cutaneous melanoma site to an interval node, that sentinel node has the same chance of harboring micrometastatic disease as a sentinel node in a recognized node field.

DESIGN

Preoperative lymphoscintigraphy with technetiumTc 99m antimony trisulfide colloid was performed to define lymphatic drainage patterns and, since 1992, to locate the sentinel lymph nodes for surgical biopsy or for permanent skin marking of their location with point tattoos.

SETTING

Melanoma unit of a university teaching hospital.

PATIENTS

A total of 2045 patients with cutaneous melanoma were studied in 13 years.

RESULTS

Interval nodes were found in 148 patients (7.2%). The incidence of interval nodes varied with the site of the primary melanoma. Interval nodes were more common with melanomas on the trunk than with those on the lower limbs. Micrometastatic disease was found in 14% of interval nodes that underwent biopsy as sentinel nodes. This incidence is similar to that found in sentinel nodes located in recognized node fields, confirming the potential clinical importance of interval nodes.

CONCLUSIONS

Interval nodes should be removed surgically along with any additional sentinel nodes in standard node fields if the sentinel node biopsy procedure is to be complete. In some patients, an interval node will be the only lymph node that contains metastatic disease.

Developing new competencies in healthcare practitioners in the field

The Life-long Learning concept is one which is appropriate for those who have (or create) the opportunities to develop their competencies once they are in an operational role. All models of healthcare delivery and management are VOLATILE and therefore the way of addressing new competencies cannot be prescriptive or stand still for too long, but the concepts do endure. Learning, in order to 'keep up to date' is very necessary--technology, new clinical practices and interventions, new drug interactions, increased patient demands ... all add to the need to move with the times. This paper addresses some of the issues surrounding this challenge in the domain of informatics in support of healthcare delivery and management.

The Preterm Prediction Study: prediction of preterm premature rupture of membranes through clinical findings and ancillary testing. The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network

OBJECTIVE

Our objective was to determine the relative importance of demographic characteristics, clinical risk factors, and ancillary screening tests in the prediction of preterm birth as a result of premature rupture of membranes.

STUDY DESIGN

A total of 2929 women were evaluated in 10 centers at 23 to 24 weeks' gestation. Demographic and clinical characteristics were ascertained. Cervicovaginal fetal fibronectin and bacterial vaginosis were evaluated. Cervical length was measured by vaginal ultrasonography. Patients were evaluated for spontaneous preterm birth caused by preterm premature rupture of membranes at <37 and <35 weeks' gestation. Multivariate analyses were performed separately for nulliparous women and multiparous women.

RESULTS

Premature rupture of membranes at <37 weeks' gestation complicated 4.5% of pregnancies, accounting for 32.6% of preterm births. Univariate analysis revealed low body mass index, pulmonary disease, contractions within 2 weeks, short cervix (</=25 mm), positive results of fetal fibronectin screening, bacterial vaginosis, and a previous preterm birth caused by premature rupture of membranes (in multiparous women) to be significantly associated with preterm birth caused by premature rupture of membranes in the current gestation. Short cervix, previous preterm birth caused by premature rupture of membranes in multiparous women, and presence of fetal fibronectin were the strongest predictors for both preterm birth caused by premature rupture of membranes at <37 and <35 weeks' gestation. Women with positive fetal fibronectin screening results and a short cervix had greater risks both of preterm birth caused by premature rupture of membranes at <37 weeks' gestation (relative risk, 4.9) and of preterm birth caused by premature rupture of membranes at <35 weeks' gestation (relative risk, 13.5) than did those without these risk factors. Multiparous women with all three risk factors had a 31. 3-fold increased risk of preterm birth caused by premature rupture of membranes at <35 weeks' gestation.

CONCLUSION

The combination of short cervical length, previous preterm birth caused by preterm premature rupture of membranes, and positive fetal fibronectin screening results was highly associated with preterm delivery caused by preterm premature rupture of membranes in the current gestation.

