Fetal and neonatal neuroimaging in twin-twin transfusion syndrome

OBJECTIVES

To describe the types of brain injury and subsequent neurodevelopmental outcome, to determine risk factors for brain injury and to review the use of neuroimaging modalities in fetuses and neonates with twin-twin transfusion syndrome (TTTS).

METHODS

Retrospective cohort study of consecutive TTTS pregnancies treated with laser surgery in a single fetal therapy center between January 2010 and January 2020. Primary outcome was the incidence of brain injury, divided into predefined groups. Secondary outcomes included adverse outcome (perinatal mortality or neurodevelopmental impairment (NDI)), risk factors for brain injury and the numbers of magnetic resonance imaging (MRI) scans.

RESULTS

Fetal and neonatal brain ultrasound was performed in all 466 TTTS pregnancies and 685/749 (91%) liveborn neonates. MRI was performed in 3% of pregnancies and 4% of neonates. Brain injury was diagnosed in 16/935 (2%) fetuses and 37/685 (5%) neonates and all predefined injury groups were represented. Four fetal and four neonatal cases of cerebellar hemorrhage were detected. In the group with brain injury, perinatal mortality occurred in 11/16 (69%) fetuses and 8/37 (22%) neonates. Follow-up was available for 29/34 (85%) long-term survivors with brain injury and mean age at follow-up was 46 months. NDI was present in 9/29 (31%) survivors with brain injury. Adverse outcome occurred in 28/53 (53%) TTTS individuals with brain injury. The risk of brain injury was increased after recurrent TTTS/post-laser twin anemia polycythemia sequence (TAPS) (OR 3.095, 95%-CI 1.581 - 6.059, p = .001) and lower gestational age (GA) at birth (OR 1.381 for each week less, 95%-CI 1.238 - 1.541, p < .001).

CONCLUSIONS

Based on dedicated neurosonography and limited use of MRI, brain injury was diagnosed in 2% of fetuses and 5% of neonates with TTTS. Adverse outcome was seen in over half of cases with brain injury. Brain injury was related to recurrent TTTS/post-laser TAPS and a lower GA at birth. This article is protected by copyright. All rights reserved.

Epidural analgesia and emergency delivery for presumed fetal compromise: post-hoc analysis of RAVEL multicenter randomized controlled trial

OBJECTIVE

To investigate the association between epidural analgesia (EDA) vs patient-controlled remifentanil analgesia (PCRA) and emergency delivery for presumed fetal compromise, in relation to birth-weight quintile.

METHODS

This was a post-hoc per-protocol analysis of the RAVEL multicenter equivalence randomized controlled trial. Non-anomalous singleton pregnancies between 36 + 0 and 42 + 6 weeks' gestation were randomized at the time of requesting pain relief to receive EDA or PCRA. The primary outcome was emergency delivery for presumed fetal compromise. Secondary outcomes included mode of delivery and neonatal outcomes. Analysis was performed according to birth-weight quintile and was corrected for relevant confounding variables.

RESULTS

Of 619 pregnant women, 336 received PCRA and 283 received EDA. Among women receiving EDA, 14.8% had an emergency delivery for presumed fetal compromise, compared with 8.3% of women who received PCRA. After adjusting for parity, women receiving EDA had higher odds of presumed fetal compromise compared to those receiving PCRA (odds ratio, 1.69 (95% CI, 1.01-2.83)). A statistically significant linear-by-linear association was observed between presumed fetal compromise and birth-weight quintile (P = 0.003). The incidence of emergency delivery for presumed fetal compromise was highest in women receiving EDA and delivering a neonate with a birth weight in the lowest quintile.

CONCLUSIONS

Intrapartum EDA is associated with a higher rate of emergency delivery for presumed fetal compromise compared to treatment with PCRA. Birth-weight quintile is a strong predictor of this outcome, independent of pain management method. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Age-associated systemic factors change central and peripheral immunity in adult male mice

Aging coincides with major changes in brain immunity that aid in a decline in neuronal function. Here, we postulate that systemic, pro-aging factors contribute to immunological changes that occur within the brain during aging. To investigate this hypothesis, we comprehensively characterized the central and peripheral immune landscape of 20-month-old male mice using cytometry by time-of-flight (CyTOF) and investigated the role of age-associated circulating factors. We found that CD8+ T cells expressing programmed cell death protein 1 (PD1) and tissue-resident memory CD8+ T cells accumulated in the aged brain while levels of memory T cells rose in the periphery. Injections of plasma derived from 20-month-old mice into 5-month-old receiving mice decreased the frequency of splenic and circulating naïve T cells, increased memory CD8+ T cells, and non-classical, patrolling monocytes in the spleen, and elevated levels of regulatory T cells and non-classical monocytes in the blood. Notably, CD8+ T cells accumulated within white matter areas of plasma-treated mice, which coincided with the expression of vascular cell adhesion molecule 1 (VCAM-1), a mediator of immune cell trafficking, on the brain vasculature. Taken together, we here describe age-related immune cell changes in the mouse brain and circulation and show that age-associated systemic factors induce the expansion of CD8+ T cells in the aged brain.

Perinatal outcome after selective fetal reduction in monochorionic twin pregnancies: A comparison of techniques over a 20-year period

OBJECTIVE

To assess perinatal outcome after fetal reduction in complicated monochorionic (MC) twin pregnancies comparing different techniques.

METHODS

A retrospective cohort study at a national referral center, comparing data between four techniques: interstitial laser coagulation (ILC), radiofrequency ablation (RFA), fetoscopic laser coagulation (FLC) and bipolar cord coagulation (BCC). The primary outcome was mortality of the co-twin. Secondary outcomes were preterm pre-labor rupture of membranes (PPROM), gestational age at delivery and neonatal morbidity.

RESULTS

259 MC twin pregnancies underwent selective fetal reduction: 29 IL, 64 RFA, 85 FLC and 81 BCC. Perinatal mortality rate was 29% and fetal demise of the co-twin occurred in 19%. The lowest mortality rate was seen after BCC (17%, P=0.012). PPROM occurred in 18% without significant differences between techniques. Mean gestational age at delivery in liveborn children was 35 weeks and did not differ between techniques. Severe cerebral injury and neonatal morbidity were reported in 4% and 14% respectively, without significant differences between techniques.

CONCLUSIONS

Selective fetal reductions in MC twins are precarious procedures with an increased risk of perinatal mortality of the co-twin. Our results show the lowest mortality rates after BCC. However, high PPROM rates were seen irrespective of the technique. This article is protected by copyright. All rights reserved.

Fetal anemia in monochorionic twins: a review on diagnosis, management, and outcome

INTRODUCTION

Monochorionic twins may develop fetal anemia when blood is unequally distributed via the placental vascular anastomoses. This review focuses on the causes of fetal anemia in complicated monochorionic twins and highlights the differences in management and outcome.

AREAS COVERED

Fetal anemia can occur in the context of twin anemia polycythemia sequence (TAPS), chronic twin-twin transfusion syndrome (TTTS) and acute peripartum TTTS, and in cotwins after single fetal demise. Diagnosis of fetal anemia is based on abnormal Doppler ultrasound measurements. Management options include fetoscopic laser surgery, intrauterine blood transfusion, or expectant management, depending on the type of complication and the severity of the disease. In all complications, fetal anemia may lead to perinatal mortality, neonatal morbidity, severe cerebral injury, and long-term neurodevelopmental impairment. In TAPS specifically, anemic donors may also show bilateral deafness.

EXPERT OPINION

Knowledge on the diagnosis and optimal treatment in TTTS is nowadays widespread, but caregivers often fail to distinguish TAPS from acute peripartum TTTS at birth. A full blood count including reticulocyte count is required, and placental dye injection is extremely helpful to reach the correct diagnosis and establish the optimal management.

Markers of aging: Unsupervised integrated analyses of the human plasma proteome

Aging associates with an increased susceptibility for disease and decreased quality of life. To date, processes underlying aging are still not well understood, leading to limited interventions with unknown mechanisms to promote healthy aging. Previous research suggests that changes in the blood proteome are reflective of age-associated phenotypes such as frailty. Moreover, experimentally induced changes in the blood proteome composition can accelerate or decelerate underlying aging processes. The aim of this study is to identify a set of proteins in the human plasma associated with aging by integration of the data of four independent, large-scaled datasets using the aptamer-based SomaScan platform on the human aging plasma proteome. Using this approach, we identified a set of 273 plasma proteins significantly associated with aging (aging proteins, APs) across these cohorts consisting of healthy individuals and individuals with comorbidities and highlight their biological functions. We validated the age-associated effects in an independent study using a centenarian population, showing highly concordant effects. Our results suggest that APs are more associated to diseases than other plasma proteins. Plasma levels of APs can predict chronological age, and a reduced selection of 15 APs can still predict individuals' age accurately, highlighting their potential as biomarkers of aging processes. Furthermore, we show that individuals presenting accelerated or decelerated aging based on their plasma proteome, respectively have a more aged or younger systemic environment. These results provide novel insights in the understanding of the aging process and its underlying mechanisms and highlight potential modulators contributing to healthy aging.

