Genetic risk for dengue hemorrhagic fever and dengue fever in multiple ancestries

Background

Genetic risk factors for dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) and dengue fever (DF) are limited, in particular there are sparse data on genetic risk across diverse populations.

Methods

We conducted a genome-wide association study (GWAS) in a derivation and validation sample of 7, 460 participants of Latin American, South Asian, and South East Asian ancestries. We then developed a weighted polygenic risk score (PRS) for each participant in each of the validation cohorts of the three ancestries to predict the risk of DHF/DSS compared to DF, DHF/DSS compared to controls, and, DF compared to controls.

Findings

The risk of DHF/DSS was significantly increased, odds ratio [OR] 1.84 (95%CI 1.47 to 2.31) (195 SNPs), compared to DF, fourth PRS quartile versus first quartile, in the validation cohort. The risk of DHF/DSS compared to controls was increased (OR=3.94; 95% CI 2.84 to 5.45) (278 SNPs), as was the risk of DF compared to controls (OR=1.97; 95%CI 1.63 to 2.39) (251 SNPs). Risk increased in a dose-dependent manner with increase in quartiles of PRS across comparisons. Significant associations persisted for PRS built within ancestries and applied to the same or different ancestries as well as for PRS built for one outcome (DHF/DSS or DF) and applied to the other.

Interpretation

There is a strong genetic effect that predisposes to risk of DHF/DSS and DF. The genetic risk for DHF/DSS is higher than that for DF when compared to controls, and this effect persists across multiple ancestries.

Comparative evaluation of three dengue duo rapid test kits to detect NS1, IgM, and IgG associated with acute dengue in children in Myanmar

Dengue is an increasing public health concern worldwide and requires efficient laboratory diagnostics. We evaluated three commercially available dengue rapid diagnostic tests-the Humasis Dengue Combo NS1 & IgG/IgM (Humasis, Korea), SD Bioline Dengue Duo NS1 Ag & IgG/IgM (SD Bioline, Korea), and CareUS Dengue Combo NS1 and IgM/IgG kits (WellsBio, Korea)-and compared them to reference immunoglobulin M (IgM) or immunoglobulin G (IgG) ELISAs and quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. In total, 109 dengue-positive samples from children with acute symptomatic dengue and 63 dengue-negative samples from febrile and asymptomatic individuals were collected. For the nonstructural 1 protein (NS1) Ag test, the sensitivity and specificity were in the following order: CareUS (79.82 and 100%), Humasis (63.30 and 100%), and SD Bioline (48.62 and 100%). For IgM and IgG, CareUS had the highest sensitivities and specificities (89.91 and 100%; 82.57 and 100%, respectively), followed by SD Bioline (60.55 and 100%, 77.98 and 100%, respectively), and Humasis (51.38 and 98.21%, 72.48 and 95.24%, respectively). The IgM kits were more sensitive than the NS1 Ag or IgG kits; however, combining NS1 Ag and IgM reduced the number of missed cases. Therefore, the NS1 Ag plus IgM dengue kits increase the accuracy of the results. In our study, the CareUS Dengue Combo NS1 and IgM/IgG kit showed higher accuracy in performance with reference to qRT-PCR and ELISA results.

Impact of glucose-6-phosphate dehydrogenase deficiency on dengue infection in Myanmar children

Glucose-6-phosphate dehydrogenase (G6PD) deficiency may affect the clinical presentation of dengue due to the altered redox state in immune cells. We aimed to determine the association between G6PD deficiency and severity of dengue infection in paediatric patients in Myanmar. A cross-sectional study was conducted among paediatric patients aged 2–13 years with dengue in Yankin Children Hospital, Myanmar. One hundred and ninety-six patients positive for dengue infection, as determined via PCR or ELISA, were enrolled. Dengue severity was determined according to the 2009 WHO classification guidelines. Spectrophotometric assays determined G6PD levels. The adjusted median G6PD value of males in the study population was used to define various cut-off points according to the WHO classification guidelines. G6PD genotyping for Mahidol, Kaiping and Mediterranean mutations was performed for 128 out of 196 samples by real-time multiplex PCR. 51 of 196 (26.0%) patients had severe dengue. The prevalence of G6PD phenotype deficiency (< 60% activity) in paediatric patients was 14.8% (29/196), specifically, 13.6% (14/103) in males and 16.2% (15/93) in females. Severe deficiency (< 10% activity) accounted for 7.1% (14/196) of our cohort, occurring 11.7% (12/103) in males and 2.2% (2/93) in females. Among 128 samples genotyped, the G6PD gene mutations were detected in 19.5% (25/128) of patients, with 20.3% (13/ 64) in males and 18.8% (12/64) in females. The G6PD Mahidol mutation was 96.0% (24/25) while the G6PD Kaiping mutation was 4.0% (1/25). Severe dengue was not associated with G6PD enzyme deficiency or presence of the G6PD gene mutation. Thus, no association between G6PD deficiency and dengue severity could be detected.