Immunotherapy with dendritic cells and tumor major histocompatibility complex class I-derived peptides requires a high density of antigen on tumor cells

Immunization with dendritic cells and unfractionated MHC class I-binding peptides derived from autologous tumor cells has been shown to induce effective antitumor immunity. However, the importance of the relative abundance of tumor peptides on the surface of tumor cells is not known. We have addressed this question using peptides isolated from three tumor cell lines transfected with a minigene encoding amino acids 33-41 of the lymphocytic choriomeningitis virus glycoprotein (LCMV(33-41)). The three cell lines expressed different levels of MHC class I molecules and had different abilities to stimulate proliferation of LCMV(33-41)-specific T cells in vitro. We found that antitumor immune responses were best elicited by immunizing mice with dendritic cells and synthetic LCMV(33-41) peptide. Peptide preparations from a given tumor cell line conferred protection against challenge with the same tumor cell line. However, protective immunity to a different tumor could be induced only if the cell line used for peptide preparation presented a high relative proportion of LCMV(33-41) in association with MHC class I. Our results suggest that multiple peptide epitopes are required for the induction of an effective antitumor immune response using MHC class I-binding peptides from tumor cells. Also, the ability to induce an antitumor immune response appears to correlate with the proportion, rather than the absolute amount, of tumor-specific peptide in the mixture used for immunization.

Giardiasis surveillance--United States, 1992-1997

PROBLEM/CONDITION

Giardia intestinalis, the organism that causes the gastrointestinal illness giardiasis, is the most commonly diagnosed intestinal parasite in public health laboratories in the United States. In 1992, the Council of State and Territorial Epidemiologists assigned giardiasis an event code that enabled states to begin voluntarily reporting surveillance data on giardiasis to CDC.

REPORTING PERIOD

This report includes data that were reported from January 1992 through December 1997.

DESCRIPTION OF THE SYSTEM

The National Giardiasis Surveillance System includes data about reported cases of giardiasis from participating states. Because most states were already collecting data on occurrence of giardiasis, the assignment of an event code to giardiasis has allowed voluntary reporting of these data to CDC via the National Electronic Telecommunications System for Surveillance.

RESULTS

Since 1992, the number of states reporting cases of giardiasis to CDC has risen from 23 to 43. The annual number of giardiasis cases reported has ranged from 12,793 in 1992 to 27,778 in 1996. In 1997, cases per 100,000 state population ranged from 0.9 to 42.3, with 10 states reporting >20.0 cases per 100,000 population and a national average of 9.5 cases per 100,000 population. In 1997, New York State, including New York City, reported the highest number of cases (3,673, or 20.3 cases per 100,000 population), accounting for 14.5% of cases nationally; however, Vermont reported the highest incidence rate in 1997 (42.3 cases per 100,000 population). Both states have active surveillance systems in place for giardiasis. Cases have an approximately equal sex distribution. Nationally, rates were the highest among children aged 0-5 years, followed closely by persons aged 31-40 years. In these two age groups, most cases were reported during late summer and early fall--an indication that transmission occurred during the summer.

INTERPRETATION

This report documents the first nationwide look at epidemiologic parameters and disease burden estimates for giardiasis in the United States. Transmission occurs in all major geographic areas of the country. The seasonal peak in age-specific case reports coincides with the summer recreational water season and might reflect the heavy use by young children of communal swimming venues (e.g., lakes, rivers, swimming pools, and water parks)--a finding consistent with Giardia's low infectious dose, the high prevalence of diaper-aged children in swimming venues, the extended periods of cyst shedding that can occur, and Giardia's environmental resistance. Estimates based on state surveillance data indicate that as many as 2.5 million cases of giardiasis occur annually in the United States.

PUBLIC HEALTH ACTION

Giardiasis surveillance provides data to educate public health practitioners and health-care providers about the scope and magnitude of giardiasis in the United States. These data can be used to establish research priorities and to plan future prevention efforts.

Free leptin is increased in normal pregnancy and further increased in preeclampsia