Crossing borders in Alzheimer's disease: A T cell's perspective

Alzheimer's disease (AD) is the most common form of dementia affecting millions of people worldwide. While different immunotherapies are imminent, currently only disease-modifying medications are available and a cure is lacking. Over the past decade, immunological interfaces of the central nervous system (CNS) and their role in neurodegenerative diseases received increasing attention. Specifically, emerging evidence shows that subsets of circulating CD8⁺ T cells cross the brain barriers and associate with AD pathology. To gain more insight into how the adaptive immune system is involved in disease pathogenesis, we here provide a comprehensive overview of the contribution of T cells to AD pathology, incorporating changes at the brain barriers. In addition, we review studies that provide translation of these findings by targeting T cells to combat AD pathology and cognitive decline. Importantly, these data show that immunological changes in AD are not confined to the CNS and that AD-associated systemic immune changes appear to affect brain homeostasis.

High risk of long-term neurodevelopmental impairment in donor twins with spontaneous twin anemia-polycythemia sequence

OBJECTIVES

To evaluate the long-term neurodevelopmental and behavioral outcomes in surviving infants of pregnancies with spontaneous twin anemia-polycythemia sequence (TAPS), to compare outcome between donors and recipients, and to investigate potential risk factors for neurodevelopmental impairment (NDI).

METHODS

This was a retrospective study of a consecutive cohort of spontaneous-TAPS survivors delivered between 2005 and 2017 at the Leiden University Medical Center, The Netherlands. Neurological, motor, cognitive and behavioral development were assessed at a median age of 4 years. The primary outcome was NDI, which was a composite outcome of cerebral palsy, deafness, blindness and motor and/or cognitive delay. NDI was subdivided into two grades of severity: mild-to-moderate and severe NDI. Outcome was compared between surviving donor and recipient twins. Logistic regression analysis was used to assess risk factors for NDI.

RESULTS

Forty-nine twin pregnancies complicated by spontaneous TAPS were eligible for inclusion. The perinatal survival rate was 83% (81/98) of twins. Neurodevelopmental assessment was performed in 91% (74/81) of surviving twins. NDI occurred in 30% (22/74) of TAPS survivors, and was found more often in donors (44%; 15/34) than in recipients (18%; 7/40) (odds ratio (OR), 4.1; 95% CI, 1.8-9.1; P = 0.001). Severe NDI was detected in 9% (7/74) of survivors and was higher in donors compared with recipients (18% (6/34) vs 3% (1/40)), although the difference did not reach statistical significance; P = 0.056). Donors demonstrated lower cognitive scores compared with recipients (P = 0.011). Bilateral deafness was identified in 15% (5/34) of donors compared with 0% (0/40) of recipients (P = 0.056). Parental concern regarding development was reported more often for donor than for recipient twins (P = 0.001). On multivariate analysis, independent risk factors for NDI were gestational age at delivery (OR, 0.7; 95% CI, 0.5-0.9; P = 0.003) and severe anemia (OR, 6.4; 95% CI, 2.4-17.0; P < 0.001).

CONCLUSION

Surviving donor twins of pregnancies complicated by spontaneous TAPS have four-fold higher odds of NDI compared with recipient cotwins, are at increased risk of cognitive delay and have a high rate of deafness. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Impact of cannula size on recurrent twin-twin transfusion syndrome and twin anemia-polycythemia sequence after fetoscopic laser surgery

OBJECTIVE

The optimal outcome after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) depends on the successful ablation of all placental anastomoses. The objective of this study was to determine the incidence of and risk factors for recurrent TTTS (rTTTS) or twin anemia-polycythemia sequence (TAPS) after FLS, focusing on the impact of cannula diameter.

METHODS

This was a secondary analysis of data collected prospectively at two centers from 666 consecutive patients undergoing FLS for TTTS. The main outcomes were rTTTS and TAPS following FLS. Variables assessed included gestational age at intervention, stage of disease, recipient maximum vertical pocket, anterior placenta, number of anastomoses ablated, cannula diameter/operative scopes and use of the Solomon technique. Cannula diameter and corresponding scopes used were as follows: 8 Fr and 1.3 mm/0°; 9 Fr and 2.7 mm/0°; 10 Fr and 3 mm/0°; or 12 Fr and 3.3-3.7 mm/30-70°. Cannula diameter was used as a surrogate for scopes during analysis. Multivariate logistic regression analysis was performed to identify risk factors associated with rTTTS or TAPS after FLS; 'center' was considered an independent variable to account for variations in practice. In a nested cohort of pregnancies in which both fetuses survived, placental dye injection was performed in 315 placentae. Multivariate logistic regression analysis was performed to evaluate variables associated with the presence of residual anastomoses.

RESULTS

rTTTS or TAPS occurred in 61 (9%) cases following FLS (rTTTS in eight (1%) and TAPS in 53 (8%)). Factors associated significantly with the risk of rTTTS/TAPS on multivariate analysis were cannula diameter (when an 8-Fr, 9-Fr, 10-Fr or 12-Fr cannula was used, there was rTTTS/TAPS in 24%, 13%, 2% or 0.8% of cases, respectively (P < 0.001)) and use of the Solomon technique (rTTTS/TAPS occurred in 4.2% of those in which it was used vs 18.1% in those in which it was not (P < 0.001)). Only use of the Solomon technique was associated significantly with no residual anastomoses found after delivery.

CONCLUSIONS

Following FLS for TTTS, a lower incidence of rTTTS/TAPS was seen when the Solomon technique was used, as well as when a 10-Fr or 12-Fr cannula was used. A lower complication rate may be due to the use of a scope with better optics during placental mapping. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Placental characteristics in monochorionic twins with selective intrauterine growth restriction in relation to the umbilical artery Doppler classification

INTRODUCTION

The objective of this study was to evaluate the placental characteristics of monochorionic twin pregnancies with selective intrauterine growth restriction (sIUGR) classified according to the Gratacós classification based on umbilical artery Doppler measurements.

METHODS

All consecutive placentas from monochorionic twin pregnancies with sIUGR, (defined as a birthweight discordance > 25% and/or an estimated fetal weight in one twin <10th centile) examined between May 2002 and February 2018 were included in the study. Each placenta was injected with colored dye to study the angioarchitecture. Primary outcomes were placental share discordance and diameter of the arterio-arterial anastomoses in relation to the umbilical artery Doppler types of sIUGR (Gratacós classification).

RESULTS

Of the 83 sIUGR twins included, 27 were classified as Gratacós type I, 24 as type II and 32 as type III. The median gestational age at delivery was 34.3 weeks for type I, compared to 31.2 weeks and 31.6 weeks for type II and type III respectively. A trend towards a higher placental share discordance in type III sIUGR was observed. The median arterio-arterial diameter was 1.7 mm (0.8-2.6) in type I, 1.7 mm (1.2-2.2) in type II and 2.8 (2.0-3.5) mm in type III (p < 0.01).

DISCUSSION

Type III sIUGR placentas appear to be characterized by a larger diameter of the arterio-arterial anastomoses and a larger placental share discordance compared to type I and II sIUGR. The insights in the placental architecture of sIUGR placentas may offer new views on the pathophysiology of the disease.

Right ventricular outflow tract obstruction in complicated monochorionic twin pregnancy

OBJECTIVES

Severe right ventricular outflow tract obstruction (RVOTO) is a potential complication in recipient twins of twin-to-twin transfusion syndrome (TTTS) that requires postnatal follow-up or treatment. We aimed to evaluate pregnancy characteristics of neonates with RVOTO from complicated monochorionic twin pregnancies, determine the incidence of RVOTO in TTTS cases and construct a prediction model for its development.

METHODS

This was an observational cohort study of all complicated monochorionic twin pregnancies with a postnatal diagnosis of RVOTO examined at our center. Cases were referred for evaluation of the need for fetal therapy or intervention because of TTTS, selective intrauterine growth restriction (sIUGR) or multiple congenital malformations in one of the twins. Ultrasound data were retrieved from our monochorionic twin database. Among liveborn TTTS recipients treated prenatally with laser therapy, those with RVOTO were compared with those without RVOTO (controls). We describe four additional cases with RVOTO that were not TTTS recipients.