Trial registration: The study was registered following the WHO International Clinical Trials Registry Platform (WHO-ICTRP) on Thai Clinical Trials Registry (TCTR) website, registration number # TCTR20180720001

Density of GFAP-immunoreactive astrocytes is decreased in left hippocampi in major depressive disorder

Neuroimaging and postmortem studies of subjects with major depressive disorder (MDD) reveal smaller hippocampal volume with lengthening duration of illness. Pathology in astrocytes may contribute significantly to this reduced volume and to the involvement of the hippocampus in MDD. Postmortem hippocampal tissues were collected from 17 subjects with MDD and 17 psychiatrically-normal control subjects. Sections from the body of the hippocampus were immunostained for glial fibrillary acidic protein (GFAP), a marker of intermediate filament protein expressed in astrocytes. The density of GFAP-immunoreactive astrocytes was measured in the hippocampus using 3-dimensional cell counting. Hippocampal subfields were also assessed for GFAP-immunoreactive area fraction. In CA1, there was a significant positive correlation between age and either density or area fraction in MDD. The density of astrocytes in the hilus, but not CA1 or CA2/3, was significantly decreased only in depressed subjects not taking an antidepressant drug, but not for depressed subjects taking an antidepressant drug. The area fraction of GFAP-immunoreactivity was significantly decreased in the dentate gyrus in women but not men with depression. In CA2/3, the area fraction of GFAP-immunoreactivity was inversely correlated with the duration of depression in suicide victims. Astrocyte contributions to neuronal function in the hilus may be compromised in depressed subjects not taking antidepressant medication. Due to the cross-sectional nature of the present study of postmortem brain tissue, it remains to be determined whether antidepressant drug treatment prevented a decrease in GFAP-immunoreactive astrocyte density or restored cell density to normal levels.

Randomized, placebo controlled, double blind trial evaluating early pregnancy phytonutrient supplementation in the prevention of preeclampsia

OBJECTIVE

Daily provision of pregnant patients with dietary supplements containing antioxidants and phytonutrients, if initiated in the first trimester of pregnancy and continued throughout the gestation, may significantly decrease the incidence of preeclampsia.

STUDY DESIGN

We conducted a single center, randomized, placebo-controlled investigation in which women were randomized by their risk status and assigned to daily ingestion of a supplement consisting primarily of a blended fruit and vegetable juice powder concentrate or placebo.

RESULT

Of the 684 patients randomized to the trial, 267 (39.0%) completed it. The final analysis is based on those participants who completed the study. For the primary outcome of preeclampsia, there was no difference observed between the phytonutrient supplement group and the placebo group: 15.9% vs 16.3%, respectively, (R.R. 0.97 (0.56-1.69)). Non-significant trends toward lower placenta-related obstetrical complications were observed in the supplement group compared with the placebo cohort (8.3% vs 15.5%, respectively, (R.R. 0.57 (0.29-1.14). Those infants born to mothers taking the supplement in the high-risk stratified group demonstrated non-significant trends toward lower rates of respiratory distress syndrome (RDS); 5.3% in the supplement group vs 15.4% in the placebo group: R.R. 0.34 (0.12-1.01).

CONCLUSION

Initiation of antioxidant/phytonutrient supplementation in the first trimester did not decrease rates of preeclampsia. Non-significant trends toward lower incidences of placental derived morbidity in those mothers taking the supplement in addition to decreased rates of RDS in infants born to supplemented mothers considered to be high-risk for preeclampsia, warrant further investigation.

Reduced placental perfusion causes an increase in maternal serum leptin

OBJECTIVE

We tested the hypothesis that the inadequately perfused placenta increases production of leptin, which can be detected in maternal serum.

STUDY DESIGN

Sprague-Dawley rats (n=13), on day 14 of gestation, had placement of clips on the aorta and the ovarian arteries providing 35 per cent occlusion of the vessels. Eight rats had sham surgery and 14 rats served as non-surgical controls. All animals were sacrificed on day 19 of gestation. Maternal serum was obtained, and pups and placentae were weighed.

RESULTS

Both placental weights and pup weights were reduced due to reduced uterine perfusion and were negatively correlated with maternal serum leptin (P=0.018 and 0.028, respectively). Maternal serum leptin was increased in the treatment group (2.21 ng/ml+/-64 ng/ml) compared to controls (1.66 ng/ml+/-38 ng/ml) (P=0.031).

CONCLUSIONS

Our findings suggest that reduced placental perfusion results in an increase in maternal serum leptin. Further investigation is needed to determine if maternal serum leptin may be useful in identifying pregnancies with uteroplacental insufficiency.

Combined analysis of cytokine genotype polymorphism and the level of expression with allograft function in African-American renal transplant patients

Cytokine gene polymorphism and expression levels were evaluated in a group of African-American patients who had undergone renal transplantation. It was hypothesized that possession of specific cytokine alleles might be influential in predisposing the recipient to allograft rejection. Thus, we sought to establish a relationship between cytokine gene polymorphism, the levels of cytokine expression, and the outcome of allograft function. Cytokine genotypes and mRNA transcript levels of IL-2, TNF-alpha, TGF-beta1, IL-10, IL-6 and IFN-gamma were determined using peripheral blood cells. Genomic DNA samples from 77 transplant recipients and 77 controls were tested by a multiplex PCR with specific primers for the above cytokines. The frequency distributions of cytokines were analyzed in respect to the clinical characterization, including delayed graft function (DGF), rejection episodes (REs) and stable graft function (SGF). The mRNA transcript level was tested both at pre- and early post-transplantation (day 1 and day 4) with primers for coding regions of the above cytokines in a RT-PCR assay. The majority of recipients with successful graft function were matched with their donors for only three out of the six HLA alleles. We have shown that the TGF-beta1 T/C G/G high producer and IFN-gamma T/A intermediate producer genotypes were associated with allograft rejection, whereas low IFN-gamma producer and high IL-10 producer genotypes were significantly protective of the allograft. There was some correlation between the TGF-beta1 high producer genotype and DGF, but it was not statistically significant. Overall, 77% of those who experienced REs carried the TGF-beta1 T/C G/G, high producer genotype as compared with 52% who experienced DGF, 39% with SGF (P<0.01, RR=2.0), and 27.3% of controls (P<0.003, RR=2.6). The IFN-gamma T/A intermediate producer genotype was found in 69.2% of patients with REs as compared with 26.8% of patients with SGF (P<0.008, RR=2.85). The IL-10, ATA/ATA low producer genotype was found in 38.5% of recipients with REs and 14.6% of recipients without REs (P<0.04, RR=0.53). Expression levels of mRNA transcript were correlated with genotype data, except for the TGF-beta1 high producer genotype where there was no significant difference between the level of mRNA transcript at pre- and post-transplantation. Low DRbeta1 and high DPbeta1 expression by recipient peripheral blood mononuclear cells before transplantation was associated with more SGF, whereas high DRbeta1 and low DPbeta1 expression at pretransplantation was associated with more REs (DRbeta1, P<0.001 and DPbeta1, P<0.05, respectively). We concluded that, dual analysis of cytokine genotype and expression levels by peripheral cells may be an important clue to understanding the contribution of the recipient's immune response to an allograft pre- and post-transplantation. Identification of peripheral markers diagnostic of rejection could allow advance anticipation of clinical outcome, and might reduce the need for tissue biopsy.