We measured bound and free leptin levels in preeclamptic and matched normal pregnant and never-pregnant women to determine whether the free component of leptin is increased during pregnancy and further increased in preeclampsia. Two milliliters of serum was obtained from 18 normal and 18 preeclamptic patients matched by pre-pregnancy body mass index (BMI), and from 18 never-pregnant women matched by BMI with the pregnant groups. The sample was subjected to gel filtration using Sephadex G-100. Radioimmunoassay (RIA) was performed on all fractions, and the proportions of bound and free leptin were determined by analyzing the areas under the curve of the chromatographic profile. The total maternal serum leptin concentration was significantly higher in normal pregnancy compared with the nonpregnant state and was further increased in preeclampsia (33.8 +/- 4.1 v 15.2 +/- 1.8 ng/mL, P = .002, and 48.1 +/- 5.6 ng/mL, P = .02, respectively). Free leptin was increased in normal pregnant compared with never-pregnant women (25.9 +/- 4.1 v 11.0 +/- 2.0 ng/mL, respectively, P = .01), while the increase of total leptin in preeclampsia was exclusively in the free fraction that was significantly higher versus the normal pregnant group (41.8 +/- 5.6 v25.9 +/- 4.1 ng/mL, respectively, P = .01). The bound leptin fraction, by contrast, was significantly increased in the normal pregnant group compared with the preeclamptic group and the never-pregnant group (7.9 +/- 0.56 v 6.2 +/- 0.36 and 4.1 +/- 0.36 ng/mL, respectively, P = .009 and P = <.0001). In conclusion, the free leptin concentration increases in normal pregnancy and is further increased in preeclampsia. This supports the hypothesis that biologically active leptin is elevated in normal pregnancy and is increased more in women with preeclampsia.

Vaginal fetal fibronectin measurements from 8 to 22 weeks' gestation and subsequent spontaneous preterm birth

OBJECTIVE

We sought to determine the range of fetal fibronectin values in the vagina from 8 to 22 weeks' gestation, the factors associated with both low and high values, and whether high values are associated with gestational age at birth.

STUDY DESIGN

Vaginal fetal fibronectin was quantitatively determined in a prospective cohort study of 13,360 women being evaluated for participation in the National Institute of Child Health and Human Development Maternal-Fetal Medicine Unit treatment trials for bacterial vaginosis and Trichomonas vaginalis. Fetal fibronectin values were correlated with gestational age at screening, race, the presence of bacterial vaginosis and Trichomonas vaginalis, and gestational age at delivery.

RESULTS

Vaginal fetal fibronectin values at each gestational age ranged from unmeasurable to >1000 ng/mL, with median values always being <10 ng/mL. Fetal fibronectin values declined progressively with increasing gestational age at sampling. Bacterial vaginosis and black race were associated with higher values, whereas nulliparity was associated with lower values. High values after 13 weeks' gestation were associated with a 2- to 3-fold increased risk of subsequent spontaneous preterm birth overall and a 4-fold increased risk of very early preterm birth.

CONCLUSION

Elevated vaginal fetal fibronectin levels from 13 to 22 weeks' gestation are associated with a significantly increased risk of spontaneous preterm birth.

A multiyear prospective study of the risk factors for and incidence of diarrheal illness in a cohort of Peace Corps volunteers in Guatemala

BACKGROUND

Diarrheal illness is the most common medical disorder among travelers from developed to developing countries and is common among expatriate residents in developing countries.

OBJECTIVE

To assess the risk factors for and incidence of diarrheal illness among Americans living in a developing country.

DESIGN

Prospective longitudinal study.

SETTING

Rural Guatemala.

PATIENTS

Cohort of 36 Peace Corps volunteers.

MEASUREMENTS

Collection of daily dietary and symptom data for more than 2 years; identification by multivariate Poisson regression analyses of risk factors for clinically defined episodes of diarrheal illness.

RESULTS

The 36 Peace Corps volunteers in this study had 307 diarrheal episodes (median, 7 per person), which lasted a median of 4 days (range, 1 to 112) and a total of 10.1% of the 23 689 person-days in the study. The incidence density (episodes per person-year) was 4.7 for the study as a whole, 6.1 for the first 6-month period, 5.2 for the second 6-month period, and 3.6 thereafter. Statistically significant risk factors for diarrheal illness included drinking water whose source (for example, the tap) and, therefore, quality, was unknown to the person; eating food prepared by a Guatemalan friend or family; eating food at a small, working-class restaurant; eating fruit peeled by someone other than a Peace Corps volunteer; drinking an iced beverage; and eating ice cream, ice milk, or flavored ices. The relative risks comparing the presence of these exposures during the first 6-month period overseas with their absence during the second year of residence ranged from 1.90 to 2.67, and the summary attributable risk percentage (that is, the percentage of diarrheal episodes that could be ascribed to the exposures) was 75.4%. Exposures generally were riskier if they occurred during travel elsewhere in Guatemala rather than in the person's usual work area.

CONCLUSIONS

Diarrheal illness of mild-to-moderate severity continued to occur throughout Peace Corps service but decreased in incidence as length of stay increased. Various dietary behaviors increased the risk for diarrheal illness, which suggests that avoidance of potentially risky foods and beverages is beneficial.