RESULTS

A total of 485 twin pregnancies received laser therapy for TTTS during the study period. RVOTO was diagnosed in 3% (11/368) of liveborn TTTS recipients, of whom two showed mild Ebstein's anomaly. Before laser therapy, pericardial effusion was seen in 45% (5/11) of RVOTO cases (P < 0.01) and abnormal A-wave in the ductus venosus (DV) in 73% (8/11) (P = 0.03), significantly higher proportions than in controls. Mean gestational age at laser therapy was 17 + 3 weeks in RVOTO cases compared with 20 + 3 weeks in controls (P = 0.03). A prediction model for RVOTO was constructed incorporating these three significant variables. One TTTS donor had RVOTO after the development of transient hydrops following laser therapy. Three larger twins in pregnancies complicated by sIUGR developed RVOTO, the onset of which was detectable early in the second trimester.

CONCLUSIONS

RVOTO occurs in TTTS recipient twins but can also develop in TTTS donors and larger twins of pregnancies complicated by sIUGR. Abnormal flow in the DV, pericardial effusion and early gestational age at onset of TTTS are predictors of RVOTO in TTTS recipients, which suggests increased vulnerability to hemodynamic imbalances in the fetal heart in early pregnancy. These findings could guide diagnostic follow-up protocols after TTTS treatment. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Quantitative multi-target RNA profiling in Epstein-Barr virus infected tumor cells

Epstein-Barr virus (EBV) is etiologically linked to multiple acute, chronic and malignant diseases. Detection of EBV-RNA transcripts in tissues or biofluids besides EBV-DNA can help in diagnosing EBV related syndromes. Sensitive EBV transcription profiling yields new insights on its pathogenic role and may be useful for monitoring virus targeted therapy. Here we describe a multi-gene quantitative RT-PCR profiling method that simultaneously detects a broad spectrum (n=16) of crucial latent and lytic EBV transcripts. These transcripts include (but are not restricted to), EBNA1, EBNA2, LMP1, LMP2, BARTs, EBER1, BARF1 and ZEBRA, Rta, BGLF4 (PK), BXLF1 (TK) and BFRF3 (VCAp18) all of which have been implicated in EBV-driven oncogenesis and viral replication. With this method we determine the amount of RNA copies per infected (tumor) cell in bulk populations of various origin. While we confirm the expected RNA profiles within classic EBV latency programs, this sensitive quantitative approach revealed the presence of rare cells undergoing lytic replication. Inducing lytic replication in EBV tumor cells supports apoptosis and is considered as therapeutic approach to treat EBV-driven malignancies. This sensitive multi-primed quantitative RT-PCR approach can provide broader understanding of transcriptional activity in latent and lytic EBV infection and is suitable for monitoring virus-specific therapy responses in patients with EBV associated cancers.

Prediction of single fetal demise after laser therapy for twin-twin transfusion syndrome

OBJECTIVE

Single fetal demise (SFD) occurs in up to 20% of monochorionic pregnancies treated with laser coagulation for twin-twin transfusion syndrome (TTTS). We aimed to determine the independent factors associated with SFD to improve outcome in the care of TTTS pregnancies in the future.

METHODS

This was a case-control study on twin pregnancies treated for TTTS between 2007 and 2013. Data on ultrasound, laser surgery and outcome were retrieved from our monochorionic twin database. We analyzed separately cases of SFD in donor and recipient twins, and compared them with treated pregnancies that resulted in two live births.

RESULTS

Of the 273 TTTS pregnancies treated with laser coagulation, SFD occurred in 30 donors (11.0%) and 27 recipients (9.9%). In 67% of pregnancies with SFD, the death occurred within 1 week after laser treatment. For SFD in donors, absent/reversed end-diastolic flow in the umbilical artery was the strongest predictor (odds ratio (OR), 3.0 (95% CI, 1.1-8.0); P = 0.01), followed by the presence of an arterioarterial anastomosis (OR, 4.2 (95% CI, 1.4-13.1); P = 0.03) and discordance in estimated fetal weight (OR, 1.0 (95% CI, 1.0-1.1); P = 0.04). For SFD in recipients, independent predictors were absent/reversed A-wave in the ductus venosus (OR, 3.6 (95% CI, 1.2-10.5); P = 0.02) and the absence of recipient-to-donor arteriovenous anastomoses (OR, 10.6 (95% CI, 1.8-62.0); P < 0.01).

CONCLUSIONS

Our findings confirm earlier reports that suggest that abnormal blood flow is associated with SFD after laser treatment for TTTS. The association of SFD with the type of anastomoses is a new finding. We speculate that the type of anastomoses present determines the degree of hemodynamic change during laser therapy. Future strategies should aim at stabilizing fetal circulation before laser therapy to decrease the vulnerability to acute preload and afterload changes. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Operator competence in fetoscopic laser surgery for twin-twin transfusion syndrome: validation of a procedure-specific evaluation tool

OBJECTIVES

Fetoscopic laser surgery for twin-twin transfusion syndrome is a procedure for which no objective tools exist to assess technical skills. To ensure that future fetal surgeons reach competence prior to performing the procedure unsupervised, we developed a performance assessment tool. The aim of this study was to validate this assessment tool for reliability and construct validity.

METHODS

We made use of a procedure-specific evaluation instrument containing all essential steps of the fetoscopic laser procedure, which was previously created using Delphi methodology. Eleven experts and 13 novices from three fetal medicine centers performed the procedure on the same simulator. Two independent observers assessed each surgery using the instrument (maximum score: 52). Interobserver reliability was assessed using Spearman correlation. We compared the performance of novices and experts to assess construct validity.

RESULTS

The interobserver reliability was high (Rs  = 0.974, P < 0.001). Checklist scores for experts and novices were significantly different; the median score for novices was 28/52 (54%), whereas that for experts was 47.5/52 (91%) (P < 0.001). The procedure time and fetoscopy time were significantly shorter (P < 0.001) for experts. Residual anastomoses were found in 1/11 (9%) procedures performed by experts and in 9/13 (69%) procedures performed by novices (P = 0.005). Multivariable analysis showed that the checklist score, independent of age and gender, predicted competence.

CONCLUSIONS

The procedure-specific assessment tool for fetoscopic laser surgery shows good interobserver reliability and discriminates experts from novices. This instrument may therefore be a useful tool in the training curriculum for fetal surgeons. Further intervention studies with reassessment before and after training may increase the construct validity of the tool. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Middle cerebral artery peak systolic velocity to predict fetal hemoglobin levels in twin anemia-polycythemia sequence

OBJECTIVE

To evaluate the diagnostic accuracy of middle cerebral artery peak systolic velocity (MCA-PSV) Doppler measurements in prediction of hemoglobin levels in twin anemia-polycythemia sequence (TAPS).

METHODS

This study involved a consecutive cohort comprising monochorionic twin pregnancies complicated by TAPS managed at three European fetal medicine centers between 2005 and 2013. The accuracy of MCA-PSV, measured immediately prior to fetal hemoglobin (Hb) measurement by fetal or cord blood sampling, for prediction of anemia and polycythemia was assessed using 2 × 2 tables.

RESULTS

A total of 116 measurements (74 recorded in donors and 42 in recipients) from 43 twin pregnancies complicated by TAPS were available for analysis. MCA-PSV multiples of the median (MoM) values correlated well with Hb levels (r = - 0.86; P < 0.001). The sensitivity of MCA-PSV ≥ 1.5 MoM to predict severe anemia (Hb deficit > 5 SD below the mean) in TAPS donors was 94% (95% CI, 85-98%); specificity was 74% (95% CI, 62-83%); positive and negative predictive values were 76% (95% CI, 65-85%) and 94% (95% CI, 83-98%), respectively. The sensitivity of MCA-PSV ≤ 1.0 MoM to predict polycythemia (Hb level > 5 SD above the mean) in TAPS recipients was 97% (95% CI, 87-99%); specificity was 96% (95% CI, 89-99%); positive and negative predictive values were 93% (95% CI, 81-97%) and 99% (95% CI, 93-100%), respectively.

CONCLUSION

MCA-PSV measurement has high diagnostic accuracy for predicting abnormal Hb levels in fetuses with TAPS.

Simulator training in fetoscopic laser surgery for twin-twin transfusion syndrome: a pilot randomized controlled trial

OBJECTIVE

To evaluate the effect of a newly developed training curriculum on the performance of fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS) using an advanced high-fidelity simulator model.

METHODS

Ten novices were randomized to receive verbal instructions and either skills training using the simulator (study group; n = 5) or no training (control group; n = 5). Both groups were evaluated with a pre-training and post-training test on the simulator. Performance was assessed by two independent observers and comprised a 52-item checklist for surgical performance (SP) score, measurement of procedure time and number of anastomoses missed. Eleven experts set the benchmark level of performance. Face validity and educational value of the simulator were assessed using a questionnaire.