The myth of transient hypertension: descriptor or disease process?

The objective of this study is to describe the incidence of transient hypertension and to evaluate if transient hypertension is associated with increased maternal or fetal morbidity as compared to other hypertensive disorders of pregnancy and normotensive controls. Data were collected from all deliveries at the University of Mississippi Medical Center from July 1, 1996 through January 1, 1997. Patients were grouped according to ACOG criteria for pregnancy induced hypertension. Specific maternal and fetal morbidities were compared among the groups and controls. There were 1489 deliveries during the study period. Nearly 30% of patients met the criteria for transient hypertension. There were no significant differences between patients with transient hypertension and controls in regard to maternal and fetal outcomes. Transient hypertension occurs more often than expected, however, it appears to be of limited clinical significance.

Effects of long-term cigarette smoking on the human locus coeruleus

BACKGROUND

It has been hypothesized that cigarette smoking among subjects with major depression is a form of self-medication. To explore a possible biological basis for this hypothesis, noradrenergic proteins in the locus coeruleus (LC) were measured in long-term cigarette smokers and in nonsmokers. The LC was studied because elevated amounts of alpha2-adrenoceptors and tyrosine hydroxylase have been observed postmortem in the LCs of subjects with major depression or who commit suicide, and because long-term administration of antidepressant drugs to rats down-regulates these proteins in the LC.

METHODS

Postmortem LCs were obtained from long-term cigarette smokers (n=7) and from nonsmokers (n = 9), all of whom lacked diagnoses of major depression. Amounts of tyrosine hydroxylase immunoreactivity and radioligand binding to the norepinephrine transporter, monoamine oxidase A, and alpha2-adrenoceptors were measured.

RESULTS

Amounts of tyrosine hydroxylase immunoreactivity and radioligand binding to alpha2-adrenoceptors were significantly lower (approximately 60% and 40%, respectively) along the axis of the LCs of long-term smokers compared with nonsmokers. Smoking had no statistically significant effects on binding to monoamine oxidase A or to the norepinephrine transporter.

CONCLUSION

This is the first demonstration that cigarette smoking affects noradrenergic proteins in the LC. The direction of these changes is opposite to that observed when comparing subjects who have major depression with normal controls and the same as that produced by long-term antidepressant treatment in animals. If the present observations reflect long-term effects of smoking on premortem noradrenergic biochemistry, smoking-induced changes in LC biochemistry may strengthen the smoking habit among subjects with major depression.

Physicians' reliance on specialists, therapists, and vendors when prescribing therapies and durable medical equipment for children with special health care needs

OBJECTIVES

Physicians who care for children with special (health care) needs (CWSN) often must prescribe therapies and/or specialized, durable medical equipment (DME). Given this responsibility and the increasing scrutiny of prescribing practices by various oversight agencies, understanding the extent to which pediatricians rely on their own expertise when prescribing therapies and DME is an important area of research.

METHODS

As part of an ongoing investigation of physician preparedness for and practice in prescribing therapies, DME, or procedures for CWSN, we mailed surveys to practicing pediatricians in each of 2 states-Ohio and Mississippi-and to a senior resident at all identified pediatric residency-training programs. The surveys polled recipients as to who they would rely on themselves-specialists, therapists or vendors-to make prescription decisions for a variety of therapies and DME of increasing complexity. We report results as proportions of returned and completed questionnaires. Comparisons among the 3 groups (pediatricians from Ohio and Mississippi and residents) were made with the use of chi(2) analysis.

RESULTS

For some categories of therapy and DME, physicians and residents reported that they would take an active role in prescription decisions, and their reliance on specialty consultation increased appropriately with the increasing complexity of the device or therapy. However, respondents generally seemed to share responsibility rather than rely on themselves as sole decision makers for most categories; fewer than one fourth took sole responsibility. Reliance on nonphysician health care providers was evident for all categories; in some cases, up to half of the respondents would allow therapists to take over these decisions, and a small but significant percentage of physicians would entrust DME prescription decisions to vendors alone.

CONCLUSIONS

Our findings indicate that many practicing pediatricians and those in training may be unwilling to assume sole responsibility in prescribing and managing therapies and DME for CWSN. Although the number who would rely on consultation with specialists is somewhat reassuring, we found that a significant percentage would turn to nonphysician health care providers and even vendors to make these decisions in some cases, raising liability implications, conflict-of-interest issues, and quality-of-care issues. To protect themselves and their patients from fraud and inappropriate prescriptions and medical management, pediatricians must become increasingly conscientious about complying with American Medical Association guidelines and federal and state laws regarding initiation and supervision of therapies and DME. We offer some recommendations that may help to address this problem.