Dyslipoproteinaemia in postmenopausal women with a history of eclampsia

OBJECTIVE

To test the hypothesis that postmenopausal women with a history of eclampsia manifest a more high risk lipid profile than postmenopausal women with a history of normal pregnancy.

SETTING

The Department of Obstetrics and Gynaecology, National University Hospital, Reykjavik, Iceland, and the Magee-Womens Research Institute, Pittsburgh, Pennsylvania, USA.

PARTICIPANTS

Thirty Icelandic women with a history of eclampsia, aged between 50 and 67 years at the time of re-examination (cases) were individually matched for current age, and for age and parity at index pregnancy, to 30 unrelated Icelandic women with a history of normal pregnancy (controls).

METHODS

The participating women completed a health and family history questionnaire and underwent a physical examination. Fasting plasma low density lipoprotein diameter, serum lipids, insulin, and glucose were measured.

RESULTS

Mean low density lipoprotein size was significantly smaller and apolipoprotein B concentration was higher in women with prior eclampsia. The percentage of cases receiving blood pressure medication (33%) was significantly greater than controls (6.7%). Thirteen cases had had hypertensive complications in at least one other pregnancy (recurrent subgroup); postmenopausally, these women displayed significantly increased diastolic blood pressures, smaller-sized low density lipoprotein, increased apolipoprotein B, decreased high density lipoprotein2 (HDL2) cholesterol, and increased total cholesterol: HDL cholesterol ratio compared with their controls. Fourteen cases were normotensive in all other pregnancies (nonrecurrent); these showed no differences from their controls.

CONCLUSIONS

Dyslipoproteinaemia is more prevalent among postmenopausal women with prior eclampsia, especially with recurrent hypertension in pregnancy, than in postmenopausal women with prior normal pregnancies.

Second-trimester levels of maternal serum human chorionic gonadotropin and inhibin a as predictors of preeclampsia in the third trimester of pregnancy

OBJECTIVE

To determine whether second-trimester maternal serum levels of inhibin A, human chorionic gonadotropin (hCG), unconjugated estriol (uE3), and alpha-fetoprotein (AFP) are predictive of the later onset of preeclampsia in pregnancy.

METHODS

Retrospective evaluation of serum analyte levels in 60 women with preeclampsia compared with 300 controls. Levels of each analyte were compared in women with preeclampsia and controls using matched rank analysis. Analytes that were significantly different between groups were examined with univariate and bivariate Gaussian distribution analysis.

RESULTS

Second-trimester inhibin A (1.36 multiples of the median [MoM]) and hCG (1.40 MoM) levels were significantly but modestly elevated in women who later developed preeclampsia. A combination test of maternal age plus inhibin A and hCG predicted 23% of cases of preeclampsia with 95% specificity. There was a statistically significant trend for inhibin A, but not hCG, levels to be higher when the onset of preeclampsia occurred within a shorter (<17 weeks) interval after collection of the second-trimester screening sample.

CONCLUSIONS

Second-trimester serum levels of inhibin A and hCG are modest predictors of the later onset of preeclampsia. Inhibin A may be a better predictor of early-onset preeclampsia, which is associated with a higher maternal and perinatal morbidity and mortality, than preeclampsia at or near term.

Subdividing atypical glandular cells of undetermined significance according to the Australian modified Bethesda, system: analysis of outcomes

BACKGROUND

The Australian modification of the Bethesda system (TBS) for reporting endocervical cellular abnormalities differs from TBS in having a "high grade" category for prediction of adenocarcinoma in situ (AIS), an "inconclusive" category requiring that AIS be excluded (AISEX), and a "low grade" category (Enatyp) for when only minor changes are seen in endocervical cells.

METHODS

From subsequent follow-up, the authors evaluated the proportion of histologically confirmed high grade lesions (squamous, glandular, or endometrial) in each cytologic reporting category, for cases in which no concurrent squamous abnormality was also predicted.

RESULTS

From information was available for 95.9% of 172 AIS predictions, 81.5% of 119 AISEX predictions, and 89.0% of 237 reports of Enatyp. The histologic positive predictive values for high grade lesions were 95.7% for AIS, 71.1% for AISEX, and 7.1% for Enatyp. In the first 2 categories, a minority of lesions proved to be purely squamous (3.8% for AIS and 33.3% for AISEX), whereas in the Enatyp category 87.0% were squamous only.