RESULTS

Both groups showed an improvement in SP score at the post-training test compared with the pre-training test. The simulator-trained group significantly outperformed the control group, with a median SP score of 28 (54%) in the pre-test and 46 (88%) in the post-test vs 25 (48%) and 36 (69%), respectively (P = 0.008). Procedure time decreased by 11 min (from 44 to 33 min) in the study group vs 1 min (from 39 to 38 min) in the control group (P = 0.69). There was no significant difference in the number of missed anastomoses at the post-training test between the two groups (1 vs 0). Subsequent feedback provided by the participants indicated that training on the simulator was perceived as a useful educational activity.

CONCLUSIONS

Proficiency-based simulator training improves performance, indicated by SP score, for fetoscopic laser therapy. Despite the small sample size of this study, practice on a simulator is recommended before trainees carry out laser therapy for TTTS in pregnant women.

Long-term neurodevelopmental outcome after selective feticide in monochorionic pregnancies

OBJECTIVE

To assess the incidence of and risk factors for adverse long-term neurodevelopmental outcome in complicated monochorionic pregnancies treated with selective feticide at our centre between 2000 and 2011.

DESIGN

Observational cohort study.

SETTING

National referral centre for fetal therapy (Leiden University Medical Centre, the Netherlands).

POPULATION

Neurodevelopmental outcome was assessed in 74 long-term survivors.

METHODS

Children, at least 2 years of age, underwent an assessment of neurologic, motor and cognitive development using standardised psychometric tests and the parents completed a behavioural questionnaire.

MAIN OUTCOME MEASURES

A composite outcome termed neurodevelopmental impairment including cerebral palsy (GMFCS II-V), cognitive and/or motor test score of <70, bilateral blindness or bilateral deafness requiring amplification.

RESULTS

A total of 131 monochorionic pregnancies were treated with selective feticide at the Leiden University Medical Centre. Overall survival rate was 88/131 (67%). Long-term outcome was assessed in 74/88 (84%). Neurodevelopmental impairment was detected in 5/74 [6.8%, 95% confidence interval (CI), 1.1-12.5] of survivors. Overall adverse outcome, including perinatal mortality or neurodevelopmental impairment was 48/131 (36.6%). In multivariate analysis, parental educational level was associated with cognitive test scores (regression coefficient B 3.9, 95% CI 1.8-6.0). Behavioural problems were reported in 10/69 (14.5%).

CONCLUSIONS

Adverse long-term outcome in survivor twins of complicated monochorionic pregnancies treated with selective feticide appears to be more prevalent than in the general population. Cognitive test scores were associated with parental educational level.

TWEETABLE ABSTRACT

Neurodevelopmental impairment after selective feticide was detected in 5/74 (6.8%, 95% CI 1.1-12.5) of survivors.

Identification of essential steps in laser procedure for twin-twin transfusion syndrome using the Delphi methodology: SILICONE study

OBJECTIVE

To determine, by expert consensus, the essential substeps of fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) that could be used to create an authority-based curriculum for training in this procedure among fetal medicine specialists.

METHODS

A Delphi survey was conducted among an international panel of experts (n = 98) in FLS. Experts rated the substeps of FLS on a five-point Likert-type scale to indicate whether they considered them to be essential, and were able to comment on each substep, using a dedicated online platform accessed by the invited tertiary care facilities that specialize in fetal therapy. Responses were returned to the panel until consensus was reached (Cronbach's α ≥ 0.80). All substeps that were rated  ≥ 4 by 80% of the experts were included in the evaluation instrument.

RESULTS

After the first iteration of the Delphi procedure, a response rate of 74% (73/98) was reached, and in the second and third iterations response rates of 90% (66/73) and 81% (59/73) were reached, respectively. Among a total of 81 substeps rated in the first round, 21 substeps had to be re-rated in the second round. Finally, from the initial list of substeps, 55 were agreed by experts to be essential. In the third round, the 18 categorized substeps were ranked in order of importance, with 'coagulation of all anastomoses that cross the equator' and 'determination of fetoscope insertion site' as the most important.

CONCLUSIONS

A total of 55 substeps of FLS for TTTS were defined by a panel of experts to be essential in the procedure. This list is the first authority-based evidence to be used in the development of a final training model for future fetal surgeons.

A worldwide survey of laser surgery for twin-twin transfusion syndrome

OBJECTIVES

To evaluate differences between international fetal centers in their treatment of twin-twin transfusion syndrome (TTTS) by fetoscopic placental laser coagulation.

METHODS

Fetal therapy centers worldwide were sent a web-based questionnaire. Participants were identified through networks and through scientific presentations and papers. Questions included physician and center demographics, treatment criteria, operative technique and instrumentation. Laser treatment was compared between low-volume (< 20 procedures/year) and high-volume (≥ 20 procedures/year) centers. Data were analyzed using descriptive statistics.

RESULTS

Of 106 fetal therapy specialists approached, 76 (72%) from 64 centers in 25 countries responded. Of these, 48% (31/64) of centers and 63% (48/76) of operators performed fewer than 20 laser procedures annually. Comparison of low- and high-volume centers showed differences in technique, gestational age limits for treatment and geography. High-volume centers more often used the Solomon technique and applied wider gestational age limits for treatment. Europe and Asia had more high-volume centers, whereas South America, the Middle East and Australia had mainly low-volume centers.

CONCLUSION

This survey revealed significant differences between fetal centers in several aspects of fetoscopic placental laser therapy for TTTS. Increasing awareness of TTTS, and of laser coagulation as its preferred treatment, will lead to an increase in centers offering this modality, especially in Asia, Africa, South America and the Middle East. Considering the rarity of TTTS and the relative complexity of the procedure, developing international guidelines for techniques, instrumentation and suggested minimum volumes per center may aid in optimizing perinatal outcome.

Iatrogenic perforation of intertwin membrane after laser surgery for twin-to-twin transfusion syndrome

OBJECTIVE

To evaluate management and outcome of iatrogenic monoamniotic twins (iMAT) compared with twins with intact intertwin dividing membranes after laser surgery for twin-to-twin transfusion syndrome (TTTS).

METHODS

This was a retrospective analysis of twins with and without iatrogenic rupture of the intertwin membranes that had been treated for TTTS with laser surgery at our center between 2004 and 2012. Primary outcomes were perinatal survival and severe neonatal morbidity. Secondary outcomes were mode of delivery, gestational age at birth and cord entanglement.

RESULTS

In total, 338 pregnancies were included. In 67/338 (20%) pregnancies, iMAT was suspected antenatally. In 47 of these 67 (70%), a preterm Cesarean section was performed for monoamnionicity. Perinatal survival was 108/134 (81%) vs 396/542 (73%) in twins with intact intertwin membranes (P = 0.13). Mean gestational age at birth in iMAT was 31 completed weeks, compared to 33 weeks in twins with intact membranes (P < 0.01). At birth, cord entanglement was present in 8/67 (12%) iMAT pregnancies. Severe neonatal morbidity was assessed in 106/110 (96%) in iMAT cases and 392/416 (94%) in controls. The incidence of severe neonatal morbidity was 28/106 (26%) in iMAT vs 72/392 (18%) in controls (P = 0.25). Severe cerebral injury was significantly increased in the iMAT group as compared with controls, at 16/106 (15%) vs 18/392 (5%) (P < 0.01).

CONCLUSIONS

Iatrogenic rupture of intertwin membranes was suspected in 20% of pregnancies treated with laser therapy for TTTS and was associated with a lower gestational age at birth and increased neonatal morbidity.

Neurodevelopmental outcome in twin anemia-polycythemia sequence after laser surgery for twin-twin transfusion syndrome

OBJECTIVE

To evaluate the long-term neurodevelopmental outcome in children who developed twin anemia-polycythemia sequence (TAPS) after fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS).

METHODS

Neurological, motor and cognitive development was assessed in a consecutive cohort of TTTS survivors treated with laser surgery between 2004 and 2011 and complicated by post-laser TAPS. Primary outcome was neurodevelopmental impairment, a composite outcome including any of the following: cerebral palsy, bilateral deafness, blindness, severe motor and/or cognitive developmental delay (>2 SD below the mean). A risk analysis on cognitive outcome was performed.

RESULTS

During the study period, 33/306 (11%) monochorionic twin pairs developed TAPS after laser surgery for TTTS. Survival was 53/66 (80%). Long-term outcome was assessed in 47/53 (89%) children. The incidence of neurodevelopmental impairment was 4/47 (9%), occurring in one donor (1/20; 5%) and three recipients (3/27; 11%) (P=0.63). Mild-to-moderate cognitive delay, i.e. scores below 85, was detected in 8/47 (17%) children. Risk factors for low cognitive scores were low gestational age at birth (P=0.02) and low birth weight (P<0.01). The lowest cognitive scores were detected in the subgroup of TAPS survivors treated with intrauterine transfusion (median score, 82.5).