Symmetry in square contingency tables: tests of hypotheses and confidence interval construction

Bowker's test, a generalization of McNemar's test, performs well under the hypothesis of symmetry, but the estimator of variance used in the test is biased when the table is asymmetric and this calls into question the test's performance in non-null situations. We seek an alternative to Bowker's test in search of methods for simultaneous inference that are valid when the hypothesis of symmetry is false. We apply multivariate normal theory to develop chi-square tests and simultaneous confidence intervals for inferences concerning symmetry in k X k contingency tables. We propose a modified Wald statistic as a competitor to Bowker's test. We also proffer quadratic estimators of confidence intervals. In large samples, the recommended test statistic rejects the null hypothesis at the stated level of significance when the null hypothesis is true and always rejects with greater power than Bowker's test. The proffered interval estimators provide good simultaneous coverage of the pairwise differences between the population proportions at the stated confidence level.

Change in platelet count predicts eventual maternal outcome with syndrome of hemolysis, elevated liver enzymes and low platelet count

OBJECTIVE

To profile the rates of change for platelets and lactate dehydrogenase (LDH) in patients with the syndrome of hemolysis, elevated liver enzymes and low platelet count (HELLP) to reflect and possibly predict disease severity.

METHODS

Serial determinations of the platelet count and serum LDH were analyzed retrospectively for 545 patients with HELLP syndrome and 94 severely pre-eclamptic patients. A repeated measures (mixed model) analysis of variance (ANOVA) was utilized to estimate the rates of change for LDH and platelets in each group.

RESULTS

Patients who developed class 1 or 2 HELLP syndrome exhibited a rapid deterioration in platelet count of 45-50,000/microl per day compared to 30,000/microl per day for class 3 and non-HELLP severe pre-eclampsia. For LDH, values increased at a rate of approximately 1400 IU/l per day, 600 IU/l per day, 300 IU/l per day and 200 IU/l per day for patients with classes 1, 2 and 3 and for non-HELLP severe pre-eclampsia, respectively.

CONCLUSION

The rate of change of platelets and LDH appeared to correlate well with eventual syndrome severity and this can be used to enhance patient assessment beyond the value of a single test for either laboratory parameter.

Leukocytosis is proportional to HELLP syndrome severity: evidence for an inflammatory form of preeclampsia

BACKGROUND

We investigated the possibility that HELLP syndrome is in part a systemic inflammatory response.

METHODS

We evaluated total white blood cell (WBC) counts of all patients with severe preeclampsia with and without HELLP syndrome admitted to our hospital between 1995 and 1997. Patients were grouped by diagnosis and timing of platelet nadir. Analysis of variance and regression analysis were used for data analysis.

RESULTS

Of 177 patients, 91 had HELLP syndrome, and 86 had severe preeclampsia alone. The WBC counts were significantly higher in patients with HELLP syndrome (12.5 +/- .442 x 10(9)/L) than in patients with severe preeclampsia (10.3 +/- .288 x 10(9)/L). Regression analysis showed that platelet counts varied inversely with WBC counts. Also, patients with class I HELLP syndrome had significantly higher WBC counts than patients with other classes of HELLP syndrome.

CONCLUSION

The finding of an association between increasing leukocytosis and worsening thrombocytopenia early in the course of HELLP syndrome supports the hypothesis that it may represent an inflammatory process.

Increasing maternal weight: a risk factor for preeclampsia/eclampsia but apparently not for HELLP syndrome

BACKGROUND

Maternal obesity is a risk factor for severe preeclampsia. We sought to ascertain whether a similar relationship exists between maternal weight and HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets) as an atypical form of severe preeclampsia.

METHODS

In this retrospective investigation, 434 patients with HELLP syndrome were assigned to one of four study groups according to maternal weight and were analyzed in relation to selected maternal and perinatal data reflective of disease severity.

RESULTS

We found no significant associations between maternal weight and parameters of HELLP syndrome severity, race, delivery mode, gestational age, or perinatal outcome. Significantly associated with increasing maternal weight were maternal age, parity, admission mean arterial pressure, peak peripartum systolic blood pressures, concurrent essential hypertension, and the interval between admission and delivery. Inversely associated were eclampsia and the interval between delivery and discharge.

CONCLUSIONS

Severity and complications attendant with HELLP syndrome appear unrelated to maternal weight. Paradoxically, eclampsia occurs most commonly in the lighter gravida with HELLP syndrome.

A prospective, randomized, controlled trial of high and low maintenance doses of magnesium sulfate for acute tocolysis

OBJECTIVE

This study was undertaken to compare a high-dose protocol for magnesium sulfate tocolytic therapy with a low-dose regimen with respect to time needed to achieve tocolysis.

STUDY DESIGN

Patients between 24 and 34 weeks' gestation with preterm labor were included. Patients with ruptured membranes or nonreassuring fetal assessments were excluded. Gravid women received a 4-g loading dose of magnesium sulfate and were prospectively randomly assigned to receive a maintenance dose of 2 or 5 g/h.

RESULTS

The median times to tocolysis were 120 minutes (semi-interquartile range, 30 minutes) in the low-dose group and 90 minutes (semi-interquartile range, 28 minutes) in the high-dose group (P <.001).

CONCLUSION

Patients treated with a higher maintenance dose of magnesium sulfate had a higher frequency of side effects; however, tocolysis was achieved more rapidly and they required shorter admissions to the labor and delivery unit without increased maternal or neonatal morbidity.

Relationship between serum inositol concentration and development of retinopathy of prematurity: a prospective study

PURPOSE

To examine the relationship between the intake of sugar inositol, serum inositol levels, and ROP in three groups of low birthweight infants receiving feedings containing various concentrations of inositol.

METHODS

Infants with a birthweight <1500 g, with severe lung disease, were eligible for the study when they began enteral feedings. Infant formulas contained three different inositol concentrations: 2500, 710, and 242 micromol/L. Serum inositol concentrations were averaged over specific time intervals. A logistic regression model was used to investigate the confounding effect of duration of mechanical ventilation and oxygen therapy, birthweight, Apgar score, and serum inositol concentration on development of ROP.