CONCLUSIONS

Compared with TBS, the Australian terminology for reporting of endocervical abnormalities better reflects the risk of underlying high grade abnormalities and may result in more appropriate management recommendations. For Enatyp reports, which constitute over 85% of reported endocervical abnormalities, repeat cytology should be considered appropriate management. However, cone biopsy should be the investigative method of choice for women with reports of AIS and AISEX.

CD8+ T cell-dependent elimination of dendritic cells in vivo limits the induction of antitumor immunity

The fate of dendritic cells (DC) after they have initiated a T cell immune response is still undefined. We have monitored the migration of DC labeled with a fluorescent tracer and injected s.c. into naive mice or into mice with an ongoing immune response. DC not loaded with Ag were detected in the draining lymph node in excess of 7 days after injection with maximum numbers detectable approximately 40 h after transfer. In contrast, DC that had been loaded with an MHC class I-binding peptide disappeared from the lymph node with kinetics that parallel the known kinetics of activation of CD8+ T cells to effector function. In the presence of high numbers of specific CTL precursors, as in TCR transgenic mice, DC numbers were significantly decreased by 72 h after injection. The rate of DC disappearance was extremely rapid and efficient in recently immunized mice and was slower in "memory" mice in which memory CD8+ cells needed to reacquire effector function before mediating DC elimination. We also show that CTL-mediated clearance of Ag-loaded DC has a notable effect on immune responses in vivo. Ag-specific CD8+ T cells failed to divide in response to Ag presented on a DC if the DC were targets of a pre-existing CTL response. The induction of antitumor immunity by tumor Ag-loaded DC was also impaired. Therefore, CTL-mediated clearance of Ag-loaded DC may serve as a negative feedback mechanism to limit the activity of DC within the lymph node.

The Preterm Prediction Study: sequential cervical length and fetal fibronectin testing for the prediction of spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network

OBJECTIVES

This study was undertaken to further elucidate the pathogenesis of preterm birth by means of traditional risk factors and new markers for preterm birth derived from the Preterm Prediction Study.

STUDY DESIGN

A total of 3076 women (2929 with singleton gestations and 147 with twin pregnancies) were categorized according to the presence of risk factors including black race, low body mass index, the presence of bacterial vaginosis, and previous preterm birth. At 24 and 28 weeks' gestation cervical length was measured and categorized as short (</=25 mm) or normal (>25 mm). Vaginal and cervical fetal fibronectin concentrations were measured at 24, 26, 28, and 30 weeks' gestation and results were categorized as positive (>/=50 ng/mL) or negative (<50 ng/mL).

RESULTS

At 24 to 26 weeks' gestation women with each of the risk factors were more likely to have positive fibronectin test results or to have a short cervix. Among women with negative fetal fibronectin results at 24 to 26 weeks' gestation those with a short cervix were more likely to have positive fetal fibronectin results at 28 to 30 weeks' gestation, and among those with normal cervical length those women who had positive fetal fibronectin results were more likely to have a short cervix at later evaluation. Most women who had positive fetal fibronectin results at 24 to 26 weeks' gestation had negative results at 28 to 30 weeks' gestation, whereas most but not all women who had a short cervix at 24 to 26 weeks' gestation still had a short cervix at 28 to 30 weeks' gestation. In each period women with both a positive fetal fibronectin result and a short cervix were at substantially increased risk of spontaneous preterm birth; women with either marker alone had intermediate and approximately equal risks of spontaneous preterm birth, and women without either marker had a low risk of spontaneous preterm birth.

CONCLUSION

Regardless of other risk factors, a short cervix predicts a subsequent positive fetal fibronectin result, and a positive fetal fibronectin result predicts subsequent cervical shortening. These data do not support a single sequence of events leading to spontaneous preterm birth.

The preterm prediction study: cervical lactoferrin concentration, other markers of lower genital tract infection, and preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network

OBJECTIVE

This study was undertaken to determine the relationship among cervical lactoferrin concentration, other cervical markers potentially related to infection, and spontaneous preterm birth.

STUDY DESIGN

Cervical lactoferrin concentrations obtained at 22 to 24 weeks' gestation among 121 women who had a spontaneous preterm birth <35 weeks' gestation were compared with cervical lactoferrin concentrations among 121 women matched for race, parity, and center who were delivered at >/=37 weeks' gestation. Results were compared against levels of cervical interleukin 6, fetal fibronectin, and sialidase, against cervical length according to ultrasonography, and according to the bacterial vaginosis Gram stain score.