CONCLUSIONS

Neurodevelopmental impairment and cognitive delay were found in almost one in five children surviving post-laser TAPS. Better treatment and, ideally, prevention of this complication after laser treatment for TTTS is urgently needed.

Laser surgery as a management option for twin anemia-polycythemia sequence

OBJECTIVE

To evaluate the effectiveness of laser treatment for antenatally detected twin anemia-polycythemia sequence (TAPS) compared with intrauterine transfusion or expectant management.

METHODS

All monochorionic twin pregnancies with TAPS managed between 2005 and 2013 in two European fetal therapy centers were evaluated. The outcomes of TAPS cases treated primarily with laser surgery were compared with the outcomes of cases managed expectantly or treated with intrauterine transfusion.

RESULTS

In this retrospective study 52 cases of TAPS were detected antenatally and were managed with either laser surgery (n=8; 15%) or intrauterine blood transfusion (n=17; 33%) or expectantly (n=27; 52%). Perinatal survival in the laser group was 94% (15/16) vs 85% (29/34) in the intrauterine-transfusion group and 83% (45/54) in the expectant-management group (P=0.30). The rates of severe neonatal morbidity in liveborn neonates in the laser, intrauterine-transfusion and expectant-management groups were 7% (1/15), 38% (12/32) and 24% (12/50), respectively (P=0.17). There was a significant reduction in respiratory distress syndrome in cases treated by laser. No severe postnatal hematological complications were detected in the laser group compared with 72% (23/32) in the intrauterine-transfusion group and 52% (26/50) in the expectant-management group (P<0.01). Median time between diagnosis and birth was 11 weeks in the laser group compared to 5 weeks after intrauterine transfusion and 8 weeks after expectant management (P<0.01). After injection of colored dye no residual anastomoses were found in the laser group.

CONCLUSIONS

Laser surgery for TAPS appears to improve perinatal outcome by prolonging pregnancy and reducing respiratory distress syndrome. Larger, adequately controlled studies are needed to reach firm conclusions on the optimal management of TAPS.

Termination of pregnancy for maternal indications at the limits of fetal viability: a retrospective cohort study in the Dutch tertiary care centres

OBJECTIVE

Maternal morbidity, either pregnancy related or pre-existent, can become life threatening and of such severity as to warrant termination of pregnancy (TOP). In this situation, chances of fetal survival are usually poor, either because of low gestational age and/or because of the fetal effects of the maternal condition. Examples include severe growth restriction in pre-eclampsia and intrauterine infection due to the very early preterm prelabour rupture of membranes. There are very few reports on the prevalence of TOP for maternal indication at the limits of fetal viability. We investigated the prevalence of and indications for TOP on maternal indication in the 10 tertiary care centres in the Netherlands during the past decade.

STUDY DESIGN

We conducted a retrospective review of the medical records of all women who underwent TOP for maternal indications between 22 and 27 completed weeks of gestation in all 10 tertiary care centres from 2000 to 2009.

RESULTS

During the study period, there were 1 929 470 deliveries; 163 052 (8.4%) of these took place in one of the 10 tertiary care centres and 177 pregnancies were terminated for severe maternal disease, 131 for hypertensive disorders, 29 for intrauterine infection and 17 for other reasons. The mean gestational age at TOP was 171 days (24(3/7))±10 days. No maternal deaths were recorded. The overall perinatal mortality was 99.4%.

CONCLUSIONS

Over a 10-year period, TOP for maternal indications was performed in 1 in 1000 deliveries in the 10 Dutch tertiary care centres. Hypertensive disorders comprised three-quarters of the cases.

Perinatal outcome after selective feticide in monochorionic twin pregnancies

OBJECTIVE

To evaluate the incidence and risk factors of adverse perinatal outcome in complicated monochorionic twin pregnancies treated with selective feticide.

METHODS

This was a retrospective analysis of prospectively collected data from a consecutive, national cohort. All monochorionic twin pregnancies treated with selective feticide at Leiden University Medical Center between June 2000 and November 2011 were included. Obstetric and neonatal data were recorded. The primary outcome measure was adverse perinatal outcome, including fetal or neonatal demise or severe neonatal morbidity.

RESULTS

Data on perinatal outcome were obtained in all cases (n = 131). Overall perinatal survival rate was 67.2% (88/131). Median gestational age at delivery was 34 (interquartile range, 23-38) weeks. Neonatal mortality and morbidity rate in liveborn children was 4.3% (4/92) and 12.0 % (11/92), respectively. Severe cerebral injury was detected in three children. The overall incidence of adverse perinatal outcome was 41.2% (54/131). Median gestational age at occurrence of preterm prelabor rupture of membranes (PPROM) was 19.0 weeks and 32.0 weeks in cases with and without adverse perinatal outcome, respectively (P = 0.017). Liveborn children with adverse perinatal outcome were born at a lower median gestational age (29.0 weeks) than were children without adverse perinatal outcome (38.0 weeks) (P < 0.001).

CONCLUSIONS

The risk of adverse perinatal outcome after selective feticide is high and associated with low gestational age at occurrence of PPROM and low gestational age at delivery. Long-term follow-up to assess neurodevelopmental outcome in survivors is required.

Severe cerebral injury in a recipient with twin anemia-polycythemia sequence

Twin anemia-polycythemia sequence (TAPS) results from slow intertwin blood transfusion through minuscule placental vascular anastomoses and is characterized by large intertwin hemoglobin differences in the absence of amniotic fluid discordance. The optimal management of TAPS is not clear. We report a case of TAPS detected antenatally by Doppler ultrasound examination at 15 + 6 weeks' gestation. After counseling, the parents opted for expectant management. Regular Doppler measurements were performed and these remained fairly stable. An emergency Cesarean section was performed at 34 + 5 weeks following signs of fetal distress. The donor twin was severely anemic while the recipient twin had severe polycythemia-hyperviscosity syndrome. On day 1, the recipient developed respiratory insufficiency and subclinical status epilepticus. Magnetic resonance imaging showed a total loss of gray-white matter differentiation as a sign of severe diffuse cerebral ischemia and bilateral intra- and extra-axial hemorrhages. There was almost complete lack of arterial and venous cerebral blood flow. On day 3 intensive care treatment was withdrawn in view of the severity of the brain injury. This case report demonstrates that TAPS may lead to severe cerebral injury and fatal outcome in the recipient twin, and highlights the importance of antenatal Doppler ultrasound monitoring and choice of management.

Association of innate immune activation with latent Epstein-Barr virus in active MS lesions

OBJECTIVE

To determine whether the activation of innate immune responses, which can be elicited by pathogenic and endogenous triggers, is associated with the presence of Epstein-Barr virus (EBV) infection in the multiple sclerosis (MS) brain.

METHODS

White matter postmortem MS (n = 10) and control tissue (n = 11) was analyzed for the expression of the proinflammatory cytokine interferon α (IFNα) by immunohistochemistry and for EBV by using the highly sensitive method of EBV-encoded RNA (EBER) in situ hybridization.

RESULTS

We detected overexpression of IFNα in active areas of white matter MS lesions but not in inactive MS lesions, normal-appearing white matter, or normal brains. The presence of IFNα in macrophages and microglia (expressing human leukocyte antigen class II) is suggestive of local production as part of an acute inflammatory process. Interestingly, EBERs were also specifically detected in areas where IFNα was overexpressed in these preselected active MS lesions. EBER+ cells were also found in CNS lymphoma and stroke cases, but were absent in other control brains. We next addressed a potential mechanism, e.g., the role of EBERs in eliciting IFNα production, and transfected EBERs into human embryonic kidney (HEK) cells. We used HEK cells that stably expressed Toll-like receptor-3, which recognizes double-stranded RNAs, associated with many viral infections. EBERs elicited IFNα production in vitro.

CONCLUSION

These findings suggest that latent EBV infection may contribute to the inflammatory milieu in active MS lesions by activating innate immune responses, e.g., IFNα production. Unraveling the underlying mechanisms may help in uncovering causal pathways and developing better treatment strategies for MS and other neuroinflammatory diseases.

Prophylaxis with low-dose low-molecular-weight heparin during pregnancy and postpartum: is it effective?

BACKGROUND

The optimal approach for venous thrombosis (VTE) prophylaxis during pregnancy and postpartum in women with an increased risk of VTE is not established.

OBJECTIVES

To evaluate the effectiveness, represented as the incidence of pregnancy-related VTE, and safety, represented as incidence of postpartum hemorrhage (PPH), of a protocol recommending prophylaxis with low-dose low-molecular-weight heparin (LMWH) in women at intermediate to high risk of VTE.