RESULTS

Infants receiving high inositol formula and with higher serum inositol concentrations at birth and after 30 days had a statistically significant lower incidence of severe ROP than those receiving the lower inositol formula and with lower serum concentrations (P<.05). The effective serum inositol concentration (EC90) associated with lesser disease was >215 micromol/L. By logistic regression, the odds of developing severe ROP were greater among infants with low serum inositol concentration (odds ratio=4.7, 95% confidence interval 0.90-24.8, P=.017).

CONCLUSION

Inositol supplementation may help prevent the most severe form of ROP.

Training of pediatricians in care of physical disabilities in children with special health needs: results of a two-state survey of practicing pediatricians and national resident training programs

OBJECTIVE

One goal of the American Academy of Pediatrics' Future of Pediatric Education II Project is to establish guidelines in training physicians to care for children with special health care needs (CWSN). Assessment of current practices in prescribing therapies and devices is necessary to meet this goal. Although much has been written about CWSN, there is a paucity of literature describing pediatricians' preparedness in prescribing such therapies and devices to children with physical disabilities. In an effort to assess physician preparedness, we surveyed pediatric residents nationwide and practicing pediatricians from 2 states, 1 urban and 1 rural. METHODS. A questionnaire aimed at identifying areas of concern regarding preparedness of physicians in practice and in training was prepared and mailed to prospective participants in Ohio and Mississippi. After follow-up mailings to nonresponders, approximately 59% responded. Summary statistics were reported as proportions with 95% confidence intervals.

RESULTS

Among those polled, >70% reported no training in prescribing certain durable medical equipment and over 50% reported no training in prescribing certain therapies. In addition, at least 20% reported no training in treating some of the more common childhood physical disabilities. Nearly three fourths of the respondents indicated that they did not believe that they were adequately prepared to take an active role in prescribing therapies and durable medical equipment. Fewer respondents believed that they should be the sole providers of these therapies and durable medical equipment.

CONCLUSIONS

The results of the survey indicate a lack of specific training and physician confidence in prescribing therapies and devices to CWSN, establishing the necessity of expanding training programs to better ensure quality health care for special needs children. Although additional ongoing research is necessary to fully evaluate the preparedness of physicians in caring for CWSN, this survey does help to identify areas of physician training that require improvement to provide quality health care for CWSN.

Cardiopulmonary morbidity as a complication of severe preeclampsia HELLP syndrome

OBJECTIVE

To profile the types and frequencies of cardiopulmonary morbidity encountered in patients with severe preeclampsia with or without hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome).

STUDY DESIGN

We initiated a retrospective study of 979 patients with severe preeclampsia with and without HELLP syndrome. Types of cardiopulmonary morbidity were analyzed among the three classes of HELLP syndrome and severe preeclampsia without HELLP syndrome.

RESULTS

Cardiopulmonary morbidity occurred in 7.6% of study patients. As a group, patients with cardiopulmonary complications were more likely to have cesareans (11% vs 6%, p = 0.019) earlier in gestation (1366 +/- 700 gm birth weight versus 1734 +/- 892 gm birth weight, p = 0.021), with higher peak postpartum blood pressures (< 0.001) and with more abnormal laboratory values indicative of multisystem disease, compared with patients without this complication. Patients with cardiopulmonary complications required almost twice as long to achieve diuresis as comparison patients (22 +/- 23 hours versus 12 +/- 11 hours, p < 0.001).

CONCLUSION

The probability of cardiopulmonary complications increases significantly when patients develop class 1 HELLP syndrome. Of all cardiopulmonary complications, acute lung injury/acute respiratory distress syndrome is most specific to class 1 HELLP syndrome. Transient renal dysfunction is closely related to cardiopulmonary morbidity.

Oral nicardipine versus intravenous magnesium sulfate for the treatment of preterm labor

OBJECTIVE

The aim of this study was to compare the efficacy and safety of oral nicardipine in acute therapy for preterm labor with those of parenteral magnesium sulfate.

STUDY DESIGN

Patients between 24 and 34 weeks' gestation with documented preterm labor were randomly assigned to receive oral nicardipine (n = 57) or intravenous magnesium sulfate (n = 65) as initial tocolytic therapy. Patients in the nicardipine group received a 40-mg loading dose and then 20 mg every 2 hours as needed to stop contractions (total 80 mg). Patients in the magnesium sulfate group received a 6-g bolus followed by 2 to 4 g/h to provide uterine quiescence. Patients could be switched to another tocolytic regimen if they continued to have contractions after 6 hours of therapy. The main outcome variables examined were time to uterine quiescence, time gained in utero, recurrence of preterm labor, failure of tocolysis, and pertinent maternal and neonatal outcomes.

RESULTS

There were no significant differences in maternal demographic characteristics between the groups. Among patients who responded with uterine quiescence within 6 hours, there was a significant decrease in the time to uterine quiescence in the nicardipine group (P <.01). Patients in the magnesium sulfate group were more likely to have recurrence of preterm labor necessitating further tocolytic attempts (P =.048). The patients in the magnesium sulfate group had more adverse side effects, mainly nausea and vomiting (P =.004). There were no differences in birth weight, estimated gestational age at delivery, or neonatal complications between the 2 groups.

CONCLUSIONS

Oral nicardipine is an effective, safe, and well-tolerated tocolytic agent. In this prospective clinical trial patients randomly assigned to receive oral nicardipine had arrest of preterm labor more rapidly than did those randomly assigned to receive parenteral magnesium sulfate. Patients who received magnesium sulfate were more likely to have adverse medication effects and recurrent preterm labor.

Second-trimester uterine evacuation: A comparison of intra-amniotic (15S)-15-methyl-prostaglandin F2alpha and intravaginal misoprostol

OBJECTIVE

Our purpose was to compare the efficacy, safety, and adverse effects of intra-amniotically administered (15S)-15-methyl-prostaglandin F(2alpha) and intravaginally administered misoprostol for second-trimester uterine evacuation.