RESULTS

Cervical lactoferrin concentrations ranged from not measurable (19% of the concentrations were below the threshold for this assay) to a titer of >/=1:64. There was no significant difference in the overall distributions of lactoferrin concentrations between the case patients and control subjects (P =.18). Only when the highest titers of lactoferrin were considered were there more women in the spontaneous preterm birth group (6/121 vs 0/121; P =.03). According to Spearman correlation analyses the cervical lactoferrin concentrations were strongly related to interleukin 6 concentration (r =.51; P =.0001), sialidase activity (r =.38; P =.0001), and bacterial vaginosis (r =.38; P =.0001), were weakly related to fetal fibronectin (r =. 16; P =.01), and were not related to cervical length. With the 90th percentile (a dilution of 1:32) used as a cutoff to establish a dichotomous variable, lactoferrin concentration had the following odds ratios and 95% confidence intervals for associations with other potential markers of infection: bacterial vaginosis odds ratio, 4.8 (95% confidence interval, 2.2-10.3); interleukin 6 concentration odds ratio, 2.8 (95% confidence interval, 1.2-6.5); sialidase activity odds ratio, 5. 5 (95% confidence interval, 2.2-13.7); fetal fibronectin concentration odds ratio, 0.6 (95% confidence interval, 0.2-2.0); chlamydiosis odds ratio, 2.3 (95% confidence interval, 0.8-6.9); and short cervix odds ratio, 0.5 (95% confidence interval, 0.2-1.4).

CONCLUSIONS

Lactoferrin found in the cervix correlated well with other markers of lower genital tract infection. High lactoferrin levels were associated with spontaneous preterm birth but had a very low predictive sensitivity.

The preterm prediction study: granulocyte colony-stimulating factor and spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network

OBJECTIVE

Granulocyte colony-stimulating factor is elevated in the amniotic fluid and plasma of women with chorioamnionitis and active preterm labor. We investigated the relationship between plasma granulocyte colony-stimulating factor and subsequent spontaneous preterm birth in pregnant women without symptoms.

STUDY DESIGN

We performed a nested case-control study involving 194 women who had a singleton spontaneous preterm birth and 194 matched term control subjects from the patient pool (n = 2929) enrolled in the Preterm Prediction Study. Plasma collected at 24 and 28 weeks' gestation was analyzed for granulocyte colony-stimulating factor, and the results were compared with subsequent spontaneous preterm birth.

RESULTS

Compared with term control subjects, women who were delivered of their infants spontaneously at <28 weeks' gestation had increased mean granulocyte colony-stimulating factor values at 24 weeks' gestation (84.7 +/- 38.4 vs 67.7 +/- 28.6 pg/mL; P =.049), and women who were delivered of their infants at <32 weeks' gestation had increased mean plasma granulocyte colony-stimulating factor values at 28 weeks' gestation (80.4 +/- 24.1 vs 55.9 +/- 16.5 pg/mL; P =. 001). At 24 weeks' gestation a granulocyte colony-stimulating factor value >75th percentile in control subjects (approximately 80 pg/mL) was found in 48.9% (23/47) of all women delivered of their infants at <32 weeks' gestation versus 14.9% (7/47) of the term control subjects (adjusted odds ratio, 6.2; 95% confidence interval, 1.8-20. 8). At 28 weeks' gestation a granulocyte colony-stimulating factor value >75th percentile was found in 36.8% (7/19) of women delivered of their infants at <32 weeks' gestation versus 5.3% (1/19) of term control subjects (adjusted odds ratio, 25.7; 95% confidence interval, 1.5-470.4). When measured at 24 or 28 weeks' gestation, granulocyte colony-stimulating factor did not predict spontaneous preterm birth at 32 to 34 weeks' gestation or at 35 to 36 weeks' gestation.

CONCLUSION

In pregnant women without symptoms at 24 and 28 weeks' gestation, elevated plasma granulocyte colony-stimulating factor levels are associated with subsequent early (<32 weeks' gestation) spontaneous preterm birth, especially within the next 4 weeks, but not with late spontaneous preterm birth. These data provide further evidence that early spontaneous preterm birth is associated with an inflammatory process that is identifiable by the presence of a cytokine in maternal plasma several weeks before the early spontaneous preterm birth; however, later spontaneous preterm birth is not associated with this process.