PATIENTS/METHODS

In this retrospective cohort study, we analyzed 34 women (44 pregnancies) with intermediate risk of VTE who received low-dose LMWH for 6 weeks postpartum and 57 women (82 pregnancies) with high risk of VTE who received low-dose LMWH during pregnancy and for 6 weeks postpartum. Pregnancy-related VTE was defined as VTE during pregnancy or ≤ 3 months postpartum. PPH was defined as blood loss >500 mL and severe PPH as blood loss > 1000 mL.

RESULTS

The incidence of pregnancy-related VTE was 5.5% (95% CI, 2.4-12.3) despite prophylaxis with low-dose LMWH. All events occurred in women at high risk, with a postpartum incidence of 7.0% (95% CI, 2.9-16.7) and antepartum incidence of 1.8% (95% CI, 0.4-9.2). The risk of PPH was 21.6% (95% CI, 14.3-31.3) and severe PPH 9.1% (95% CI, 4.7-16.9), which was not different in women who started LMWH postpartum and those who used LMWH during pregnancy.

CONCLUSIONS

Although prophylaxis with low-dose LMWH during pregnancy and postpartum proved to be safe, the risk of pregnancy-related VTE is considerable in women with a high risk of VTE. VTE prophylaxis with low-dose LMWH may not be sufficiently effective in these women.

Is routine TORCH screening and urine CMV culture warranted in small for gestational age neonates?

BACKGROUND

congenital infections are associated with a wide variety of clinical symptoms, including small for gestational age (SGA).

AIMS

to determine the co-occurrence of SGA and congenital TORCH infections, as diagnosed by TORCH serologic tests and/or cytomegalovirus (CMV) urine culture.

STUDY DESIGN

we performed a retrospective study of all neonates admitted to our neonatal intensive care unit from January 2004 to February 2010 in whom SGA was diagnosed and TORCH serologic tests and/or CMV urine cultures were performed.

RESULTS

TORCH serologic tests (in neonatal or maternal serum) and/or a CMV urine culture were performed in 112 neonates with SGA. None of the neonates tested positive for Toxoplasma gondii, Rubella, and Herpes simplex virus. Positive CMV urine culture was detected in 2% (2/112) of neonates, but their CMV IgM titers were negative.

CONCLUSIONS

the co-occurrence of TORCH congenital infection in infants with SGA is rare. Routine TORCH screening in neonates with isolated SGA does not seem warranted and should be limited to CMV urine cultures.

GFAP in health and disease

Glial fibrillary acidic protein (GFAP) is the main intermediate filament protein in mature astrocytes, but also an important component of the cytoskeleton in astrocytes during development. Major recent developments in astrocyte biology and the discovery of novel intermediate filament functions enticed the interest in the function of GFAP. The discovery of various GFAP splice variants gave an additional boost to explore this protein in more detail. The structural role of GFAP in astrocytes has been widely accepted for a long time, but over the years, GFAP has been shown to be involved in astrocyte functions, which are important during regeneration, synaptic plasticity and reactive gliosis. Moreover, different subpopulations of astrocytes have been identified, which are likely to have distinctive tasks in brain physiology and pathology, and which are not only classified by their spatial and temporal appearance, but also by their specific expression of intermediate filaments, including distinct GFAP isoforms. The presence of these isoforms enhances the complexity of the astrocyte cytoskeleton and is likely to underlie subtype specific functions. In this review we discuss the versatility of the GFAP cytoskeletal network from gene to function with a focus on astrocytes during human brain development, aging and disease.

Hematological characteristics in neonates with twin anemia-polycythemia sequence (TAPS)

OBJECTIVE

To evaluate the neonatal hematological features of monochorionic twins with twin anemia-polycythemia sequence (TAPS) and to determine the additional diagnostic value of reticulocyte count measurement.

METHODS

A cohort of consecutive monochorionic twins with TAPS (n = 19) was included in the study and each twin pair was compared with two monochorionic twin pairs (n = 38) unaffected by TAPS or twin-twin transfusion syndrome (TTTS), matched for gestational age at birth. We measured full blood counts on day 1 and determined the incidence of anemia, polycythemia, reticulocytosis and thrombocytopenia.

RESULTS

Median inter-twin hemoglobin (Hb) difference in monochorionic twins with and without TAPS was 13.7 g/dL and 2.4 g/dL, respectively (p < 0.01). Median inter-twin reticulocyte count ratio in twins with and without TAPS was 3.1 and 1.0, respectively (p < 0.01). Thrombocytopenia (platelet count < 150 x 10(9)/L) occurred more often in the TAPS group than in the control group, 45% (17/38) versus 11% (11/38), respectively (p < 0.01). In the TAPS group, mean platelet count was significantly lower in recipients than in donors, 133 x 10(9)/L versus 218 x 10(9)/L, respectively (p < 0.01).

CONCLUSIONS

TAPS twins have a large inter-twin Hb difference in combination with a large inter-twin reticulocyte count ratio. Recipients are more often thrombocytopenic than donors, probably due to polycythemia.

Expression patterns of glial fibrillary acidic protein (GFAP)-delta in epilepsy-associated lesional pathologies

AIMS

Glial fibrillary acidic protein (GFAP)-delta is a novel isoform that differs in its C-terminal sequence from other GFAP isoforms. Previous studies suggest restriction of expression to the subpial layer, subventricular zone and the subgranular zone astrocytes, with an absence in pathological conditions causing reactive gliosis. GFAP-delta is speculated to have roles in regulation of astrocyte size and motility and a subpopulation of GFAP-delta-positive glia may be multipotent stem cells. The aim of this study was to investigate its expression in common causes of lesion-related refractory epilepsy.

METHODS

Hippocampal sclerosis (HS), focal cortical dysplasia (FCD) type IIB, cortical tuberous sclerosis (TSC) lesions, gangliogliomas, grey matter heterotopias and hemimegalencephaly from a wide age range of patients using both surgical and post mortem tissue specimens were studied.

RESULTS

GFAP-delta expression was observed in CA4 and CA1 astrocytes in HS with less frequent labelling in the granule cell layer, even where granule cell dispersion was present. No significant labelling was noted in the subiculum in HS cases or in any subfields in non-HS epilepsy cases. Balloon cells in FCDIIB and hemimegalencephaly, giant cells in TSC and the astrocytic component of gangliogliomas showed immunoreactivity, colocalizing with conventional GFAP. No neuronal expression for GFAP-delta was seen in any of the pathologies. Quantitative analysis in 10 FCDIIB and five TSC cases revealed greater numbers of GFAP-delta-positive balloon cells than conventional GFAP. There was no GFAP-delta expression within nodular heterotopia.

CONCLUSIONS

GFAP-delta expression patterns in HS overall appears to mirror regional reactive gliosis. It is a useful marker for the demonstration of balloon cells in FCD and TSC, which may be relevant to their abnormal size and localization. The lack of GFAP-delta within heterotopia supports their composition from cells destined for deeper cortical layers.

Fetal cardiac output in monochorionic twins

OBJECTIVES

To compare fetal cardiac output (CO) in donor and recipient twins of twin-twin transfusion syndrome (TTTS) pregnancies after laser therapy with that of monochorionic twins without TTTS and normal singletons.

METHODS

In a longitudinal, prospective study, we sonographically assessed fetal CO in donors (n = 10) and recipients (n = 10) with TTTS after fetoscopic laser therapy, in monochorionic twins without TTTS (n = 20) and in normal singleton pregnancies (n = 20). The fetal CO of TTTS twins was determined 1 day and 1 week after laser treatment, and from then on every 2-4 weeks until birth. Twins without TTTS were examined biweekly until birth. Singletons were examined twice, with an 8-week interval, at different gestational ages between 17 and 35 weeks.

RESULTS

Absolute CO increased exponentially with advancing gestational age (P < 0.0001), and was significantly related to fetal weight in all groups (P < 0.0001). The median CO/kg in donors after laser therapy, recipients after laser therapy and non-TTTS monochorionic twins was significantly higher than that in singletons (all P < 0.001). Median CO/kg in donors after laser therapy, recipients after laser therapy, and non-TTTS monochorionic twins was not significantly different between groups.

CONCLUSIONS

Monochorionic twins with TTTS have higher CO after laser therapy than normal singletons.