STUDY DESIGN

Fifty-one patients were randomly assigned to receive either a single 2.5-mg intra-amniotic injection of (15S)-15-methyl-prostaglandin F(2)(alpha) (n = 26) or two 200-microg intravaginal doses of misoprostol (n = 25) at 12-hour intervals. The primary outcome measured was evacuation of the uterus within 24 hours.

RESULTS

The mean time from initiation of termination to uterine evacuation was less in the prostaglandin group than in the misoprostol group (17.5 +/- 8.6 hours vs 22.3 +/- 12.5 hours), but this was not statistically significant (P >.05). The rate of successful fetal evacuation at 24 hours was significantly higher in the prostaglandin group than in the misoprostol group (88% vs 60%, P =.02). The complete-abortion rate and the incidence of adverse effects were similar in both groups.

CONCLUSION

The use of an intra-amniotic injection of (15S)-15-methyl-prostaglandin F(2alpha) for midtrimester pregnancy termination is safe and is associated with a greater number of successful uterine evacuations within 24 hours, without an increase in adverse effects, than intravaginal administration of misoprostol.

The spectrum of severe preeclampsia: comparative analysis by HELLP (hemolysis, elevated liver enzyme levels, and low platelet count) syndrome classification

OBJECTIVE

This study was undertaken to explore the spectrum of maternal disease with a triple classification system of HELLP (hemolysis, elevated liver enzyme levels, and low platelet count) syndrome and compare these classes with severe preeclampsia without HELLP syndrome.

STUDY DESIGN

In this retrospective analytic study the pregnancies of 777 patients with class 1, 2, or 3 HELLP syndrome were compared and contrasted with those of 193 women with severe preeclampsia but without HELLP syndrome.

RESULTS

Eclampsia, epigastric pain, nausea and vomiting, significant proteinuria, major maternal morbidity, and stillbirth increased as HELLP syndrome worsened from class 3 to class 1. In contrast, headache and diastolic hypertension were more common among the significantly heavier patients with severe preeclampsia without HELLP syndrome. Approximately half of pregnancies complicated by class 1 HELLP syndrome exhibited significant maternal morbidity, compared with only 11% of those complicated by severe preeclampsia without HELLP syndrome. Although a significant trend was apparent in increasing levels of lactate dehydrogenase, aspartate aminotransferase, and uric acid as HELLP syndrome worsened, there was considerable variation within groups.

CONCLUSION

Laboratory and clinical indices of disease severity in patients with severe preeclampsia or eclampsia generally were highest with class 1 HELLP syndrome and were lowest when HELLP syndrome was absent. Class 3 HELLP syndrome is considered a clinically significant transitional group.

Early risk assessment of severe preeclampsia: admission battery of symptoms and laboratory tests to predict likelihood of subsequent significant maternal morbidity

OBJECTIVE

This study was undertaken to investigate the utility of an admission battery of findings and laboratory data in the discrimination of patients with severe preeclampsia with or without HELLP (hemolysis, elevated liver enzyme levels, and low platelet count) syndrome at high risk for development of significant maternal morbidity.

STUDY DESIGN

The clinical and laboratory findings at hospital admission for 970 patients with severe preeclampsia with or without HELLP syndrome were studied retrospectively to develop parameters associated with low, moderate, and high risks for the subsequent development of significant maternal morbidity involving the hematologic and coagulation, cardiopulmonary, and hepatorenal systems.

RESULTS

Nausea and vomiting and epigastric pain are independent risk factors for complicated severe preeclampsia. Results of a panel of tests with values including lactate dehydrogenase level >1400 IU/L, aspartate aminotransferase level >150 IU/L, alanine aminotransferase level >100 IU/L, uric acid level >7.8 mg/dL, serum creatinine level >1.0 mg/dL, and 4+ urinary protein by dipstick can be used to discriminate the patient at high risk for significant maternal morbidity. Concentrations of lactate dehydrogenase, aspartate aminotransferase, and uric acid above these cut points have the strongest predictive value and are risk additive with worsening thrombocytopenia.

CONCLUSION

The presence of nausea and vomiting, epigastric pain, or both in association with admission laboratory values that are in excess of the cutoffs for lactate dehydrogenase, aspartate aminotransferase, and uric acid concentrations or for all 6 tests is predictive of high risk of morbidity for the patient with severe preeclampsia. These factors are independent of and additive with the rising maternal risk associated with decreasing platelet count.

Preeclampsia-associated hepatic hemorrhage and rupture: mode of management related to maternal and perinatal outcome

This article is a critical review of the obstetric literature concerning preeclampsia-associated hepatic hemorrhage to develop guidelines conducive to optimal maternal and perinatal outcomes. An English literature search was performed for reports of hepatic hemorrhage or hepatic rupture in pregnancy during 1960 to 1997. Data were analyzed by Statmost packages using ANOVA, Chi-square, and Fisher's exact tests. One hundred forty-one patients with hepatic rupture/hemorrhage were reported. The three most common presenting findings were epigastric pain, hypertension, and shock. With rare exception, patients had evidence of preeclampsia. Diagnosis was elusive and most frequently accomplished at laparotomy. When utilized, ultrasound and computed tomography (CT) were helpful diagnostic modalities. Maternal survival was highest in the arterial embolization treatment group. Maternal and perinatal survival improved considerably during the study interval. Route of delivery did not seem to impact survival rates. It was concluded that the application of ultrasound and CT for diagnosis and the use of hepatic artery embolization for treatment of hepatic hemorrhage/rupture seem to be beneficial management options for this rare event.

Individually determined postpartum magnesium sulfate therapy with clinical parameters to safely and cost-effectively shorten treatment for pre-eclampsia

OBJECTIVE

The purpose of this study was to investigate the safety of treating pre-eclampsia with magnesium sulfate, with clinical determinants used for drug discontinuation.

STUDY DESIGN

One hundred sixty-eight patients were enrolled. After delivery, women with mild pre-eclampsia received a minimum of 6 hours of intravenous magnesium sulfate, whereas women with severe pre-eclampsia received a minimum of 12 hours. Magnesium sulfate was discontinued in the absence of clinical symptoms associated with spontaneous diuresis, minimal protein by urinary dipstick, and satisfaction of predetermined blood pressure criteria.

RESULTS

Patients with mild pre-eclampsia required significantly less magnesium sulfate (mean 9.5 +/- 4.2 hours) than did those with severe pre-eclampsia alone (mean 16 +/- 5.9 hours); pre-eclampsia superimposed on chronic hypertension (mean 16 +/- 5.8 hours); or hemolysis, elevated liver enzyme, and low platelet count syndrome (mean 20 +/- 6.7 hours). With this protocol there was no eclampsia, and recovery room time was reduced by 50%.

CONCLUSION

Individual determination of postpartum magnesium sulfate therapy for pre-eclampsia appears to be a safe approach that carries minimal risk of eclampsia.

Cervical ripening: a randomized comparison between intravaginal misoprostol and an intracervical balloon catheter combined with intravaginal dinoprostone

OBJECTIVES

Our purpose was to compare the efficacy of intravaginal misoprostol and intracervical Foley catheter/intravaginal dinoprostone for cervical ripening.

STUDY DESIGN

Patients admitted for induction of labor were randomized to receive intravaginal misoprostol 25 microg every 4 hours or intracervical Foley catheter/intravaginal dinoprostone 4 mg every 4 hours. Patients not entering active labor and having ruptured membranes or arrest of dilatation received intravenous oxytocin.

RESULTS

Sixty-five patients received Foley catheter/dinoprostone gel and 62 patients received misoprostol. The mean time until cervical ripening was less in the catheter/gel group (7.5 +/- 3.4 vs 12.0 +/- 5.9 hours, p < 0.01). The mean time until vaginal delivery was less in the catheter/gel group (17.4 +/- 6.9 vs 21.2 +/- 7.5 hours, p = 0.004). Among vaginal deliveries, more patients in the catheter/gel group delivered within 24 hours (90% vs 69%, p = 0.013).

CONCLUSIONS

Intracervical Foley catheter/intravaginal dinoprostone was associated with more rapid cervical ripening, shorter induction to vaginal delivery interval, and greater number of vaginal deliveries within 24 hours.

On the singularity of the covariance matrix for estimates of multinomial proportions

It is well known that the covariance matrix for the multinomial distribution is singular and, therefore, does not have a unique inverse. If, however, any row and corresponding column are removed, the reduced matrix is nonsingular and the unique inverse has a closed form. We elucidate some of the properties of the multinomial covariance matrix and its reduced forms. We state and prove a theorem that gives insight into the singularity and its removal. Based on these results, we establish that the covariance matrix for the multinomial distribution is positive semidefinite and that the reduced matrix is positive definite. In addition, we show that the determinant of the reduced matrix is invariant to the particular row and column that are removed. Goodness-of-fit statistics, including Pearson's chi-square, and justification of the degrees of freedom follow from the multivariate central limit theorem once the singularity is removed.

Hypothesis testing and confidence interval construction in 2 x 2 tables of correlated proportions

The 2 x 2 table is an invaluable tool for displaying bivariate binary data. It is easy to find examples of correlated binary response in biopharmaceutical experiments and clinical research and analysis of these data is a current research topic. The most common hypothesis tested for 2 x 2 tables of correlated proportions is that of homogeneity of the marginal proportions or, equivalently, the hypothesis of table symmetry. The 2 x 2 table of correlated proportions is rich with information and we present a survey of some of the analyses relevant for these data. Using asymptotic theory, we develop estimators of relevant parameters and associated test statistics that are of interest. We discuss interval estimation using arguments proposed by Quesenberry and Hurst (1) and Goodman (2). These interval estimators do not rely on estimation of the covariance matrix and are not necessarily equivalent to those obtained using modified chi-square statistics.

Confidence intervals for differences in correlated binary proportions

An experiment to assess the efficacy of a particular treatment or process often produces dichotomous responses, either favourable or unfavourable. When we administer the treatment on two occasions to the same subjects, we often use McNemar's test to investigate the hypothesis of no difference in the proportions on the two occasions, that is, the hypothesis of marginal homogeneity. A disadvantage in using McNemar's statistic is that we estimate the variance of the sample difference under the restriction that the marginal proportions are equal. A competitor to McNemar's statistic is a Wald statistic that uses an unrestricted estimator of the variance. Because the Wald statistic tends to reject too often in small samples, we investigate an adjusted form that is useful for constructing confidence intervals. Quesenberry and Hurst and Goodman discussed methods of construction that we adapt for constructing confidence intervals for the differences in correlated proportions. We empirically compare the coverage probabilities and average interval lengths for the competing methods through simulation and give recommendations based on the simulation results.

A SAS macro for constructing simultaneous confidence intervals for multinomial proportions

Quesenberry and Hurst (1964), Goodman (1965) and Fitzpatrick and Scott (1987) proposed simultaneous construction of confidence intervals for multinomial proportions, however. statistical computing packages do not generally give one the option of specifying the type of construction to be used. We have written a SAS macro using PROC IML that takes multinomial cell counts as input and returns simultaneous confidence intervals with the user-specified coverage probability. Two main features of the macro are its ease of use and its flexibility in allowing the user to choose among six methods of constructing confidence intervals for multinomial proportions. Based on simulation May and Johnson (1997) recommended the intervals proposed by Goodman (1965) in most practical applications.