Multiple roles of LMP1 in Epstein-Barr virus induced immune escape

The life cycle of Epstein-Barr virus (EBV) is intriguing in that the virus resides within the immune system and utilizes distinct latency expression programs to establish a persistent infection yet escaping elimination. To achieve this EBV has hijacked cellular signaling pathways to its own benefit, but deregulated viral gene expression can turn into oncogenesis. EBV like many other persistent herpes viruses has evolved ingenious tricks to evade the immune system in part by mimicking host gene function(s). Latent membrane protein 1 (LMP1) mimics CD40 signaling as part of its "normal" biological function and when deregulated, functions as a viral oncogene. LMP1 also affects cell-cell contact, cytokine and chemokine production, Ag presentation and is secreted in the extracellular milieu via immunogenic exosomes. Thus, besides its well-known growth promoting properties LMP1 modulates immune responses. Herein we discuss current knowledge regarding the role of LMP1 in immune evasion of EBV and how this strategy for establishment of persistence contributes to immune escape of EBV+ tumors.

The effect of fetoscopic laser therapy on fetal cardiac size in twin-twin transfusion syndrome

OBJECTIVES

To evaluate the influence of fetoscopic laser therapy on fetal cardiac size in monochorionic twins complicated by twin-twin transfusion syndrome (TTTS).

METHODS

In a longitudinal, prospective study, we assessed fetal cardiac size sonographically in monochorionic diamniotic twins with TTTS treated by laser therapy and in monochorionic twins without TTTS. The fetal cardiothoracic ratio (cardiac circumference divided by thoracic circumference) of TTTS twins was determined within 24 h before, 12-24 h after and 1 week after laser treatment, and from then on every 2-4 weeks until birth. TTTS twins were classified into Quintero Stages 1-2 (n = 18) and Stages 3-4 (n = 16), and measurements were compared with biweekly measurements of non-TTTS monochorionic twins matched for gestational age (n = 38). Cardiomegaly was defined as a cardiothoracic ratio above the 97.5th percentile.

RESULTS

Before laser treatment, cardiomegaly was observed in 44% (8/18) and 50% (8/16) of recipients in Quintero Stages 1-2 and Stages 3-4, respectively. Cardiomegaly occurred in none of the donors before treatment. After laser treatment, cardiomegaly was observed in 76% (13/17) and 50% (7/14) of recipients in Stages 1-2 and Stages 3-4, respectively, and in 17% (3/18) and 13% (2/15) of donors in Stages 1-2 and Stages 3-4, respectively. Cardiomegaly was present in 18% (7/38) and 8% (2/25) of non-TTTS monochorionic twins and singletons. After laser therapy, the cardiothoracic ratio of recipients in Stages 1-2 and Stages 3-4 was not significantly changed (P = 0.34 and P = 0.67, respectively). The cardiothoracic ratio of donors in Stages 1-2 and Stages 3-4 was increased compared with that before laser therapy (P = 0.0002 and P = 0.005, respectively). Cardiothoracic ratios of non-TTTS monochorionic twins were not significantly different from our reference range in singletons throughout gestation, and were smaller than those in both recipients and donors after laser therapy.

CONCLUSIONS

TTTS recipients show cardiomegaly before as well as after fetoscopic laser therapy for TTTS. Donors develop cardiomegaly only after laser treatment. Our findings emphasize the significant effect of TTTS and fetoscopic laser therapy on the fetal heart of both recipient and donor twins.

Twin-to-twin transfusion syndrome after 26 weeks of gestation: is there a role for fetoscopic laser surgery?

OBJECTIVE

To compare fetoscopic laser surgery with amniodrainage in the treatment of twin-to-twin transfusion syndrome (TTTS) diagnosed after 26 weeks of gestation.

DESIGN

A retrospective cohort study.

SETTING

Leiden University Medical Centre, a tertiary referral hospital for fetal therapy.

POPULATION

Between January 1991 and February 2006, 21 TTTS cases were diagnosed and treated after 26 weeks of gestation.

METHODS

Treatment of TTTS consisted of either amniodrainage or fetoscopic laser coagulation of vascular anastomoses.

MAIN OUTCOME MEASURES

PRIMARY OUTCOME

adverse outcome (intrauterine or neonatal death, major neonatal morbidity and/or severe cerebral injury). Secondary outcome: gestational age at birth.

RESULTS

Eleven TTTS cases were treated with amniodrainage and ten with laser surgery. Median gestational age at birth in the amniodrainage group and in the laser surgery group was 29 and 31 weeks, respectively (P = 0.17) All infants were born alive. Major neonatal morbidity occurred more often in the amniodrainage group than in the laser surgery group, 27% (6/22) and 0% (0/20), respectively (P = 0.02). Severe cerebral injury in the amniodrainage group and in the laser surgery group occurred in 23% (5/22) and 15% (3/20) of infants, respectively (P = 0.70). Neonatal mortality in the amniodrainage group and in the laser surgery group was 14% (3/22) and 0% (0/20), respectively (P = 0.23). Overall adverse outcome was 36% (8/22) in the amniodrainage group and 15% (3/20) in the laser surgery group (P = 0.17).

CONCLUSION

In TTTS diagnosed after 26 weeks of gestation, amniodrainage and laser surgery both result in 100% survival. However, infants born after laser surgery have less major neonatal morbidity.

Residual Anastomoses After Fetoscopic Laser Surgery in Twin-to-Twin Transfusion Syndrome: Frequency, Associated Risks and Outcome

Fetoscopic laser coagulation of placental vascular anastomoses is considered to be the treatment of choice in severe twin-to-twin transfusion syndrome. The aim of fetoscopic laser surgery is to separate completely the inter-twin placental circulation. Incomplete laser coagulation may result in residual vascular anastomoses. The incidence and clinical implications of residual anastomoses in twin-to-twin transfusion syndrome treated with fetoscopic laser surgery has not yet been studied. We examined all placentas treated with fetoscopic laser surgery and delivered at our center between June 2002 and December 2005 with vascular injection using colored dyes. Presence of residual anastomoses was studied in association with adverse outcome and inter-twin hemoglobin difference at birth. Adverse outcome was defined as fetal demise, neonatal death or severe cerebral injury. The relation between residual anastomoses and placental localization (anterior or posterior uterine wall) was evaluated. A total of 52 laser-treated placentas were studied. Residual anastomoses were detected in 33% (17/52) of placentas. Adverse outcome was similar in the groups with and without residual anastomoses, 18% (6/34) and 29% (20/70), respectively (p=0.23). Large inter-twin hemoglobin differences (>5g/dL) were found in 65% (11/17) of cases with residual anastomoses and 20% (7/35) of cases without residual anastomoses (p<0.01). Anterior placental localization was not associated with a more frequent presence of residual anastomoses. In conclusion, residual anastomoses at our institution are seen in one-third of monochorionic placentas treated with fetoscopic laser surgery. Although residual anastomoses in our study were not associated with adverse outcome, they were often associated with neonatal hematological complications.

Assessment of Feto-fetal Transfusion Flow Through Placental Arterio-venous Anastomoses in a Unique Case of Twin-to-Twin Transfusion Syndrome

In vivo measurements of blood flow through arterio-venous anastomoses in monochorionic twin placentas have recently been attempted with Doppler ultrasound, but the accuracy is questionable. We present a case of twin-to-twin transfusion syndrome treated with fetoscopic laser surgery. The ex-recipient subsequently became severely anaemic and was treated with an intrauterine blood transfusion at 29 weeks' gestation. After birth, a placental injection study identified residual unidirectional arterio-venous anastomoses from the ex-recipient to the ex-donor without arterio-venous anastomoses in the opposite direction. Prospective measurements of decreasing haemoglobin levels between the intrauterine transfusion and birth allowed us to assess the net blood flow through the anastomoses as 27.9mL/24h. This finding may also explain the inaccuracy of Doppler flow measurements, as such low flow velocities cannot possibly be detected with current Doppler techniques.

Fetoscopic laser surgery in 100 pregnancies with severe twin-to-twin transfusion syndrome in the Netherlands

OBJECTIVE

In this prospective cohort study, we evaluated the initial results of fetoscopic laser surgery for severe second trimester twin-to-twin transfusion syndrome (TTTS) treated at our centre.

METHOD

A total of 100 consecutive pregnancies with severe second trimester TTTS treated at our centre with selective fetoscopic laser coagulation of vascular anastomoses on the placental surface between August 2000 and November 2004 were included in the study. Perinatal survival was analysed in relation to Quintero stage.

RESULTS

Median gestational age was 20 weeks at fetoscopy (range: 16-26) and 33 weeks at delivery (range: 18-40). Perinatal survival rate was 70% (139/200). The treatment resulted in at least one survivor at the age of 4 weeks in 81% of pregnancies. Perinatal survival was significantly higher when treatment was performed in the early Quintero stages (95% in stage 1, 76% in stage 2, 70% in stage 3, 50% in stage 4) (p = 0.02).