The validity and power of tests for equality of two correlated proportions

With measurements taken on subjects over time, on matched pairs of subjects or on clusters of subjects, the data often contain pairs of correlated dichotomous responses. McNemar's test is perhaps the best known test to compare two correlated binomial proportions. The salient feature of McNemar's test is that we compute the variance of the contrast estimator under the restriction that the null hypothesis is true. Wald's test, on the other hand, does not require that restriction. As a consequence, Wald's statistic is always greater in magnitude than McNemar's statistic when the marginal proportions are unequal, but there is a problem with the validity of both McNemar's test and Wald's test with small to moderate samples. There have been various modifications suggested for McNemar's test to improve its performance. We propose a modified Wald's test that is valid in small to moderate samples and maintains good power. We also evaluate the performance of McNemar's test and Wald's test with and without modifications to enhance validity as well as the performance of the large sample likelihood ratio test and an exact test of the equality of correlated binomial proportions. In a smaller study, we compare the behaviour of a test based on the James-Stein estimator of the common odds ratio proposed by Liang and Zeger to McNemar's test and Wald's test.

Generalized estimating equations for multivariate response with the variates having different distributions

This paper addresses the problem of analyzing multivariate response with the variates having different distributions. We use the generalized estimating equations proposed by Prentice and Zhao (1) to estimate mean and covariance parameters. Wald statistics are used to test hypotheses about the parameters. Data from a two-group study of competing programs to increase memory recall in geriatric patients are analyzed. We are interested in determining whether there is a simultaneous increase in test scores with one variate being continuous and another being dichotomous. In a second example, comparisons of before-and-after treatment serum cholesterol levels and number of snacks eaten per day are made in an experiment to determine efficacy of a program aimed at simultaneously reducing both measurements.

Combining 2 x 2 tables that contain structural zeros

When one cell or more of a contingency table is necessarily zero, the table is said to contain structural zeros. These structural voids may be inherent to the problem at hand, or, in some applications, they may be introduced intentionally through the experimental design. With data classified by a third stratification variable, one needs a method for analysing a set of independent 2 x 2 tables. We propose Cochran-Mantel-Haenszel type analyses that combine observations across strata. We also propose tests of hypotheses pertaining to the marginal and conditional probabilities.

Some applications of the analysis of multivariate normal data with missing observations

Methods are proposed for the analysis of data from a multivariate normal distribution when observations are missing completely at random on some of the variates. Park (1) proved the equivalence of the solutions given by maximum likelihood and generalized estimating equations when data are complete and an unstructured covariance is assumed. He suggested that generalized estimating equations may be used if sample sizes are large relative to the amount of missing data and the estimated covariance matrix is positive definite. We give several examples indicating that the estimating equations give results similar to those of maximum likelihood when smoothing of the covariance matrix to eliminate nonpositive definiteness is not encountered as, for example, under an assumption of exchangeable correlation. Generalized linear models are formulated that are appropriate for a wide class of experimental plans.

Effect of out-of-hospital albuterol inhalation treatments on patient comfort and morbidity

STUDY OBJECTIVE

To determine the effect of the institution of out-of-hospital albuterol treatments for acute asthma on out-of-hospital time intervals emergency department (ED) morbidity.

DESIGN

Retrospective chart and ambulance run report review.

PARTICIPANTS

All patients who presented with a diagnosis of asthma on the ED record and ambulance run report during 1988 and 1990.

RESULTS

Ninety patients treated prior to the routine use of nebulized albuterol (in 1988) and 86 patients treated during the period after the institution of nebulized albuterol (in 1990) were compared. Age, sex, scene and travel times, vital signs, peak expiratory flow rates, length of ED stay, hospitalizations, ED treatment, and mortality were recorded for each patient. Changes over time were determined using a cohort of asthma patients in each year as controls. Severity was recorded as low (less than 3) or high (3 or more) on a modified Fischl index for asthma. Groups were compared by F test, chi 2, or t test with P < .05 considered significant. Because there were differences for admission rates, first-hospital peak expiratory flow rates, and aminophylline use in control groups, the experimental groups could not be compared. No significant difference in travel interval, steroid use, albuterol treatments, or length of ED stay was determined in either the experimental or control group. Scene time (9.7 minutes versus 12.1 minutes) was significantly shorter in 1988 than in 1990 (difference, 2.4 minutes; 95% confidence interval, 0.2 to 4.6; P < .01). The percentage of patients with high initial severity of disease (85% versus 66%; P < .001) and the percentage of patients with first posttreatment peak expiratory flow rates of less than 120 L/min (77% versus 58%; P < .001) were significantly higher in 1988 than in 1990. There was no significant difference in scene time, severity scores, or first posttreatment peak expiratory flow rates in control groups.

CONCLUSION

The institution of out-of-hospital use of nebulized albuterol increased scene time and increased first posttreatment peak expiratory flow rates significantly. There was a significant decrease in initial patient severity as measured on the modified Fischl index, although the validity of this index has not been established. It did not affect travel interval, length of stay in the ED, or medication use after ED presentation.

A computer package for the multivariate nonparametric rank test in completely randomized experimental designs

When research data are measured on at least an ordinal scale and the assumptions required in the theory underlying parametric statistical methods are in question, nonparameteric procedures based on the ranks provide a sound approach to statistical analysis. Biomedical investigations, especially clinical trials, typically involve multivariate response and therefore multivariate statistical methods are called for in the interpretation of results. We discuss applications of the nonparametric multivariate rank test for completely randomized designs. Large sample theory can be used to support these statistical methods for assessing group differences in location. In small samples, randomization tests provide a basis for inferences. The execution of the procedure is facilitated by a computer program developed by the authors.