CONCLUSION

Results of fetoscopic laser surgery for TTTS in our centre are similar to those in specialised centres in other countries. Diagnosis and treatment in the early Quintero stages resulted in significantly higher perinatal survival.

Twin Anemia–Polycythemia Sequence in Two Monochorionic Twin Pairs Without Oligo-Polyhydramnios Sequence

Placental vascular anastomoses in monochorionic twins may lead to acute or chronic inter-twin transfusion. We report an uncommon form of chronic inter-twin transfusion, referred to as twin anemia-polycythemia sequence (TAPS), with severe anemia in one twin and polycythemia in the other, without the characteristically associated twin oligo-polyhydramnios sequence (TOPS) seen in the classical twin-to-twin transfusion syndrome (TTTS). The clinical course and placental characteristics of two pairs of monochorionic twins with TAPS born at, respectively, 33 and 34 weeks' gestation were reviewed. Serial fetal ultrasound examinations revealed no signs of TOPS. At birth, both donor twins were severely anemic requiring blood transfusion and both recipients were polycythemic, one requiring partial volume exchange transfusions. Inter-twin difference in reticulocyte counts was extremely high, suggesting a chronic form of inter-twin blood transfusion. Placental injection studies revealed a preponderance of very small (<1mm) arterio-venous anastomoses in one direction. In conclusion, chronic inter-twin transfusion may lead to an uncommon form of inter-twin transfusion, named TAPS, not associated with TOPS, resulting in severe fetal or neonatal hematological complications. We hypothesize that TAPS is mediated through minuscule unidirectional anastomoses. TAPS can be diagnosed antenatally with Doppler studies and postnatally by hemoglobin and reticulocyte measurements.

Single-assay combination of Epstein-Barr Virus (EBV) EBNA1- and viral capsid antigen-p18-derived synthetic peptides for measuring anti-EBV immunoglobulin G (IgG) and IgA antibody levels in sera from nasopharyngeal carcinoma patients: options for field screening

Assessment of immunoglobulin A (IgA) antibody responses to various Epstein-Barr virus (EBV) antigen complexes, usually involving multiple serological assays, is important for the early diagnosis of nasopharyngeal carcinoma (NPC). Through combination of two synthetic peptides representing immunodominant epitopes of EBNA1 and viral capsid antigen (VCA)-p18 we developed a one-step sandwich enzyme-linked immunosorbent assay (ELISA) for the specific detection of EBV reactive IgG and IgA antibodies in NPC patients (EBV IgG/IgA ELISA). Sera were obtained from healthy donors (n = 367), non-NPC head and neck cancer patients (n = 43), and biopsy-proven NPC patients (n = 296) of Indonesian and Chinese origin. Higher values of optical density at 450 nm for EBV IgG were observed in NPC patients compared to the healthy EBV carriers, but the large overlap limits its use for NPC diagnosis. Using either EBNA1 or VCA-p18 peptides alone IgA ELISA correctly identified 88.5% and 79.8% of Indonesian NPC patients, with specificities of 80.1% and 70.9%, whereas combined single-well coating with both peptides yielded sensitivity and specificity values of 90.1 and 85.4%, respectively. The positive and negative predictive values (PPV and NPV, respectively) for the combined EBNA1 plus VCA EBV IgA ELISA were 78.7% and 93.9%, respectively. In the Indonesia panel, the level of EBV IgA reactivity was not associated with NPC tumor size, lymph node involvement, and metastasis stage, sex, and age group. In the China panel the sensitivity/specificity values were 86.2/92.0% (EBNA1 IgA) and 84.1/90.3% (VCA-p18 IgA) for single-peptide assays and 95.1/90.6% for the combined VCA plus EBNA1 IgA ELISA, with a PPV and an NPV for the combined EBV IgA ELISA of 95.6 and 89.3%, respectively. Virtually all NPC patients had abnormal anti-EBV IgG diversity patterns as determined by immunoblot analysis. On the other hand, healthy EBV carriers with positive EBV IgA ELISA result showed normal IgG diversity patterns. By using EBV IgG immunoblot diversity as confirmation assay for EBV IgA ELISA-positive samples, the sensitivity and specificity for NPC diagnosis increased to 98% and 99.2%, respectively, in the Indonesian NPC samples. The use of these combined methods for seroepidemiological screening studies is proposed.

Amnioinfusion to facilitate external cephalic version after initial failure

OBJECTIVE

To evaluate the effectiveness of antepartum transabdominal amnioinfusion to facilitate external cephalic version after initial failure.

METHODS

Women with a structurally normal fetus in breech lie at term, with a failed external cephalic version and an amniotic fluid index (AFI) less than 15 cm, were asked to participate in our study. After tocolysis with indomethacin, a transabdominal amnioinfusion was performed with an 18G spinal needle. Lactated Ringers solution was infused until the AFI reached 15 cm, with a maximum of 1 L. External cephalic version was performed directly afterward.

RESULTS

Seven women participated in the study. The gestational age of the women was between 36(+4) and 38(+3) weeks, and three women were primiparous. The AFI ranged from 4 cm to 13 cm. A median amount of 1,000 mL Ringers solution (range 700-1,000 mL) was infused per procedure. The repeat external cephalic versions after amnioinfusion were not successful in any of the patients.

CONCLUSION

In our experience, amnioinfusion does not facilitate external cephalic version.

Timely diagnosis of twin-to-twin transfusion syndrome in monochorionic twin pregnancies by biweekly sonography combined with patient instruction to report onset of symptoms

OBJECTIVES

To assess the value of serial ultrasound examinations together with patient instructions to report the onset of symptoms in achieving timely detection of twin-to-twin transfusion syndrome (TTTS) in a cohort of monochorionic diamniotic twin pregnancies, and to evaluate sonographic TTTS predictors.

METHODS

Timely detection of TTTS was defined as diagnosis before severe complications of TTTS occurred, such as preterm prelabor rupture of membranes, very preterm delivery (24-32 weeks of pregnancy), fetal hydrops, or intrauterine fetal death. During a 2-year period, a prospective series of 23 monochorionic twin pregnancies was monitored from the first trimester until delivery. At least every 2 weeks we performed ultrasound and Doppler measurements (nuchal translucency thickness, presence of membrane folding, estimated fetal weight, deepest vertical pocket, bladder filling, and Doppler waveforms of the umbilical artery, ductus venosus and umbilical vein). Measurements of TTTS cases were compared with those of non-TTTS cases matched for gestational age. Furthermore, patients were informed about the symptoms caused by TTTS, and instructed to consult us immediately in case of rapidly increasing abdominal size or premature contractions.

RESULTS

In all four TTTS cases, the diagnosis was timely. At the time of diagnosis, one case was at Quintero Stage 1, two at Quintero Stage 2, and one at Quintero Stage 3. Two of the TTTS cases became apparent after the patients' feeling of rapidly increasing girth. The identification of TTTS predictors was successful with respect to one parameter: isolated polyhydramnios in one sac, without oligohydramnios in the other, preceded the ultimate diagnosis of TTTS in two of the four TTTS cases. All other ultrasound measurements of TTTS cases, prior to the diagnosis of TTTS, were within the range of measurements of non-TTTS cases.

CONCLUSION

Biweekly ultrasound examinations, with special attention to the amniotic fluid compartments of both fetuses, combined with detailed patient instructions to report the onset of symptoms resulted in timely diagnosis of all TTTS cases and appears to be a safe program for monitoring monochorionic twin pregnancies.

The antibody 2B4 directed against the Epstein-Barr virus (EBV)-encoded nuclear antigen 1 (EBNA1) detects MAGE-4: implications for studies on the EBV association of human cancers

We have previously developed two monoclonal antibodies against the Epstein-Barr Virus (EBV) nuclear antigen 1 (EBNA1), designated 1H4 and 2B4. Both detect EBNA1 by in situ staining in established EBV-positive tumours, e.g. Hodgkin's lymphoma and nasopharyngeal carcinoma. An association of EBV with other tumours, notably breast carcinomas, has been reported but remains controversial. Using the antibody 2B4, a nuclear protein has been detected in breast carcinomas that were EBV-negative by other methods, suggesting cross-reactivity with a cellular protein. Furthermore, an association of EBV with various other carcinomas has been reported on the basis of 2B4 immunohistochemistry. Here we show that 2B4 also binds to MAGE-4, a cancer testis antigen expressed in a variety of tumour cells, including breast carcinoma, seminoma and EBV-negative cases of Hodgkin's lymphoma. We conclude that the 2B4 antibody is not suitable for the detection of EBV infection but that additional techniques, particularly in situ hybridization for the detection of the EBV-encoded RNAs (EBERs), should be employed to confirm the presence of EBV. Our results add to the evidence indicating that breast cancer is not an EBV-associated disease.